From 9324463f36580f22888ff8fe8ea695cbad0fd734 Mon Sep 17 00:00:00 2001
From: manoflearning <77jwk0724@gmail.com>
Date: Sun, 4 Jan 2026 01:58:59 +0900
Subject: [PATCH 1/6] chore: apply pb macro

---
 src/1-ds/li_chao_tree.cpp                     |  6 ++---
 src/1-ds/merge_sort_tree.cpp                  |  4 ++--
 src/1-ds/segment_tree.cpp                     | 20 ++++++++--------
 src/2-graph/bcc.cpp                           | 20 ++++++++--------
 src/2-graph/euler_circuit.cpp                 |  2 +-
 src/2-graph/kth_shortest_path.cpp             | 10 ++++----
 src/2-graph/offline_dynamic_connectivity.cpp  |  4 ++--
 src/2-graph/scc_2_sat.cpp                     | 24 +++++++++----------
 src/2-graph/shortest_path.cpp                 |  4 ++--
 src/3-tree/centroid_decomp.cpp                |  6 ++---
 src/3-tree/hld.cpp                            |  4 ++--
 src/3-tree/lca_sparse_table.cpp               |  4 ++--
 src/3-tree/tree_composition.cpp               | 12 +++++-----
 src/3-tree/tree_exchange_argument.cpp         |  4 ++--
 src/4-optimizations/flow.cpp                  | 22 ++++++++---------
 src/5-string/aho_corasick.cpp                 |  6 ++---
 src/5-string/kmp_algorithm.cpp                |  2 +-
 src/5-string/rabin_karp_algorithm.cpp         |  2 +-
 src/5-string/trie.cpp                         |  4 ++--
 src/6-geometry/bulldozer_trick.cpp            |  6 ++---
 src/6-geometry/convex_hull.cpp                |  4 ++--
 src/6-geometry/half_plane_intersection.cpp    |  8 +++----
 src/6-geometry/segment_intersection.cpp       |  4 ++--
 src/7-math/misc_sqrt.cpp                      | 10 ++++----
 src/7-math/nt_mr_rho.cpp                      |  2 +-
 src/7-math/nt_sieve.cpp                       | 10 ++++----
 src/8-misc/dp_opt.cpp                         |  2 +-
 src/8-misc/lis_in_o_nlogn.cpp                 |  8 +++----
 .../sqrt_decomposition_mos_algorithm.cpp      |  2 +-
 .../system_of_difference_constraints.cpp      |  2 +-
 src/common/common.hpp                         |  4 ++--
 tests/1-ds/test_li_chao_tree.cpp              |  6 ++---
 tests/1-ds/test_segment_tree.cpp              | 20 ++++++++--------
 tests/2-graph/test_bcc.cpp                    | 14 +++++------
 tests/2-graph/test_kth_shortest_path.cpp      |  8 +++----
 .../test_offline_dynamic_connectivity.cpp     |  4 ++--
 tests/2-graph/test_scc_2_sat.cpp              |  4 ++--
 tests/2-graph/test_shortest_path.cpp          |  6 ++---
 tests/3-tree/test_centroid_decomp.cpp         | 10 ++++----
 tests/3-tree/test_hld.cpp                     | 12 +++++-----
 tests/3-tree/test_lca_sparse_table.cpp        |  4 ++--
 tests/3-tree/test_tree_composition.cpp        | 10 ++++----
 tests/3-tree/test_tree_exchange_argument.cpp  | 12 +++++-----
 tests/4-optimizations/test_flow.cpp           | 16 ++++++-------
 tests/5-string/test_aho_corasick.cpp          |  4 ++--
 tests/5-string/test_kmp_algorithm.cpp         |  4 ++--
 tests/5-string/test_manachers_algorithm.cpp   |  2 +-
 tests/5-string/test_rabin_karp_algorithm.cpp  |  4 ++--
 tests/5-string/test_suffix_array.cpp          |  2 +-
 tests/5-string/test_trie.cpp                  |  2 +-
 tests/5-string/test_z_algorithm.cpp           |  2 +-
 tests/6-geometry/test_bulldozer_trick.cpp     | 22 ++++++++---------
 tests/6-geometry/test_convex_hull.cpp         |  4 ++--
 .../test_half_plane_intersection.cpp          | 24 +++++++++----------
 .../test_minimum_enclosing_circle.cpp         |  2 +-
 tests/6-geometry/test_ray_casting.cpp         |  2 +-
 tests/6-geometry/test_rotating_callipers.cpp  |  2 +-
 .../6-geometry/test_segment_intersection.cpp  |  4 ++--
 tests/6-geometry/test_sort_by_angular.cpp     |  2 +-
 tests/7-math/test_misc_sqrt.cpp               |  6 ++---
 tests/7-math/test_nt_crt.cpp                  |  2 +-
 tests/7-math/test_nt_mr_rho.cpp               |  4 ++--
 tests/7-math/test_nt_sieve.cpp                |  4 ++--
 tests/8-misc/test_kitamasa.cpp                |  2 +-
 .../test_system_of_difference_constraints.cpp |  2 +-
 65 files changed, 225 insertions(+), 225 deletions(-)

diff --git a/src/1-ds/li_chao_tree.cpp b/src/1-ds/li_chao_tree.cpp
index 7f30cc8..9b498c8 100644
--- a/src/1-ds/li_chao_tree.cpp
+++ b/src/1-ds/li_chao_tree.cpp
@@ -22,7 +22,7 @@ struct li_chao {
     void init(ll xl, ll xr) {
         // goal: set x-range and clear tree.
         t.clear();
-        t.push_back({xl, xr, -1, -1, LINE_E});
+        t.pb({xl, xr, -1, -1, LINE_E});
     }
     void add(lc_line nw, int v = 0) {
         // goal: insert a new line into the segment.
@@ -40,14 +40,14 @@ struct li_chao {
             t[v].ln = hi;
             if (t[v].r == -1) {
                 t[v].r = sz(t);
-                t.push_back({mid + 1, xr, -1, -1, LINE_E});
+                t.pb({mid + 1, xr, -1, -1, LINE_E});
             }
             add(lo, t[v].r);
         } else {
             t[v].ln = lo;
             if (t[v].l == -1) {
                 t[v].l = sz(t);
-                t.push_back({xl, mid, -1, -1, LINE_E});
+                t.pb({xl, mid, -1, -1, LINE_E});
             }
             add(hi, t[v].l);
         }
diff --git a/src/1-ds/merge_sort_tree.cpp b/src/1-ds/merge_sort_tree.cpp
index 7f6aba8..50b5b70 100644
--- a/src/1-ds/merge_sort_tree.cpp
+++ b/src/1-ds/merge_sort_tree.cpp
@@ -10,7 +10,7 @@ struct merge_seg {
     void build(const vector<int> &a) {
         // goal: build sorted lists for each node.
         for (int i = 0; i < sz(a); i++)
-            t[i + MAX_MST].push_back(a[i]);
+            t[i + MAX_MST].pb(a[i]);
         for (int i = MAX_MST - 1; i >= 1; i--) {
             t[i].resize(sz(t[i << 1]) + sz(t[i << 1 | 1]));
             merge(all(t[i << 1]), all(t[i << 1 | 1]), t[i].begin());
@@ -35,7 +35,7 @@ struct merge_seg_it {
     void build(const vector<int> &a) {
         // goal: build sorted lists for each node.
         for (int i = 0; i < sz(a); i++)
-            t[i + MAX_MST].push_back(a[i]);
+            t[i + MAX_MST].pb(a[i]);
         for (int i = MAX_MST - 1; i >= 1; i--) {
             t[i].resize(sz(t[i << 1]) + sz(t[i << 1 | 1]));
             merge(all(t[i << 1]), all(t[i << 1 | 1]), t[i].begin());
diff --git a/src/1-ds/segment_tree.cpp b/src/1-ds/segment_tree.cpp
index 9ed43da..6f595d6 100644
--- a/src/1-ds/segment_tree.cpp
+++ b/src/1-ds/segment_tree.cpp
@@ -151,14 +151,14 @@ struct seg_pst {
     vector<node> t;
     vector<int> root;
 
-    void newnd() { t.push_back({-1, -1, 0}); }
+    void newnd() { t.pb({-1, -1, 0}); }
     void build(int n_, const vector<ll> &a) {
         // goal: build initial version.
         n = n_;
         t.clear();
         root.clear();
         newnd();
-        root.push_back(0);
+        root.pb(0);
         build(1, n, root[0], a);
     }
     void build(int l, int r, int v, const vector<ll> &a) {
@@ -179,7 +179,7 @@ struct seg_pst {
     void set(int p, ll val) {
         // goal: create new version with a[p] = val.
         newnd();
-        root.push_back(sz(t) - 1);
+        root.pb(sz(t) - 1);
         set(p, val, 1, n, root[sz(root) - 2], root.back());
     }
     void set(int p, ll val, int l, int r, int v1, int v2) {
@@ -246,13 +246,13 @@ struct seg_sparse {
         if (p <= mid) {
             if (t[v].l == -1) {
                 t[v].l = sz(t);
-                t.push_back({0, -1, -1});
+                t.pb({0, -1, -1});
             }
             add(p, x, t[v].l, nl, mid);
         } else {
             if (t[v].r == -1) {
                 t[v].r = sz(t);
-                t.push_back({0, -1, -1});
+                t.pb({0, -1, -1});
             }
             add(p, x, t[v].r, mid + 1, nr);
         }
@@ -331,18 +331,18 @@ struct seg2d_comp { // 0-indexed
     seg2d_comp(int n) : n(n), a(2 * n), used(2 * n) {}
     void mark_set(int x, int y) {
         // goal: record y-coordinates that will be updated.
-        for (x += n; x >= 1; x >>= 1) used[x].push_back(y);
+        for (x += n; x >= 1; x >>= 1) used[x].pb(y);
     }
     void mark_qry(int x1, int x2, int y1, int y2) {
         // goal: record y-coordinates needed for queries.
         for (x1 += n, x2 += n + 1; x1 < x2; x1 >>= 1, x2 >>= 1) {
             if (x1 & 1) {
-                used[x1].push_back(y1);
-                used[x1++].push_back(y2);
+                used[x1].pb(y1);
+                used[x1++].pb(y2);
             }
             if (x2 & 1) {
-                used[--x2].push_back(y1);
-                used[x2].push_back(y2);
+                used[--x2].pb(y1);
+                used[x2].pb(y2);
             }
         }
     }
diff --git a/src/2-graph/bcc.cpp b/src/2-graph/bcc.cpp
index a95b928..c59257d 100644
--- a/src/2-graph/bcc.cpp
+++ b/src/2-graph/bcc.cpp
@@ -25,9 +25,9 @@ struct bcc_graph {
     }
     void add(int u, int v) {
         int id = sz(ed);
-        ed.push_back({u, v});
-        adj[u].push_back({v, id});
-        adj[v].push_back({u, id});
+        ed.pb({u, v});
+        adj[u].pb({v, id});
+        adj[v].pb({u, id});
     }
     void dfs(int v, int pe) {
         dfn[v] = low[v] = ++tim;
@@ -37,27 +37,27 @@ struct bcc_graph {
             if (dfn[to] != -1) {
                 // edge: back edge to ancestor.
                 low[v] = min(low[v], dfn[to]);
-                if (dfn[to] < dfn[v]) st.push_back(id);
+                if (dfn[to] < dfn[v]) st.pb(id);
                 continue;
             }
-            st.push_back(id);
+            st.pb(id);
             ch++;
             dfs(to, id);
             low[v] = min(low[v], low[to]);
-            if (pe != -1 && low[to] >= dfn[v]) ap.push_back(v);
-            if (low[to] > dfn[v]) ae.push_back({min(v, to), max(v, to)});
+            if (pe != -1 && low[to] >= dfn[v]) ap.pb(v);
+            if (low[to] > dfn[v]) ae.pb({min(v, to), max(v, to)});
             if (low[to] >= dfn[v]) {
                 vector<pii> comp;
                 while (1) {
                     int eid = st.back();
                     st.pop_back();
-                    comp.push_back(ed[eid]);
+                    comp.pb(ed[eid]);
                     if (eid == id) break;
                 }
-                bccs.push_back(comp);
+                bccs.pb(comp);
             }
         }
-        if (pe == -1 && ch > 1) ap.push_back(v);
+        if (pe == -1 && ch > 1) ap.pb(v);
     }
     void run() {
         for (int v = 1; v <= n; v++)
diff --git a/src/2-graph/euler_circuit.cpp b/src/2-graph/euler_circuit.cpp
index df6e943..265e431 100644
--- a/src/2-graph/euler_circuit.cpp
+++ b/src/2-graph/euler_circuit.cpp
@@ -58,7 +58,7 @@ struct euler_cir {
                 dfs(i);
             }
         }
-        path.push_back(v);
+        path.pb(v);
     }
     vector<int> run(int s = 1) {
         // result: Euler circuit starting from s (if exists).
diff --git a/src/2-graph/kth_shortest_path.cpp b/src/2-graph/kth_shortest_path.cpp
index bd1382b..c86093a 100644
--- a/src/2-graph/kth_shortest_path.cpp
+++ b/src/2-graph/kth_shortest_path.cpp
@@ -19,7 +19,7 @@ struct kth_walk {
         vector<nd> h;
         void init() { h.assign(1, {{0, 0}, 0, 0, 0}); }
         int mk(pll x) {
-            h.push_back({x, 0, 0, 1});
+            h.pb({x, 0, 0, 1});
             return sz(h) - 1;
         }
         void norm(int x) {
@@ -43,8 +43,8 @@ struct kth_walk {
         hp.init();
     }
     void add(int u, int v, ll w) {
-        g[u].push_back({w, v});
-        rg[v].push_back({w, u});
+        g[u].pb({w, v});
+        rg[v].pb({w, u});
     }
 
     vector<ll> run(int s, int e, int k) {
@@ -62,7 +62,7 @@ struct kth_walk {
             if (vis[x]) continue;
             vis[x] = 1;
             nxt[x] = p;
-            ord.push_back(x);
+            ord.pb(x);
             for (auto [c, y] : rg[x]) {
                 if (!vis[y] && dist[y] > d + c) {
                     dist[y] = d + c;
@@ -92,7 +92,7 @@ struct kth_walk {
         while (sz(ans) < k && !pq2.empty()) {
             auto [d, x] = pq2.top();
             pq2.pop();
-            ans.push_back(dist[s] + d);
+            ans.pb(dist[s] + d);
             int y = hp.h[x].x.sc;
             if (rt[y]) pq2.push({d + hp.h[rt[y]].x.fr, rt[y]});
             if (hp.h[x].l) pq2.push({d - hp.h[x].x.fr + hp.h[hp.h[x].l].x.fr, hp.h[x].l});
diff --git a/src/2-graph/offline_dynamic_connectivity.cpp b/src/2-graph/offline_dynamic_connectivity.cpp
index 040e982..465d6dc 100644
--- a/src/2-graph/offline_dynamic_connectivity.cpp
+++ b/src/2-graph/offline_dynamic_connectivity.cpp
@@ -18,7 +18,7 @@ struct dyn_conn {
             if (nr == -1) nr = flg;
             if (r < nl || nr < l) return;
             if (l <= nl && nr <= r) {
-                t[n].push_back(e);
+                t[n].pb(e);
                 return;
             }
             int mid = (nl + nr) >> 1;
@@ -48,7 +48,7 @@ struct dyn_conn {
             if (siz[a] < siz[b]) swap(a, b);
             par[b] = a;
             siz[a] += siz[b];
-            st.push_back(b);
+            st.pb(b);
             return 1;
         }
         void undo() {
diff --git a/src/2-graph/scc_2_sat.cpp b/src/2-graph/scc_2_sat.cpp
index 7f1ccde..88a3a4f 100644
--- a/src/2-graph/scc_2_sat.cpp
+++ b/src/2-graph/scc_2_sat.cpp
@@ -19,18 +19,18 @@ struct scc_kosa {
         ord.clear();
     }
     void add(int u, int v) {
-        g[u].push_back(v);
-        rg[v].push_back(u);
+        g[u].pb(v);
+        rg[v].pb(u);
     }
     void dfs1(int v) {
         vis[v] = 1;
         for (int to : rg[v])
             if (!vis[to]) dfs1(to);
-        ord.push_back(v);
+        ord.pb(v);
     }
     void dfs2(int v, int id) {
         comp[v] = id;
-        sccs[id].push_back(v);
+        sccs[id].pb(v);
         for (int to : g[v])
             if (comp[to] == -1) dfs2(to, id);
     }
@@ -40,7 +40,7 @@ struct scc_kosa {
         reverse(all(ord));
         for (int v : ord) {
             if (comp[v] != -1) continue;
-            sccs.push_back({});
+            sccs.pb({});
             dfs2(v, sz(sccs) - 1);
         }
         return sz(sccs);
@@ -67,10 +67,10 @@ struct scc_tarjan {
         ins.assign(n + 1, 0);
         st.clear();
     }
-    void add(int u, int v) { g[u].push_back(v); }
+    void add(int u, int v) { g[u].pb(v); }
     void dfs(int v) {
         dfn[v] = low[v] = ++tim;
-        st.push_back(v);
+        st.pb(v);
         ins[v] = 1;
         for (int to : g[v]) {
             if (dfn[to] == -1) {
@@ -81,14 +81,14 @@ struct scc_tarjan {
             }
         }
         if (low[v] != dfn[v]) return;
-        sccs.push_back({});
+        sccs.pb({});
         int id = sz(sccs) - 1;
         while (1) {
             int x = st.back();
             st.pop_back();
             ins[x] = 0;
             comp[x] = id;
-            sccs[id].push_back(x);
+            sccs[id].pb(x);
             if (x == v) break;
         }
     }
@@ -126,12 +126,12 @@ struct two_sat {
     }
     void add(int a, int b) {
         // goal: (a v b) == (!a -> b) & (!b -> a)
-        g[id(-a)].push_back(id(b));
-        g[id(-b)].push_back(id(a));
+        g[id(-a)].pb(id(b));
+        g[id(-b)].pb(id(a));
     }
     void dfs(int v) {
         dfn[v] = low[v] = ++tim;
-        st.push_back(v);
+        st.pb(v);
         ins[v] = 1;
         for (int to : g[v]) {
             if (dfn[to] == -1) {
diff --git a/src/2-graph/shortest_path.cpp b/src/2-graph/shortest_path.cpp
index 854cd6b..3dfc933 100644
--- a/src/2-graph/shortest_path.cpp
+++ b/src/2-graph/shortest_path.cpp
@@ -14,7 +14,7 @@ struct dijkstra {
         n = n_;
         adj.assign(n + 1, {});
     }
-    void add(int u, int v, ll w) { adj[u].push_back({w, v}); }
+    void add(int u, int v, ll w) { adj[u].pb({w, v}); }
     vector<ll> run(int s) {
         // result: dist[i] = shortest distance from s to i.
         vector<ll> dist(n + 1, INF);
@@ -50,7 +50,7 @@ struct bell_ford {
         n = n_;
         ed.clear();
     }
-    void add(int u, int v, ll w) { ed.push_back({u, v, w}); }
+    void add(int u, int v, ll w) { ed.pb({u, v, w}); }
     bool run(int s, vector<ll> &dist) {
         // result: false if a negative cycle is reachable.
         dist.assign(n + 1, INF);
diff --git a/src/3-tree/centroid_decomp.cpp b/src/3-tree/centroid_decomp.cpp
index 0b87991..8837a41 100644
--- a/src/3-tree/centroid_decomp.cpp
+++ b/src/3-tree/centroid_decomp.cpp
@@ -19,8 +19,8 @@ struct cen_decomp {
         used.assign(n + 1, 0);
     }
     void add(int u, int v) {
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     }
     int get_sz(int v, int p) {
         // goal: subtree sizes for centroid search.
@@ -43,7 +43,7 @@ struct cen_decomp {
         int tot = get_sz(v, p);
         int c = get_cent(v, p, tot);
         par[c] = p;
-        if (p) chd[p].push_back(c);
+        if (p) chd[p].pb(c);
         used[c] = 1;
         for (int to : adj[c])
             if (!used[to]) build(to, c);
diff --git a/src/3-tree/hld.cpp b/src/3-tree/hld.cpp
index 035d48a..d02bf92 100644
--- a/src/3-tree/hld.cpp
+++ b/src/3-tree/hld.cpp
@@ -23,8 +23,8 @@ struct hld_tree {
         in.assign(n + 1, 0);
     }
     void add(int u, int v) {
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     }
     int dfs_sz(int v, int p) {
         // goal: compute subtree sizes and heavy child.
diff --git a/src/3-tree/lca_sparse_table.cpp b/src/3-tree/lca_sparse_table.cpp
index 905ad65..17a415a 100644
--- a/src/3-tree/lca_sparse_table.cpp
+++ b/src/3-tree/lca_sparse_table.cpp
@@ -18,8 +18,8 @@ struct lca_sparse {
         dep.assign(n + 1, 0);
     }
     void add(int u, int v) {
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     }
     void dfs(int v, int p) {
         // goal: set parent and depth.
diff --git a/src/3-tree/tree_composition.cpp b/src/3-tree/tree_composition.cpp
index a80c689..88ea68a 100644
--- a/src/3-tree/tree_composition.cpp
+++ b/src/3-tree/tree_composition.cpp
@@ -22,8 +22,8 @@ struct tree_comp {
         tim = 0;
     }
     void add(int u, int v) {
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     }
     void dfs(int v, int p) {
         // goal: build tin/tout, depth, and parents.
@@ -62,18 +62,18 @@ struct tree_comp {
         sort(all(vs), [&](int a, int b) { return tin[a] < tin[b]; });
         vs.erase(unique(all(vs)), vs.end());
         int m = sz(vs);
-        for (int i = 0; i + 1 < m; i++) vs.push_back(lca(vs[i], vs[i + 1]));
+        for (int i = 0; i + 1 < m; i++) vs.pb(lca(vs[i], vs[i + 1]));
         sort(all(vs), [&](int a, int b) { return tin[a] < tin[b]; });
         vs.erase(unique(all(vs)), vs.end());
         for (int v : vs) vt_adj[v].clear();
         vector<int> st;
-        st.push_back(vs[0]);
+        st.pb(vs[0]);
         for (int i = 1; i < sz(vs); i++) {
             int v = vs[i];
             // invariant: stack is ancestor chain.
             while (!is_anc(st.back(), v)) st.pop_back();
-            vt_adj[st.back()].push_back(v);
-            st.push_back(v);
+            vt_adj[st.back()].pb(v);
+            st.pb(v);
         }
         return vs;
     }
diff --git a/src/3-tree/tree_exchange_argument.cpp b/src/3-tree/tree_exchange_argument.cpp
index 3abf125..d0ab5c6 100644
--- a/src/3-tree/tree_exchange_argument.cpp
+++ b/src/3-tree/tree_exchange_argument.cpp
@@ -43,8 +43,8 @@ struct tree_xchg {
         ds.init(n);
     }
     void add(int u, int v) {
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     }
     void dfs(int v, int p) {
         par[v] = p;
diff --git a/src/4-optimizations/flow.cpp b/src/4-optimizations/flow.cpp
index 21e656a..38b26cd 100644
--- a/src/4-optimizations/flow.cpp
+++ b/src/4-optimizations/flow.cpp
@@ -36,8 +36,8 @@ struct dinic {
         // goal: add forward + reverse edge
         edge a{v, (int)g[v].size(), cap};
         edge b{u, (int)g[u].size(), 0};
-        g[u].push_back(a);
-        g[v].push_back(b);
+        g[u].pb(a);
+        g[v].pb(b);
         return {u, (int)g[u].size() - 1};
     }
 
@@ -126,7 +126,7 @@ struct hk {
 
     void add_edge(int l, int r) {
         // goal: add edge from left to right
-        g[l].push_back(r);
+        g[l].pb(r);
     }
 
     bool bfs() {
@@ -214,8 +214,8 @@ struct mcmf {
         // goal: add forward + reverse edge with costs
         edge a{v, (int)g[v].size(), cap, cost};
         edge b{u, (int)g[u].size(), 0, -cost};
-        g[u].push_back(a);
-        g[v].push_back(b);
+        g[u].pb(a);
+        g[v].pb(b);
         return {u, (int)g[u].size() - 1};
     }
 
@@ -340,7 +340,7 @@ struct lr_dinic {
         // goal: store lower bounds via node demands
         demand[u] -= lo;
         demand[v] += lo;
-        edges.push_back({mf.add_edge(u, v, hi - lo), lo});
+        edges.pb({mf.add_edge(u, v, hi - lo), lo});
         return (int)edges.size() - 1;
     }
 
@@ -355,10 +355,10 @@ struct lr_dinic {
         int ss = n, tt = n + 1;
         for (int i = 0; i < n; i++) {
             if (demand[i] > 0) {
-                aux.push_back(mf.add_edge(ss, i, demand[i]));
+                aux.pb(mf.add_edge(ss, i, demand[i]));
                 total += demand[i];
             } else if (demand[i] < 0) {
-                aux.push_back(mf.add_edge(i, tt, -demand[i]));
+                aux.pb(mf.add_edge(i, tt, -demand[i]));
             }
         }
         return total;
@@ -429,7 +429,7 @@ struct lr_mcmf {
         demand[u] -= lo;
         demand[v] += lo;
         base_cost += lo * cost;
-        edges.push_back({mf.add_edge(u, v, hi - lo, cost), lo});
+        edges.pb({mf.add_edge(u, v, hi - lo, cost), lo});
         return (int)edges.size() - 1;
     }
 
@@ -444,10 +444,10 @@ struct lr_mcmf {
         int ss = n, tt = n + 1;
         for (int i = 0; i < n; i++) {
             if (demand[i] > 0) {
-                aux.push_back(mf.add_edge(ss, i, demand[i], 0));
+                aux.pb(mf.add_edge(ss, i, demand[i], 0));
                 total += demand[i];
             } else if (demand[i] < 0) {
-                aux.push_back(mf.add_edge(i, tt, -demand[i], 0));
+                aux.pb(mf.add_edge(i, tt, -demand[i], 0));
             }
         }
         return total;
diff --git a/src/5-string/aho_corasick.cpp b/src/5-string/aho_corasick.cpp
index 9d87406..f21cbf6 100644
--- a/src/5-string/aho_corasick.cpp
+++ b/src/5-string/aho_corasick.cpp
@@ -26,10 +26,10 @@ struct aho_corasick {
             int c = ch - 'a';
             if (nxt[v][c] == -1) {
                 nxt[v][c] = sz(nxt);
-                nxt.push_back({});
+                nxt.pb({});
                 nxt.back().fill(-1);
-                fail.push_back(0);
-                out.push_back(0);
+                fail.pb(0);
+                out.pb(0);
             }
             v = nxt[v][c];
         }
diff --git a/src/5-string/kmp_algorithm.cpp b/src/5-string/kmp_algorithm.cpp
index 0e434bb..5c32e49 100644
--- a/src/5-string/kmp_algorithm.cpp
+++ b/src/5-string/kmp_algorithm.cpp
@@ -23,7 +23,7 @@ vector<int> kmp_match(const string &t, const string &p) {
         while (j && t[i] != p[j]) j = pi[j - 1];
         if (t[i] != p[j]) continue;
         if (j == sz(p) - 1) {
-            res.push_back(i - (sz(p) - 1));
+            res.pb(i - (sz(p) - 1));
             j = pi[j];
         } else {
             j++;
diff --git a/src/5-string/rabin_karp_algorithm.cpp b/src/5-string/rabin_karp_algorithm.cpp
index cbcbb80..5ea0b87 100644
--- a/src/5-string/rabin_karp_algorithm.cpp
+++ b/src/5-string/rabin_karp_algorithm.cpp
@@ -46,6 +46,6 @@ vector<int> rk_match(const string &t, const string &p) {
     hp.build(p);
     pll hp0 = hp.get(0, m);
     for (int i = 0; i + m <= n; i++)
-        if (ht.get(i, i + m) == hp0) res.push_back(i);
+        if (ht.get(i, i + m) == hp0) res.pb(i);
     return res;
 }
diff --git a/src/5-string/trie.cpp b/src/5-string/trie.cpp
index 51ee707..ad652db 100644
--- a/src/5-string/trie.cpp
+++ b/src/5-string/trie.cpp
@@ -25,9 +25,9 @@ struct trie {
             int c = ch - 'a';
             if (nxt[v][c] == -1) {
                 nxt[v][c] = sz(nxt);
-                nxt.push_back({});
+                nxt.pb({});
                 nxt.back().fill(-1);
-                term.push_back(0);
+                term.pb(0);
             }
             v = nxt[v][c];
         }
diff --git a/src/6-geometry/bulldozer_trick.cpp b/src/6-geometry/bulldozer_trick.cpp
index 373f8d1..ad66628 100644
--- a/src/6-geometry/bulldozer_trick.cpp
+++ b/src/6-geometry/bulldozer_trick.cpp
@@ -35,7 +35,7 @@ void bulldozer(vector<pt> &p, F f) {
                 dx = -dx, dy = -dy;
                 swap(u, v);
             }
-            ln.push_back({u, v, dx, dy});
+            ln.pb({u, v, dx, dy});
         }
     }
     sort(all(ln));
@@ -49,8 +49,8 @@ void bulldozer(vector<pt> &p, F f) {
         for (int k = i; k < j; k++) {
             int u = ln[k].u, v = ln[k].v;
             ll c = -dy * base[u].x + dx * base[u].y;
-            mp[c].push_back(u);
-            mp[c].push_back(v);
+            mp[c].pb(u);
+            mp[c].pb(v);
         }
         for (auto &it : mp) {
             auto &vec = it.sc;
diff --git a/src/6-geometry/convex_hull.cpp b/src/6-geometry/convex_hull.cpp
index c925465..60c6cad 100644
--- a/src/6-geometry/convex_hull.cpp
+++ b/src/6-geometry/convex_hull.cpp
@@ -13,12 +13,12 @@ vector<pt> convex_hull(vector<pt> p) {
     vector<pt> lo, hi;
     for (auto &v : p) {
         while (sz(lo) >= 2 && cross(lo[sz(lo) - 2], lo.back(), v) <= 0) lo.pop_back();
-        lo.push_back(v);
+        lo.pb(v);
     }
     for (int i = n - 1; i >= 0; i--) {
         auto v = p[i];
         while (sz(hi) >= 2 && cross(hi[sz(hi) - 2], hi.back(), v) <= 0) hi.pop_back();
-        hi.push_back(v);
+        hi.pb(v);
     }
     lo.pop_back();
     hi.pop_back();
diff --git a/src/6-geometry/half_plane_intersection.cpp b/src/6-geometry/half_plane_intersection.cpp
index 8c339f4..a134d7a 100644
--- a/src/6-geometry/half_plane_intersection.cpp
+++ b/src/6-geometry/half_plane_intersection.cpp
@@ -42,12 +42,12 @@ vector<ptd> hpi(vector<hp_line> ln) {
     vector<hp_line> v;
     for (auto &l : ln) {
         if (v.empty()) {
-            v.push_back(l);
+            v.pb(l);
             continue;
         }
         ptd da = dir(v.back()), db = dir(l);
         if (!eq(cross(da, db), 0)) {
-            v.push_back(l);
+            v.pb(l);
             continue;
         }
         if (cross(da, l.s - v.back().s) > 0) v.back() = l;
@@ -56,7 +56,7 @@ vector<ptd> hpi(vector<hp_line> ln) {
     for (auto &l : v) {
         while (sz(dq) >= 2 && bad(dq[sz(dq) - 2], dq.back(), l)) dq.pop_back();
         while (sz(dq) >= 2 && bad(dq[0], dq[1], l)) dq.pop_front();
-        dq.push_back(l);
+        dq.pb(l);
     }
     while (sz(dq) >= 3 && bad(dq[sz(dq) - 2], dq.back(), dq[0])) dq.pop_back();
     while (sz(dq) >= 3 && bad(dq[0], dq[1], dq.back())) dq.pop_front();
@@ -66,7 +66,7 @@ vector<ptd> hpi(vector<hp_line> ln) {
             ptd p;
             if (line_inter(dq[i].s, dq[i].t, dq[(i + 1) % sz(dq)].s,
                            dq[(i + 1) % sz(dq)].t, p)) {
-                poly.push_back(p);
+                poly.pb(p);
             }
         }
     }
diff --git a/src/6-geometry/segment_intersection.cpp b/src/6-geometry/segment_intersection.cpp
index 35f32a9..a852057 100644
--- a/src/6-geometry/segment_intersection.cpp
+++ b/src/6-geometry/segment_intersection.cpp
@@ -19,8 +19,8 @@ bool seg_inter_p(const pt &a, const pt &b, const pt &c, const pt &d, ptd &out) {
         return 1;
     }
     ptd pa{(ld)a.x, (ld)a.y};
-    ptd pb{(ld)b.x, (ld)b.y};
+    ptd p_b{(ld)b.x, (ld)b.y};
     ptd pc{(ld)c.x, (ld)c.y};
     ptd pd{(ld)d.x, (ld)d.y};
-    return line_inter(pa, pb, pc, pd, out);
+    return line_inter(pa, p_b, pc, pd, out);
 }
diff --git a/src/7-math/misc_sqrt.cpp b/src/7-math/misc_sqrt.cpp
index b0e06eb..a6a30bf 100644
--- a/src/7-math/misc_sqrt.cpp
+++ b/src/7-math/misc_sqrt.cpp
@@ -11,8 +11,8 @@ struct sqrt_alg {
         vector<ll> d;
         for (ll i = 1; i <= x / i; i++) {
             if (x % i) continue;
-            d.push_back(i);
-            if (i * i != x) d.push_back(x / i);
+            d.pb(i);
+            if (i * i != x) d.pb(x / i);
         }
         sort(all(d));
         return d;
@@ -22,16 +22,16 @@ struct sqrt_alg {
         // result: prime factors of x (with repetition).
         vector<ll> p;
         while ((x & 1) == 0) {
-            p.push_back(2);
+            p.pb(2);
             x >>= 1;
         }
         for (ll i = 3; i <= x / i; i += 2) {
             while (x % i == 0) {
-                p.push_back(i);
+                p.pb(i);
                 x /= i;
             }
         }
-        if (x > 1) p.push_back(x);
+        if (x > 1) p.pb(x);
         return p;
     }
 };
diff --git a/src/7-math/nt_mr_rho.cpp b/src/7-math/nt_mr_rho.cpp
index 305a8cf..76e97ac 100644
--- a/src/7-math/nt_mr_rho.cpp
+++ b/src/7-math/nt_mr_rho.cpp
@@ -63,7 +63,7 @@ struct pollard_rho {
     static void rec(ll n, vector<ll> &out) {
         if (n == 1) return;
         if (miller_rabin::is_prime(n)) {
-            out.push_back(n);
+            out.pb(n);
             return;
         }
         ll d = rho(n);
diff --git a/src/7-math/nt_sieve.cpp b/src/7-math/nt_sieve.cpp
index e32754a..8a4451b 100644
--- a/src/7-math/nt_sieve.cpp
+++ b/src/7-math/nt_sieve.cpp
@@ -26,9 +26,9 @@ struct era_sieve {
             for (ll j = i * i; j <= n; j += i << 1) isp[j] = 0;
         }
         primes.clear();
-        if (n >= 2) primes.push_back(2);
+        if (n >= 2) primes.pb(2);
         for (int i = 3; i <= n; i += 2)
-            if (isp[i]) primes.push_back(i);
+            if (isp[i]) primes.pb(i);
     }
 
     bool is_prime(int x) const { return x >= 2 && x <= n && isp[x]; }
@@ -57,7 +57,7 @@ struct lin_sieve {
         for (int i = 2; i <= n; i++) {
             if (!lp[i]) {
                 lp[i] = i;
-                primes.push_back(i);
+                primes.pb(i);
                 mu[i] = -1;
                 phi[i] = i - 1;
             }
@@ -83,7 +83,7 @@ struct lin_sieve {
         vector<int> ret;
         while (x > 1) {
             int p = lp[x];
-            ret.push_back(p);
+            ret.pb(p);
             x /= p;
         }
         return ret;
@@ -96,7 +96,7 @@ struct lin_sieve {
             int p = lp[x];
             int e = 0;
             while (x % p == 0) x /= p, e++;
-            ret.push_back({p, e});
+            ret.pb({p, e});
         }
         return ret;
     }
diff --git a/src/8-misc/dp_opt.cpp b/src/8-misc/dp_opt.cpp
index a519d46..bf806a5 100644
--- a/src/8-misc/dp_opt.cpp
+++ b/src/8-misc/dp_opt.cpp
@@ -35,7 +35,7 @@ struct cht_mono {
             st.pop_back();
         }
         if (st.empty()) cur.x = NEG_INF;
-        st.push_back(cur);
+        st.pb(cur);
     }
 
     ll get(ll x) const {
diff --git a/src/8-misc/lis_in_o_nlogn.cpp b/src/8-misc/lis_in_o_nlogn.cpp
index c418849..6b0f1db 100644
--- a/src/8-misc/lis_in_o_nlogn.cpp
+++ b/src/8-misc/lis_in_o_nlogn.cpp
@@ -10,7 +10,7 @@ int lis_len(const vector<ll> &a) {
     vector<ll> tail;
     for (ll x : a) {
         auto it = lower_bound(tail.begin(), tail.end(), x);
-        if (it == tail.end()) tail.push_back(x);
+        if (it == tail.end()) tail.pb(x);
         else *it = x;
     }
     return sz(tail);
@@ -26,8 +26,8 @@ vector<ll> lis_seq(const vector<ll> &a) {
         ll x = a[i];
         int pos = lower_bound(tail.begin(), tail.end(), x) - tail.begin();
         if (pos == sz(tail)) {
-            tail.push_back(x);
-            tail_idx.push_back(i);
+            tail.pb(x);
+            tail_idx.pb(i);
         } else {
             tail[pos] = x;
             tail_idx[pos] = i;
@@ -37,7 +37,7 @@ vector<ll> lis_seq(const vector<ll> &a) {
     vector<ll> ret;
     int cur = tail_idx.empty() ? -1 : tail_idx.back();
     while (cur != -1) {
-        ret.push_back(a[cur]);
+        ret.pb(a[cur]);
         cur = pre[cur];
     }
     reverse(all(ret));
diff --git a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
index 4f1b6bd..4e1de81 100644
--- a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
+++ b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
@@ -21,7 +21,7 @@ struct mo {
         q.clear();
     }
 
-    void add_query(int l, int r, int idx) { q.push_back({l, r, idx}); }
+    void add_query(int l, int r, int idx) { q.pb({l, r, idx}); }
 
     template <class Add, class Del, class Out>
     void run(Add add, Del del, Out out) {
diff --git a/src/8-misc/system_of_difference_constraints.cpp b/src/8-misc/system_of_difference_constraints.cpp
index 19ce17e..45c632a 100644
--- a/src/8-misc/system_of_difference_constraints.cpp
+++ b/src/8-misc/system_of_difference_constraints.cpp
@@ -24,7 +24,7 @@ struct diff_cons {
 
     void add_le(int u, int v, ll w) {
         // goal: x_v - x_u <= w
-        g[u].push_back({v, w});
+        g[u].pb({v, w});
     }
 
     void add_ge(int u, int v, ll w) {
diff --git a/src/common/common.hpp b/src/common/common.hpp
index e28326e..5e8de73 100644
--- a/src/common/common.hpp
+++ b/src/common/common.hpp
@@ -2,14 +2,14 @@
 
 #include <bits/stdc++.h>
 using namespace std;
-
 using ll = long long;
 using ld = long double;
 using ull = unsigned long long;
 using pii = pair<int, int>;
 using pll = pair<ll, ll>;
-
 #define fr first
 #define sc second
+#define pb push_back
 #define sz(x) (int)(x).size()
 #define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
diff --git a/tests/1-ds/test_li_chao_tree.cpp b/tests/1-ds/test_li_chao_tree.cpp
index da90d97..9c8fbb0 100644
--- a/tests/1-ds/test_li_chao_tree.cpp
+++ b/tests/1-ds/test_li_chao_tree.cpp
@@ -23,12 +23,12 @@ void test_li_chao_basic() {
     li_chao lc;
     lc.init(-5, 5);
     vector<lc_line> lns;
-    lns.push_back({2, 1});
+    lns.pb({2, 1});
     lc.add(lns.back());
     assert(lc.query(-5) == max_naive(lns, -5));
     assert(lc.query(5) == max_naive(lns, 5));
 
-    lns.push_back({2, -3});
+    lns.pb({2, -3});
     lc.add(lns.back());
     assert(lc.query(0) == max_naive(lns, 0));
 }
@@ -44,7 +44,7 @@ void test_li_chao_random() {
         if (op == 0) {
             ll a = rnd(-5, 5);
             ll b = rnd(-20, 20);
-            lns.push_back({a, b});
+            lns.pb({a, b});
             lc.add(lns.back());
         } else {
             ll x = rnd(xl, xr);
diff --git a/tests/1-ds/test_segment_tree.cpp b/tests/1-ds/test_segment_tree.cpp
index dfbd828..1cda5a1 100644
--- a/tests/1-ds/test_segment_tree.cpp
+++ b/tests/1-ds/test_segment_tree.cpp
@@ -173,7 +173,7 @@ void test_pst_random() {
     vector<vector<ll>> ver;
     vector<ll> a(n + 1, 0);
     for (int i = 1; i <= n; i++) a[i] = rnd(-5, 5);
-    ver.push_back(a);
+    ver.pb(a);
 
     seg_pst st;
     st.build(n, a);
@@ -185,7 +185,7 @@ void test_pst_random() {
             ll v = rnd(-5, 5);
             vector<ll> nw = ver.back();
             nw[p] = v;
-            ver.push_back(nw);
+            ver.pb(nw);
             st.set(p, v);
         } else {
             int id = (int)rnd(0, (int)ver.size() - 1);
@@ -217,7 +217,7 @@ void test_pst_kth_random() {
     vector<vector<ll>> ver;
     vector<ll> a(n + 1, 0);
     for (int i = 1; i <= n; i++) a[i] = rnd(0, 3);
-    ver.push_back(a);
+    ver.pb(a);
 
     seg_pst st;
     st.build(n, a);
@@ -229,7 +229,7 @@ void test_pst_kth_random() {
             ll v = rnd(0, 5);
             vector<ll> nw = ver.back();
             nw[p] = v;
-            ver.push_back(nw);
+            ver.pb(nw);
             st.set(p, v);
         } else {
             int id = (int)rnd(0, (int)ver.size() - 1);
@@ -329,10 +329,10 @@ void test_seg2dc_basic() {
     int n = 1;
     seg2d_comp st(n);
     vector<op2d> ops;
-    ops.push_back({0, 0, 0, 0, 0, 5});
-    ops.push_back({1, 0, 0, 0, 0, 0});
-    ops.push_back({0, 0, 0, 0, 0, -2});
-    ops.push_back({1, 0, 0, 0, 0, 0});
+    ops.pb({0, 0, 0, 0, 0, 5});
+    ops.pb({1, 0, 0, 0, 0, 0});
+    ops.pb({0, 0, 0, 0, 0, -2});
+    ops.pb({1, 0, 0, 0, 0, 0});
 
     for (auto &op : ops) {
         if (op.type == 0) st.mark_set(op.x1, op.y1);
@@ -370,13 +370,13 @@ void test_seg2dc_random() {
             int x = (int)rnd(0, n - 1);
             int y = (int)rnd(0, n - 1);
             ll v = rnd(-5, 5);
-            ops.push_back({0, x, 0, y, 0, v});
+            ops.pb({0, x, 0, y, 0, v});
         } else {
             int x1 = (int)rnd(0, n - 1);
             int x2 = (int)rnd(x1, n - 1);
             int y1 = (int)rnd(0, n - 1);
             int y2 = (int)rnd(y1, n - 1);
-            ops.push_back({1, x1, x2, y1, y2, 0});
+            ops.pb({1, x1, x2, y1, y2, 0});
         }
     }
 
diff --git a/tests/2-graph/test_bcc.cpp b/tests/2-graph/test_bcc.cpp
index 695e0f1..5508f79 100644
--- a/tests/2-graph/test_bcc.cpp
+++ b/tests/2-graph/test_bcc.cpp
@@ -17,8 +17,8 @@ int ccnt(int n, const vector<pii> &ed, int sv, int se) {
         if (i == se) continue;
         int u = ed[i].fr, v = ed[i].sc;
         if (u == sv || v == sv) continue;
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     }
     vector<int> vis(n + 1);
     int cnt = 0;
@@ -43,7 +43,7 @@ vector<int> ap_na(int n, const vector<pii> &ed) {
     int base = ccnt(n, ed, 0, -1);
     vector<int> ap;
     for (int v = 1; v <= n; v++)
-        if (ccnt(n, ed, v, -1) > base) ap.push_back(v);
+        if (ccnt(n, ed, v, -1) > base) ap.pb(v);
     return ap;
 }
 
@@ -54,7 +54,7 @@ vector<pii> ae_na(int n, const vector<pii> &ed) {
         if (ccnt(n, ed, 0, i) > base) {
             int u = ed[i].fr, v = ed[i].sc;
             if (u > v) swap(u, v);
-            ae.push_back({u, v});
+            ae.pb({u, v});
         }
     }
     sort(all(ae));
@@ -81,8 +81,8 @@ void chk_bcc(int n, const vector<pii> &ed, bcc_graph &g) {
         vector<vector<pair<int, int>>> adj(n + 1);
         for (int i = 0; i < sz(comp); i++) {
             int u = comp[i].fr, v = comp[i].sc;
-            adj[u].push_back({v, i});
-            adj[v].push_back({u, i});
+            adj[u].pb({v, i});
+            adj[v].pb({u, i});
         }
         for (int i = 0; i < sz(comp); i++) {
             int u = comp[i].fr, v = comp[i].sc;
@@ -131,7 +131,7 @@ void t_rnd() {
                 i--;
                 continue;
             }
-            ed.push_back({u, v});
+            ed.pb({u, v});
         }
         bcc_graph g;
         g.init(n);
diff --git a/tests/2-graph/test_kth_shortest_path.cpp b/tests/2-graph/test_kth_shortest_path.cpp
index 9ec3daa..e8c5f25 100644
--- a/tests/2-graph/test_kth_shortest_path.cpp
+++ b/tests/2-graph/test_kth_shortest_path.cpp
@@ -23,7 +23,7 @@ vector<ll> kth_na(int n, const vector<vector<pll>> &g, int s, int e, int k) {
         pq.pop();
         cnt[v]++;
         if (cnt[v] > k) continue;
-        if (v == e) res.push_back(d);
+        if (v == e) res.pb(d);
         if (cnt[v] <= k)
             for (auto [w, to] : g[v]) pq.push({d + w, to});
     }
@@ -33,8 +33,8 @@ vector<ll> kth_na(int n, const vector<vector<pll>> &g, int s, int e, int k) {
 void t_fix() {
     int n = 3;
     vector<vector<pll>> g(n + 1);
-    g[1].push_back({1, 2});
-    g[2].push_back({1, 3});
+    g[1].pb({1, 2});
+    g[2].pb({1, 3});
     ks.init(n);
     ks.add(1, 2, 1);
     ks.add(2, 3, 1);
@@ -52,7 +52,7 @@ void t_rnd() {
         for (int i = 0; i < m; i++) {
             int u = rnd(1, n), v = rnd(1, n);
             ll w = rnd(1, 5);
-            g[u].push_back({w, v});
+            g[u].pb({w, v});
             ks.add(u, v, w);
         }
         int s = rnd(1, n), e = rnd(1, n), k = rnd(1, 10);
diff --git a/tests/2-graph/test_offline_dynamic_connectivity.cpp b/tests/2-graph/test_offline_dynamic_connectivity.cpp
index 416abec..e446d07 100644
--- a/tests/2-graph/test_offline_dynamic_connectivity.cpp
+++ b/tests/2-graph/test_offline_dynamic_connectivity.cpp
@@ -15,8 +15,8 @@ int conn(int n, const set<pii> &act, int s, int e) {
     if (s == e) return 1;
     vector<vector<int>> adj(n + 1);
     for (auto [u, v] : act) {
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     }
     vector<int> vis(n + 1);
     queue<int> q;
diff --git a/tests/2-graph/test_scc_2_sat.cpp b/tests/2-graph/test_scc_2_sat.cpp
index 0593310..9565f46 100644
--- a/tests/2-graph/test_scc_2_sat.cpp
+++ b/tests/2-graph/test_scc_2_sat.cpp
@@ -68,7 +68,7 @@ void t_scc() {
         vector<vector<int>> g(n + 1);
         for (int i = 0; i < m; i++) {
             int u = rnd(1, n), v = rnd(1, n);
-            g[u].push_back(v);
+            g[u].pb(v);
         }
         auto cmp = cmp_na(n, g);
 
@@ -104,7 +104,7 @@ void t_sat() {
             int a = rnd(1, n), b = rnd(1, n);
             if (rnd(0, 1)) a = -a;
             if (rnd(0, 1)) b = -b;
-            cl.push_back({a, b});
+            cl.pb({a, b});
         }
         vector<int> val;
         bool ok2 = sat_br(n, cl, val);
diff --git a/tests/2-graph/test_shortest_path.cpp b/tests/2-graph/test_shortest_path.cpp
index 800dd76..63dcc1a 100644
--- a/tests/2-graph/test_shortest_path.cpp
+++ b/tests/2-graph/test_shortest_path.cpp
@@ -36,7 +36,7 @@ void t_dijk() {
         for (int i = 0; i < m; i++) {
             int u = rnd(1, n), v = rnd(1, n);
             ll w = rnd(0, 9);
-            ed.push_back({u, v, w});
+            ed.pb({u, v, w});
             dj.add(u, v, w);
         }
         auto d = floy(n, ed);
@@ -62,7 +62,7 @@ void t_bell() {
         for (int i = 0; i < m; i++) {
             int u = rnd(1, n), v = rnd(1, n);
             ll w = rnd(-5, 9);
-            ed.push_back({u, v, w});
+            ed.pb({u, v, w});
             bl.add(u, v, w);
         }
         auto d = floy(n, ed);
@@ -97,7 +97,7 @@ void t_floy() {
         for (int i = 0; i < m; i++) {
             int u = rnd(1, n), v = rnd(1, n);
             ll w = rnd(-5, 9);
-            ed.push_back({u, v, w});
+            ed.pb({u, v, w});
             fl.add(u, v, w);
         }
         auto d = floy(n, ed);
diff --git a/tests/3-tree/test_centroid_decomp.cpp b/tests/3-tree/test_centroid_decomp.cpp
index e15e797..3404b05 100644
--- a/tests/3-tree/test_centroid_decomp.cpp
+++ b/tests/3-tree/test_centroid_decomp.cpp
@@ -12,8 +12,8 @@ int rnd(int l, int r) {
 }
 
 void add_edge(vector<vector<int>> &adj, int u, int v) {
-    adj[u].push_back(v);
-    adj[v].push_back(u);
+    adj[u].pb(v);
+    adj[v].pb(u);
 }
 
 vector<vector<int>> gen_tree(int n) {
@@ -47,8 +47,8 @@ vector<int> get_nodes(int v, const vector<vector<int>> &chd) {
     while (!st.empty()) {
         int x = st.back();
         st.pop_back();
-        res.push_back(x);
-        for (int to : chd[x]) st.push_back(to);
+        res.pb(x);
+        for (int to : chd[x]) st.pb(to);
     }
     return res;
 }
@@ -121,7 +121,7 @@ void check_one(const vector<vector<int>> &adj) {
         for (int x : cd.chd[c]) {
             int lab = first[x];
             assert(lab);
-            labs.push_back(lab);
+            labs.pb(lab);
             auto nodes_x = get_nodes(x, cd.chd);
             for (int v : nodes_x) assert(first[v] == lab);
         }
diff --git a/tests/3-tree/test_hld.cpp b/tests/3-tree/test_hld.cpp
index bfe0a08..e498e74 100644
--- a/tests/3-tree/test_hld.cpp
+++ b/tests/3-tree/test_hld.cpp
@@ -29,10 +29,10 @@ vector<int> path_nodes(int n, const vector<vector<int>> &adj, int s, int e) {
     vector<int> res;
     int v = e;
     while (v != par[v]) {
-        res.push_back(v);
+        res.pb(v);
         v = par[v];
     }
-    res.push_back(s);
+    res.pb(s);
     return res;
 }
 
@@ -40,8 +40,8 @@ void t_fix() {
     int n = 4;
     vector<vector<int>> adj(n + 1);
     auto add = [&](int u, int v) {
-        adj[u].push_back(v);
-        adj[v].push_back(u);
+        adj[u].pb(v);
+        adj[v].pb(u);
     };
     add(1, 2);
     add(2, 3);
@@ -68,8 +68,8 @@ void t_rnd() {
         vector<vector<int>> adj(n + 1);
         for (int v = 2; v <= n; v++) {
             par[v] = rnd(1, v - 1);
-            adj[v].push_back(par[v]);
-            adj[par[v]].push_back(v);
+            adj[v].pb(par[v]);
+            adj[par[v]].pb(v);
         }
         hld_tree h;
         h.init(n);
diff --git a/tests/3-tree/test_lca_sparse_table.cpp b/tests/3-tree/test_lca_sparse_table.cpp
index d595a91..251db0f 100644
--- a/tests/3-tree/test_lca_sparse_table.cpp
+++ b/tests/3-tree/test_lca_sparse_table.cpp
@@ -39,8 +39,8 @@ void t_rnd() {
         vector<vector<int>> adj(n + 1);
         for (int v = 2; v <= n; v++) {
             par[v] = rnd(1, v - 1);
-            adj[v].push_back(par[v]);
-            adj[par[v]].push_back(v);
+            adj[v].pb(par[v]);
+            adj[par[v]].pb(v);
         }
         lca_sparse l;
         l.init(n);
diff --git a/tests/3-tree/test_tree_composition.cpp b/tests/3-tree/test_tree_composition.cpp
index 4baacff..389bd2f 100644
--- a/tests/3-tree/test_tree_composition.cpp
+++ b/tests/3-tree/test_tree_composition.cpp
@@ -12,8 +12,8 @@ int rnd(int l, int r) {
 }
 
 void add_edge(vector<vector<int>> &adj, int u, int v) {
-    adj[u].push_back(v);
-    adj[v].push_back(u);
+    adj[u].pb(v);
+    adj[v].pb(u);
 }
 
 vector<vector<int>> gen_tree(int n) {
@@ -64,7 +64,7 @@ vector<int> lca_closure(vector<int> vs, const vector<int> &par, const vector<int
                 int c = lca_na(vs[i], vs[j], par, dep);
                 if (!in_set[c]) {
                     in_set[c] = 1;
-                    vs.push_back(c);
+                    vs.pb(c);
                     chg = 1;
                 }
             }
@@ -140,7 +140,7 @@ void check_one(const vector<vector<int>> &adj, const vector<int> &vs) {
         st.pop_back();
         for (int to : tc.vt_adj[v]) {
             vis[to] = 1;
-            st.push_back(to);
+            st.pb(to);
         }
     }
     for (int v : exp_nodes) assert(vis[v]);
@@ -170,7 +170,7 @@ void t_rnd() {
         auto adj = gen_tree(n);
         int k = rnd(0, n);
         vector<int> vs;
-        for (int i = 0; i < k; i++) vs.push_back(rnd(1, n));
+        for (int i = 0; i < k; i++) vs.pb(rnd(1, n));
         check_one(adj, vs);
     }
 }
diff --git a/tests/3-tree/test_tree_exchange_argument.cpp b/tests/3-tree/test_tree_exchange_argument.cpp
index 6a877eb..798e991 100644
--- a/tests/3-tree/test_tree_exchange_argument.cpp
+++ b/tests/3-tree/test_tree_exchange_argument.cpp
@@ -12,8 +12,8 @@ int rnd(int l, int r) {
 }
 
 void add_edge(vector<vector<int>> &adj, int u, int v) {
-    adj[u].push_back(v);
-    adj[v].push_back(u);
+    adj[u].pb(v);
+    adj[v].pb(u);
 }
 
 vector<vector<int>> gen_tree(int n) {
@@ -35,7 +35,7 @@ vector<vector<int>> get_child(int n, const vector<vector<int>> &adj, int root) {
             if (to == par[v]) continue;
             if (par[to] != -1) continue;
             par[to] = v;
-            ch[v].push_back(to);
+            ch[v].pb(to);
             q.push(to);
         }
     }
@@ -49,7 +49,7 @@ ll brute_max(int n, const vector<vector<int>> &ch, const vector<ll> &w, const ve
         for (int to : ch[v]) indeg[to]++;
     vector<int> avail;
     for (int v = 1; v <= n; v++)
-        if (!indeg[v]) avail.push_back(v);
+        if (!indeg[v]) avail.pb(v);
 
     ll best = -(1LL << 62);
     vector<int> ord;
@@ -62,7 +62,7 @@ ll brute_max(int n, const vector<vector<int>> &ch, const vector<ll> &w, const ve
         }
         for (int i = 0; i < sz(av); i++) {
             int v = av[i];
-            ord.push_back(v);
+            ord.pb(v);
             vector<int> id2 = id;
             vector<int> av2 = av;
             av2.erase(av2.begin() + i);
@@ -70,7 +70,7 @@ ll brute_max(int n, const vector<vector<int>> &ch, const vector<ll> &w, const ve
             ll cost2 = cost + w[v] * tm2;
             for (int to : ch[v]) {
                 id2[to]--;
-                if (!id2[to]) av2.push_back(to);
+                if (!id2[to]) av2.pb(to);
             }
             dfs(id2, av2, tm2, cost2);
             ord.pop_back();
diff --git a/tests/4-optimizations/test_flow.cpp b/tests/4-optimizations/test_flow.cpp
index cb2732c..d0f4942 100644
--- a/tests/4-optimizations/test_flow.cpp
+++ b/tests/4-optimizations/test_flow.cpp
@@ -25,8 +25,8 @@ struct ek_flow {
     void add_edge(int u, int v, ll cap) {
         edge a{v, (int)g[v].size(), cap};
         edge b{u, (int)g[u].size(), 0};
-        g[u].push_back(a);
-        g[v].push_back(b);
+        g[u].pb(a);
+        g[v].pb(b);
     }
     ll max_flow(int s, int t) {
         if (s == t) return 0;
@@ -90,8 +90,8 @@ struct mcmf_spfa {
     void add_edge(int u, int v, ll cap, ll cost) {
         edge a{v, (int)g[v].size(), cap, cost};
         edge b{u, (int)g[u].size(), 0, -cost};
-        g[u].push_back(a);
-        g[v].push_back(b);
+        g[u].pb(a);
+        g[v].pb(b);
     }
     pll min_cost_mf(int s, int t, ll max_f) {
         const ll INF = (1LL << 62);
@@ -210,7 +210,7 @@ void t_hk() {
         vector<vector<int>> g(n_l);
         for (int l = 0; l < n_l; l++)
             for (int r = 0; r < n_r; r++)
-                if (rnd(0, 1)) bm.add_edge(l, r), g[l].push_back(r);
+                if (rnd(0, 1)) bm.add_edge(l, r), g[l].pb(r);
         assert(bm.max_matching() == brute_match(n_l, n_r, g));
     }
 }
@@ -229,7 +229,7 @@ void t_mcmf() {
             ll cap = rnd(0, 3);
             ll cost = rnd(-5, 5);
             nonneg &= (cost >= 0);
-            es.push_back({u, v, cap, cost});
+            es.pb({u, v, cap, cost});
         }
         mcmf mf1(n), mf2(n);
         mcmf_spfa na;
@@ -260,7 +260,7 @@ void t_lr_dinic() {
             if (u == v) continue;
             int lo = rnd(0, 2);
             int hi = lo + rnd(0, 2);
-            es.push_back({u, v, lo, hi, 0});
+            es.pb({u, v, lo, hi, 0});
             f.add_edge(u, v, lo, hi);
         }
         auto exp = brute_lr(n, s, t, es);
@@ -285,7 +285,7 @@ void t_lr_mcmf() {
             int lo = rnd(0, 2);
             int hi = lo + rnd(0, 2);
             int c = rnd(0, 5);
-            es.push_back({u, v, lo, hi, c});
+            es.pb({u, v, lo, hi, c});
             f.add_edge(u, v, lo, hi, c);
         }
         auto exp = brute_lr(n, s, t, es);
diff --git a/tests/5-string/test_aho_corasick.cpp b/tests/5-string/test_aho_corasick.cpp
index 96c243b..7b80c01 100644
--- a/tests/5-string/test_aho_corasick.cpp
+++ b/tests/5-string/test_aho_corasick.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 string rnd_s(int n) {
     string s;
-    for (int i = 0; i < n; i++) s.push_back('a' + rnd(0, 2));
+    for (int i = 0; i < n; i++) s.pb('a' + rnd(0, 2));
     return s;
 }
 
@@ -41,7 +41,7 @@ void t_rnd() {
         aho_corasick ac;
         for (int i = 0; i < n; i++) {
             string p = rnd_s(rnd(1, 6));
-            ps.push_back(p);
+            ps.pb(p);
             ac.add(p);
         }
         ac.build();
diff --git a/tests/5-string/test_kmp_algorithm.cpp b/tests/5-string/test_kmp_algorithm.cpp
index 9cb328e..dd98755 100644
--- a/tests/5-string/test_kmp_algorithm.cpp
+++ b/tests/5-string/test_kmp_algorithm.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 string rnd_s(int n) {
     string s;
-    for (int i = 0; i < n; i++) s.push_back('a' + rnd(0, 2));
+    for (int i = 0; i < n; i++) s.pb('a' + rnd(0, 2));
     return s;
 }
 
@@ -20,7 +20,7 @@ vector<int> na_match(const string &t, const string &p) {
     vector<int> res;
     if (p.empty()) return res;
     for (int i = 0; i + sz(p) <= sz(t); i++)
-        if (!t.compare(i, sz(p), p)) res.push_back(i);
+        if (!t.compare(i, sz(p), p)) res.pb(i);
     return res;
 }
 
diff --git a/tests/5-string/test_manachers_algorithm.cpp b/tests/5-string/test_manachers_algorithm.cpp
index 83a44bf..0d51ac9 100644
--- a/tests/5-string/test_manachers_algorithm.cpp
+++ b/tests/5-string/test_manachers_algorithm.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 string rnd_s(int n) {
     string s;
-    for (int i = 0; i < n; i++) s.push_back('a' + rnd(0, 2));
+    for (int i = 0; i < n; i++) s.pb('a' + rnd(0, 2));
     return s;
 }
 
diff --git a/tests/5-string/test_rabin_karp_algorithm.cpp b/tests/5-string/test_rabin_karp_algorithm.cpp
index e50f849..24b9ffb 100644
--- a/tests/5-string/test_rabin_karp_algorithm.cpp
+++ b/tests/5-string/test_rabin_karp_algorithm.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 string rnd_s(int n) {
     string s;
-    for (int i = 0; i < n; i++) s.push_back('a' + rnd(0, 2));
+    for (int i = 0; i < n; i++) s.pb('a' + rnd(0, 2));
     return s;
 }
 
@@ -20,7 +20,7 @@ vector<int> na_match(const string &t, const string &p) {
     vector<int> res;
     if (p.empty()) return res;
     for (int i = 0; i + sz(p) <= sz(t); i++)
-        if (!t.compare(i, sz(p), p)) res.push_back(i);
+        if (!t.compare(i, sz(p), p)) res.pb(i);
     return res;
 }
 
diff --git a/tests/5-string/test_suffix_array.cpp b/tests/5-string/test_suffix_array.cpp
index d96bcfb..2f016bd 100644
--- a/tests/5-string/test_suffix_array.cpp
+++ b/tests/5-string/test_suffix_array.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 string rnd_s(int n) {
     string s;
-    for (int i = 0; i < n; i++) s.push_back('a' + rnd(0, 2));
+    for (int i = 0; i < n; i++) s.pb('a' + rnd(0, 2));
     return s;
 }
 
diff --git a/tests/5-string/test_trie.cpp b/tests/5-string/test_trie.cpp
index 8dd9184..1673435 100644
--- a/tests/5-string/test_trie.cpp
+++ b/tests/5-string/test_trie.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 string rnd_s(int n) {
     string s;
-    for (int i = 0; i < n; i++) s.push_back('a' + rnd(0, 2));
+    for (int i = 0; i < n; i++) s.pb('a' + rnd(0, 2));
     return s;
 }
 
diff --git a/tests/5-string/test_z_algorithm.cpp b/tests/5-string/test_z_algorithm.cpp
index 23a855c..a24cf95 100644
--- a/tests/5-string/test_z_algorithm.cpp
+++ b/tests/5-string/test_z_algorithm.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 string rnd_s(int n) {
     string s;
-    for (int i = 0; i < n; i++) s.push_back('a' + rnd(0, 2));
+    for (int i = 0; i < n; i++) s.pb('a' + rnd(0, 2));
     return s;
 }
 
diff --git a/tests/6-geometry/test_bulldozer_trick.cpp b/tests/6-geometry/test_bulldozer_trick.cpp
index 489ba3a..4e4f499 100644
--- a/tests/6-geometry/test_bulldozer_trick.cpp
+++ b/tests/6-geometry/test_bulldozer_trick.cpp
@@ -15,7 +15,7 @@ vector<ld> uniq_ang(vector<ld> v) {
     sort(all(v));
     vector<ld> u;
     for (auto &x : v) {
-        if (u.empty() || fabsl(u.back() - x) > 1e-12) u.push_back(x);
+        if (u.empty() || fabsl(u.back() - x) > 1e-12) u.pb(x);
     }
     return u;
 }
@@ -23,7 +23,7 @@ vector<ld> uniq_ang(vector<ld> v) {
 vector<int> perm(const vector<pt> &p, map<pll, int> &id) {
     vector<int> res;
     res.reserve(sz(p));
-    for (auto &v : p) res.push_back(id[{v.x, v.y}]);
+    for (auto &v : p) res.pb(id[{v.x, v.y}]);
     return res;
 }
 
@@ -33,7 +33,7 @@ vector<int> proj_ord(const vector<pt> &p, map<pll, int> &id, ld ang) {
     arr.reserve(sz(p));
     for (auto &v : p) {
         ld pr = (ld)v.x * cs + (ld)v.y * sn;
-        arr.push_back({pr, id[{v.x, v.y}]});
+        arr.pb({pr, id[{v.x, v.y}]});
     }
     sort(all(arr), [&](auto &a, auto &b) {
         if (fabsl(a.fr - b.fr) > 1e-18) return a.fr < b.fr;
@@ -41,7 +41,7 @@ vector<int> proj_ord(const vector<pt> &p, map<pll, int> &id, ld ang) {
     });
     vector<int> ord;
     ord.reserve(sz(p));
-    for (auto &x : arr) ord.push_back(x.sc);
+    for (auto &x : arr) ord.pb(x.sc);
     return ord;
 }
 
@@ -55,12 +55,12 @@ void test_bulldozer_small() {
             pt v{rnd(-10, 10), rnd(-10, 10)};
             if (id.count({v.x, v.y})) continue;
             id[{v.x, v.y}] = sz(pts);
-            pts.push_back(v);
+            pts.pb(v);
         }
 
         vector<vector<int>> got;
         vector<pt> cur = pts;
-        bulldozer(cur, [&](const vector<pt> &p) { got.push_back(perm(p, id)); });
+        bulldozer(cur, [&](const vector<pt> &p) { got.pb(perm(p, id)); });
 
         vector<ld> th;
         for (int i = 0; i < n; i++) {
@@ -72,17 +72,17 @@ void test_bulldozer_small() {
                 ld t = a + PI / 2;
                 t = fmodl(t, PI);
                 if (t < 0) t += PI;
-                th.push_back(t);
+                th.pb(t);
             }
         }
         th = uniq_ang(th);
 
         vector<ld> bnd;
-        bnd.push_back(0);
+        bnd.pb(0);
         for (auto &t : th) {
-            if (t > 1e-12 && t < PI - 1e-12) bnd.push_back(t);
+            if (t > 1e-12 && t < PI - 1e-12) bnd.pb(t);
         }
-        bnd.push_back(PI);
+        bnd.pb(PI);
         bnd = uniq_ang(bnd);
 
         vector<vector<int>> exp;
@@ -90,7 +90,7 @@ void test_bulldozer_small() {
         sort(all(st));
         for (int i = 0; i + 1 < sz(bnd); i++) {
             ld mid = (bnd[i] + bnd[i + 1]) / 2;
-            exp.push_back(proj_ord(st, id, mid));
+            exp.pb(proj_ord(st, id, mid));
         }
         assert(got == exp);
     }
diff --git a/tests/6-geometry/test_convex_hull.cpp b/tests/6-geometry/test_convex_hull.cpp
index 4232600..62199b8 100644
--- a/tests/6-geometry/test_convex_hull.cpp
+++ b/tests/6-geometry/test_convex_hull.cpp
@@ -37,7 +37,7 @@ vector<pt> jarvis(vector<pt> p) {
     vector<pt> h;
     int cur = st;
     while (1) {
-        h.push_back(p[cur]);
+        h.pb(p[cur]);
         int nxt = (cur == 0 ? 1 : 0);
         for (int i = 0; i < n; i++)
             if (i != cur) {
@@ -92,7 +92,7 @@ void test_hull_random() {
         int n = (int)rnd(1, 50);
         vector<pt> p;
         p.reserve(n);
-        for (int i = 0; i < n; i++) p.push_back({rnd(-20, 20), rnd(-20, 20)});
+        for (int i = 0; i < n; i++) p.pb({rnd(-20, 20), rnd(-20, 20)});
         auto h1 = convex_hull(p);
         auto h2 = jarvis(p);
         auto s1 = uniq_pts(h1);
diff --git a/tests/6-geometry/test_half_plane_intersection.cpp b/tests/6-geometry/test_half_plane_intersection.cpp
index 3a66732..979bda8 100644
--- a/tests/6-geometry/test_half_plane_intersection.cpp
+++ b/tests/6-geometry/test_half_plane_intersection.cpp
@@ -27,10 +27,10 @@ bool in_hp(const hp_line &l, const ptd &p) {
 
 void test_hpi_square() {
     vector<hp_line> ln;
-    ln.push_back({{0, 1}, {0, 0}}); // x >= 0
-    ln.push_back({{1, 0}, {1, 1}}); // x <= 1
-    ln.push_back({{0, 0}, {1, 0}}); // y >= 0
-    ln.push_back({{1, 1}, {0, 1}}); // y <= 1
+    ln.pb({{0, 1}, {0, 0}}); // x >= 0
+    ln.pb({{1, 0}, {1, 1}}); // x <= 1
+    ln.pb({{0, 0}, {1, 0}}); // y >= 0
+    ln.pb({{1, 1}, {0, 1}}); // y <= 1
     auto poly = hpi(ln);
     assert(sz(poly) == 4);
     assert(fabsl(area_poly(poly) - 1.0L) < 1e-7);
@@ -41,9 +41,9 @@ void test_hpi_square() {
 
 void test_hpi_triangle() {
     vector<hp_line> ln;
-    ln.push_back({{0, 1}, {0, 0}}); // x >= 0
-    ln.push_back({{0, 0}, {1, 0}}); // y >= 0
-    ln.push_back({{1, 0}, {0, 1}}); // x + y <= 1
+    ln.pb({{0, 1}, {0, 0}}); // x >= 0
+    ln.pb({{0, 0}, {1, 0}}); // y >= 0
+    ln.pb({{1, 0}, {0, 1}}); // x + y <= 1
     auto poly = hpi(ln);
     assert(sz(poly) == 3);
     assert(fabsl(area_poly(poly) - 0.5L) < 1e-7);
@@ -54,8 +54,8 @@ void test_hpi_triangle() {
 
 void test_hpi_empty() {
     vector<hp_line> ln;
-    ln.push_back({{0, 1}, {0, 0}});   // x >= 0
-    ln.push_back({{-1, 0}, {-1, 1}}); // x <= -1
+    ln.pb({{0, 1}, {0, 0}});   // x >= 0
+    ln.pb({{-1, 0}, {-1, 1}}); // x <= -1
     auto poly = hpi(ln);
     assert(poly.empty());
 }
@@ -65,15 +65,15 @@ void test_hpi_random_convex() {
         int n = (int)rnd(10, 30);
         vector<pt> p;
         p.reserve(n);
-        for (int i = 0; i < n; i++) p.push_back({rnd(-20, 20), rnd(-20, 20)});
+        for (int i = 0; i < n; i++) p.pb({rnd(-20, 20), rnd(-20, 20)});
         auto h = convex_hull(p);
         if (sz(h) < 3) continue;
 
         vector<ptd> hp;
-        for (auto &v : h) hp.push_back({(ld)v.x, (ld)v.y});
+        for (auto &v : h) hp.pb({(ld)v.x, (ld)v.y});
         vector<hp_line> ln;
         for (int i = 0; i < sz(hp); i++) {
-            ln.push_back({hp[i], hp[(i + 1) % sz(hp)]});
+            ln.pb({hp[i], hp[(i + 1) % sz(hp)]});
         }
         auto poly = hpi(ln);
         assert(sz(poly) == sz(hp));
diff --git a/tests/6-geometry/test_minimum_enclosing_circle.cpp b/tests/6-geometry/test_minimum_enclosing_circle.cpp
index e4e8110..eaefbfa 100644
--- a/tests/6-geometry/test_minimum_enclosing_circle.cpp
+++ b/tests/6-geometry/test_minimum_enclosing_circle.cpp
@@ -89,7 +89,7 @@ void test_mec_random_brute() {
         p.reserve(n);
         for (int i = 0; i < n; i++) {
             ptd v{(ld)rnd(-5, 5), (ld)rnd(-5, 5)};
-            p.push_back(v);
+            p.pb(v);
         }
         auto got = min_circle(p);
         auto exp = brute_mec(p);
diff --git a/tests/6-geometry/test_ray_casting.cpp b/tests/6-geometry/test_ray_casting.cpp
index 0e959ad..19fd397 100644
--- a/tests/6-geometry/test_ray_casting.cpp
+++ b/tests/6-geometry/test_ray_casting.cpp
@@ -43,7 +43,7 @@ void test_in_poly_random_convex() {
         int n = (int)rnd(3, 40);
         vector<pt> p;
         p.reserve(n);
-        for (int i = 0; i < n; i++) p.push_back({rnd(-20, 20), rnd(-20, 20)});
+        for (int i = 0; i < n; i++) p.pb({rnd(-20, 20), rnd(-20, 20)});
         auto h = convex_hull(p);
         if (sz(h) < 3) continue;
 
diff --git a/tests/6-geometry/test_rotating_callipers.cpp b/tests/6-geometry/test_rotating_callipers.cpp
index 6bee9b2..e81555c 100644
--- a/tests/6-geometry/test_rotating_callipers.cpp
+++ b/tests/6-geometry/test_rotating_callipers.cpp
@@ -34,7 +34,7 @@ void test_diam_random() {
         int n = (int)rnd(1, 50);
         vector<pt> p;
         p.reserve(n);
-        for (int i = 0; i < n; i++) p.push_back({rnd(-30, 30), rnd(-30, 30)});
+        for (int i = 0; i < n; i++) p.pb({rnd(-30, 30), rnd(-30, 30)});
         auto h = convex_hull(p);
         if (sz(h) == 0) continue;
         auto res = hull_diam(h);
diff --git a/tests/6-geometry/test_segment_intersection.cpp b/tests/6-geometry/test_segment_intersection.cpp
index 1279ae6..1c5a7c3 100644
--- a/tests/6-geometry/test_segment_intersection.cpp
+++ b/tests/6-geometry/test_segment_intersection.cpp
@@ -17,8 +17,8 @@ pt rnd_pt(ll l, ll r) {
 
 bool on_seg_ld(const pt &a, const pt &b, const ptd &p) {
     ptd pa{(ld)a.x, (ld)a.y};
-    ptd pb{(ld)b.x, (ld)b.y};
-    ptd ab = pb - pa;
+    ptd p_b{(ld)b.x, (ld)b.y};
+    ptd ab = p_b - pa;
     ptd ap = p - pa;
     if (fabsl(cross(ab, ap)) > 1e-8) return 0;
     ld lx = min((ld)a.x, (ld)b.x) - 1e-8;
diff --git a/tests/6-geometry/test_sort_by_angular.cpp b/tests/6-geometry/test_sort_by_angular.cpp
index 263b811..7a8e361 100644
--- a/tests/6-geometry/test_sort_by_angular.cpp
+++ b/tests/6-geometry/test_sort_by_angular.cpp
@@ -45,7 +45,7 @@ void test_sort_ang_random() {
                 pt a = u - o, b = v - o;
                 if (cross(a, b) == 0) ok = 0;
             }
-            if (ok) p.push_back(v);
+            if (ok) p.pb(v);
         }
         assert(sz(p) == n);
 
diff --git a/tests/7-math/test_misc_sqrt.cpp b/tests/7-math/test_misc_sqrt.cpp
index 5304da1..bd51083 100644
--- a/tests/7-math/test_misc_sqrt.cpp
+++ b/tests/7-math/test_misc_sqrt.cpp
@@ -21,7 +21,7 @@ bool is_prime_ref(ll x) {
 vector<ll> div_ref(ll x) {
     vector<ll> d;
     for (ll i = 1; i <= x; i++)
-        if (x % i == 0) d.push_back(i);
+        if (x % i == 0) d.pb(i);
     return d;
 }
 
@@ -29,11 +29,11 @@ vector<ll> fac_ref(ll x) {
     vector<ll> p;
     for (ll i = 2; i <= x / i; i++) {
         while (x % i == 0) {
-            p.push_back(i);
+            p.pb(i);
             x /= i;
         }
     }
-    if (x > 1) p.push_back(x);
+    if (x > 1) p.pb(x);
     return p;
 }
 
diff --git a/tests/7-math/test_nt_crt.cpp b/tests/7-math/test_nt_crt.cpp
index 2c45e14..ab2fe5e 100644
--- a/tests/7-math/test_nt_crt.cpp
+++ b/tests/7-math/test_nt_crt.cpp
@@ -57,7 +57,7 @@ void test_merge_all() {
         for (int i = 0; i < k; i++) {
             ll m = rnd(1, 30);
             ll r = rnd(-30, 30);
-            cs.push_back({r, m});
+            cs.pb({r, m});
         }
         pll ans = crt::merge_all(cs);
         ll brute = brute_crt(cs);
diff --git a/tests/7-math/test_nt_mr_rho.cpp b/tests/7-math/test_nt_mr_rho.cpp
index 510210f..d4f95f6 100644
--- a/tests/7-math/test_nt_mr_rho.cpp
+++ b/tests/7-math/test_nt_mr_rho.cpp
@@ -22,11 +22,11 @@ vector<ll> fac_ref(ll x) {
     vector<ll> f;
     for (ll p = 2; p * p <= x; p++) {
         while (x % p == 0) {
-            f.push_back(p);
+            f.pb(p);
             x /= p;
         }
     }
-    if (x > 1) f.push_back(x);
+    if (x > 1) f.pb(x);
     sort(all(f));
     return f;
 }
diff --git a/tests/7-math/test_nt_sieve.cpp b/tests/7-math/test_nt_sieve.cpp
index 5661cf1..ba0704c 100644
--- a/tests/7-math/test_nt_sieve.cpp
+++ b/tests/7-math/test_nt_sieve.cpp
@@ -49,8 +49,8 @@ vector<int> divisors(int x) {
     vector<int> d;
     for (int i = 1; 1LL * i * i <= x; i++) {
         if (x % i) continue;
-        d.push_back(i);
-        if (i * i != x) d.push_back(x / i);
+        d.pb(i);
+        if (i * i != x) d.pb(x / i);
     }
     return d;
 }
diff --git a/tests/8-misc/test_kitamasa.cpp b/tests/8-misc/test_kitamasa.cpp
index 88fc9c4..99e832d 100644
--- a/tests/8-misc/test_kitamasa.cpp
+++ b/tests/8-misc/test_kitamasa.cpp
@@ -20,7 +20,7 @@ ll naive_rec(const vector<ll> &coef, const vector<ll> &init, ll n, ll mod) {
         for (int j = 1; j <= k; j++) {
             v = mod_norm(v + (__int128)coef[j - 1] * a[i - j], mod);
         }
-        a.push_back(v);
+        a.pb(v);
     }
     return a[n];
 }
diff --git a/tests/8-misc/test_system_of_difference_constraints.cpp b/tests/8-misc/test_system_of_difference_constraints.cpp
index d536a65..0173ed9 100644
--- a/tests/8-misc/test_system_of_difference_constraints.cpp
+++ b/tests/8-misc/test_system_of_difference_constraints.cpp
@@ -42,7 +42,7 @@ void test_random() {
             int v = rnd_int(0, n - 1);
             ll w = rnd_int(-5, 5);
             dc.add_le(u, v, w);
-            edges.push_back({u, v, w});
+            edges.pb({u, v, w});
         }
         bool ok = dc.solve();
         bool neg = has_neg_cycle(n, edges);

From 7bcb0654c5582985c9d5552043413f2c23095020 Mon Sep 17 00:00:00 2001
From: manoflearning <77jwk0724@gmail.com>
Date: Sun, 4 Jan 2026 02:11:31 +0900
Subject: [PATCH 2/6] chore: apply sz, all, rall

---
 src/1-ds/erasable_pq.cpp                      |  2 +-
 src/2-graph/offline_dynamic_connectivity.cpp  |  2 +-
 src/4-optimizations/flow.cpp                  | 28 +++++++++----------
 src/8-misc/dp_opt.cpp                         |  2 +-
 src/8-misc/lis_in_o_nlogn.cpp                 |  4 +--
 .../sqrt_decomposition_mos_algorithm.cpp      |  2 +-
 tests/1-ds/test_erasable_pq.cpp               |  4 +--
 tests/1-ds/test_pbds.cpp                      |  8 +++---
 tests/1-ds/test_segment_tree.cpp              |  6 ++--
 tests/2-graph/test_bcc.cpp                    |  2 +-
 tests/4-optimizations/test_flow.cpp           |  8 +++---
 tests/7-math/test_conv_fft.cpp                |  4 +--
 tests/8-misc/test_fraction_data_type.cpp      | 10 +++----
 .../test_sqrt_decomposition_mos_algorithm.cpp |  6 ++--
 14 files changed, 44 insertions(+), 44 deletions(-)

diff --git a/src/1-ds/erasable_pq.cpp b/src/1-ds/erasable_pq.cpp
index a450e9d..10f972e 100644
--- a/src/1-ds/erasable_pq.cpp
+++ b/src/1-ds/erasable_pq.cpp
@@ -7,7 +7,7 @@
 template <class T, class cmp = less<T>>
 struct erase_pq {
     priority_queue<T, vector<T>, cmp> q, del;
-    int size() { return (int)q.size() - (int)del.size(); }
+    int size() { return sz(q) - sz(del); }
     bool empty() { return size() == 0; }
     const T &top() { return (fix(), q.top()); } // result: current extreme element.
     void push(const T &x) { q.push(x); }
diff --git a/src/2-graph/offline_dynamic_connectivity.cpp b/src/2-graph/offline_dynamic_connectivity.cpp
index 465d6dc..d16c7ab 100644
--- a/src/2-graph/offline_dynamic_connectivity.cpp
+++ b/src/2-graph/offline_dynamic_connectivity.cpp
@@ -84,7 +84,7 @@ struct dyn_conn {
         } else if (op == 2) {
             auto it = mp.find({u, v});
             if (it == mp.end()) return;
-            sg.add(it->second, i - 1, {u, v});
+            sg.add(it->sc, i - 1, {u, v});
             mp.erase(it);
         } else if (op == 3) {
             qry[i] = {u, v};
diff --git a/src/4-optimizations/flow.cpp b/src/4-optimizations/flow.cpp
index 38b26cd..9ec4e38 100644
--- a/src/4-optimizations/flow.cpp
+++ b/src/4-optimizations/flow.cpp
@@ -34,11 +34,11 @@ struct dinic {
 
     edge_ref add_edge(int u, int v, ll cap) {
         // goal: add forward + reverse edge
-        edge a{v, (int)g[v].size(), cap};
-        edge b{u, (int)g[u].size(), 0};
+        edge a{v, sz(g[v]), cap};
+        edge b{u, sz(g[u]), 0};
         g[u].pb(a);
         g[v].pb(b);
-        return {u, (int)g[u].size() - 1};
+        return {u, sz(g[u]) - 1};
     }
 
     ll edge_flow(edge_ref e) const {
@@ -75,7 +75,7 @@ struct dinic {
 
     ll dfs(int v, int t, ll f) {
         if (v == t || f == 0) return f;
-        for (int &i = work[v]; i < (int)g[v].size(); i++) {
+        for (int &i = work[v]; i < sz(g[v]); i++) {
             edge &e = g[v][i];
             if (e.cap == 0 || level[e.to] != level[v] + 1) continue;
             // invariant: level strictly increases along augmenting path
@@ -132,7 +132,7 @@ struct hk {
     bool bfs() {
         // goal: build layers for shortest augmenting paths
         queue<int> q;
-        fill(dist.begin(), dist.end(), -1);
+        fill(all(dist), -1);
         for (int i = 0; i < n_l; i++) {
             if (match_l[i] == -1) {
                 dist[i] = 0;
@@ -171,8 +171,8 @@ struct hk {
 
     int max_matching() {
         // goal: compute maximum matching size
-        fill(match_l.begin(), match_l.end(), -1);
-        fill(match_r.begin(), match_r.end(), -1);
+        fill(all(match_l), -1);
+        fill(all(match_r), -1);
         int match = 0;
         while (bfs()) {
             for (int i = 0; i < n_l; i++) {
@@ -212,11 +212,11 @@ struct mcmf {
 
     edge_ref add_edge(int u, int v, ll cap, ll cost) {
         // goal: add forward + reverse edge with costs
-        edge a{v, (int)g[v].size(), cap, cost};
-        edge b{u, (int)g[u].size(), 0, -cost};
+        edge a{v, sz(g[v]), cap, cost};
+        edge b{u, sz(g[u]), 0, -cost};
         g[u].pb(a);
         g[v].pb(b);
-        return {u, (int)g[u].size() - 1};
+        return {u, sz(g[u]) - 1};
     }
 
     ll edge_flow(edge_ref e) const {
@@ -267,7 +267,7 @@ struct mcmf {
 
         while (flow < max_f) {
             // goal: shortest path in reduced costs
-            fill(dist.begin(), dist.end(), INF);
+            fill(all(dist), INF);
             dist[s] = 0;
             priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
             pq.push({0, s});
@@ -275,7 +275,7 @@ struct mcmf {
                 auto [d, v] = pq.top();
                 pq.pop();
                 if (d != dist[v]) continue;
-                for (int i = 0; i < (int)g[v].size(); i++) {
+                for (int i = 0; i < sz(g[v]); i++) {
                     const auto &e = g[v][i];
                     if (e.cap == 0) continue;
                     ll nd = d + e.cost + pot[v] - pot[e.to];
@@ -341,7 +341,7 @@ struct lr_dinic {
         demand[u] -= lo;
         demand[v] += lo;
         edges.pb({mf.add_edge(u, v, hi - lo), lo});
-        return (int)edges.size() - 1;
+        return sz(edges) - 1;
     }
 
     ll edge_flow(int id) const {
@@ -430,7 +430,7 @@ struct lr_mcmf {
         demand[v] += lo;
         base_cost += lo * cost;
         edges.pb({mf.add_edge(u, v, hi - lo, cost), lo});
-        return (int)edges.size() - 1;
+        return sz(edges) - 1;
     }
 
     ll edge_flow(int id) const {
diff --git a/src/8-misc/dp_opt.cpp b/src/8-misc/dp_opt.cpp
index bf806a5..fdb80ef 100644
--- a/src/8-misc/dp_opt.cpp
+++ b/src/8-misc/dp_opt.cpp
@@ -104,7 +104,7 @@ struct dnc_opt {
         prv = base;
         cur.assign(n, INF);
         for (int g = 1; g <= k; g++) {
-            fill(cur.begin(), cur.end(), INF);
+            fill(all(cur), INF);
             solve(0, n - 1, 0, n - 1, cost);
             prv.swap(cur);
         }
diff --git a/src/8-misc/lis_in_o_nlogn.cpp b/src/8-misc/lis_in_o_nlogn.cpp
index 6b0f1db..126350d 100644
--- a/src/8-misc/lis_in_o_nlogn.cpp
+++ b/src/8-misc/lis_in_o_nlogn.cpp
@@ -9,7 +9,7 @@ int lis_len(const vector<ll> &a) {
     // result: length of LIS.
     vector<ll> tail;
     for (ll x : a) {
-        auto it = lower_bound(tail.begin(), tail.end(), x);
+        auto it = lower_bound(all(tail), x);
         if (it == tail.end()) tail.pb(x);
         else *it = x;
     }
@@ -24,7 +24,7 @@ vector<ll> lis_seq(const vector<ll> &a) {
     vector<int> pre(n, -1);
     for (int i = 0; i < n; i++) {
         ll x = a[i];
-        int pos = lower_bound(tail.begin(), tail.end(), x) - tail.begin();
+        int pos = lower_bound(all(tail), x) - tail.begin();
         if (pos == sz(tail)) {
             tail.pb(x);
             tail_idx.pb(i);
diff --git a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
index 4e1de81..684f55c 100644
--- a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
+++ b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
@@ -26,7 +26,7 @@ struct mo {
     template <class Add, class Del, class Out>
     void run(Add add, Del del, Out out) {
         // goal: process queries in Mo order with callbacks.
-        sort(q.begin(), q.end(), [&](const qry &a, const qry &b) {
+        sort(all(q), [&](const qry &a, const qry &b) {
             int ba = a.l / bs, bb = b.l / bs;
             if (ba != bb) return ba < bb;
             return (ba & 1) ? a.r > b.r : a.r < b.r;
diff --git a/tests/1-ds/test_erasable_pq.cpp b/tests/1-ds/test_erasable_pq.cpp
index 9336e72..0f26519 100644
--- a/tests/1-ds/test_erasable_pq.cpp
+++ b/tests/1-ds/test_erasable_pq.cpp
@@ -12,7 +12,7 @@ ll rnd(ll l, ll r) {
 }
 
 ll pick_multiset(multiset<ll> &ms) {
-    int idx = (int)rnd(0, (int)ms.size() - 1);
+    int idx = (int)rnd(0, sz(ms) - 1);
     auto it = ms.begin();
     advance(it, idx);
     return *it;
@@ -59,7 +59,7 @@ void test_randomized() {
         } else {
             assert(pq.top() == *prev(ms.end()));
         }
-        assert(pq.size() == (int)ms.size());
+        assert(pq.size() == sz(ms));
         if (ms.empty()) {
             assert(pq.empty());
         } else {
diff --git a/tests/1-ds/test_pbds.cpp b/tests/1-ds/test_pbds.cpp
index 6dae4b4..558574b 100644
--- a/tests/1-ds/test_pbds.cpp
+++ b/tests/1-ds/test_pbds.cpp
@@ -45,14 +45,14 @@ void test_oset_random() {
             st.insert(x);
         } else if (op == 1) {
             if (st.empty()) continue;
-            ll x = kth_set(st, (int)rnd(0, (ll)st.size() - 1));
+            ll x = kth_set(st, (int)rnd(0, sz(st) - 1));
             s.erase(x);
             st.erase(x);
         } else {
             ll x = rnd(-10, 10);
             assert((int)s.order_of_key(x) == (int)distance(st.begin(), st.lower_bound(x)));
             if (!st.empty()) {
-                int k = (int)rnd(0, (ll)st.size() - 1);
+                int k = (int)rnd(0, sz(st) - 1);
                 assert(*s.find_by_order(k) == kth_set(st, k));
             }
         }
@@ -83,14 +83,14 @@ void test_omset_random() {
             ms.insert(x);
         } else if (op == 1) {
             if (ms.empty()) continue;
-            ll x = kth_multiset(ms, (int)rnd(0, (ll)ms.size() - 1));
+            ll x = kth_multiset(ms, (int)rnd(0, sz(ms) - 1));
             m_erase(s, x);
             ms.erase(ms.find(x));
         } else {
             ll x = rnd(-5, 5);
             assert(m_order(s, x) == (int)distance(ms.begin(), ms.lower_bound(x)));
             if (!ms.empty()) {
-                int k = (int)rnd(0, (ll)ms.size() - 1);
+                int k = (int)rnd(0, sz(ms) - 1);
                 assert(m_kth(s, k) == kth_multiset(ms, k));
             }
         }
diff --git a/tests/1-ds/test_segment_tree.cpp b/tests/1-ds/test_segment_tree.cpp
index 1cda5a1..b564e35 100644
--- a/tests/1-ds/test_segment_tree.cpp
+++ b/tests/1-ds/test_segment_tree.cpp
@@ -188,7 +188,7 @@ void test_pst_random() {
             ver.pb(nw);
             st.set(p, v);
         } else {
-            int id = (int)rnd(0, (int)ver.size() - 1);
+            int id = (int)rnd(0, sz(ver) - 1);
             int l = (int)rnd(1, n);
             int r = (int)rnd(l, n);
             assert(st.query(l, r, id) == sum_range(ver[id], l, r));
@@ -232,7 +232,7 @@ void test_pst_kth_random() {
             ver.pb(nw);
             st.set(p, v);
         } else {
-            int id = (int)rnd(0, (int)ver.size() - 1);
+            int id = (int)rnd(0, sz(ver) - 1);
             ll tot = 0;
             for (int i = 1; i <= n; i++) tot += ver[id][i];
             if (tot == 0) continue;
@@ -270,7 +270,7 @@ void test_dyseg_random() {
             int r = (int)rnd(l, hi);
             ll ret = 0;
             for (auto &kv : mp)
-                if (l <= kv.first && kv.first <= r) ret += kv.second;
+                if (l <= kv.fr && kv.fr <= r) ret += kv.sc;
             assert(st.query(l, r) == ret);
         }
     }
diff --git a/tests/2-graph/test_bcc.cpp b/tests/2-graph/test_bcc.cpp
index 5508f79..35b34df 100644
--- a/tests/2-graph/test_bcc.cpp
+++ b/tests/2-graph/test_bcc.cpp
@@ -78,7 +78,7 @@ void chk_bcc(int n, const vector<pii> &ed, bcc_graph &g) {
 
     for (auto &comp : g.bccs) {
         if (sz(comp) <= 1) continue;
-        vector<vector<pair<int, int>>> adj(n + 1);
+        vector<vector<pii>> adj(n + 1);
         for (int i = 0; i < sz(comp); i++) {
             int u = comp[i].fr, v = comp[i].sc;
             adj[u].pb({v, i});
diff --git a/tests/4-optimizations/test_flow.cpp b/tests/4-optimizations/test_flow.cpp
index d0f4942..89c8bbe 100644
--- a/tests/4-optimizations/test_flow.cpp
+++ b/tests/4-optimizations/test_flow.cpp
@@ -23,8 +23,8 @@ struct ek_flow {
         g.assign(n, {});
     }
     void add_edge(int u, int v, ll cap) {
-        edge a{v, (int)g[v].size(), cap};
-        edge b{u, (int)g[u].size(), 0};
+        edge a{v, sz(g[v]), cap};
+        edge b{u, sz(g[u]), 0};
         g[u].pb(a);
         g[v].pb(b);
     }
@@ -88,8 +88,8 @@ struct mcmf_spfa {
         g.assign(n, {});
     }
     void add_edge(int u, int v, ll cap, ll cost) {
-        edge a{v, (int)g[v].size(), cap, cost};
-        edge b{u, (int)g[u].size(), 0, -cost};
+        edge a{v, sz(g[v]), cap, cost};
+        edge b{u, sz(g[u]), 0, -cost};
         g[u].pb(a);
         g[v].pb(b);
     }
diff --git a/tests/7-math/test_conv_fft.cpp b/tests/7-math/test_conv_fft.cpp
index b9eab85..543bdea 100644
--- a/tests/7-math/test_conv_fft.cpp
+++ b/tests/7-math/test_conv_fft.cpp
@@ -85,7 +85,7 @@ void test_ntt() {
         for (int i = 0; i < m; i++) b[i] = rnd_int(0, mod - 1);
         auto ref = conv_mod_ref(a, b, mod);
         auto got = ntt_conv::mul(a, b);
-        assert(got.size() == ref.size());
+        assert(sz(got) == sz(ref));
         for (int i = 0; i < sz(ref); i++) assert(got[i] == ref[i]);
     }
 }
@@ -100,7 +100,7 @@ void test_ntt_any() {
             for (int i = 0; i < m; i++) b[i] = rnd_int(0, 1000);
             auto ref = conv_mod_ref(a, b, mod);
             auto got = ntt_any::mul(a, b, mod);
-            assert(got.size() == ref.size());
+            assert(sz(got) == sz(ref));
             for (int i = 0; i < sz(ref); i++) assert(got[i] == ref[i]);
         }
     }
diff --git a/tests/8-misc/test_fraction_data_type.cpp b/tests/8-misc/test_fraction_data_type.cpp
index 08eb17f..4ab72b0 100644
--- a/tests/8-misc/test_fraction_data_type.cpp
+++ b/tests/8-misc/test_fraction_data_type.cpp
@@ -11,7 +11,7 @@ ll rnd(ll l, ll r) {
     return dis(rng);
 }
 
-pair<ll, ll> norm_pair(ll n, ll d) {
+pll norm_pair(ll n, ll d) {
     if (d < 0) n = -n, d = -d;
     ll g = fraction::gcd_ll(n, d);
     if (g) n /= g, d /= g;
@@ -48,10 +48,10 @@ void test_ops_random() {
         fraction xsub = x - y;
         fraction xmul = x * y;
         fraction xdiv = x / y;
-        assert(xadd.n == add.first && xadd.d == add.second);
-        assert(xsub.n == sub.first && xsub.d == sub.second);
-        assert(xmul.n == mul.first && xmul.d == mul.second);
-        assert(xdiv.n == div.first && xdiv.d == div.second);
+        assert(xadd.n == add.fr && xadd.d == add.sc);
+        assert(xsub.n == sub.fr && xsub.d == sub.sc);
+        assert(xmul.n == mul.fr && xmul.d == mul.sc);
+        assert(xdiv.n == div.fr && xdiv.d == div.sc);
         bool lt = (__int128)xn * yd < (__int128)yn * xd;
         assert((x < y) == lt);
     }
diff --git a/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp b/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp
index 7abc58d..022118a 100644
--- a/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp
+++ b/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp
@@ -16,7 +16,7 @@ void test_distinct() {
     vector<int> a(n);
     for (int i = 0; i < n; i++) a[i] = rnd_int(0, 30);
 
-    vector<pair<int, int>> qs(qn);
+    vector<pii> qs(qn);
     for (int i = 0; i < qn; i++) {
         int l = rnd_int(0, n - 1);
         int r = rnd_int(l, n - 1);
@@ -27,14 +27,14 @@ void test_distinct() {
     for (int i = 0; i < qn; i++) {
         vector<int> cnt(31, 0);
         int cur = 0;
-        for (int j = qs[i].first; j <= qs[i].second; j++) {
+        for (int j = qs[i].fr; j <= qs[i].sc; j++) {
             if (cnt[a[j]]++ == 0) cur++;
         }
         naive[i] = cur;
     }
 
     mo solver(n);
-    for (int i = 0; i < qn; i++) solver.add_query(qs[i].first, qs[i].second, i);
+    for (int i = 0; i < qn; i++) solver.add_query(qs[i].fr, qs[i].sc, i);
 
     vector<int> cnt(31, 0);
     int cur = 0;

From 42caa12dac997c03a70c26c3d3821b97e57ba339 Mon Sep 17 00:00:00 2001
From: manoflearning <77jwk0724@gmail.com>
Date: Sun, 4 Jan 2026 02:42:20 +0900
Subject: [PATCH 3/6] remove

---
 src/common/common.hpp | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/common/common.hpp b/src/common/common.hpp
index 5e8de73..9b740d9 100644
--- a/src/common/common.hpp
+++ b/src/common/common.hpp
@@ -4,7 +4,6 @@
 using namespace std;
 using ll = long long;
 using ld = long double;
-using ull = unsigned long long;
 using pii = pair<int, int>;
 using pll = pair<ll, ll>;
 #define fr first
@@ -12,4 +11,3 @@ using pll = pair<ll, ll>;
 #define pb push_back
 #define sz(x) (int)(x).size()
 #define all(x) (x).begin(), (x).end()
-#define rall(x) (x).rbegin(), (x).rend()

From f4ba79cf42c5e06ba5ee0ade27b287859c9ec118 Mon Sep 17 00:00:00 2001
From: manoflearning <77jwk0724@gmail.com>
Date: Sun, 4 Jan 2026 02:49:45 +0900
Subject: [PATCH 4/6] vi vl vvi vvl

---
 src/1-ds/fenwick_tree.cpp                     | 16 +++----
 src/1-ds/merge_sort_tree.cpp                  |  8 ++--
 src/1-ds/segment_tree.cpp                     | 30 ++++++-------
 src/1-ds/union_find.cpp                       |  2 +-
 src/2-graph/bcc.cpp                           |  2 +-
 src/2-graph/euler_circuit.cpp                 | 12 ++---
 src/2-graph/kth_shortest_path.cpp             | 10 ++---
 src/2-graph/offline_dynamic_connectivity.cpp  |  4 +-
 src/2-graph/scc_2_sat.cpp                     | 12 ++---
 src/2-graph/shortest_path.cpp                 | 10 ++---
 src/3-tree/centroid_decomp.cpp                |  4 +-
 src/3-tree/hld.cpp                            |  6 +--
 src/3-tree/lca_sparse_table.cpp               |  6 +--
 src/3-tree/tree_composition.cpp               | 10 ++---
 src/3-tree/tree_exchange_argument.cpp         |  8 ++--
 src/4-optimizations/flow.cpp                  | 16 +++----
 src/4-optimizations/hungarian.cpp             | 10 ++---
 src/5-string/aho_corasick.cpp                 |  2 +-
 src/5-string/kmp_algorithm.cpp                |  8 ++--
 src/5-string/manachers_algorithm.cpp          |  4 +-
 src/5-string/rabin_karp_algorithm.cpp         |  6 +--
 src/5-string/suffix_array.cpp                 | 10 ++---
 src/5-string/z_algorithm.cpp                  |  4 +-
 src/6-geometry/bulldozer_trick.cpp            |  4 +-
 src/7-math/comb_binom.cpp                     |  6 +--
 src/7-math/comb_cat_der.cpp                   |  2 +-
 src/7-math/conv_fft.cpp                       | 22 +++++-----
 src/7-math/linalg_gauss.cpp                   | 12 ++---
 src/7-math/linalg_mat.cpp                     |  4 +-
 src/7-math/misc_sqrt.cpp                      |  8 ++--
 src/7-math/nt_mr_rho.cpp                      |  6 +--
 src/7-math/nt_sieve.cpp                       | 12 ++---
 src/8-misc/dp_opt.cpp                         | 16 +++----
 src/8-misc/kitamasa.cpp                       |  4 +-
 src/8-misc/lis_in_o_nlogn.cpp                 | 14 +++---
 .../system_of_difference_constraints.cpp      |  4 +-
 src/common/common.hpp                         |  4 ++
 tests/1-ds/test_fenwick_tree.cpp              | 16 +++----
 tests/1-ds/test_merge_sort_tree.cpp           | 10 ++---
 tests/1-ds/test_segment_tree.cpp              | 44 +++++++++----------
 tests/1-ds/test_union_find.cpp                |  4 +-
 tests/2-graph/test_bcc.cpp                    | 12 ++---
 tests/2-graph/test_euler_circuit.cpp          | 20 ++++-----
 tests/2-graph/test_kth_shortest_path.cpp      |  6 +--
 .../test_offline_dynamic_connectivity.cpp     |  8 ++--
 tests/2-graph/test_scc_2_sat.cpp              | 14 +++---
 tests/2-graph/test_shortest_path.cpp          |  6 +--
 tests/3-tree/test_centroid_decomp.cpp         | 34 +++++++-------
 tests/3-tree/test_hld.cpp                     | 16 +++----
 tests/3-tree/test_lca_sparse_table.cpp        |  8 ++--
 tests/3-tree/test_tree_composition.cpp        | 28 ++++++------
 tests/3-tree/test_tree_exchange_argument.cpp  | 38 ++++++++--------
 tests/4-optimizations/test_flow.cpp           | 16 +++----
 tests/4-optimizations/test_hungarian.cpp      | 10 ++---
 tests/5-string/test_kmp_algorithm.cpp         |  8 ++--
 tests/5-string/test_rabin_karp_algorithm.cpp  |  4 +-
 tests/5-string/test_suffix_array.cpp          |  4 +-
 tests/5-string/test_z_algorithm.cpp           |  4 +-
 tests/6-geometry/test_bulldozer_trick.cpp     | 12 ++---
 tests/7-math/test_comb_cat_der.cpp            |  8 ++--
 tests/7-math/test_conv_fft.cpp                | 22 +++++-----
 tests/7-math/test_linalg_gauss.cpp            | 10 ++---
 tests/7-math/test_linalg_mat.cpp              |  4 +-
 tests/7-math/test_misc_sqrt.cpp               | 14 +++---
 tests/7-math/test_nt_mr_rho.cpp               | 12 ++---
 tests/7-math/test_nt_sieve.cpp                |  4 +-
 tests/8-misc/test_dp_opt.cpp                  | 20 ++++-----
 tests/8-misc/test_kitamasa.cpp                |  6 +--
 tests/8-misc/test_lis_in_o_nlogn.cpp          | 12 ++---
 tests/8-misc/test_simd.cpp                    |  2 +-
 .../test_sqrt_decomposition_mos_algorithm.cpp |  8 ++--
 .../test_system_of_difference_constraints.cpp |  4 +-
 72 files changed, 385 insertions(+), 381 deletions(-)

diff --git a/src/1-ds/fenwick_tree.cpp b/src/1-ds/fenwick_tree.cpp
index 6b5fa2b..cbdf86a 100644
--- a/src/1-ds/fenwick_tree.cpp
+++ b/src/1-ds/fenwick_tree.cpp
@@ -6,14 +6,14 @@
 // usage: fenwick fw; fw.build(a); fw.add(p, x); fw.sum(l, r); fw.kth(k);
 struct fenwick {
     int n;
-    vector<ll> a, t;
+    vl a, t;
     void init(int n_) {
         // goal: allocate arrays for size n.
         n = n_;
         a.assign(n, 0);
         t.assign(n, 0);
     }
-    void build(const vector<ll> &v) {
+    void build(const vl &v) {
         // goal: build fenwick in O(n) from initial array.
         n = sz(v);
         a = v;
@@ -60,7 +60,7 @@ struct fenwick {
 // usage: fenw_range fw; fw.init(n); fw.add(l, r, x); ll v = fw.get(p);
 struct fenw_range { // 1-indexed
     int n;
-    vector<ll> t;
+    vl t;
     void init(int n_) {
         // goal: allocate internal tree (1-indexed).
         n = n_;
@@ -85,19 +85,19 @@ struct fenw_range { // 1-indexed
 // usage: fenw_2d fw; fw.build(a); fw.add(x, y, v); fw.sum(x1, y1, x2, y2);
 struct fenw_2d { // 0-indexed
     int n, m;
-    vector<vector<ll>> a, t;
+    vvl a, t;
     void init(int n_, int m_) {
         // goal: allocate arrays for n x m.
         n = n_, m = m_;
-        a.assign(n, vector<ll>(m, 0));
-        t.assign(n, vector<ll>(m, 0));
+        a.assign(n, vl(m, 0));
+        t.assign(n, vl(m, 0));
     }
-    void build(const vector<vector<ll>> &v) {
+    void build(const vvl &v) {
         // goal: build 2D fenwick in O(n*m).
         n = sz(v);
         m = n ? sz(v[0]) : 0;
         a = v;
-        t.assign(n, vector<ll>(m, 0));
+        t.assign(n, vl(m, 0));
         for (int i = 0; i < n; i++) {
             for (int j = 0; j < m; j++) {
                 t[i][j] += a[i][j];
diff --git a/src/1-ds/merge_sort_tree.cpp b/src/1-ds/merge_sort_tree.cpp
index 50b5b70..2f9f3b7 100644
--- a/src/1-ds/merge_sort_tree.cpp
+++ b/src/1-ds/merge_sort_tree.cpp
@@ -6,8 +6,8 @@ constexpr int MAX_MST = 1 << 17;
 // constraint: MAX_MST >= n; values fit in int; 0-indexed [l, r]; build once.
 // usage: merge_seg st; st.build(a); st.query(l, r, k);
 struct merge_seg {
-    vector<int> t[MAX_MST << 1];
-    void build(const vector<int> &a) {
+    vi t[MAX_MST << 1];
+    void build(const vi &a) {
         // goal: build sorted lists for each node.
         for (int i = 0; i < sz(a); i++)
             t[i + MAX_MST].pb(a[i]);
@@ -31,8 +31,8 @@ struct merge_seg {
 // constraint: MAX_MST >= n; values fit in int; 0-indexed [l, r]; build once.
 // usage: merge_seg_it st; st.build(a); st.query(l, r, k);
 struct merge_seg_it {
-    vector<int> t[MAX_MST << 1];
-    void build(const vector<int> &a) {
+    vi t[MAX_MST << 1];
+    void build(const vi &a) {
         // goal: build sorted lists for each node.
         for (int i = 0; i < sz(a); i++)
             t[i + MAX_MST].pb(a[i]);
diff --git a/src/1-ds/segment_tree.cpp b/src/1-ds/segment_tree.cpp
index 6f595d6..06d0775 100644
--- a/src/1-ds/segment_tree.cpp
+++ b/src/1-ds/segment_tree.cpp
@@ -6,8 +6,8 @@
 // usage: seg_tree st; st.build(a); st.set(p, v); st.query(l, r);
 struct seg_tree {
     int flag;
-    vector<ll> t;
-    void build(const vector<ll> &a) {
+    vl t;
+    void build(const vl &a) {
         // goal: build tree from 1-indexed array.
         int n = sz(a) - 1;
         flag = 1;
@@ -36,8 +36,8 @@ struct seg_tree {
 // usage: seg_tree_it st; st.build(a); st.set(p, v); st.query(l, r);
 struct seg_tree_it { // 0-indexed
     int n;
-    vector<ll> t;
-    void build(const vector<ll> &a) {
+    vl t;
+    void build(const vl &a) {
         // goal: build tree from 0-indexed array.
         n = sz(a);
         t.assign(2 * n, 0);
@@ -65,7 +65,7 @@ struct seg_tree_it { // 0-indexed
 // usage: seg_tree_kth st; st.init(n); st.add(p, v); st.kth(k);
 struct seg_tree_kth {
     int flag;
-    vector<ll> t;
+    vl t;
     void init(int n) {
         // goal: allocate tree for size n.
         flag = 1;
@@ -91,8 +91,8 @@ struct seg_tree_kth {
 // usage: seg_tree_lz st; st.build(a); st.add(l, r, v); st.query(l, r);
 struct seg_tree_lz {
     int flag;
-    vector<ll> t, lz;
-    void build(const vector<ll> &a) {
+    vl t, lz;
+    void build(const vl &a) {
         // goal: build tree and clear lazy tags.
         int n = sz(a) - 1;
         flag = 1;
@@ -149,10 +149,10 @@ struct seg_pst {
     };
     int n;
     vector<node> t;
-    vector<int> root;
+    vi root;
 
     void newnd() { t.pb({-1, -1, 0}); }
-    void build(int n_, const vector<ll> &a) {
+    void build(int n_, const vl &a) {
         // goal: build initial version.
         n = n_;
         t.clear();
@@ -161,7 +161,7 @@ struct seg_pst {
         root.pb(0);
         build(1, n, root[0], a);
     }
-    void build(int l, int r, int v, const vector<ll> &a) {
+    void build(int l, int r, int v, const vl &a) {
         // goal: build node v for range [l, r].
         if (l == r) {
             t[v].val = a[l];
@@ -275,11 +275,11 @@ struct seg_sparse {
 // usage: seg_2d st; st.build(a); st.set(x, y, v); st.query(x1, x2, y1, y2);
 struct seg_2d { // 0-indexed
     int n;
-    vector<vector<ll>> t;
-    void build(const vector<vector<ll>> &a) {
+    vvl t;
+    void build(const vvl &a) {
         // goal: build 2D tree from initial grid.
         n = sz(a);
-        t.assign(2 * n, vector<ll>(2 * n, 0));
+        t.assign(2 * n, vl(2 * n, 0));
         for (int i = 0; i < n; i++)
             for (int j = 0; j < n; j++)
                 t[i + n][j + n] = a[i][j];
@@ -325,8 +325,8 @@ struct seg_2d { // 0-indexed
 // usage: seg2d_comp st(n); st.mark_set(x, y); st.mark_qry(x1, x2, y1, y2); st.prep(); st.set(x, y, v); st.query(x1, x2, y1, y2);
 struct seg2d_comp { // 0-indexed
     int n;
-    vector<vector<ll>> a;
-    vector<vector<int>> used;
+    vvl a;
+    vvi used;
     unordered_map<ll, ll> mp;
     seg2d_comp(int n) : n(n), a(2 * n), used(2 * n) {}
     void mark_set(int x, int y) {
diff --git a/src/1-ds/union_find.cpp b/src/1-ds/union_find.cpp
index 9412ccf..e8355bc 100644
--- a/src/1-ds/union_find.cpp
+++ b/src/1-ds/union_find.cpp
@@ -5,7 +5,7 @@
 // constraint: 1-indexed [1, n].
 // usage: dsu d; d.init(n); d.join(a, b); int r = d.find(x); int s = d.size(x);
 struct dsu {
-    vector<int> p;
+    vi p;
     void init(int n) { p.assign(n + 1, -1); }                    // goal: reset to n singletons.
     int find(int x) { return p[x] < 0 ? x : p[x] = find(p[x]); } // result: root of x.
     int size(int x) { return -p[find(x)]; }
diff --git a/src/2-graph/bcc.cpp b/src/2-graph/bcc.cpp
index c59257d..c7ce283 100644
--- a/src/2-graph/bcc.cpp
+++ b/src/2-graph/bcc.cpp
@@ -7,7 +7,7 @@
 struct bcc_graph {
     int n, tim;
     vector<vector<pii>> adj;
-    vector<int> dfn, low, ap, st;
+    vi dfn, low, ap, st;
     vector<pii> ed, ae;
     vector<vector<pii>> bccs;
 
diff --git a/src/2-graph/euler_circuit.cpp b/src/2-graph/euler_circuit.cpp
index 265e431..7552b2f 100644
--- a/src/2-graph/euler_circuit.cpp
+++ b/src/2-graph/euler_circuit.cpp
@@ -6,13 +6,13 @@
 // usage: euler_cir g; g.init(n); g.add(u,v); if (g.can()) auto path=g.run(1);
 struct euler_cir {
     int n;
-    vector<vector<int>> adj;
-    vector<int> nxt, path;
+    vvi adj;
+    vi nxt, path;
 
     void init(int n_) {
         // goal: allocate adjacency matrix and reset state.
         n = n_;
-        adj.assign(n + 1, vector<int>(n + 1));
+        adj.assign(n + 1, vi(n + 1));
         nxt.assign(n + 1, 1);
         path.clear();
     }
@@ -23,7 +23,7 @@ struct euler_cir {
     }
     bool can() {
         // result: whether an Euler circuit exists.
-        vector<int> deg(n + 1);
+        vi deg(n + 1);
         for (int i = 1; i <= n; i++)
             for (int j = 1; j <= n; j++) deg[i] += adj[i][j];
         for (int i = 1; i <= n; i++)
@@ -35,7 +35,7 @@ struct euler_cir {
                 break;
             }
         if (!s) return 1;
-        vector<int> vis(n + 1);
+        vi vis(n + 1);
         queue<int> q;
         q.push(s);
         vis[s] = 1;
@@ -60,7 +60,7 @@ struct euler_cir {
         }
         path.pb(v);
     }
-    vector<int> run(int s = 1) {
+    vi run(int s = 1) {
         // result: Euler circuit starting from s (if exists).
         for (int i = 1; i <= n; i++) nxt[i] = 1;
         path.clear();
diff --git a/src/2-graph/kth_shortest_path.cpp b/src/2-graph/kth_shortest_path.cpp
index c86093a..4986635 100644
--- a/src/2-graph/kth_shortest_path.cpp
+++ b/src/2-graph/kth_shortest_path.cpp
@@ -47,9 +47,9 @@ struct kth_walk {
         rg[v].pb({w, u});
     }
 
-    vector<ll> run(int s, int e, int k) {
-        vector<int> nxt(n + 1, -1), ord, vis(n + 1);
-        vector<ll> dist(n + 1, INF);
+    vl run(int s, int e, int k) {
+        vi nxt(n + 1, -1), ord, vis(n + 1);
+        vl dist(n + 1, INF);
 
         // goal: shortest path tree from e on reversed graph.
         dist[e] = 0;
@@ -72,7 +72,7 @@ struct kth_walk {
         }
         if (dist[s] >= INF) return {};
 
-        vector<int> rt(n + 1), chk(n + 1);
+        vi rt(n + 1), chk(n + 1);
         for (int x : ord)
             if (dist[x] < INF) {
                 if (nxt[x] != -1) rt[x] = rt[nxt[x]];
@@ -86,7 +86,7 @@ struct kth_walk {
                 }
             }
 
-        vector<ll> ans = {dist[s]};
+        vl ans = {dist[s]};
         priority_queue<pll, vector<pll>, greater<pll>> pq2;
         if (rt[s]) pq2.push({hp.h[rt[s]].x.fr, rt[s]});
         while (sz(ans) < k && !pq2.empty()) {
diff --git a/src/2-graph/offline_dynamic_connectivity.cpp b/src/2-graph/offline_dynamic_connectivity.cpp
index d16c7ab..a875c73 100644
--- a/src/2-graph/offline_dynamic_connectivity.cpp
+++ b/src/2-graph/offline_dynamic_connectivity.cpp
@@ -28,7 +28,7 @@ struct dyn_conn {
     } sg;
 
     struct dsu {
-        vector<int> par, siz, st;
+        vi par, siz, st;
         void init(int n) {
             // goal: reset to n isolated nodes.
             par.resize(n + 1);
@@ -64,7 +64,7 @@ struct dyn_conn {
     int n, q;
     map<pii, int> mp;
     vector<pii> qry;
-    vector<int> ans;
+    vi ans;
 
     void init(int n_, int q_) {
         // goal: initialize with n nodes and q operations.
diff --git a/src/2-graph/scc_2_sat.cpp b/src/2-graph/scc_2_sat.cpp
index 88a3a4f..bf0e64d 100644
--- a/src/2-graph/scc_2_sat.cpp
+++ b/src/2-graph/scc_2_sat.cpp
@@ -6,8 +6,8 @@
 // usage: scc_kosa s; s.init(n); s.add(u,v); int c=s.run();
 struct scc_kosa {
     int n;
-    vector<vector<int>> g, rg, sccs;
-    vector<int> vis, comp, ord;
+    vvi g, rg, sccs;
+    vi vis, comp, ord;
 
     void init(int n_) {
         n = n_;
@@ -53,8 +53,8 @@ struct scc_kosa {
 // usage: scc_tarjan s; s.init(n); s.add(u,v); int c=s.run();
 struct scc_tarjan {
     int n, tim;
-    vector<vector<int>> g, sccs;
-    vector<int> dfn, low, comp, st, ins;
+    vvi g, sccs;
+    vi dfn, low, comp, st, ins;
 
     void init(int n_) {
         n = n_;
@@ -105,8 +105,8 @@ struct scc_tarjan {
 // usage: two_sat s; s.init(n); s.add(a,b); bool ok=s.run(); // s.val
 struct two_sat {
     int n, tim, cid;
-    vector<vector<int>> g;
-    vector<int> dfn, low, comp, st, ins, val;
+    vvi g;
+    vi dfn, low, comp, st, ins, val;
 
     void init(int n_) {
         n = n_;
diff --git a/src/2-graph/shortest_path.cpp b/src/2-graph/shortest_path.cpp
index 3dfc933..c929df3 100644
--- a/src/2-graph/shortest_path.cpp
+++ b/src/2-graph/shortest_path.cpp
@@ -15,9 +15,9 @@ struct dijkstra {
         adj.assign(n + 1, {});
     }
     void add(int u, int v, ll w) { adj[u].pb({w, v}); }
-    vector<ll> run(int s) {
+    vl run(int s) {
         // result: dist[i] = shortest distance from s to i.
-        vector<ll> dist(n + 1, INF);
+        vl dist(n + 1, INF);
         priority_queue<pll, vector<pll>, greater<pll>> pq;
         dist[s] = 0;
         pq.push({0, s});
@@ -51,7 +51,7 @@ struct bell_ford {
         ed.clear();
     }
     void add(int u, int v, ll w) { ed.pb({u, v, w}); }
-    bool run(int s, vector<ll> &dist) {
+    bool run(int s, vl &dist) {
         // result: false if a negative cycle is reachable.
         dist.assign(n + 1, INF);
         dist[s] = 0;
@@ -78,12 +78,12 @@ struct bell_ford {
 struct floyd {
     static const ll INF = (1LL << 62);
     int n;
-    vector<vector<ll>> d;
+    vvl d;
 
     void init(int n_) {
         // goal: initialize distance matrix.
         n = n_;
-        d.assign(n + 1, vector<ll>(n + 1, INF));
+        d.assign(n + 1, vl(n + 1, INF));
         for (int i = 1; i <= n; i++) d[i][i] = 0;
     }
     void add(int u, int v, ll w) { d[u][v] = min(d[u][v], w); }
diff --git a/src/3-tree/centroid_decomp.cpp b/src/3-tree/centroid_decomp.cpp
index 8837a41..c58f79b 100644
--- a/src/3-tree/centroid_decomp.cpp
+++ b/src/3-tree/centroid_decomp.cpp
@@ -6,8 +6,8 @@
 // usage: cen_decomp cd; cd.init(n); cd.add(u,v); cd.build(); int p=cd.par[v];
 struct cen_decomp {
     int n;
-    vector<vector<int>> adj, chd;
-    vector<int> par, siz;
+    vvi adj, chd;
+    vi par, siz;
     vector<char> used;
 
     void init(int n_) {
diff --git a/src/3-tree/hld.cpp b/src/3-tree/hld.cpp
index d02bf92..fdb16b5 100644
--- a/src/3-tree/hld.cpp
+++ b/src/3-tree/hld.cpp
@@ -8,8 +8,8 @@ struct hld_tree {
     seg_tree seg;
 
     int n, tim;
-    vector<vector<int>> adj;
-    vector<int> par, dep, siz, heavy, top, in;
+    vvi adj;
+    vi par, dep, siz, heavy, top, in;
 
     void init(int n_) {
         n = n_;
@@ -51,7 +51,7 @@ struct hld_tree {
     void build(int root = 1) {
         dfs_sz(root, 0);
         dfs_hld(root, root);
-        vector<ll> a(n + 1, 0);
+        vl a(n + 1, 0);
         seg.build(a);
     }
     void set(int v, ll val) { seg.set(in[v], val); }
diff --git a/src/3-tree/lca_sparse_table.cpp b/src/3-tree/lca_sparse_table.cpp
index 17a415a..f9ebd7c 100644
--- a/src/3-tree/lca_sparse_table.cpp
+++ b/src/3-tree/lca_sparse_table.cpp
@@ -6,15 +6,15 @@
 // usage: lca_sparse l; l.init(n); l.add(u,v); l.build(1); int w=l.lca(u,v);
 struct lca_sparse {
     int n, lg;
-    vector<vector<int>> adj, up;
-    vector<int> dep;
+    vvi adj, up;
+    vi dep;
 
     void init(int n_) {
         n = n_;
         lg = 1;
         while ((1 << lg) <= n) lg++;
         adj.assign(n + 1, {});
-        up.assign(lg, vector<int>(n + 1, 0));
+        up.assign(lg, vi(n + 1, 0));
         dep.assign(n + 1, 0);
     }
     void add(int u, int v) {
diff --git a/src/3-tree/tree_composition.cpp b/src/3-tree/tree_composition.cpp
index 88ea68a..b599728 100644
--- a/src/3-tree/tree_composition.cpp
+++ b/src/3-tree/tree_composition.cpp
@@ -6,15 +6,15 @@
 // usage: tree_comp tc; tc.init(n); tc.add(u,v); tc.build(root); auto nodes=tc.make(vs); // use tc.vt_adj
 struct tree_comp {
     int n, lg, tim;
-    vector<vector<int>> adj, up, vt_adj;
-    vector<int> tin, tout, dep;
+    vvi adj, up, vt_adj;
+    vi tin, tout, dep;
 
     void init(int n_) {
         n = n_;
         lg = 1;
         while ((1 << lg) <= n) lg++;
         adj.assign(n + 1, {});
-        up.assign(lg, vector<int>(n + 1, 0));
+        up.assign(lg, vi(n + 1, 0));
         vt_adj.assign(n + 1, {});
         tin.assign(n + 1, 0);
         tout.assign(n + 1, 0);
@@ -57,7 +57,7 @@ struct tree_comp {
         }
         return up[0][a];
     }
-    vector<int> make(vector<int> vs) {
+    vi make(vi vs) {
         if (vs.empty()) return {};
         sort(all(vs), [&](int a, int b) { return tin[a] < tin[b]; });
         vs.erase(unique(all(vs)), vs.end());
@@ -66,7 +66,7 @@ struct tree_comp {
         sort(all(vs), [&](int a, int b) { return tin[a] < tin[b]; });
         vs.erase(unique(all(vs)), vs.end());
         for (int v : vs) vt_adj[v].clear();
-        vector<int> st;
+        vi st;
         st.pb(vs[0]);
         for (int i = 1; i < sz(vs); i++) {
             int v = vs[i];
diff --git a/src/3-tree/tree_exchange_argument.cpp b/src/3-tree/tree_exchange_argument.cpp
index d0ab5c6..005f6c3 100644
--- a/src/3-tree/tree_exchange_argument.cpp
+++ b/src/3-tree/tree_exchange_argument.cpp
@@ -6,8 +6,8 @@
 // usage: tree_xchg tx; tx.init(n, root); tx.add(u,v); // set tx.ds.w/t/cw; ll ans=tx.run();
 struct tree_xchg {
     struct uf {
-        vector<int> par;
-        vector<ll> cw, w, t;
+        vi par;
+        vl cw, w, t;
         void init(int n) {
             par.assign(n + 1, -1);
             cw.resize(n + 1);
@@ -32,8 +32,8 @@ struct tree_xchg {
     };
 
     int n, root;
-    vector<vector<int>> adj;
-    vector<int> par;
+    vvi adj;
+    vi par;
 
     void init(int n_, int r) {
         n = n_;
diff --git a/src/4-optimizations/flow.cpp b/src/4-optimizations/flow.cpp
index 9ec4e38..09ee0c9 100644
--- a/src/4-optimizations/flow.cpp
+++ b/src/4-optimizations/flow.cpp
@@ -23,7 +23,7 @@ struct dinic {
 
     int n;
     vector<vector<edge>> g;
-    vector<int> level, work;
+    vi level, work;
 
     dinic(int n = 0) { init(n); }
 
@@ -110,8 +110,8 @@ struct dinic {
 // usage: hk bm(n_l, n_r); bm.add_edge(l, r); int m = bm.max_matching();
 struct hk {
     int n_l, n_r;
-    vector<vector<int>> g;
-    vector<int> dist, match_l, match_r;
+    vvi g;
+    vi dist, match_l, match_r;
 
     hk(int n_l_ = 0, int n_r_ = 0) { init(n_l_, n_r_); }
 
@@ -235,12 +235,12 @@ struct mcmf {
 
     pll min_cost_mf(int s, int t, ll max_f = INF, bool init_pot = true) {
         ll flow = 0, cost = 0;
-        vector<ll> pot(n, 0), dist(n);
-        vector<int> pv(n), pe(n);
+        vl pot(n, 0), dist(n);
+        vi pv(n), pe(n);
 
         if (init_pot) {
             // goal: initial potentials for negative costs
-            vector<ll> d(n, INF);
+            vl d(n, INF);
             vector<char> in_q(n, 0);
             queue<int> q;
             d[s] = 0;
@@ -324,7 +324,7 @@ struct lr_dinic {
 
     int n;
     dinic mf;
-    vector<ll> demand;
+    vl demand;
     vector<edge_info> edges;
 
     lr_dinic(int n = 0) { init(n); }
@@ -410,7 +410,7 @@ struct lr_mcmf {
 
     int n;
     mcmf mf;
-    vector<ll> demand;
+    vl demand;
     vector<edge_info> edges;
     ll base_cost;
 
diff --git a/src/4-optimizations/hungarian.cpp b/src/4-optimizations/hungarian.cpp
index 2ab6b01..2339241 100644
--- a/src/4-optimizations/hungarian.cpp
+++ b/src/4-optimizations/hungarian.cpp
@@ -5,15 +5,15 @@
 // constraint: 1 <= n <= m, 1-indexed cost a[1..n][1..m] (minimization).
 // usage: hungarian hu; auto [cost, match_l] = hu.run(n, m, a); // match_l[i]=j
 struct hungarian {
-    pair<ll, vector<int>> run(int n, int m, const vector<vector<ll>> &a) {
+    pair<ll, vi> run(int n, int m, const vvl &a) {
         // result: {min_cost, match_l} with match_l[i]=assigned column.
         const ll INF = (1LL << 62);
-        vector<ll> u(n + 1), v(m + 1);
-        vector<int> p(m + 1), way(m + 1);
+        vl u(n + 1), v(m + 1);
+        vi p(m + 1), way(m + 1);
         for (int i = 1; i <= n; i++) {
             p[0] = i;
             int j0 = 0;
-            vector<ll> minv(m + 1, INF);
+            vl minv(m + 1, INF);
             vector<char> used(m + 1, 0);
             do {
                 used[j0] = 1;
@@ -41,7 +41,7 @@ struct hungarian {
                 j0 = j1;
             } while (j0);
         }
-        vector<int> match_l(n + 1, 0);
+        vi match_l(n + 1, 0);
         for (int j = 1; j <= m; j++)
             if (p[j]) match_l[p[j]] = j;
         return {-v[0], match_l};
diff --git a/src/5-string/aho_corasick.cpp b/src/5-string/aho_corasick.cpp
index f21cbf6..6e28bd5 100644
--- a/src/5-string/aho_corasick.cpp
+++ b/src/5-string/aho_corasick.cpp
@@ -7,7 +7,7 @@
 struct aho_corasick {
     static constexpr int ALPHA = 26;
     vector<array<int, ALPHA>> nxt;
-    vector<int> fail, out;
+    vi fail, out;
 
     aho_corasick() { init(); }
 
diff --git a/src/5-string/kmp_algorithm.cpp b/src/5-string/kmp_algorithm.cpp
index 5c32e49..ad167d3 100644
--- a/src/5-string/kmp_algorithm.cpp
+++ b/src/5-string/kmp_algorithm.cpp
@@ -4,9 +4,9 @@
 // time: O(|t|+|p|); memory: O(|p|)
 // constraint: returns 0-indexed match positions.
 // usage: auto pos = kmp_match(t, p); // p in t
-vector<int> kmp_pi(const string &p) {
+vi kmp_pi(const string &p) {
     // result: pi[i] = length of longest proper prefix ending at i.
-    vector<int> pi(sz(p));
+    vi pi(sz(p));
     for (int i = 1, j = 0; i < sz(p); i++) {
         while (j && p[i] != p[j]) j = pi[j - 1];
         if (p[i] == p[j]) pi[i] = ++j;
@@ -14,9 +14,9 @@ vector<int> kmp_pi(const string &p) {
     return pi;
 }
 
-vector<int> kmp_match(const string &t, const string &p) {
+vi kmp_match(const string &t, const string &p) {
     // result: all start indices where p matches t.
-    vector<int> res;
+    vi res;
     if (p.empty()) return res;
     auto pi = kmp_pi(p);
     for (int i = 0, j = 0; i < sz(t); i++) {
diff --git a/src/5-string/manachers_algorithm.cpp b/src/5-string/manachers_algorithm.cpp
index 65c6a1f..d728426 100644
--- a/src/5-string/manachers_algorithm.cpp
+++ b/src/5-string/manachers_algorithm.cpp
@@ -4,10 +4,10 @@
 // time: O(n); memory: O(n)
 // constraint: 0-indexed; d1[i]=odd radius, d2[i]=even radius.
 // usage: auto [d1,d2]=manacher(s); // max len = max(2*d1[i]-1,2*d2[i])
-pair<vector<int>, vector<int>> manacher(const string &s) {
+pair<vi, vi> manacher(const string &s) {
     // result: d1/d2 radii for odd/even palindromes centered at i.
     int n = sz(s);
-    vector<int> d1(n), d2(n);
+    vi d1(n), d2(n);
     for (int i = 0, l = 0, r = -1; i < n; i++) {
         int k = (i > r) ? 1 : min(d1[l + r - i], r - i + 1);
         while (i - k >= 0 && i + k < n && s[i - k] == s[i + k]) k++;
diff --git a/src/5-string/rabin_karp_algorithm.cpp b/src/5-string/rabin_karp_algorithm.cpp
index 5ea0b87..66974ed 100644
--- a/src/5-string/rabin_karp_algorithm.cpp
+++ b/src/5-string/rabin_karp_algorithm.cpp
@@ -8,7 +8,7 @@ struct rabin_karp {
     static constexpr ll MOD1 = 1000000007;
     static constexpr ll MOD2 = 1000000009;
     static constexpr ll BASE = 911382323;
-    vector<ll> p1, p2, h1, h2;
+    vl p1, p2, h1, h2;
 
     void build(const string &s) {
         // goal: precompute prefix hashes and powers.
@@ -36,9 +36,9 @@ struct rabin_karp {
     }
 };
 
-vector<int> rk_match(const string &t, const string &p) {
+vi rk_match(const string &t, const string &p) {
     // result: all positions where p matches t (by hash).
-    vector<int> res;
+    vi res;
     int n = sz(t), m = sz(p);
     if (!m || n < m) return res;
     rabin_karp ht, hp;
diff --git a/src/5-string/suffix_array.cpp b/src/5-string/suffix_array.cpp
index e77f29a..10257f5 100644
--- a/src/5-string/suffix_array.cpp
+++ b/src/5-string/suffix_array.cpp
@@ -4,12 +4,12 @@
 // time: build_sa O(n log n), build_lcp O(n); memory: O(n)
 // constraint: s is 0-indexed string, sa is 0-indexed positions.
 // usage: suffix_array sa; sa.build(s); // sa.sa, sa.lcp (lcp[i]=lcp(sa[i], sa[i-1]))
-vector<int> build_sa(const string &s) {
+vi build_sa(const string &s) {
     // result: sa[i] = starting index of i-th suffix in sorted order.
     int n = sz(s);
     if (!n) return {};
     int m = max(256, n) + 1;
-    vector<int> sa(n), r(2 * n), nr(2 * n), cnt(m), idx(n);
+    vi sa(n), r(2 * n), nr(2 * n), cnt(m), idx(n);
     for (int i = 0; i < n; i++) sa[i] = i, r[i] = (unsigned char)s[i];
     for (int d = 1; d < n; d <<= 1) {
         auto cmp = [&](int i, int j) {
@@ -32,10 +32,10 @@ vector<int> build_sa(const string &s) {
     return sa;
 }
 
-vector<int> build_lcp(const string &s, const vector<int> &sa) {
+vi build_lcp(const string &s, const vi &sa) {
     // result: lcp[i] = LCP of sa[i] and sa[i-1].
     int n = sz(s);
-    vector<int> lcp(n), rk(n);
+    vi lcp(n), rk(n);
     for (int i = 0; i < n; i++) rk[sa[i]] = i;
     for (int i = 0, k = 0; i < n; i++) {
         int r = rk[i];
@@ -49,7 +49,7 @@ vector<int> build_lcp(const string &s, const vector<int> &sa) {
 }
 
 struct suffix_array {
-    vector<int> sa, lcp;
+    vi sa, lcp;
     void build(const string &s) {
         // goal: fill sa and lcp for string s.
         sa = build_sa(s);
diff --git a/src/5-string/z_algorithm.cpp b/src/5-string/z_algorithm.cpp
index 917c31d..7ae1048 100644
--- a/src/5-string/z_algorithm.cpp
+++ b/src/5-string/z_algorithm.cpp
@@ -4,10 +4,10 @@
 // time: O(n); memory: O(n)
 // constraint: z[0]=n, 0-indexed string.
 // usage: auto z = z_func(s);
-vector<int> z_func(const string &s) {
+vi z_func(const string &s) {
     // result: z[i] = longest prefix length matching s[i..].
     int n = sz(s);
-    vector<int> z(n);
+    vi z(n);
     if (!n) return z;
     z[0] = n;
     for (int i = 1, l = 0, r = 0; i < n; i++) {
diff --git a/src/6-geometry/bulldozer_trick.cpp b/src/6-geometry/bulldozer_trick.cpp
index ad66628..8f5c335 100644
--- a/src/6-geometry/bulldozer_trick.cpp
+++ b/src/6-geometry/bulldozer_trick.cpp
@@ -22,7 +22,7 @@ void bulldozer(vector<pt> &p, F f) {
     int n = sz(p);
     sort(all(p));
     vector<pt> base = p;
-    vector<int> pos(n);
+    vi pos(n);
     iota(all(pos), 0);
     vector<bd_line> ln;
     ln.reserve(1LL * n * (n - 1) / 2);
@@ -44,7 +44,7 @@ void bulldozer(vector<pt> &p, F f) {
         while (j < sz(ln) && ln[j] == ln[i]) j++;
         ll dx = ln[i].dx, dy = ln[i].dy;
         if (dx == 0) break;
-        unordered_map<ll, vector<int>> mp;
+        unordered_map<ll, vi> mp;
         mp.reserve((j - i) * 2 + 1);
         for (int k = i; k < j; k++) {
             int u = ln[k].u, v = ln[k].v;
diff --git a/src/7-math/comb_binom.cpp b/src/7-math/comb_binom.cpp
index dcaa9b6..18add67 100644
--- a/src/7-math/comb_binom.cpp
+++ b/src/7-math/comb_binom.cpp
@@ -23,12 +23,12 @@ struct comb_lr {
 // usage: comb_dp cb; cb.init(n); ll v=cb.ncr(n,r);
 struct comb_dp {
     int n;
-    vector<vector<ll>> dp;
+    vvl dp;
 
     void init(int n_) {
         // goal: build dp up to n.
         n = n_;
-        dp.assign(n + 1, vector<ll>(n + 1, 0));
+        dp.assign(n + 1, vl(n + 1, 0));
         for (int i = 0; i <= n; i++) {
             dp[i][0] = dp[i][i] = 1;
             for (int j = 1; j < i; j++) dp[i][j] = dp[i - 1][j - 1] + dp[i - 1][j];
@@ -48,7 +48,7 @@ struct comb_dp {
 struct comb_mod {
     int n;
     ll mod;
-    vector<ll> fac, ifac;
+    vl fac, ifac;
 
     void init(int n_, ll mod_) {
         // goal: precompute fac/ifac up to n.
diff --git a/src/7-math/comb_cat_der.cpp b/src/7-math/comb_cat_der.cpp
index e22a421..d6b49a9 100644
--- a/src/7-math/comb_cat_der.cpp
+++ b/src/7-math/comb_cat_der.cpp
@@ -28,7 +28,7 @@ struct catalan_mod {
 // usage: derange_mod de; de.init(n, mod); ll v=de.get(k);
 struct derange_mod {
     ll mod;
-    vector<ll> dp;
+    vl dp;
 
     void init(int n, ll mod_) {
         // goal: precompute derangements up to n.
diff --git a/src/7-math/conv_fft.cpp b/src/7-math/conv_fft.cpp
index 28c4418..4f6434e 100644
--- a/src/7-math/conv_fft.cpp
+++ b/src/7-math/conv_fft.cpp
@@ -35,7 +35,7 @@ struct fft_conv {
             for (int i = 0; i < n; i++) a[i] /= n;
     }
 
-    static vector<ll> mul(const vector<ll> &a, const vector<ll> &b) {
+    static vl mul(const vl &a, const vl &b) {
         // result: integer convolution of a and b.
         if (a.empty() || b.empty()) return {};
         int n = 1;
@@ -47,12 +47,12 @@ struct fft_conv {
         fft(fb);
         for (int i = 0; i < n; i++) fa[i] *= fb[i];
         fft(fa, 1);
-        vector<ll> ret(n);
+        vl ret(n);
         for (int i = 0; i < n; i++) ret[i] = llround(fa[i].real());
         return ret;
     }
 
-    static vector<ll> mul_mod(const vector<ll> &a, const vector<ll> &b, ll mod) {
+    static vl mul_mod(const vl &a, const vl &b, ll mod) {
         // result: convolution of a and b modulo mod.
         if (a.empty() || b.empty()) return {};
         int n = 1;
@@ -73,7 +73,7 @@ struct fft_conv {
         }
         fft(r1, 1);
         fft(r2, 1);
-        vector<ll> ret(n);
+        vl ret(n);
         for (int i = 0; i < n; i++) {
             ll av = llround(r1[i].real()) % mod;
             ll bv = (llround(r1[i].imag()) + llround(r2[i].real())) % mod;
@@ -111,16 +111,16 @@ struct ntt_mod {
         return ans;
     }
 
-    static void ntt(vector<ll> &a) {
+    static void ntt(vl &a) {
         // goal: inplace NTT of a.
         int n = sz(a), lg = 31 - __builtin_clz(n);
-        static vector<ll> rt(2, 1);
+        static vl rt(2, 1);
         for (static int k = 2, s = 2; k < n; k <<= 1, s++) {
             rt.resize(n);
             ll z[] = {1, mod_pow(ROOT, MOD >> s)};
             for (int i = k; i < 2 * k; i++) rt[i] = rt[i / 2] * z[i & 1] % MOD;
         }
-        vector<ll> rev(n);
+        vl rev(n);
         for (int i = 0; i < n; i++) rev[i] = (rev[i / 2] | (i & 1) << lg) / 2;
         for (int i = 0; i < n; i++)
             if (i < rev[i]) swap(a[i], a[rev[i]]);
@@ -134,14 +134,14 @@ struct ntt_mod {
                 }
     }
 
-    static vector<ll> mul(const vector<ll> &a, const vector<ll> &b) {
+    static vl mul(const vl &a, const vl &b) {
         // result: convolution under MOD.
         if (a.empty() || b.empty()) return {};
         int s = sz(a) + sz(b) - 1;
         int n = 1;
         while (n < s) n <<= 1;
         int inv = mod_pow(n, MOD - 2);
-        vector<ll> l(n, 0), r(n, 0), out(n);
+        vl l(n, 0), r(n, 0), out(n);
         for (int i = 0; i < sz(a); i++) l[i] = norm(a[i]);
         for (int i = 0; i < sz(b); i++) r[i] = norm(b[i]);
         ntt(l);
@@ -168,7 +168,7 @@ struct ntt_any {
     static constexpr ll M2 = 469762049;
     static constexpr ll M3 = 1224736769;
 
-    static vector<ll> mul(const vector<ll> &a, const vector<ll> &b, ll mod) {
+    static vl mul(const vl &a, const vl &b, ll mod) {
         // result: convolution under arbitrary mod via CRT.
         if (a.empty() || b.empty()) return {};
         using ntt1 = ntt_mod<M1, 3>;
@@ -184,7 +184,7 @@ struct ntt_any {
         const ll INV_M1M2_M3 = euclid::inv_mod(M1M2 % M3, M3);
 
         int n = sz(c1);
-        vector<ll> ret(n);
+        vl ret(n);
         for (int i = 0; i < n; i++) {
             ll x1 = c1[i];
             ll x2 = c2[i] - x1;
diff --git a/src/7-math/linalg_gauss.cpp b/src/7-math/linalg_gauss.cpp
index d8a1485..16375bd 100644
--- a/src/7-math/linalg_gauss.cpp
+++ b/src/7-math/linalg_gauss.cpp
@@ -46,10 +46,10 @@ struct gauss_real {
 // constraint: mod is prime; matrix is n x (m+1) augmented.
 // usage: auto x=gauss_mod::solve(a, mod); // empty if no solution
 struct gauss_mod {
-    static vector<int> solve(vector<vector<int>> a, int mod) {
+    static vi solve(vvi a, int mod) {
         int n = sz(a);
         int m = sz(a[0]) - 1;
-        vector<int> where(m, -1);
+        vi where(m, -1);
         int r = 0;
         for (int c = 0; c < m && r < n; c++) {
             int p = r;
@@ -83,7 +83,7 @@ struct gauss_mod {
                 }
             if (all0 && a[i][m]) return {};
         }
-        vector<int> ans(m, 0);
+        vi ans(m, 0);
         for (int i = 0; i < m; i++)
             if (where[i] != -1) ans[i] = a[where[i]][m];
         return ans;
@@ -95,9 +95,9 @@ struct gauss_mod {
 // constraint: each row is size >= m+1; last bit is RHS.
 // usage: auto x=gauss_xor::solve(a, m); // empty if no solution
 struct gauss_xor {
-    static vector<int> solve(vector<bitset<GAUSS_BSZ>> a, int m) {
+    static vi solve(vector<bitset<GAUSS_BSZ>> a, int m) {
         int n = sz(a);
-        vector<int> where(m, -1);
+        vi where(m, -1);
         int r = 0;
         for (int c = 0; c < m && r < n; c++) {
             int p = -1;
@@ -122,7 +122,7 @@ struct gauss_xor {
                 }
             if (all0 && a[i][m]) return {};
         }
-        vector<int> ans(m, 0);
+        vi ans(m, 0);
         for (int i = 0; i < m; i++)
             if (where[i] != -1) ans[i] = a[where[i]][m];
         return ans;
diff --git a/src/7-math/linalg_mat.cpp b/src/7-math/linalg_mat.cpp
index d09bdbf..1bd446a 100644
--- a/src/7-math/linalg_mat.cpp
+++ b/src/7-math/linalg_mat.cpp
@@ -7,9 +7,9 @@
 // usage: matrix a(n,n,mod); auto r=matrix::power(a, e);
 struct matrix {
     ll mod;
-    vector<vector<ll>> a;
+    vvl a;
 
-    matrix(int n = 0, int m = 0, ll mod_ = 1) : mod(mod_), a(n, vector<ll>(m, 0)) {}
+    matrix(int n = 0, int m = 0, ll mod_ = 1) : mod(mod_), a(n, vl(m, 0)) {}
 
     static matrix ident(int n, ll mod) {
         matrix r(n, n, mod);
diff --git a/src/7-math/misc_sqrt.cpp b/src/7-math/misc_sqrt.cpp
index a6a30bf..8a96a0b 100644
--- a/src/7-math/misc_sqrt.cpp
+++ b/src/7-math/misc_sqrt.cpp
@@ -6,9 +6,9 @@
 // constraint: x >= 1 and fits in ll.
 // usage: auto d=sqrt_alg::divisors(x); auto pf=sqrt_alg::prime_fac(x);
 struct sqrt_alg {
-    static vector<ll> divisors(ll x) {
+    static vl divisors(ll x) {
         // result: sorted divisors of x.
-        vector<ll> d;
+        vl d;
         for (ll i = 1; i <= x / i; i++) {
             if (x % i) continue;
             d.pb(i);
@@ -18,9 +18,9 @@ struct sqrt_alg {
         return d;
     }
 
-    static vector<ll> prime_fac(ll x) {
+    static vl prime_fac(ll x) {
         // result: prime factors of x (with repetition).
-        vector<ll> p;
+        vl p;
         while ((x & 1) == 0) {
             p.pb(2);
             x >>= 1;
diff --git a/src/7-math/nt_mr_rho.cpp b/src/7-math/nt_mr_rho.cpp
index 76e97ac..fb00038 100644
--- a/src/7-math/nt_mr_rho.cpp
+++ b/src/7-math/nt_mr_rho.cpp
@@ -60,7 +60,7 @@ struct pollard_rho {
         }
     }
 
-    static void rec(ll n, vector<ll> &out) {
+    static void rec(ll n, vl &out) {
         if (n == 1) return;
         if (miller_rabin::is_prime(n)) {
             out.pb(n);
@@ -71,9 +71,9 @@ struct pollard_rho {
         rec(n / d, out);
     }
 
-    static vector<ll> factor(ll n) {
+    static vl factor(ll n) {
         // result: prime factors of |n| with repetition, sorted.
-        vector<ll> out;
+        vl out;
         if (n < 0) n = -n;
         if (n == 0) return out;
         rec(n, out);
diff --git a/src/7-math/nt_sieve.cpp b/src/7-math/nt_sieve.cpp
index 8a4451b..5dc8d75 100644
--- a/src/7-math/nt_sieve.cpp
+++ b/src/7-math/nt_sieve.cpp
@@ -8,7 +8,7 @@
 struct era_sieve {
     int n;
     vector<char> isp;
-    vector<int> primes;
+    vi primes;
 
     era_sieve(int n_ = 0) {
         if (n_ >= 0) init(n_);
@@ -40,7 +40,7 @@ struct era_sieve {
 // usage: lin_sieve sv(n); auto fc=sv.factor_cnt(x); int mu=sv.mu[x];
 struct lin_sieve {
     int n;
-    vector<int> lp, primes, mu, phi;
+    vi lp, primes, mu, phi;
 
     lin_sieve(int n_ = 0) {
         if (n_ >= 0) init(n_);
@@ -78,9 +78,9 @@ struct lin_sieve {
 
     bool is_prime(int x) const { return x >= 2 && x <= n && lp[x] == x; }
 
-    vector<int> factor(int x) const {
+    vi factor(int x) const {
         // result: prime factors of x (with repetition), in nondecreasing order
-        vector<int> ret;
+        vi ret;
         while (x > 1) {
             int p = lp[x];
             ret.pb(p);
@@ -106,7 +106,7 @@ struct lin_sieve {
 // time: O(n); memory: O(n)
 // constraint: n >= 0.
 // usage: auto mu = mobius(n); if(mu[x]) ...
-inline vector<int> mobius(int n) {
+inline vi mobius(int n) {
     lin_sieve sv(n);
     return sv.mu;
 }
@@ -129,7 +129,7 @@ struct euler_phi {
         return ret;
     }
 
-    static vector<int> phi_upto(int n) {
+    static vi phi_upto(int n) {
         lin_sieve sv(n);
         return sv.phi;
     }
diff --git a/src/8-misc/dp_opt.cpp b/src/8-misc/dp_opt.cpp
index fdb80ef..c37dca5 100644
--- a/src/8-misc/dp_opt.cpp
+++ b/src/8-misc/dp_opt.cpp
@@ -59,15 +59,15 @@ struct cht_mono {
 struct knuth_opt {
     static constexpr ll INF = (1LL << 62);
     int n;
-    vector<vector<ll>> dp;
-    vector<vector<int>> opt;
+    vvl dp;
+    vvi opt;
 
     template <class F>
     void build(int n_, F cost) {
         // goal: fill dp/opt for 0..n-1
         n = n_;
-        dp.assign(n, vector<ll>(n, 0));
-        opt.assign(n, vector<int>(n, 0));
+        dp.assign(n, vl(n, 0));
+        opt.assign(n, vi(n, 0));
         for (int i = 0; i < n; i++) opt[i][i] = i;
         for (int len = 2; len <= n; len++) {
             for (int i = 0; i + len - 1 < n; i++) {
@@ -96,10 +96,10 @@ struct knuth_opt {
 // usage: dnc_opt dc; dc.run(k, n, base, cost); auto ans = dc.dp();
 struct dnc_opt {
     static constexpr ll INF = (1LL << 62);
-    vector<ll> prv, cur;
+    vl prv, cur;
 
     template <class F>
-    void run(int k, int n, const vector<ll> &base, F cost) {
+    void run(int k, int n, const vl &base, F cost) {
         // goal: compute dp for k layers, starting from base
         prv = base;
         cur.assign(n, INF);
@@ -110,7 +110,7 @@ struct dnc_opt {
         }
     }
 
-    const vector<ll> &dp() const { return prv; }
+    const vl &dp() const { return prv; }
 
     template <class F>
     void solve(int l, int r, int opt_l, int opt_r, F cost) {
@@ -134,7 +134,7 @@ struct dnc_opt {
 // time: O(n log n); memory: O(n)
 // constraint: values fit in ll.
 // usage: ll ops = slope_trick(a);
-ll slope_trick(vector<ll> a) {
+ll slope_trick(vl a) {
     ll ret = 0;
     priority_queue<ll> pq;
     for (int i = 0; i < sz(a); i++) {
diff --git a/src/8-misc/kitamasa.cpp b/src/8-misc/kitamasa.cpp
index e6595cb..a095943 100644
--- a/src/8-misc/kitamasa.cpp
+++ b/src/8-misc/kitamasa.cpp
@@ -4,7 +4,7 @@
 // time: O(k^2 log n); memory: O(k^2)
 // constraint: coef.size() == init.size(); mod >= 1.
 // usage: coef[i] for A_{n-1-i}; ll an = kitamasa(coef, init, n, mod);
-using poly = vector<ll>;
+using poly = vl;
 
 ll mod_norm(ll x, ll mod) {
     x %= mod;
@@ -36,7 +36,7 @@ poly poly_div(const poly &a, const poly &f, ll mod) {
     return ret;
 }
 
-ll kitamasa(const vector<ll> &coef, const vector<ll> &init, ll n, ll mod) {
+ll kitamasa(const vl &coef, const vl &init, ll n, ll mod) {
     int k = sz(coef);
     assert(k == sz(init));
     if (n < k) return mod_norm(init[n], mod);
diff --git a/src/8-misc/lis_in_o_nlogn.cpp b/src/8-misc/lis_in_o_nlogn.cpp
index 126350d..9e35eef 100644
--- a/src/8-misc/lis_in_o_nlogn.cpp
+++ b/src/8-misc/lis_in_o_nlogn.cpp
@@ -5,9 +5,9 @@
 // constraint: use lower_bound for strict; use upper_bound for non-decreasing.
 // usage: int len = lis_len(a); auto seq = lis_seq(a);
 
-int lis_len(const vector<ll> &a) {
+int lis_len(const vl &a) {
     // result: length of LIS.
-    vector<ll> tail;
+    vl tail;
     for (ll x : a) {
         auto it = lower_bound(all(tail), x);
         if (it == tail.end()) tail.pb(x);
@@ -16,12 +16,12 @@ int lis_len(const vector<ll> &a) {
     return sz(tail);
 }
 
-vector<ll> lis_seq(const vector<ll> &a) {
+vl lis_seq(const vl &a) {
     // result: one LIS sequence.
     int n = sz(a);
-    vector<ll> tail;
-    vector<int> tail_idx;
-    vector<int> pre(n, -1);
+    vl tail;
+    vi tail_idx;
+    vi pre(n, -1);
     for (int i = 0; i < n; i++) {
         ll x = a[i];
         int pos = lower_bound(all(tail), x) - tail.begin();
@@ -34,7 +34,7 @@ vector<ll> lis_seq(const vector<ll> &a) {
         }
         if (pos > 0) pre[i] = tail_idx[pos - 1];
     }
-    vector<ll> ret;
+    vl ret;
     int cur = tail_idx.empty() ? -1 : tail_idx.back();
     while (cur != -1) {
         ret.pb(a[cur]);
diff --git a/src/8-misc/system_of_difference_constraints.cpp b/src/8-misc/system_of_difference_constraints.cpp
index 45c632a..3071a1e 100644
--- a/src/8-misc/system_of_difference_constraints.cpp
+++ b/src/8-misc/system_of_difference_constraints.cpp
@@ -12,7 +12,7 @@ struct diff_cons {
 
     int n;
     vector<vector<edge>> g;
-    vector<ll> dist;
+    vl dist;
 
     diff_cons(int n_ = 0) { init(n_); }
 
@@ -61,5 +61,5 @@ struct diff_cons {
         return true;
     }
 
-    vector<ll> val() const { return dist; }
+    vl val() const { return dist; }
 };
diff --git a/src/common/common.hpp b/src/common/common.hpp
index 9b740d9..4f27a97 100644
--- a/src/common/common.hpp
+++ b/src/common/common.hpp
@@ -6,6 +6,10 @@ using ll = long long;
 using ld = long double;
 using pii = pair<int, int>;
 using pll = pair<ll, ll>;
+using vi = vector<int>;
+using vl = vector<ll>;
+using vvi = vector<vector<int>>;
+using vvl = vector<vector<ll>>;
 #define fr first
 #define sc second
 #define pb push_back
diff --git a/tests/1-ds/test_fenwick_tree.cpp b/tests/1-ds/test_fenwick_tree.cpp
index afec125..02e5c8e 100644
--- a/tests/1-ds/test_fenwick_tree.cpp
+++ b/tests/1-ds/test_fenwick_tree.cpp
@@ -11,13 +11,13 @@ ll rnd(ll l, ll r) {
     return dis(rng);
 }
 
-ll sum_1d(const vector<ll> &a, int l, int r) {
+ll sum_1d(const vl &a, int l, int r) {
     ll ret = 0;
     for (int i = l; i <= r; i++) ret += a[i];
     return ret;
 }
 
-int kth_naive(const vector<ll> &a, ll k) {
+int kth_naive(const vl &a, ll k) {
     ll cur = 0;
     for (int i = 0; i < sz(a); i++) {
         cur += a[i];
@@ -26,7 +26,7 @@ int kth_naive(const vector<ll> &a, ll k) {
     return -1;
 }
 
-ll sum_2d(const vector<vector<ll>> &a, int x1, int y1, int x2, int y2) {
+ll sum_2d(const vvl &a, int x1, int y1, int x2, int y2) {
     ll ret = 0;
     for (int i = x1; i <= x2; i++)
         for (int j = y1; j <= y2; j++) ret += a[i][j];
@@ -35,7 +35,7 @@ ll sum_2d(const vector<vector<ll>> &a, int x1, int y1, int x2, int y2) {
 
 void test_fenwick_basic() {
     fenwick fw;
-    vector<ll> a = {5};
+    vl a = {5};
     fw.build(a);
     assert(fw.sum(0, 0) == 5);
     assert(fw.kth(1) == 0);
@@ -47,7 +47,7 @@ void test_fenwick_basic() {
 
 void test_fenwick_random() {
     int n = 50;
-    vector<ll> a(n);
+    vl a(n);
     for (int i = 0; i < n; i++) a[i] = rnd(0, 5);
 
     fenwick fw;
@@ -88,7 +88,7 @@ void test_fenwick_rp_basic() {
 
 void test_fenwick_rp_random() {
     int n = 40;
-    vector<ll> a(n + 1, 0);
+    vl a(n + 1, 0);
     fenw_range fw;
     fw.init(n);
 
@@ -109,7 +109,7 @@ void test_fenwick_rp_random() {
 
 void test_fenwick_2d_basic() {
     fenw_2d fw;
-    vector<vector<ll>> a = {{3}};
+    vvl a = {{3}};
     fw.build(a);
     assert(fw.sum(0, 0, 0, 0) == 3);
     fw.set(0, 0, -2);
@@ -118,7 +118,7 @@ void test_fenwick_2d_basic() {
 
 void test_fenwick_2d_random() {
     int n = 8, m = 7;
-    vector<vector<ll>> a(n, vector<ll>(m, 0));
+    vvl a(n, vl(m, 0));
     for (int i = 0; i < n; i++)
         for (int j = 0; j < m; j++) a[i][j] = rnd(-3, 3);
 
diff --git a/tests/1-ds/test_merge_sort_tree.cpp b/tests/1-ds/test_merge_sort_tree.cpp
index 5d8ef3b..4f0eada 100644
--- a/tests/1-ds/test_merge_sort_tree.cpp
+++ b/tests/1-ds/test_merge_sort_tree.cpp
@@ -11,14 +11,14 @@ ll rnd(ll l, ll r) {
     return dis(rng);
 }
 
-int count_greater(const vector<int> &a, int l, int r, int k) {
+int count_greater(const vi &a, int l, int r, int k) {
     int ret = 0;
     for (int i = l; i <= r; i++) ret += (a[i] > k);
     return ret;
 }
 
 void test_merge_sort_tree_basic() {
-    vector<int> a = {5};
+    vi a = {5};
     merge_seg st;
     st.build(a);
     assert(st.query(0, 0, 4) == 1);
@@ -27,7 +27,7 @@ void test_merge_sort_tree_basic() {
 
 void test_merge_sort_tree_random() {
     int n = 60;
-    vector<int> a(n);
+    vi a(n);
     for (int i = 0; i < n; i++) a[i] = (int)rnd(-10, 10);
 
     merge_seg st;
@@ -42,7 +42,7 @@ void test_merge_sort_tree_random() {
 }
 
 void test_merge_sort_tree_iter_basic() {
-    vector<int> a = {2};
+    vi a = {2};
     merge_seg_it st;
     st.build(a);
     assert(st.query(0, 0, 1) == 1);
@@ -51,7 +51,7 @@ void test_merge_sort_tree_iter_basic() {
 
 void test_merge_sort_tree_iter_random() {
     int n = 60;
-    vector<int> a(n);
+    vi a(n);
     for (int i = 0; i < n; i++) a[i] = (int)rnd(-10, 10);
 
     merge_seg_it st;
diff --git a/tests/1-ds/test_segment_tree.cpp b/tests/1-ds/test_segment_tree.cpp
index b564e35..a7a7744 100644
--- a/tests/1-ds/test_segment_tree.cpp
+++ b/tests/1-ds/test_segment_tree.cpp
@@ -11,13 +11,13 @@ ll rnd(ll l, ll r) {
     return dis(rng);
 }
 
-ll sum_range(const vector<ll> &a, int l, int r) {
+ll sum_range(const vl &a, int l, int r) {
     ll ret = 0;
     for (int i = l; i <= r; i++) ret += a[i];
     return ret;
 }
 
-int kth_naive_freq(const vector<ll> &a, ll k) {
+int kth_naive_freq(const vl &a, ll k) {
     ll cur = 0;
     for (int i = 1; i < sz(a); i++) {
         cur += a[i];
@@ -27,7 +27,7 @@ int kth_naive_freq(const vector<ll> &a, ll k) {
 }
 
 void test_segt_basic() {
-    vector<ll> a = {0, 3};
+    vl a = {0, 3};
     seg_tree st;
     st.build(a);
     assert(st.query(1, 1) == 3);
@@ -37,7 +37,7 @@ void test_segt_basic() {
 
 void test_segt_random() {
     int n = 50;
-    vector<ll> a(n + 1, 0);
+    vl a(n + 1, 0);
     for (int i = 1; i <= n; i++) a[i] = rnd(-5, 5);
 
     seg_tree st;
@@ -59,7 +59,7 @@ void test_segt_random() {
 }
 
 void test_segti_basic() {
-    vector<ll> a = {4};
+    vl a = {4};
     seg_tree_it st;
     st.build(a);
     assert(st.query(0, 1) == 4);
@@ -69,7 +69,7 @@ void test_segti_basic() {
 
 void test_segti_random() {
     int n = 50;
-    vector<ll> a(n, 0);
+    vl a(n, 0);
     for (int i = 0; i < n; i++) a[i] = rnd(-5, 5);
 
     seg_tree_it st;
@@ -105,7 +105,7 @@ void test_segk_basic() {
 
 void test_segk_random() {
     int n = 40;
-    vector<ll> a(n + 1, 0);
+    vl a(n + 1, 0);
     seg_tree_kth st;
     st.init(n);
 
@@ -127,7 +127,7 @@ void test_segk_random() {
 }
 
 void test_seglz_basic() {
-    vector<ll> a = {0, 1, 2};
+    vl a = {0, 1, 2};
     seg_tree_lz st;
     st.build(a);
     st.add(1, 2, 3);
@@ -136,7 +136,7 @@ void test_seglz_basic() {
 
 void test_seglz_random() {
     int n = 40;
-    vector<ll> a(n + 1, 0);
+    vl a(n + 1, 0);
     for (int i = 1; i <= n; i++) a[i] = rnd(-5, 5);
 
     seg_tree_lz st;
@@ -160,7 +160,7 @@ void test_seglz_random() {
 
 void test_pst_basic() {
     int n = 3;
-    vector<ll> a = {0, 1, 2, 3};
+    vl a = {0, 1, 2, 3};
     seg_pst st;
     st.build(n, a);
     st.set(2, 5);
@@ -170,8 +170,8 @@ void test_pst_basic() {
 
 void test_pst_random() {
     int n = 20;
-    vector<vector<ll>> ver;
-    vector<ll> a(n + 1, 0);
+    vvl ver;
+    vl a(n + 1, 0);
     for (int i = 1; i <= n; i++) a[i] = rnd(-5, 5);
     ver.pb(a);
 
@@ -183,7 +183,7 @@ void test_pst_random() {
         if (op == 0) {
             int p = (int)rnd(1, n);
             ll v = rnd(-5, 5);
-            vector<ll> nw = ver.back();
+            vl nw = ver.back();
             nw[p] = v;
             ver.pb(nw);
             st.set(p, v);
@@ -198,7 +198,7 @@ void test_pst_random() {
 
 void test_pst_kth_basic() {
     int n = 5;
-    vector<ll> a = {0, 2, 0, 1, 3, 0};
+    vl a = {0, 2, 0, 1, 3, 0};
     seg_pst st;
     st.build(n, a);
     assert(st.kth(1, 0) == 1);
@@ -214,8 +214,8 @@ void test_pst_kth_basic() {
 
 void test_pst_kth_random() {
     int n = 40;
-    vector<vector<ll>> ver;
-    vector<ll> a(n + 1, 0);
+    vvl ver;
+    vl a(n + 1, 0);
     for (int i = 1; i <= n; i++) a[i] = rnd(0, 3);
     ver.pb(a);
 
@@ -227,7 +227,7 @@ void test_pst_kth_random() {
         if (op == 0) {
             int p = (int)rnd(1, n);
             ll v = rnd(0, 5);
-            vector<ll> nw = ver.back();
+            vl nw = ver.back();
             nw[p] = v;
             ver.pb(nw);
             st.set(p, v);
@@ -276,7 +276,7 @@ void test_dyseg_random() {
     }
 }
 
-ll sum_rect(const vector<vector<ll>> &a, int x1, int y1, int x2, int y2) {
+ll sum_rect(const vvl &a, int x1, int y1, int x2, int y2) {
     ll ret = 0;
     for (int i = x1; i <= x2; i++)
         for (int j = y1; j <= y2; j++) ret += a[i][j];
@@ -284,7 +284,7 @@ ll sum_rect(const vector<vector<ll>> &a, int x1, int y1, int x2, int y2) {
 }
 
 void test_seg2d_basic() {
-    vector<vector<ll>> a = {{7}};
+    vvl a = {{7}};
     seg_2d st;
     st.build(a);
     assert(st.query(0, 0, 0, 0) == 7);
@@ -294,7 +294,7 @@ void test_seg2d_basic() {
 
 void test_seg2d_random() {
     int n = 7;
-    vector<vector<ll>> a(n, vector<ll>(n, 0));
+    vvl a(n, vl(n, 0));
     for (int i = 0; i < n; i++)
         for (int j = 0; j < n; j++) a[i][j] = rnd(-3, 3);
 
@@ -340,7 +340,7 @@ void test_seg2dc_basic() {
     }
     st.prep();
 
-    vector<vector<ll>> a(n, vector<ll>(n, 0));
+    vvl a(n, vl(n, 0));
     for (auto &op : ops) {
         if (op.type == 0) {
             a[op.x1][op.y1] = op.val;
@@ -386,7 +386,7 @@ void test_seg2dc_random() {
     }
     st.prep();
 
-    vector<vector<ll>> a(n, vector<ll>(n, 0));
+    vvl a(n, vl(n, 0));
     for (auto &op : ops) {
         if (op.type == 0) {
             a[op.x1][op.y1] = op.val;
diff --git a/tests/1-ds/test_union_find.cpp b/tests/1-ds/test_union_find.cpp
index d699179..c890040 100644
--- a/tests/1-ds/test_union_find.cpp
+++ b/tests/1-ds/test_union_find.cpp
@@ -12,8 +12,8 @@ ll rnd(ll l, ll r) {
 }
 
 struct naive_dsu {
-    vector<int> comp;
-    vector<int> siz;
+    vi comp;
+    vi siz;
 
     void init(int n) {
         comp.resize(n);
diff --git a/tests/2-graph/test_bcc.cpp b/tests/2-graph/test_bcc.cpp
index 35b34df..3ead5a1 100644
--- a/tests/2-graph/test_bcc.cpp
+++ b/tests/2-graph/test_bcc.cpp
@@ -12,7 +12,7 @@ int rnd(int l, int r) {
 }
 
 int ccnt(int n, const vector<pii> &ed, int sv, int se) {
-    vector<vector<int>> adj(n + 1);
+    vvi adj(n + 1);
     for (int i = 0; i < sz(ed); i++) {
         if (i == se) continue;
         int u = ed[i].fr, v = ed[i].sc;
@@ -20,7 +20,7 @@ int ccnt(int n, const vector<pii> &ed, int sv, int se) {
         adj[u].pb(v);
         adj[v].pb(u);
     }
-    vector<int> vis(n + 1);
+    vi vis(n + 1);
     int cnt = 0;
     for (int v = 1; v <= n; v++) {
         if (v == sv || vis[v]) continue;
@@ -39,9 +39,9 @@ int ccnt(int n, const vector<pii> &ed, int sv, int se) {
     return cnt;
 }
 
-vector<int> ap_na(int n, const vector<pii> &ed) {
+vi ap_na(int n, const vector<pii> &ed) {
     int base = ccnt(n, ed, 0, -1);
-    vector<int> ap;
+    vi ap;
     for (int v = 1; v <= n; v++)
         if (ccnt(n, ed, v, -1) > base) ap.pb(v);
     return ap;
@@ -86,7 +86,7 @@ void chk_bcc(int n, const vector<pii> &ed, bcc_graph &g) {
         }
         for (int i = 0; i < sz(comp); i++) {
             int u = comp[i].fr, v = comp[i].sc;
-            vector<int> vis(n + 1);
+            vi vis(n + 1);
             queue<int> q;
             q.push(u);
             vis[u] = 1;
@@ -115,7 +115,7 @@ void t_fix() {
     auto ae = g.ae;
     sort(all(ap));
     sort(all(ae));
-    assert(ap == vector<int>({2}));
+    assert(ap == vi({2}));
     assert(ae == vector<pii>({{1, 2}, {2, 3}}));
     chk_bcc(n, ed, g);
 }
diff --git a/tests/2-graph/test_euler_circuit.cpp b/tests/2-graph/test_euler_circuit.cpp
index 7f4795b..f245078 100644
--- a/tests/2-graph/test_euler_circuit.cpp
+++ b/tests/2-graph/test_euler_circuit.cpp
@@ -11,7 +11,7 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-int ecnt(int n, const vector<vector<int>> &cnt) {
+int ecnt(int n, const vvi &cnt) {
     int m = 0;
     for (int i = 1; i <= n; i++) m += cnt[i][i];
     for (int i = 1; i <= n; i++)
@@ -19,8 +19,8 @@ int ecnt(int n, const vector<vector<int>> &cnt) {
     return m;
 }
 
-bool can_na(int n, const vector<vector<int>> &cnt) {
-    vector<int> deg(n + 1);
+bool can_na(int n, const vvi &cnt) {
+    vi deg(n + 1);
     for (int i = 1; i <= n; i++) {
         deg[i] += 2 * cnt[i][i];
         for (int j = 1; j <= n; j++)
@@ -35,7 +35,7 @@ bool can_na(int n, const vector<vector<int>> &cnt) {
             break;
         }
     if (!s) return 1;
-    vector<int> vis(n + 1);
+    vi vis(n + 1);
     queue<int> q;
     q.push(s);
     vis[s] = 1;
@@ -53,13 +53,13 @@ bool can_na(int n, const vector<vector<int>> &cnt) {
     return 1;
 }
 
-void add_ed(euler_cir &g, vector<vector<int>> &cnt, int u, int v) {
+void add_ed(euler_cir &g, vvi &cnt, int u, int v) {
     g.add(u, v);
     if (u == v) cnt[u][u]++;
     else cnt[u][v]++, cnt[v][u]++;
 }
 
-void chk_run(int n, const vector<vector<int>> &cnt, const vector<int> &path) {
+void chk_run(int n, const vvi &cnt, const vi &path) {
     int m = ecnt(n, cnt);
     if (m == 0) {
         assert(sz(path) == 1);
@@ -86,7 +86,7 @@ void t_fix() {
     int n = 3;
     euler_cir g;
     g.init(n);
-    vector<vector<int>> cnt(n + 1, vector<int>(n + 1));
+    vvi cnt(n + 1, vi(n + 1));
     add_ed(g, cnt, 1, 2);
     add_ed(g, cnt, 2, 3);
     add_ed(g, cnt, 3, 1);
@@ -95,7 +95,7 @@ void t_fix() {
     chk_run(n, cnt, path);
 
     g.init(n);
-    cnt.assign(n + 1, vector<int>(n + 1));
+    cnt.assign(n + 1, vi(n + 1));
     add_ed(g, cnt, 1, 2);
     add_ed(g, cnt, 2, 3);
     assert(!g.can());
@@ -107,7 +107,7 @@ void t_rnd() {
         int m = rnd(0, 8);
         euler_cir g;
         g.init(n);
-        vector<vector<int>> cnt(n + 1, vector<int>(n + 1));
+        vvi cnt(n + 1, vi(n + 1));
         for (int i = 0; i < m; i++) {
             int u = rnd(1, n), v = rnd(1, n);
             add_ed(g, cnt, u, v);
@@ -117,7 +117,7 @@ void t_rnd() {
         assert(ok1 == ok2);
         if (ok1) {
             int s = 1;
-            vector<int> deg(n + 1);
+            vi deg(n + 1);
             for (int i = 1; i <= n; i++) {
                 deg[i] += 2 * cnt[i][i];
                 for (int j = 1; j <= n; j++)
diff --git a/tests/2-graph/test_kth_shortest_path.cpp b/tests/2-graph/test_kth_shortest_path.cpp
index e8c5f25..e673886 100644
--- a/tests/2-graph/test_kth_shortest_path.cpp
+++ b/tests/2-graph/test_kth_shortest_path.cpp
@@ -13,11 +13,11 @@ int rnd(int l, int r) {
 
 kth_walk ks;
 
-vector<ll> kth_na(int n, const vector<vector<pll>> &g, int s, int e, int k) {
-    vector<int> cnt(n + 1);
+vl kth_na(int n, const vector<vector<pll>> &g, int s, int e, int k) {
+    vi cnt(n + 1);
     priority_queue<pll, vector<pll>, greater<pll>> pq;
     pq.push({0, s});
-    vector<ll> res;
+    vl res;
     while (!pq.empty() && sz(res) < k) {
         auto [d, v] = pq.top();
         pq.pop();
diff --git a/tests/2-graph/test_offline_dynamic_connectivity.cpp b/tests/2-graph/test_offline_dynamic_connectivity.cpp
index e446d07..a11f68f 100644
--- a/tests/2-graph/test_offline_dynamic_connectivity.cpp
+++ b/tests/2-graph/test_offline_dynamic_connectivity.cpp
@@ -13,12 +13,12 @@ int rnd(int l, int r) {
 
 int conn(int n, const set<pii> &act, int s, int e) {
     if (s == e) return 1;
-    vector<vector<int>> adj(n + 1);
+    vvi adj(n + 1);
     for (auto [u, v] : act) {
         adj[u].pb(v);
         adj[v].pb(u);
     }
-    vector<int> vis(n + 1);
+    vi vis(n + 1);
     queue<int> q;
     q.push(s);
     vis[s] = 1;
@@ -34,7 +34,7 @@ int conn(int n, const set<pii> &act, int s, int e) {
 
 void t_fix() {
     int n = 4, q = 6;
-    vector<int> op(q + 1), u(q + 1), v(q + 1), ans(q + 1);
+    vi op(q + 1), u(q + 1), v(q + 1), ans(q + 1);
     op[1] = 1, u[1] = 1, v[1] = 2;
     op[2] = 3, u[2] = 1, v[2] = 3;
     op[3] = 1, u[3] = 2, v[3] = 3;
@@ -64,7 +64,7 @@ void t_rnd() {
     for (int it = 0; it < 200; it++) {
         int n = rnd(2, 8);
         int q = rnd(1, 40);
-        vector<int> op(q + 1), u(q + 1), v(q + 1), ans(q + 1);
+        vi op(q + 1), u(q + 1), v(q + 1), ans(q + 1);
         set<pii> act;
         for (int i = 1; i <= q; i++) {
             int t = rnd(0, 9);
diff --git a/tests/2-graph/test_scc_2_sat.cpp b/tests/2-graph/test_scc_2_sat.cpp
index 9565f46..97e303b 100644
--- a/tests/2-graph/test_scc_2_sat.cpp
+++ b/tests/2-graph/test_scc_2_sat.cpp
@@ -11,8 +11,8 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-vector<vector<int>> rch(int n, const vector<vector<int>> &g) {
-    vector<vector<int>> r(n + 1, vector<int>(n + 1));
+vvi rch(int n, const vvi &g) {
+    vvi r(n + 1, vi(n + 1));
     for (int s = 1; s <= n; s++) {
         queue<int> q;
         q.push(s);
@@ -28,9 +28,9 @@ vector<vector<int>> rch(int n, const vector<vector<int>> &g) {
     return r;
 }
 
-vector<int> cmp_na(int n, const vector<vector<int>> &g) {
+vi cmp_na(int n, const vvi &g) {
     auto r = rch(n, g);
-    vector<int> cmp(n + 1, -1);
+    vi cmp(n + 1, -1);
     int cid = 0;
     for (int i = 1; i <= n; i++) {
         if (cmp[i] != -1) continue;
@@ -41,7 +41,7 @@ vector<int> cmp_na(int n, const vector<vector<int>> &g) {
     return cmp;
 }
 
-bool sat_br(int n, const vector<pii> &cl, vector<int> &val) {
+bool sat_br(int n, const vector<pii> &cl, vi &val) {
     int lim = 1 << n;
     for (int mask = 0; mask < lim; mask++) {
         bool ok = 1;
@@ -65,7 +65,7 @@ void t_scc() {
     for (int it = 0; it < 200; it++) {
         int n = rnd(1, 7);
         int m = rnd(0, n * (n - 1));
-        vector<vector<int>> g(n + 1);
+        vvi g(n + 1);
         for (int i = 0; i < m; i++) {
             int u = rnd(1, n), v = rnd(1, n);
             g[u].pb(v);
@@ -106,7 +106,7 @@ void t_sat() {
             if (rnd(0, 1)) b = -b;
             cl.pb({a, b});
         }
-        vector<int> val;
+        vi val;
         bool ok2 = sat_br(n, cl, val);
 
         two_sat ts;
diff --git a/tests/2-graph/test_shortest_path.cpp b/tests/2-graph/test_shortest_path.cpp
index 63dcc1a..42e120d 100644
--- a/tests/2-graph/test_shortest_path.cpp
+++ b/tests/2-graph/test_shortest_path.cpp
@@ -11,9 +11,9 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-vector<vector<ll>> floy(int n, const vector<tuple<int, int, ll>> &ed) {
+vvl floy(int n, const vector<tuple<int, int, ll>> &ed) {
     const ll INF = (1LL << 60);
-    vector<vector<ll>> d(n + 1, vector<ll>(n + 1, INF));
+    vvl d(n + 1, vl(n + 1, INF));
     for (int i = 1; i <= n; i++) d[i][i] = 0;
     for (auto [u, v, w] : ed) d[u][v] = min(d[u][v], w);
     for (int k = 1; k <= n; k++)
@@ -70,7 +70,7 @@ void t_bell() {
         bool neg = 0;
         for (int v = 1; v <= n; v++)
             if (d[s][v] < INF / 2 && d[v][v] < 0) neg = 1;
-        vector<ll> dist;
+        vl dist;
         bool ok = bl.run(s, dist);
         if (neg) {
             assert(!ok);
diff --git a/tests/3-tree/test_centroid_decomp.cpp b/tests/3-tree/test_centroid_decomp.cpp
index 3404b05..8501a07 100644
--- a/tests/3-tree/test_centroid_decomp.cpp
+++ b/tests/3-tree/test_centroid_decomp.cpp
@@ -11,18 +11,18 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-void add_edge(vector<vector<int>> &adj, int u, int v) {
+void add_edge(vvi &adj, int u, int v) {
     adj[u].pb(v);
     adj[v].pb(u);
 }
 
-vector<vector<int>> gen_tree(int n) {
-    vector<vector<int>> adj(n + 1);
+vvi gen_tree(int n) {
+    vvi adj(n + 1);
     for (int v = 2; v <= n; v++) add_edge(adj, v, rnd(1, v - 1));
     return adj;
 }
 
-int get_root(int n, const vector<int> &par) {
+int get_root(int n, const vi &par) {
     int root = 0;
     for (int v = 1; v <= n; v++)
         if (!par[v]) {
@@ -33,7 +33,7 @@ int get_root(int n, const vector<int> &par) {
     return root;
 }
 
-void get_sub(int v, const vector<vector<int>> &chd, vector<int> &sub) {
+void get_sub(int v, const vvi &chd, vi &sub) {
     sub[v] = 1;
     for (int to : chd[v]) {
         get_sub(to, chd, sub);
@@ -41,9 +41,9 @@ void get_sub(int v, const vector<vector<int>> &chd, vector<int> &sub) {
     }
 }
 
-vector<int> get_nodes(int v, const vector<vector<int>> &chd) {
-    vector<int> res;
-    vector<int> st = {v};
+vi get_nodes(int v, const vvi &chd) {
+    vi res;
+    vi st = {v};
     while (!st.empty()) {
         int x = st.back();
         st.pop_back();
@@ -53,7 +53,7 @@ vector<int> get_nodes(int v, const vector<vector<int>> &chd) {
     return res;
 }
 
-void check_one(const vector<vector<int>> &adj) {
+void check_one(const vvi &adj) {
     int n = sz(adj) - 1;
     cen_decomp cd;
     cd.init(n);
@@ -65,7 +65,7 @@ void check_one(const vector<vector<int>> &adj) {
     int root = get_root(n, cd.par);
 
     // check: centroid tree is a rooted tree on [1..n].
-    vector<int> vis(n + 1);
+    vi vis(n + 1);
     queue<int> q;
     q.push(root);
     vis[root] = 1;
@@ -85,7 +85,7 @@ void check_one(const vector<vector<int>> &adj) {
     assert(cnt == n);
     assert(edges == n - 1);
 
-    vector<int> sub(n + 1);
+    vi sub(n + 1);
     get_sub(root, cd.chd, sub);
 
     // check: centroid property (each child component size <= half).
@@ -98,7 +98,7 @@ void check_one(const vector<vector<int>> &adj) {
         vector<char> in_c(n + 1, 0);
         for (int v : nodes_c) in_c[v] = 1;
 
-        vector<int> first(n + 1, 0);
+        vi first(n + 1, 0);
         queue<int> qq;
         for (int nb : adj[c]) {
             if (!in_c[nb]) continue;
@@ -117,7 +117,7 @@ void check_one(const vector<vector<int>> &adj) {
         for (int v : nodes_c)
             if (v != c) assert(first[v]);
 
-        vector<int> labs;
+        vi labs;
         for (int x : cd.chd[c]) {
             int lab = first[x];
             assert(lab);
@@ -134,24 +134,24 @@ void check_one(const vector<vector<int>> &adj) {
 void t_fix() {
     {
         int n = 1;
-        vector<vector<int>> adj(n + 1);
+        vvi adj(n + 1);
         check_one(adj);
     }
     {
         int n = 2;
-        vector<vector<int>> adj(n + 1);
+        vvi adj(n + 1);
         add_edge(adj, 1, 2);
         check_one(adj);
     }
     {
         int n = 7;
-        vector<vector<int>> adj(n + 1);
+        vvi adj(n + 1);
         for (int i = 1; i < n; i++) add_edge(adj, i, i + 1);
         check_one(adj);
     }
     {
         int n = 9;
-        vector<vector<int>> adj(n + 1);
+        vvi adj(n + 1);
         for (int i = 2; i <= n; i++) add_edge(adj, 1, i);
         check_one(adj);
     }
diff --git a/tests/3-tree/test_hld.cpp b/tests/3-tree/test_hld.cpp
index e498e74..017ace1 100644
--- a/tests/3-tree/test_hld.cpp
+++ b/tests/3-tree/test_hld.cpp
@@ -11,8 +11,8 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-vector<int> path_nodes(int n, const vector<vector<int>> &adj, int s, int e) {
-    vector<int> par(n + 1, -1);
+vi path_nodes(int n, const vvi &adj, int s, int e) {
+    vi par(n + 1, -1);
     queue<int> q;
     q.push(s);
     par[s] = s;
@@ -26,7 +26,7 @@ vector<int> path_nodes(int n, const vector<vector<int>> &adj, int s, int e) {
             q.push(to);
         }
     }
-    vector<int> res;
+    vi res;
     int v = e;
     while (v != par[v]) {
         res.pb(v);
@@ -38,7 +38,7 @@ vector<int> path_nodes(int n, const vector<vector<int>> &adj, int s, int e) {
 
 void t_fix() {
     int n = 4;
-    vector<vector<int>> adj(n + 1);
+    vvi adj(n + 1);
     auto add = [&](int u, int v) {
         adj[u].pb(v);
         adj[v].pb(u);
@@ -53,7 +53,7 @@ void t_fix() {
         for (int v : adj[u])
             if (u < v) h.add(u, v);
     h.build(1);
-    vector<ll> val = {0, 1, 2, 3, 4};
+    vl val = {0, 1, 2, 3, 4};
     for (int i = 1; i <= n; i++) h.set(i, val[i]);
     auto p = path_nodes(n, adj, 3, 4);
     ll sum = 0;
@@ -64,8 +64,8 @@ void t_fix() {
 void t_rnd() {
     for (int it = 0; it < 200; it++) {
         int n = rnd(2, 9);
-        vector<int> par(n + 1, 0);
-        vector<vector<int>> adj(n + 1);
+        vi par(n + 1, 0);
+        vvi adj(n + 1);
         for (int v = 2; v <= n; v++) {
             par[v] = rnd(1, v - 1);
             adj[v].pb(par[v]);
@@ -75,7 +75,7 @@ void t_rnd() {
         h.init(n);
         for (int v = 2; v <= n; v++) h.add(v, par[v]);
         h.build(1);
-        vector<ll> val(n + 1);
+        vl val(n + 1);
         for (int i = 1; i <= n; i++) {
             val[i] = rnd(-5, 5);
             h.set(i, val[i]);
diff --git a/tests/3-tree/test_lca_sparse_table.cpp b/tests/3-tree/test_lca_sparse_table.cpp
index 251db0f..f6e1e66 100644
--- a/tests/3-tree/test_lca_sparse_table.cpp
+++ b/tests/3-tree/test_lca_sparse_table.cpp
@@ -11,8 +11,8 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-int lca_na(int n, const vector<vector<int>> &adj, int root, int a, int b) {
-    vector<int> par(n + 1, 0), dep(n + 1, 0);
+int lca_na(int n, const vvi &adj, int root, int a, int b) {
+    vi par(n + 1, 0), dep(n + 1, 0);
     queue<int> q;
     q.push(root);
     par[root] = root;
@@ -35,8 +35,8 @@ int lca_na(int n, const vector<vector<int>> &adj, int root, int a, int b) {
 void t_rnd() {
     for (int it = 0; it < 200; it++) {
         int n = rnd(2, 20);
-        vector<int> par(n + 1, 0);
-        vector<vector<int>> adj(n + 1);
+        vi par(n + 1, 0);
+        vvi adj(n + 1);
         for (int v = 2; v <= n; v++) {
             par[v] = rnd(1, v - 1);
             adj[v].pb(par[v]);
diff --git a/tests/3-tree/test_tree_composition.cpp b/tests/3-tree/test_tree_composition.cpp
index 389bd2f..fd806ca 100644
--- a/tests/3-tree/test_tree_composition.cpp
+++ b/tests/3-tree/test_tree_composition.cpp
@@ -11,18 +11,18 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-void add_edge(vector<vector<int>> &adj, int u, int v) {
+void add_edge(vvi &adj, int u, int v) {
     adj[u].pb(v);
     adj[v].pb(u);
 }
 
-vector<vector<int>> gen_tree(int n) {
-    vector<vector<int>> adj(n + 1);
+vvi gen_tree(int n) {
+    vvi adj(n + 1);
     for (int v = 2; v <= n; v++) add_edge(adj, v, rnd(1, v - 1));
     return adj;
 }
 
-void root_tree(int n, const vector<vector<int>> &adj, int root, vector<int> &par, vector<int> &dep) {
+void root_tree(int n, const vvi &adj, int root, vi &par, vi &dep) {
     par.assign(n + 1, -1);
     dep.assign(n + 1, 0);
     queue<int> q;
@@ -42,14 +42,14 @@ void root_tree(int n, const vector<vector<int>> &adj, int root, vector<int> &par
     for (int v = 1; v <= n; v++) assert(par[v] != -1);
 }
 
-int lca_na(int a, int b, const vector<int> &par, const vector<int> &dep) {
+int lca_na(int a, int b, const vi &par, const vi &dep) {
     while (dep[a] > dep[b]) a = par[a];
     while (dep[b] > dep[a]) b = par[b];
     while (a != b) a = par[a], b = par[b];
     return a;
 }
 
-vector<int> lca_closure(vector<int> vs, const vector<int> &par, const vector<int> &dep) {
+vi lca_closure(vi vs, const vi &par, const vi &dep) {
     int n = sz(par) - 1;
     sort(all(vs));
     vs.erase(unique(all(vs)), vs.end());
@@ -76,9 +76,9 @@ vector<int> lca_closure(vector<int> vs, const vector<int> &par, const vector<int
     return vs;
 }
 
-void check_one(const vector<vector<int>> &adj, const vector<int> &vs) {
+void check_one(const vvi &adj, const vi &vs) {
     int n = sz(adj) - 1;
-    vector<int> par, dep;
+    vi par, dep;
     root_tree(n, adj, 1, par, dep);
 
     tree_comp tc;
@@ -102,7 +102,7 @@ void check_one(const vector<vector<int>> &adj, const vector<int> &vs) {
     vector<char> in_set(n + 1, 0);
     for (int v : exp_nodes) in_set[v] = 1;
 
-    vector<int> in_cnt(n + 1, 0), par_vt(n + 1, 0);
+    vi in_cnt(n + 1, 0), par_vt(n + 1, 0);
     int edges = 0;
     for (int v : exp_nodes)
         for (int to : tc.vt_adj[v]) {
@@ -132,8 +132,8 @@ void check_one(const vector<vector<int>> &adj, const vector<int> &vs) {
         }
     }
 
-    vector<int> vis(n + 1);
-    vector<int> st = {root};
+    vi vis(n + 1);
+    vi st = {root};
     vis[root] = 1;
     while (!st.empty()) {
         int v = st.back();
@@ -149,13 +149,13 @@ void check_one(const vector<vector<int>> &adj, const vector<int> &vs) {
 void t_fix() {
     {
         int n = 1;
-        vector<vector<int>> adj(n + 1);
+        vvi adj(n + 1);
         check_one(adj, {});
         check_one(adj, {1});
     }
     {
         int n = 5;
-        vector<vector<int>> adj(n + 1);
+        vvi adj(n + 1);
         for (int i = 1; i < n; i++) add_edge(adj, i, i + 1);
         check_one(adj, {3});
         check_one(adj, {2, 4});
@@ -169,7 +169,7 @@ void t_rnd() {
         int n = rnd(2, 30);
         auto adj = gen_tree(n);
         int k = rnd(0, n);
-        vector<int> vs;
+        vi vs;
         for (int i = 0; i < k; i++) vs.pb(rnd(1, n));
         check_one(adj, vs);
     }
diff --git a/tests/3-tree/test_tree_exchange_argument.cpp b/tests/3-tree/test_tree_exchange_argument.cpp
index 798e991..14f0023 100644
--- a/tests/3-tree/test_tree_exchange_argument.cpp
+++ b/tests/3-tree/test_tree_exchange_argument.cpp
@@ -11,20 +11,20 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-void add_edge(vector<vector<int>> &adj, int u, int v) {
+void add_edge(vvi &adj, int u, int v) {
     adj[u].pb(v);
     adj[v].pb(u);
 }
 
-vector<vector<int>> gen_tree(int n) {
-    vector<vector<int>> adj(n + 1);
+vvi gen_tree(int n) {
+    vvi adj(n + 1);
     for (int v = 2; v <= n; v++) add_edge(adj, v, rnd(1, v - 1));
     return adj;
 }
 
-vector<vector<int>> get_child(int n, const vector<vector<int>> &adj, int root) {
-    vector<vector<int>> ch(n + 1);
-    vector<int> par(n + 1, -1);
+vvi get_child(int n, const vvi &adj, int root) {
+    vvi ch(n + 1);
+    vi par(n + 1, -1);
     queue<int> q;
     q.push(root);
     par[root] = 0;
@@ -43,19 +43,19 @@ vector<vector<int>> get_child(int n, const vector<vector<int>> &adj, int root) {
     return ch;
 }
 
-ll brute_max(int n, const vector<vector<int>> &ch, const vector<ll> &w, const vector<ll> &t) {
-    vector<int> indeg(n + 1, 0);
+ll brute_max(int n, const vvi &ch, const vl &w, const vl &t) {
+    vi indeg(n + 1, 0);
     for (int v = 1; v <= n; v++)
         for (int to : ch[v]) indeg[to]++;
-    vector<int> avail;
+    vi avail;
     for (int v = 1; v <= n; v++)
         if (!indeg[v]) avail.pb(v);
 
     ll best = -(1LL << 62);
-    vector<int> ord;
+    vi ord;
     ord.reserve(n);
-    function<void(vector<int> &, vector<int> &, ll, ll)> dfs = [&](vector<int> &id, vector<int> &av,
-                                                                   ll tm, ll cost) {
+    function<void(vi &, vi &, ll, ll)> dfs = [&](vi &id, vi &av,
+                                                 ll tm, ll cost) {
         if (sz(ord) == n) {
             best = max(best, cost);
             return;
@@ -63,8 +63,8 @@ ll brute_max(int n, const vector<vector<int>> &ch, const vector<ll> &w, const ve
         for (int i = 0; i < sz(av); i++) {
             int v = av[i];
             ord.pb(v);
-            vector<int> id2 = id;
-            vector<int> av2 = av;
+            vi id2 = id;
+            vi av2 = av;
             av2.erase(av2.begin() + i);
             ll tm2 = tm + t[v];
             ll cost2 = cost + w[v] * tm2;
@@ -80,7 +80,7 @@ ll brute_max(int n, const vector<vector<int>> &ch, const vector<ll> &w, const ve
     return best;
 }
 
-void check_one(const vector<vector<int>> &adj, int root, const vector<ll> &w, const vector<ll> &t) {
+void check_one(const vvi &adj, int root, const vl &w, const vl &t) {
     int n = sz(adj) - 1;
     auto ch = get_child(n, adj, root);
     ll exp = brute_max(n, ch, w, t);
@@ -102,11 +102,11 @@ void check_one(const vector<vector<int>> &adj, int root, const vector<ll> &w, co
 void t_fix() {
     {
         int n = 3;
-        vector<vector<int>> adj(n + 1);
+        vvi adj(n + 1);
         add_edge(adj, 1, 2);
         add_edge(adj, 1, 3);
-        vector<ll> w = {0, 1, 2, 3};
-        vector<ll> t = {0, 1, 1, 1};
+        vl w = {0, 1, 2, 3};
+        vl t = {0, 1, 1, 1};
         check_one(adj, 1, w, t);
     }
 }
@@ -116,7 +116,7 @@ void t_rnd() {
         int n = rnd(1, 9);
         auto adj = gen_tree(n);
         int root = rnd(1, n);
-        vector<ll> w(n + 1), t(n + 1);
+        vl w(n + 1), t(n + 1);
         for (int i = 1; i <= n; i++) {
             w[i] = rnd(0, 7);
             t[i] = rnd(1, 4);
diff --git a/tests/4-optimizations/test_flow.cpp b/tests/4-optimizations/test_flow.cpp
index 89c8bbe..4598806 100644
--- a/tests/4-optimizations/test_flow.cpp
+++ b/tests/4-optimizations/test_flow.cpp
@@ -32,7 +32,7 @@ struct ek_flow {
         if (s == t) return 0;
         ll flow = 0;
         while (1) {
-            vector<int> pv(n, -1), pe(n, -1);
+            vi pv(n, -1), pe(n, -1);
             queue<int> q;
             q.push(s);
             pv[s] = s;
@@ -62,8 +62,8 @@ struct ek_flow {
     }
 };
 
-int brute_match(int n_l, int n_r, const vector<vector<int>> &g) {
-    vector<vector<int>> dp(n_l + 1, vector<int>(1 << n_r, -1));
+int brute_match(int n_l, int n_r, const vvi &g) {
+    vvi dp(n_l + 1, vi(1 << n_r, -1));
     function<int(int, int)> go = [&](int i, int mask) {
         if (i == n_l) return 0;
         int &ret = dp[i][mask];
@@ -97,8 +97,8 @@ struct mcmf_spfa {
         const ll INF = (1LL << 62);
         ll flow = 0, cost = 0;
         while (flow < max_f) {
-            vector<ll> dist(n, INF);
-            vector<int> pv(n, -1), pe(n, -1);
+            vl dist(n, INF);
+            vi pv(n, -1), pe(n, -1);
             queue<int> q;
             vector<char> in_q(n, 0);
             dist[s] = 0;
@@ -145,11 +145,11 @@ struct lr_res {
 
 lr_res brute_lr(int n, int s, int t, const vector<tuple<int, int, int, int, int>> &es) {
     int m = sz(es);
-    vector<int> f(m, 0);
+    vi f(m, 0);
     ll best_f = -(1LL << 62), best_c = (1LL << 62);
     function<void(int)> dfs = [&](int i) {
         if (i == m) {
-            vector<int> bal(n, 0);
+            vi bal(n, 0);
             ll cost = 0;
             for (int k = 0; k < m; k++) {
                 auto [u, v, lo, hi, c] = es[k];
@@ -207,7 +207,7 @@ void t_hk() {
     for (int it = 0; it < 300; it++) {
         int n_l = rnd(0, 10), n_r = rnd(0, 10);
         hk bm(n_l, n_r);
-        vector<vector<int>> g(n_l);
+        vvi g(n_l);
         for (int l = 0; l < n_l; l++)
             for (int r = 0; r < n_r; r++)
                 if (rnd(0, 1)) bm.add_edge(l, r), g[l].pb(r);
diff --git a/tests/4-optimizations/test_hungarian.cpp b/tests/4-optimizations/test_hungarian.cpp
index bbd518e..4f880f4 100644
--- a/tests/4-optimizations/test_hungarian.cpp
+++ b/tests/4-optimizations/test_hungarian.cpp
@@ -11,10 +11,10 @@ int rnd(int l, int r) {
     return dis(rng);
 }
 
-pair<ll, vector<int>> brute(int n, int m, const vector<vector<ll>> &a) {
+pair<ll, vi> brute(int n, int m, const vvl &a) {
     ll best = (1LL << 62);
-    vector<int> best_m(n + 1, 0);
-    vector<int> cur(n + 1, 0);
+    vi best_m(n + 1, 0);
+    vi cur(n + 1, 0);
     vector<char> used(m + 1, 0);
     function<void(int, ll)> dfs = [&](int i, ll cost) {
         if (i == n + 1) {
@@ -35,7 +35,7 @@ pair<ll, vector<int>> brute(int n, int m, const vector<vector<ll>> &a) {
 
 void t_fix() {
     int n = 1, m = 1;
-    vector<vector<ll>> a(n + 1, vector<ll>(m + 1, 0));
+    vvl a(n + 1, vl(m + 1, 0));
     a[1][1] = 7;
     hungarian hu;
     auto [cost, match_l] = hu.run(n, m, a);
@@ -47,7 +47,7 @@ void t_rnd() {
     for (int it = 0; it < 200; it++) {
         int n = rnd(1, 6);
         int m = rnd(n, 7);
-        vector<vector<ll>> a(n + 1, vector<ll>(m + 1, 0));
+        vvl a(n + 1, vl(m + 1, 0));
         for (int i = 1; i <= n; i++)
             for (int j = 1; j <= m; j++) a[i][j] = rnd(-5, 7);
         hungarian hu;
diff --git a/tests/5-string/test_kmp_algorithm.cpp b/tests/5-string/test_kmp_algorithm.cpp
index dd98755..2869571 100644
--- a/tests/5-string/test_kmp_algorithm.cpp
+++ b/tests/5-string/test_kmp_algorithm.cpp
@@ -16,8 +16,8 @@ string rnd_s(int n) {
     return s;
 }
 
-vector<int> na_match(const string &t, const string &p) {
-    vector<int> res;
+vi na_match(const string &t, const string &p) {
+    vi res;
     if (p.empty()) return res;
     for (int i = 0; i + sz(p) <= sz(t); i++)
         if (!t.compare(i, sz(p), p)) res.pb(i);
@@ -25,8 +25,8 @@ vector<int> na_match(const string &t, const string &p) {
 }
 
 void t_fix() {
-    assert((kmp_match("ababa", "aba") == vector<int>{0, 2}));
-    assert((kmp_match("aaaaa", "aa") == vector<int>{0, 1, 2, 3}));
+    assert((kmp_match("ababa", "aba") == vi{0, 2}));
+    assert((kmp_match("aaaaa", "aa") == vi{0, 1, 2, 3}));
 }
 
 void t_rnd() {
diff --git a/tests/5-string/test_rabin_karp_algorithm.cpp b/tests/5-string/test_rabin_karp_algorithm.cpp
index 24b9ffb..9ff82db 100644
--- a/tests/5-string/test_rabin_karp_algorithm.cpp
+++ b/tests/5-string/test_rabin_karp_algorithm.cpp
@@ -16,8 +16,8 @@ string rnd_s(int n) {
     return s;
 }
 
-vector<int> na_match(const string &t, const string &p) {
-    vector<int> res;
+vi na_match(const string &t, const string &p) {
+    vi res;
     if (p.empty()) return res;
     for (int i = 0; i + sz(p) <= sz(t); i++)
         if (!t.compare(i, sz(p), p)) res.pb(i);
diff --git a/tests/5-string/test_suffix_array.cpp b/tests/5-string/test_suffix_array.cpp
index 2f016bd..bd214dd 100644
--- a/tests/5-string/test_suffix_array.cpp
+++ b/tests/5-string/test_suffix_array.cpp
@@ -39,11 +39,11 @@ void check_one(const string &s) {
         assert(sa.lcp.empty());
         return;
     }
-    vector<int> exp(n);
+    vi exp(n);
     iota(all(exp), 0);
     sort(all(exp), [&](int i, int j) { return suf_lt(s, i, j); });
     assert(sa.sa == exp);
-    vector<int> exp_lcp(n, 0);
+    vi exp_lcp(n, 0);
     for (int i = 1; i < n; i++) exp_lcp[i] = lcp2(s, exp[i], exp[i - 1]);
     assert(sa.lcp == exp_lcp);
 }
diff --git a/tests/5-string/test_z_algorithm.cpp b/tests/5-string/test_z_algorithm.cpp
index a24cf95..ca04a38 100644
--- a/tests/5-string/test_z_algorithm.cpp
+++ b/tests/5-string/test_z_algorithm.cpp
@@ -16,9 +16,9 @@ string rnd_s(int n) {
     return s;
 }
 
-vector<int> na_z(const string &s) {
+vi na_z(const string &s) {
     int n = sz(s);
-    vector<int> z(n);
+    vi z(n);
     for (int i = 0; i < n; i++) {
         int k = 0;
         while (i + k < n && s[k] == s[i + k]) k++;
diff --git a/tests/6-geometry/test_bulldozer_trick.cpp b/tests/6-geometry/test_bulldozer_trick.cpp
index 4e4f499..ddc07b5 100644
--- a/tests/6-geometry/test_bulldozer_trick.cpp
+++ b/tests/6-geometry/test_bulldozer_trick.cpp
@@ -20,14 +20,14 @@ vector<ld> uniq_ang(vector<ld> v) {
     return u;
 }
 
-vector<int> perm(const vector<pt> &p, map<pll, int> &id) {
-    vector<int> res;
+vi perm(const vector<pt> &p, map<pll, int> &id) {
+    vi res;
     res.reserve(sz(p));
     for (auto &v : p) res.pb(id[{v.x, v.y}]);
     return res;
 }
 
-vector<int> proj_ord(const vector<pt> &p, map<pll, int> &id, ld ang) {
+vi proj_ord(const vector<pt> &p, map<pll, int> &id, ld ang) {
     ld cs = cosl(ang), sn = sinl(ang);
     vector<pair<ld, int>> arr;
     arr.reserve(sz(p));
@@ -39,7 +39,7 @@ vector<int> proj_ord(const vector<pt> &p, map<pll, int> &id, ld ang) {
         if (fabsl(a.fr - b.fr) > 1e-18) return a.fr < b.fr;
         return a.sc < b.sc;
     });
-    vector<int> ord;
+    vi ord;
     ord.reserve(sz(p));
     for (auto &x : arr) ord.pb(x.sc);
     return ord;
@@ -58,7 +58,7 @@ void test_bulldozer_small() {
             pts.pb(v);
         }
 
-        vector<vector<int>> got;
+        vvi got;
         vector<pt> cur = pts;
         bulldozer(cur, [&](const vector<pt> &p) { got.pb(perm(p, id)); });
 
@@ -85,7 +85,7 @@ void test_bulldozer_small() {
         bnd.pb(PI);
         bnd = uniq_ang(bnd);
 
-        vector<vector<int>> exp;
+        vvi exp;
         vector<pt> st = pts;
         sort(all(st));
         for (int i = 0; i + 1 < sz(bnd); i++) {
diff --git a/tests/7-math/test_comb_cat_der.cpp b/tests/7-math/test_comb_cat_der.cpp
index 410dea5..043e9af 100644
--- a/tests/7-math/test_comb_cat_der.cpp
+++ b/tests/7-math/test_comb_cat_der.cpp
@@ -5,16 +5,16 @@
 // constraint: small n.
 // usage: g++ -std=c++17 test_comb_cat_der.cpp && ./a.out
 
-vector<ll> cat_ref(int n) {
-    vector<ll> dp(n + 1, 0);
+vl cat_ref(int n) {
+    vl dp(n + 1, 0);
     dp[0] = 1;
     for (int i = 1; i <= n; i++)
         for (int j = 0; j < i; j++) dp[i] += dp[j] * dp[i - 1 - j];
     return dp;
 }
 
-vector<ll> der_ref(int n) {
-    vector<ll> dp(max(3, n + 1), 0);
+vl der_ref(int n) {
+    vl dp(max(3, n + 1), 0);
     dp[0] = 1;
     dp[1] = 0;
     dp[2] = 1;
diff --git a/tests/7-math/test_conv_fft.cpp b/tests/7-math/test_conv_fft.cpp
index 543bdea..c81b596 100644
--- a/tests/7-math/test_conv_fft.cpp
+++ b/tests/7-math/test_conv_fft.cpp
@@ -11,18 +11,18 @@ int rnd_int(int l, int r) {
     return dis(rng);
 }
 
-vector<ll> conv_ref(const vector<ll> &a, const vector<ll> &b) {
+vl conv_ref(const vl &a, const vl &b) {
     int n = sz(a), m = sz(b);
-    vector<ll> c(n + m - 1, 0);
+    vl c(n + m - 1, 0);
     for (int i = 0; i < n; i++)
         for (int j = 0; j < m; j++) c[i + j] += a[i] * b[j];
     return c;
 }
 
-vector<ll> conv_mod_ref(const vector<ll> &a, const vector<ll> &b, ll mod) {
+vl conv_mod_ref(const vl &a, const vl &b, ll mod) {
     int n = sz(a), m = sz(b);
-    if (mod == 1) return vector<ll>(n + m - 1, 0);
-    vector<ll> c(n + m - 1, 0);
+    if (mod == 1) return vl(n + m - 1, 0);
+    vl c(n + m - 1, 0);
     for (int i = 0; i < n; i++)
         for (int j = 0; j < m; j++) {
             ll v = (ll)((__int128)a[i] * b[j] % mod);
@@ -38,7 +38,7 @@ void test_fft() {
     for (int it = 0; it < 200; it++) {
         int n = rnd_int(1, 20);
         int m = rnd_int(1, 20);
-        vector<ll> a(n), b(m);
+        vl a(n), b(m);
         for (int i = 0; i < n; i++) a[i] = rnd_int(-5, 5);
         for (int i = 0; i < m; i++) b[i] = rnd_int(-5, 5);
         auto ref = conv_ref(a, b);
@@ -48,7 +48,7 @@ void test_fft() {
     for (int it = 0; it < 100; it++) {
         int n = rnd_int(1, 60);
         int m = rnd_int(1, 60);
-        vector<ll> a(n), b(m);
+        vl a(n), b(m);
         for (int i = 0; i < n; i++) a[i] = rnd_int(-100, 100);
         for (int i = 0; i < m; i++) b[i] = rnd_int(-100, 100);
         auto ref = conv_ref(a, b);
@@ -63,14 +63,14 @@ void test_fft_mod() {
     for (int it = 0; it < 200; it++) {
         int n = rnd_int(1, 20);
         int m = rnd_int(1, 20);
-        vector<ll> a(n), b(m);
+        vl a(n), b(m);
         for (int i = 0; i < n; i++) a[i] = rnd_int(0, 1000);
         for (int i = 0; i < m; i++) b[i] = rnd_int(0, 1000);
         auto ref = conv_mod_ref(a, b, mod);
         auto got = fft_conv::mul_mod(a, b, mod);
         for (int i = 0; i < sz(ref); i++) assert(got[i] == ref[i]);
     }
-    auto all0 = fft_conv::mul_mod(vector<ll>(5, 0), vector<ll>(7, 0), mod);
+    auto all0 = fft_conv::mul_mod(vl(5, 0), vl(7, 0), mod);
     for (ll v : all0) assert(v == 0);
 }
 
@@ -80,7 +80,7 @@ void test_ntt() {
     for (int it = 0; it < 200; it++) {
         int n = rnd_int(1, 20);
         int m = rnd_int(1, 20);
-        vector<ll> a(n), b(m);
+        vl a(n), b(m);
         for (int i = 0; i < n; i++) a[i] = rnd_int(0, mod - 1);
         for (int i = 0; i < m; i++) b[i] = rnd_int(0, mod - 1);
         auto ref = conv_mod_ref(a, b, mod);
@@ -95,7 +95,7 @@ void test_ntt_any() {
         for (int it = 0; it < 200; it++) {
             int n = rnd_int(1, 20);
             int m = rnd_int(1, 20);
-            vector<ll> a(n), b(m);
+            vl a(n), b(m);
             for (int i = 0; i < n; i++) a[i] = rnd_int(0, 1000);
             for (int i = 0; i < m; i++) b[i] = rnd_int(0, 1000);
             auto ref = conv_mod_ref(a, b, mod);
diff --git a/tests/7-math/test_linalg_gauss.cpp b/tests/7-math/test_linalg_gauss.cpp
index 1c314e1..25c71a4 100644
--- a/tests/7-math/test_linalg_gauss.cpp
+++ b/tests/7-math/test_linalg_gauss.cpp
@@ -38,8 +38,8 @@ void test_gauss_real() {
 void test_gauss_mod() {
     int n = 6, m = 6;
     int mod = 101;
-    vector<vector<int>> A(n, vector<int>(m));
-    vector<int> x(m), b(n);
+    vvi A(n, vi(m));
+    vi x(m), b(n);
     for (int i = 0; i < m; i++) x[i] = rnd_int(0, mod - 1);
     for (int i = 0; i < n; i++)
         for (int j = 0; j < m; j++) A[i][j] = rnd_int(0, mod - 1);
@@ -48,7 +48,7 @@ void test_gauss_mod() {
         for (int j = 0; j < m; j++) sum += (ll)A[i][j] * x[j];
         b[i] = sum % mod;
     }
-    vector<vector<int>> aug(n, vector<int>(m + 1));
+    vvi aug(n, vi(m + 1));
     for (int i = 0; i < n; i++) {
         for (int j = 0; j < m; j++) aug[i][j] = A[i][j];
         aug[i][m] = b[i];
@@ -61,7 +61,7 @@ void test_gauss_mod() {
         assert(sum % mod == b[i]);
     }
 
-    vector<vector<int>> bad = {
+    vvi bad = {
         {1, 0, 0},
         {1, 0, 1},
     };
@@ -71,7 +71,7 @@ void test_gauss_mod() {
 
 void test_gauss_xor() {
     int n = 40, m = 20;
-    vector<int> x(m);
+    vi x(m);
     for (int i = 0; i < m; i++) x[i] = rnd_int(0, 1);
     vector<bitset<GAUSS_BSZ>> aug(n);
     for (int i = 0; i < n; i++) {
diff --git a/tests/7-math/test_linalg_mat.cpp b/tests/7-math/test_linalg_mat.cpp
index 4075ee0..6211ddc 100644
--- a/tests/7-math/test_linalg_mat.cpp
+++ b/tests/7-math/test_linalg_mat.cpp
@@ -21,9 +21,9 @@ ll fib_ref(int n, ll mod) {
     return a;
 }
 
-vector<vector<ll>> mul_ref(const vector<vector<ll>> &a, const vector<vector<ll>> &b, ll mod) {
+vvl mul_ref(const vvl &a, const vvl &b, ll mod) {
     int n = sz(a), m = sz(b[0]), k = sz(a[0]);
-    vector<vector<ll>> r(n, vector<ll>(m, 0));
+    vvl r(n, vl(m, 0));
     for (int i = 0; i < n; i++)
         for (int t = 0; t < k; t++)
             for (int j = 0; j < m; j++) {
diff --git a/tests/7-math/test_misc_sqrt.cpp b/tests/7-math/test_misc_sqrt.cpp
index bd51083..803c1b8 100644
--- a/tests/7-math/test_misc_sqrt.cpp
+++ b/tests/7-math/test_misc_sqrt.cpp
@@ -18,15 +18,15 @@ bool is_prime_ref(ll x) {
     return 1;
 }
 
-vector<ll> div_ref(ll x) {
-    vector<ll> d;
+vl div_ref(ll x) {
+    vl d;
     for (ll i = 1; i <= x; i++)
         if (x % i == 0) d.pb(i);
     return d;
 }
 
-vector<ll> fac_ref(ll x) {
-    vector<ll> p;
+vl fac_ref(ll x) {
+    vl p;
     for (ll i = 2; i <= x / i; i++) {
         while (x % i == 0) {
             p.pb(i);
@@ -38,10 +38,10 @@ vector<ll> fac_ref(ll x) {
 }
 
 int main() {
-    assert(sqrt_alg::divisors(1) == vector<ll>({1}));
+    assert(sqrt_alg::divisors(1) == vl({1}));
     assert(sqrt_alg::prime_fac(1).empty());
-    assert(sqrt_alg::divisors(36) == vector<ll>({1, 2, 3, 4, 6, 9, 12, 18, 36}));
-    assert(sqrt_alg::prime_fac(36) == vector<ll>({2, 2, 3, 3}));
+    assert(sqrt_alg::divisors(36) == vl({1, 2, 3, 4, 6, 9, 12, 18, 36}));
+    assert(sqrt_alg::prime_fac(36) == vl({2, 2, 3, 3}));
     for (int it = 0; it < 1000; it++) {
         ll x = rnd_ll(1, 5000);
         auto d1 = sqrt_alg::divisors(x);
diff --git a/tests/7-math/test_nt_mr_rho.cpp b/tests/7-math/test_nt_mr_rho.cpp
index d4f95f6..ee01015 100644
--- a/tests/7-math/test_nt_mr_rho.cpp
+++ b/tests/7-math/test_nt_mr_rho.cpp
@@ -18,8 +18,8 @@ bool is_prime_ref(ll x) {
     return 1;
 }
 
-vector<ll> fac_ref(ll x) {
-    vector<ll> f;
+vl fac_ref(ll x) {
+    vl f;
     for (ll p = 2; p * p <= x; p++) {
         while (x % p == 0) {
             f.pb(p);
@@ -56,15 +56,15 @@ void test_factor() {
     assert(pollard_rho::factor(1).empty());
     assert(pollard_rho::factor(0).empty());
     auto fneg = pollard_rho::factor(-12);
-    assert(fneg == vector<ll>({2, 2, 3}));
+    assert(fneg == vl({2, 2, 3}));
     auto fp = pollard_rho::factor(1000000007LL);
-    assert(fp == vector<ll>({1000000007LL}));
+    assert(fp == vl({1000000007LL}));
     ll p = 1000003, q = 1000033;
     auto fs = pollard_rho::factor(p * q);
-    assert(fs == vector<ll>({p, q}));
+    assert(fs == vl({p, q}));
     ll big = 1000000007LL * 1000000009LL;
     auto fb = pollard_rho::factor(big);
-    assert(fb == vector<ll>({1000000007LL, 1000000009LL}));
+    assert(fb == vl({1000000007LL, 1000000009LL}));
 }
 
 int main() {
diff --git a/tests/7-math/test_nt_sieve.cpp b/tests/7-math/test_nt_sieve.cpp
index ba0704c..de243de 100644
--- a/tests/7-math/test_nt_sieve.cpp
+++ b/tests/7-math/test_nt_sieve.cpp
@@ -45,8 +45,8 @@ int phi_ref(int x) {
     return ret;
 }
 
-vector<int> divisors(int x) {
-    vector<int> d;
+vi divisors(int x) {
+    vi d;
     for (int i = 1; 1LL * i * i <= x; i++) {
         if (x % i) continue;
         d.pb(i);
diff --git a/tests/8-misc/test_dp_opt.cpp b/tests/8-misc/test_dp_opt.cpp
index 1c8ea3e..f9380df 100644
--- a/tests/8-misc/test_dp_opt.cpp
+++ b/tests/8-misc/test_dp_opt.cpp
@@ -13,7 +13,7 @@ ll rnd(ll l, ll r) {
 
 void test_cht() {
     int n = 200, q = 200;
-    vector<ll> m(n), b(n);
+    vl m(n), b(n);
     ll cur = 1000;
     for (int i = 0; i < n; i++) {
         cur -= rnd(0, 5);
@@ -32,13 +32,13 @@ void test_cht() {
 
 void test_knuth() {
     int n = 40;
-    vector<ll> a(n);
+    vl a(n);
     for (int i = 0; i < n; i++) a[i] = rnd(0, 10);
-    vector<ll> ps(n + 1, 0);
+    vl ps(n + 1, 0);
     for (int i = 0; i < n; i++) ps[i + 1] = ps[i] + a[i];
     auto cost = [&](int i, int j) { return ps[j + 1] - ps[i]; };
     const ll INF = (1LL << 62);
-    vector<vector<ll>> dp(n, vector<ll>(n, 0));
+    vvl dp(n, vl(n, 0));
     for (int len = 2; len <= n; len++) {
         for (int i = 0; i + len - 1 < n; i++) {
             int j = i + len - 1;
@@ -56,7 +56,7 @@ void test_knuth() {
 
 void test_dnc() {
     int n = 50, k = 4;
-    vector<ll> base(n, 0);
+    vl base(n, 0);
     auto cost = [&](int j, int i) {
         ll d = i - j;
         return d * d;
@@ -64,7 +64,7 @@ void test_dnc() {
     dnc_opt dc;
     dc.run(k, n, base, cost);
     const ll INF = (1LL << 62);
-    vector<vector<ll>> dp(k + 1, vector<ll>(n, INF));
+    vvl dp(k + 1, vl(n, INF));
     dp[0] = base;
     for (int g = 1; g <= k; g++) {
         for (int i = 0; i < n; i++) {
@@ -73,17 +73,17 @@ void test_dnc() {
             }
         }
     }
-    const vector<ll> &got = dc.dp();
+    const vl &got = dc.dp();
     for (int i = 0; i < n; i++) assert(got[i] == dp[k][i]);
 }
 
-ll slope_naive(const vector<ll> &a) {
+ll slope_naive(const vl &a) {
     int n = sz(a);
     ll mn = *min_element(all(a)) - n;
     ll mx = *max_element(all(a)) + n;
     int m = (int)(mx - mn + 1);
     const ll INF = (1LL << 62);
-    vector<ll> dp_prev(m, INF), dp_cur(m, INF);
+    vl dp_prev(m, INF), dp_cur(m, INF);
     for (int v = 0; v < m; v++) dp_prev[v] = llabs(a[0] - (mn + v));
     for (int i = 1; i < n; i++) {
         ll best = INF;
@@ -99,7 +99,7 @@ ll slope_naive(const vector<ll> &a) {
 void test_slope_trick() {
     for (int it = 0; it < 200; it++) {
         int n = (int)rnd(1, 8);
-        vector<ll> a(n);
+        vl a(n);
         for (int i = 0; i < n; i++) a[i] = rnd(-5, 5);
         assert(slope_trick(a) == slope_naive(a));
     }
diff --git a/tests/8-misc/test_kitamasa.cpp b/tests/8-misc/test_kitamasa.cpp
index 99e832d..db7bf59 100644
--- a/tests/8-misc/test_kitamasa.cpp
+++ b/tests/8-misc/test_kitamasa.cpp
@@ -11,9 +11,9 @@ ll rnd(ll l, ll r) {
     return dis(rng);
 }
 
-ll naive_rec(const vector<ll> &coef, const vector<ll> &init, ll n, ll mod) {
+ll naive_rec(const vl &coef, const vl &init, ll n, ll mod) {
     int k = sz(coef);
-    vector<ll> a = init;
+    vl a = init;
     if (n < k) return mod_norm(a[n], mod);
     for (ll i = k; i <= n; i++) {
         ll v = 0;
@@ -29,7 +29,7 @@ void test_random() {
     const ll mod = 1000000007LL;
     for (int it = 0; it < 200; it++) {
         int k = (int)rnd(1, 6);
-        vector<ll> coef(k), init(k);
+        vl coef(k), init(k);
         for (int i = 0; i < k; i++) {
             coef[i] = rnd(0, mod - 1);
             init[i] = rnd(0, mod - 1);
diff --git a/tests/8-misc/test_lis_in_o_nlogn.cpp b/tests/8-misc/test_lis_in_o_nlogn.cpp
index 5bd5a7b..56cd208 100644
--- a/tests/8-misc/test_lis_in_o_nlogn.cpp
+++ b/tests/8-misc/test_lis_in_o_nlogn.cpp
@@ -11,9 +11,9 @@ ll rnd(ll l, ll r) {
     return dis(rng);
 }
 
-int lis_naive(const vector<ll> &a) {
+int lis_naive(const vl &a) {
     int n = sz(a);
-    vector<int> dp(n, 1);
+    vi dp(n, 1);
     int best = 0;
     for (int i = 0; i < n; i++) {
         for (int j = 0; j < i; j++) {
@@ -24,7 +24,7 @@ int lis_naive(const vector<ll> &a) {
     return best;
 }
 
-bool is_subseq(const vector<ll> &a, const vector<ll> &b) {
+bool is_subseq(const vl &a, const vl &b) {
     int i = 0, j = 0;
     while (i < sz(a) && j < sz(b)) {
         if (a[i] == b[j]) j++;
@@ -33,7 +33,7 @@ bool is_subseq(const vector<ll> &a, const vector<ll> &b) {
     return j == sz(b);
 }
 
-bool is_strict_inc(const vector<ll> &a) {
+bool is_strict_inc(const vl &a) {
     for (int i = 1; i < sz(a); i++)
         if (a[i - 1] >= a[i]) return false;
     return true;
@@ -42,11 +42,11 @@ bool is_strict_inc(const vector<ll> &a) {
 void test_random() {
     for (int it = 0; it < 200; it++) {
         int n = (int)rnd(1, 60);
-        vector<ll> a(n);
+        vl a(n);
         for (int i = 0; i < n; i++) a[i] = rnd(-10, 10);
         int exp = lis_naive(a);
         assert(lis_len(a) == exp);
-        vector<ll> seq = lis_seq(a);
+        vl seq = lis_seq(a);
         assert(sz(seq) == exp);
         assert(is_subseq(a, seq));
         assert(is_strict_inc(seq));
diff --git a/tests/8-misc/test_simd.cpp b/tests/8-misc/test_simd.cpp
index c1b7859..f2a4da9 100644
--- a/tests/8-misc/test_simd.cpp
+++ b/tests/8-misc/test_simd.cpp
@@ -13,7 +13,7 @@ int rnd_int(int l, int r) {
 
 void test_i32() {
     int n = 257;
-    vector<int> a(n), b(n), c(n), d(n);
+    vi a(n), b(n), c(n), d(n);
     for (int i = 0; i < n; i++) {
         a[i] = rnd_int(-1000, 1000);
         b[i] = rnd_int(-1000, 1000);
diff --git a/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp b/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp
index 022118a..48da46b 100644
--- a/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp
+++ b/tests/8-misc/test_sqrt_decomposition_mos_algorithm.cpp
@@ -13,7 +13,7 @@ int rnd_int(int l, int r) {
 
 void test_distinct() {
     int n = 200, qn = 200;
-    vector<int> a(n);
+    vi a(n);
     for (int i = 0; i < n; i++) a[i] = rnd_int(0, 30);
 
     vector<pii> qs(qn);
@@ -23,9 +23,9 @@ void test_distinct() {
         qs[i] = {l, r};
     }
 
-    vector<int> naive(qn, 0), ans(qn, 0);
+    vi naive(qn, 0), ans(qn, 0);
     for (int i = 0; i < qn; i++) {
-        vector<int> cnt(31, 0);
+        vi cnt(31, 0);
         int cur = 0;
         for (int j = qs[i].fr; j <= qs[i].sc; j++) {
             if (cnt[a[j]]++ == 0) cur++;
@@ -36,7 +36,7 @@ void test_distinct() {
     mo solver(n);
     for (int i = 0; i < qn; i++) solver.add_query(qs[i].fr, qs[i].sc, i);
 
-    vector<int> cnt(31, 0);
+    vi cnt(31, 0);
     int cur = 0;
     auto add = [&](int idx) {
         if (cnt[a[idx]]++ == 0) cur++;
diff --git a/tests/8-misc/test_system_of_difference_constraints.cpp b/tests/8-misc/test_system_of_difference_constraints.cpp
index 0173ed9..b9951cd 100644
--- a/tests/8-misc/test_system_of_difference_constraints.cpp
+++ b/tests/8-misc/test_system_of_difference_constraints.cpp
@@ -13,7 +13,7 @@ int rnd_int(int l, int r) {
 
 bool has_neg_cycle(int n, const vector<tuple<int, int, ll>> &edges) {
     const ll INF = (1LL << 60);
-    vector<vector<ll>> d(n, vector<ll>(n, INF));
+    vvl d(n, vl(n, INF));
     for (int i = 0; i < n; i++) d[i][i] = 0;
     for (auto [u, v, w] : edges) d[u][v] = min(d[u][v], w);
     for (int k = 0; k < n; k++) {
@@ -48,7 +48,7 @@ void test_random() {
         bool neg = has_neg_cycle(n, edges);
         assert(ok == !neg);
         if (ok) {
-            vector<ll> x = dc.val();
+            vl x = dc.val();
             for (auto [u, v, w] : edges) {
                 assert(x[v] <= x[u] + w);
             }

From 6371eaf1d585d3320c02419d651af02fbb854541 Mon Sep 17 00:00:00 2001
From: manoflearning <77jwk0724@gmail.com>
Date: Sun, 4 Jan 2026 03:17:46 +0900
Subject: [PATCH 5/6] blank

---
 src/1-ds/pbds.cpp                             |  3 ---
 src/4-optimizations/flow.cpp                  | 21 -------------------
 src/5-string/aho_corasick.cpp                 |  4 ----
 src/5-string/trie.cpp                         |  2 --
 src/7-math/comb_binom.cpp                     |  2 --
 src/7-math/comb_cat_der.cpp                   |  2 --
 src/7-math/conv_fft.cpp                       |  1 -
 src/7-math/linalg_mat.cpp                     |  3 ---
 src/7-math/modint.hpp                         |  6 ------
 src/7-math/nt_crt.cpp                         |  2 --
 src/7-math/nt_mr_rho.cpp                      |  4 ----
 src/7-math/nt_sieve.cpp                       |  7 -------
 src/7-math/num.hpp                            |  3 ---
 src/8-misc/dp_opt.cpp                         |  3 ---
 src/8-misc/fraction_data_type.cpp             |  3 ---
 src/8-misc/simd.cpp                           |  4 ----
 .../sqrt_decomposition_mos_algorithm.cpp      |  2 --
 .../system_of_difference_constraints.cpp      |  5 -----
 18 files changed, 77 deletions(-)

diff --git a/src/1-ds/pbds.cpp b/src/1-ds/pbds.cpp
index 6c0d056..f7a1ef5 100644
--- a/src/1-ds/pbds.cpp
+++ b/src/1-ds/pbds.cpp
@@ -20,18 +20,15 @@ void m_insert(omset &os, ll val) {
     // goal: insert one occurrence of val.
     os.insert({val, om_uid++});
 }
-
 void m_erase(omset &os, ll val) {
     // goal: erase one occurrence of val.
     auto it = os.lower_bound({val, LLONG_MIN});
     os.erase(it);
 }
-
 int m_order(const omset &os, ll val) {
     // result: number of elements strictly less than val.
     return os.order_of_key({val, LLONG_MIN});
 }
-
 ll m_kth(const omset &os, int k) {
     // result: k-th value (0-indexed) by order.
     return os.find_by_order(k)->fr;
diff --git a/src/4-optimizations/flow.cpp b/src/4-optimizations/flow.cpp
index 09ee0c9..0a4c17c 100644
--- a/src/4-optimizations/flow.cpp
+++ b/src/4-optimizations/flow.cpp
@@ -26,12 +26,10 @@ struct dinic {
     vi level, work;
 
     dinic(int n = 0) { init(n); }
-
     void init(int n_) {
         n = n_;
         g.assign(n, {});
     }
-
     edge_ref add_edge(int u, int v, ll cap) {
         // goal: add forward + reverse edge
         edge a{v, sz(g[v]), cap};
@@ -40,13 +38,11 @@ struct dinic {
         g[v].pb(b);
         return {u, sz(g[u]) - 1};
     }
-
     ll edge_flow(edge_ref e) const {
         // goal: current flow on original edge
         const edge &ed = g[e.u][e.idx];
         return g[ed.to][ed.rev].cap;
     }
-
     void clear_edge(edge_ref e) {
         // goal: remove edge from residual graph
         edge &ed = g[e.u][e.idx];
@@ -72,7 +68,6 @@ struct dinic {
         }
         return level[t] != -1;
     }
-
     ll dfs(int v, int t, ll f) {
         if (v == t || f == 0) return f;
         for (int &i = work[v]; i < sz(g[v]); i++) {
@@ -114,7 +109,6 @@ struct hk {
     vi dist, match_l, match_r;
 
     hk(int n_l_ = 0, int n_r_ = 0) { init(n_l_, n_r_); }
-
     void init(int n_l_, int n_r_) {
         n_l = n_l_;
         n_r = n_r_;
@@ -123,7 +117,6 @@ struct hk {
         match_l.assign(n_l, -1);
         match_r.assign(n_r, -1);
     }
-
     void add_edge(int l, int r) {
         // goal: add edge from left to right
         g[l].pb(r);
@@ -155,7 +148,6 @@ struct hk {
         }
         return found;
     }
-
     bool dfs(int v) {
         for (int r : g[v]) {
             int u = match_r[r];
@@ -204,12 +196,10 @@ struct mcmf {
     vector<vector<edge>> g;
 
     mcmf(int n = 0) { init(n); }
-
     void init(int n_) {
         n = n_;
         g.assign(n, {});
     }
-
     edge_ref add_edge(int u, int v, ll cap, ll cost) {
         // goal: add forward + reverse edge with costs
         edge a{v, sz(g[v]), cap, cost};
@@ -218,13 +208,11 @@ struct mcmf {
         g[v].pb(b);
         return {u, sz(g[u]) - 1};
     }
-
     ll edge_flow(edge_ref e) const {
         // goal: current flow on original edge
         const edge &ed = g[e.u][e.idx];
         return g[ed.to][ed.rev].cap;
     }
-
     void clear_edge(edge_ref e) {
         // goal: remove edge from residual graph
         edge &ed = g[e.u][e.idx];
@@ -264,7 +252,6 @@ struct mcmf {
             for (int i = 0; i < n; i++)
                 if (d[i] < INF) pot[i] = d[i];
         }
-
         while (flow < max_f) {
             // goal: shortest path in reduced costs
             fill(all(dist), INF);
@@ -328,14 +315,12 @@ struct lr_dinic {
     vector<edge_info> edges;
 
     lr_dinic(int n = 0) { init(n); }
-
     void init(int n_) {
         n = n_;
         mf.init(n + 2);
         demand.assign(n, 0);
         edges.clear();
     }
-
     int add_edge(int u, int v, ll lo, ll hi) {
         // goal: store lower bounds via node demands
         demand[u] -= lo;
@@ -343,12 +328,10 @@ struct lr_dinic {
         edges.pb({mf.add_edge(u, v, hi - lo), lo});
         return sz(edges) - 1;
     }
-
     ll edge_flow(int id) const {
         // goal: actual flow with lower bound restored
         return edges[id].lo + mf.edge_flow(edges[id].ref);
     }
-
     ll add_demands(vector<dinic::edge_ref> &aux) {
         // goal: connect ss/tt for feasible circulation
         ll total = 0;
@@ -415,7 +398,6 @@ struct lr_mcmf {
     ll base_cost;
 
     lr_mcmf(int n = 0) { init(n); }
-
     void init(int n_) {
         n = n_;
         mf.init(n + 2);
@@ -423,7 +405,6 @@ struct lr_mcmf {
         edges.clear();
         base_cost = 0;
     }
-
     int add_edge(int u, int v, ll lo, ll hi, ll cost) {
         // goal: store lower bounds via node demands
         demand[u] -= lo;
@@ -432,12 +413,10 @@ struct lr_mcmf {
         edges.pb({mf.add_edge(u, v, hi - lo, cost), lo});
         return sz(edges) - 1;
     }
-
     ll edge_flow(int id) const {
         // goal: actual flow with lower bound restored
         return edges[id].lo + mf.edge_flow(edges[id].ref);
     }
-
     ll add_demands(vector<mcmf::edge_ref> &aux) {
         // goal: connect ss/tt for feasible circulation
         ll total = 0;
diff --git a/src/5-string/aho_corasick.cpp b/src/5-string/aho_corasick.cpp
index 6e28bd5..e935927 100644
--- a/src/5-string/aho_corasick.cpp
+++ b/src/5-string/aho_corasick.cpp
@@ -10,7 +10,6 @@ struct aho_corasick {
     vi fail, out;
 
     aho_corasick() { init(); }
-
     void init() {
         // goal: reset to a single root node.
         nxt.assign(1, {});
@@ -18,7 +17,6 @@ struct aho_corasick {
         fail.assign(1, 0);
         out.assign(1, 0);
     }
-
     int add(const string &s) {
         // goal: insert a pattern and return its terminal node.
         int v = 0;
@@ -66,7 +64,6 @@ struct aho_corasick {
     }
 
     int step(int v, char ch) const { return nxt[v][ch - 'a']; }
-
     bool match_any(const string &t) const {
         // result: true if any pattern appears in t.
         int v = 0;
@@ -76,7 +73,6 @@ struct aho_corasick {
         }
         return false;
     }
-
     ll count(const string &t) const {
         // result: total number of pattern occurrences in t.
         ll res = 0;
diff --git a/src/5-string/trie.cpp b/src/5-string/trie.cpp
index ad652db..723470e 100644
--- a/src/5-string/trie.cpp
+++ b/src/5-string/trie.cpp
@@ -10,14 +10,12 @@ struct trie {
     vector<char> term;
 
     trie() { init(); }
-
     void init() {
         // goal: reset to empty trie.
         nxt.assign(1, {});
         nxt[0].fill(-1);
         term.assign(1, 0);
     }
-
     int add(const string &s) {
         // goal: insert a string and mark its terminal node.
         int v = 0;
diff --git a/src/7-math/comb_binom.cpp b/src/7-math/comb_binom.cpp
index 18add67..4044de6 100644
--- a/src/7-math/comb_binom.cpp
+++ b/src/7-math/comb_binom.cpp
@@ -34,7 +34,6 @@ struct comb_dp {
             for (int j = 1; j < i; j++) dp[i][j] = dp[i - 1][j - 1] + dp[i - 1][j];
         }
     }
-
     ll ncr(int n_, int r) const {
         if (r < 0 || n_ < r || n_ > n) return 0;
         return dp[n_][r];
@@ -60,7 +59,6 @@ struct comb_mod {
         ifac[n] = pow_mod(fac[n], mod - 2, mod);
         for (int i = n; i >= 1; i--) ifac[i - 1] = (ll)((__int128)ifac[i] * i % mod);
     }
-
     ll ncr(int n_, int r) const {
         if (r < 0 || n_ < r || n_ > n) return 0;
         ll ret = (ll)((__int128)fac[n_] * ifac[r] % mod);
diff --git a/src/7-math/comb_cat_der.cpp b/src/7-math/comb_cat_der.cpp
index d6b49a9..ae93d11 100644
--- a/src/7-math/comb_cat_der.cpp
+++ b/src/7-math/comb_cat_der.cpp
@@ -14,7 +14,6 @@ struct catalan_mod {
         mod = mod_;
         cb.init(2 * n, mod);
     }
-
     ll catalan(int n) const {
         ll ret = cb.ncr(2 * n, n);
         ll inv = euclid::inv_mod(n + 1, mod);
@@ -42,6 +41,5 @@ struct derange_mod {
             dp[i] = (ll)((__int128)(i - 1) * sum % mod);
         }
     }
-
     ll get(int n) const { return dp[n]; }
 };
diff --git a/src/7-math/conv_fft.cpp b/src/7-math/conv_fft.cpp
index 4f6434e..671cf6b 100644
--- a/src/7-math/conv_fft.cpp
+++ b/src/7-math/conv_fft.cpp
@@ -100,7 +100,6 @@ struct ntt_mod {
         if (x < 0) x += MOD;
         return x;
     }
-
     static ll mod_pow(ll b, ll e) {
         ll ans = 1;
         while (e) {
diff --git a/src/7-math/linalg_mat.cpp b/src/7-math/linalg_mat.cpp
index 1bd446a..c886336 100644
--- a/src/7-math/linalg_mat.cpp
+++ b/src/7-math/linalg_mat.cpp
@@ -10,13 +10,11 @@ struct matrix {
     vvl a;
 
     matrix(int n = 0, int m = 0, ll mod_ = 1) : mod(mod_), a(n, vl(m, 0)) {}
-
     static matrix ident(int n, ll mod) {
         matrix r(n, n, mod);
         for (int i = 0; i < n; i++) r.a[i][i] = 1 % mod;
         return r;
     }
-
     matrix operator*(const matrix &o) const {
         int n = sz(a);
         int m = sz(o.a[0]);
@@ -34,7 +32,6 @@ struct matrix {
         }
         return r;
     }
-
     static matrix power(matrix base, ll exp) {
         // goal: fast exponentiation.
         matrix res = ident(sz(base.a), base.mod);
diff --git a/src/7-math/modint.hpp b/src/7-math/modint.hpp
index 16612cd..f82c697 100644
--- a/src/7-math/modint.hpp
+++ b/src/7-math/modint.hpp
@@ -21,7 +21,6 @@ struct modint {
 
     modint(ll x = 0) : v(norm(x)) {}
     static ll mod() { return MOD; }
-
     modint &operator+=(const modint &o) {
         v += o.v;
         if (v >= MOD) v -= MOD;
@@ -39,7 +38,6 @@ struct modint {
     modint &operator/=(const modint &o) { return (*this) *= o.inv(); }
 
     modint operator-() const { return modint(v ? MOD - v : 0); }
-
     friend modint operator+(modint a, const modint &b) { return a += b; }
     friend modint operator-(modint a, const modint &b) { return a -= b; }
     friend modint operator*(modint a, const modint &b) { return a *= b; }
@@ -52,7 +50,6 @@ struct modint {
     modint inv() const { return euclid::inv_mod(v, MOD); }
 
     explicit operator ll() const { return v; }
-
     friend ostream &operator<<(ostream &os, const modint &x) { return os << x.v; }
     friend istream &operator>>(istream &is, modint &x) {
         ll t;
@@ -82,7 +79,6 @@ struct dyn_modint {
     dyn_modint(ll x = 0) : v(norm(x)) {}
     static void set_mod(ll m) { mod_ = m; }
     static ll mod() { return mod_; }
-
     dyn_modint &operator+=(const dyn_modint &o) {
         v += o.v;
         if (v >= mod_) v -= mod_;
@@ -100,7 +96,6 @@ struct dyn_modint {
     dyn_modint &operator/=(const dyn_modint &o) { return (*this) *= o.inv(); }
 
     dyn_modint operator-() const { return dyn_modint(v ? mod_ - v : 0); }
-
     friend dyn_modint operator+(dyn_modint a, const dyn_modint &b) { return a += b; }
     friend dyn_modint operator-(dyn_modint a, const dyn_modint &b) { return a -= b; }
     friend dyn_modint operator*(dyn_modint a, const dyn_modint &b) { return a *= b; }
@@ -113,7 +108,6 @@ struct dyn_modint {
     dyn_modint inv() const { return euclid::inv_mod(v, mod_); }
 
     explicit operator ll() const { return v; }
-
     friend ostream &operator<<(ostream &os, const dyn_modint &x) { return os << x.v; }
     friend istream &operator>>(istream &is, dyn_modint &x) {
         ll t;
diff --git a/src/7-math/nt_crt.cpp b/src/7-math/nt_crt.cpp
index b368a98..af594f4 100644
--- a/src/7-math/nt_crt.cpp
+++ b/src/7-math/nt_crt.cpp
@@ -13,7 +13,6 @@ struct crt {
         if (a.fr < 0) a.fr += a.sc;
         return a;
     }
-
     static pll merge(pll a, pll b) {
         // result: x = ret.fr (mod ret.sc), or {-1,-1} if no solution.
         a = norm(a);
@@ -39,7 +38,6 @@ struct crt {
         if (r < 0) r += l;
         return {r, l};
     }
-
     static pll merge_all(const vector<pll> &cs) {
         pll cur = {0, 1};
         for (auto c : cs) cur = merge(cur, c);
diff --git a/src/7-math/nt_mr_rho.cpp b/src/7-math/nt_mr_rho.cpp
index fb00038..f4f7eb0 100644
--- a/src/7-math/nt_mr_rho.cpp
+++ b/src/7-math/nt_mr_rho.cpp
@@ -8,7 +8,6 @@
 struct miller_rabin {
     static ll mul(ll a, ll b, ll mod) { return (ll)((__int128)a * b % mod); }
     static ll pow_mod(ll a, ll e, ll mod) { return ::pow_mod(a, e, mod); }
-
     static bool is_prime(ll n) {
         if (n < 2) return 0;
         for (ll p : {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37}) {
@@ -43,7 +42,6 @@ struct miller_rabin {
 // usage: auto f=pollard_rho::factor(n);
 struct pollard_rho {
     static ll f(ll x, ll c, ll mod) { return (miller_rabin::mul(x, x, mod) + c) % mod; }
-
     static ll rho(ll n) {
         if ((n & 1) == 0) return 2;
         static mt19937_64 rng(712367);
@@ -59,7 +57,6 @@ struct pollard_rho {
             if (d != n) return d;
         }
     }
-
     static void rec(ll n, vl &out) {
         if (n == 1) return;
         if (miller_rabin::is_prime(n)) {
@@ -70,7 +67,6 @@ struct pollard_rho {
         rec(d, out);
         rec(n / d, out);
     }
-
     static vl factor(ll n) {
         // result: prime factors of |n| with repetition, sorted.
         vl out;
diff --git a/src/7-math/nt_sieve.cpp b/src/7-math/nt_sieve.cpp
index 5dc8d75..d2d2a47 100644
--- a/src/7-math/nt_sieve.cpp
+++ b/src/7-math/nt_sieve.cpp
@@ -13,7 +13,6 @@ struct era_sieve {
     era_sieve(int n_ = 0) {
         if (n_ >= 0) init(n_);
     }
-
     void init(int n_) {
         // goal: build isp/primes for [0..n]
         n = n_;
@@ -30,7 +29,6 @@ struct era_sieve {
         for (int i = 3; i <= n; i += 2)
             if (isp[i]) primes.pb(i);
     }
-
     bool is_prime(int x) const { return x >= 2 && x <= n && isp[x]; }
 };
 
@@ -45,7 +43,6 @@ struct lin_sieve {
     lin_sieve(int n_ = 0) {
         if (n_ >= 0) init(n_);
     }
-
     void init(int n_) {
         // goal: fill lp/primes/mu/phi for [0..n]
         n = n_;
@@ -75,9 +72,7 @@ struct lin_sieve {
             }
         }
     }
-
     bool is_prime(int x) const { return x >= 2 && x <= n && lp[x] == x; }
-
     vi factor(int x) const {
         // result: prime factors of x (with repetition), in nondecreasing order
         vi ret;
@@ -88,7 +83,6 @@ struct lin_sieve {
         }
         return ret;
     }
-
     vector<pii> factor_cnt(int x) const {
         // result: {{p, e}} s.t. x = prod p^e, increasing p
         vector<pii> ret;
@@ -128,7 +122,6 @@ struct euler_phi {
         if (x > 1) ret = ret / x * (x - 1);
         return ret;
     }
-
     static vi phi_upto(int n) {
         lin_sieve sv(n);
         return sv.phi;
diff --git a/src/7-math/num.hpp b/src/7-math/num.hpp
index e2ebe6d..e0456a9 100644
--- a/src/7-math/num.hpp
+++ b/src/7-math/num.hpp
@@ -23,7 +23,6 @@ struct euclid {
         if (v < 0) v = -v;
         return v;
     }
-
     static pair<pll, ll> egcd(ll a, ll b) {
         // result: {{x, y}, g} s.t. a*x + b*y = g = gcd(a, b)
         ll s = 0, os = 1;
@@ -48,7 +47,6 @@ struct euclid {
         }
         return {{os, ot}, orr};
     }
-
     static ll inv_mod(ll a, ll mod) {
         // result: x in [0, mod) s.t. a*x = 1 (mod mod), or -1 if not invertible.
         a %= mod;
@@ -59,7 +57,6 @@ struct euclid {
         if (x < 0) x += mod;
         return x;
     }
-
     static ll lin_cong(ll a, ll b, ll mod) {
         // what: solve linear congruence a*x = b (mod mod).
         // result: one x in [0, mod) if exists, else -1.
diff --git a/src/8-misc/dp_opt.cpp b/src/8-misc/dp_opt.cpp
index c37dca5..ed1b76a 100644
--- a/src/8-misc/dp_opt.cpp
+++ b/src/8-misc/dp_opt.cpp
@@ -21,7 +21,6 @@ struct cht_mono {
     ld isect(const line &a, const line &b) const {
         return (ld)(b.b - a.b) / (a.m - b.m);
     }
-
     void add_line(ll m, ll b) {
         // goal: maintain lower hull with decreasing slopes
         if (!st.empty() && st.back().m == m) {
@@ -37,7 +36,6 @@ struct cht_mono {
         if (st.empty()) cur.x = NEG_INF;
         st.pb(cur);
     }
-
     ll get(ll x) const {
         // invariant: st is sorted by x; pick last with x_i <= x
         int l = 0, r = sz(st) - 1;
@@ -109,7 +107,6 @@ struct dnc_opt {
             prv.swap(cur);
         }
     }
-
     const vl &dp() const { return prv; }
 
     template <class F>
diff --git a/src/8-misc/fraction_data_type.cpp b/src/8-misc/fraction_data_type.cpp
index f19882e..3d9f6b6 100644
--- a/src/8-misc/fraction_data_type.cpp
+++ b/src/8-misc/fraction_data_type.cpp
@@ -8,7 +8,6 @@ struct fraction {
     ll n, d;
 
     fraction(ll n_ = 0, ll d_ = 1) { set(n_, d_); }
-
     static ll gcd_ll(ll a, ll b) {
         if (a < 0) a = -a;
         if (b < 0) b = -b;
@@ -19,14 +18,12 @@ struct fraction {
         }
         return a;
     }
-
     void set(ll n_, ll d_) {
         // goal: normalize sign + reduce
         n = n_;
         d = d_;
         norm();
     }
-
     void norm() {
         if (d < 0) n = -n, d = -d;
         ll g = gcd_ll(n, d);
diff --git a/src/8-misc/simd.cpp b/src/8-misc/simd.cpp
index 8408fc4..d7600bb 100644
--- a/src/8-misc/simd.cpp
+++ b/src/8-misc/simd.cpp
@@ -19,7 +19,6 @@ struct simd_i32 {
         }
         for (; i < n; i++) c[i] = a[i] + b[i];
     }
-
     static ll sum(const int *a, int n) {
         // goal: sum all values with 64-bit accumulation
         int i = 0;
@@ -40,7 +39,6 @@ struct simd_i32 {
         for (; i < n; i++) res += a[i];
         return res;
     }
-
     static int range_min(const int *a, int l, int r) {
         // goal: min in [l, r]
         int i = l;
@@ -56,7 +54,6 @@ struct simd_i32 {
         for (; i <= r; i++) res = min(res, a[i]);
         return res;
     }
-
     static int count_eq(const int *a, int n, int v) {
         // goal: count occurrences of v
         int i = 0;
@@ -84,7 +81,6 @@ struct simd_f32 {
         }
         for (; i < n; i++) a[i] += b[i];
     }
-
     static float dot(const float *a, const float *b, int n) {
         // goal: dot product
         int i = 0;
diff --git a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
index 684f55c..cdfeac5 100644
--- a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
+++ b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
@@ -13,14 +13,12 @@ struct mo {
     vector<qry> q;
 
     mo(int n_ = 0) { init(n_); }
-
     void init(int n_) {
         // goal: set array size and reset queries.
         n = n_;
         bs = max(1, (int)sqrt(n));
         q.clear();
     }
-
     void add_query(int l, int r, int idx) { q.pb({l, r, idx}); }
 
     template <class Add, class Del, class Out>
diff --git a/src/8-misc/system_of_difference_constraints.cpp b/src/8-misc/system_of_difference_constraints.cpp
index 3071a1e..7820813 100644
--- a/src/8-misc/system_of_difference_constraints.cpp
+++ b/src/8-misc/system_of_difference_constraints.cpp
@@ -15,23 +15,19 @@ struct diff_cons {
     vl dist;
 
     diff_cons(int n_ = 0) { init(n_); }
-
     void init(int n_) {
         n = n_;
         g.assign(n, {});
         dist.assign(n, 0);
     }
-
     void add_le(int u, int v, ll w) {
         // goal: x_v - x_u <= w
         g[u].pb({v, w});
     }
-
     void add_ge(int u, int v, ll w) {
         // goal: x_v - x_u >= w  <=>  x_u - x_v <= -w
         add_le(v, u, -w);
     }
-
     void add_eq(int u, int v, ll w) {
         // goal: x_v - x_u = w
         add_le(u, v, w);
@@ -60,6 +56,5 @@ struct diff_cons {
         }
         return true;
     }
-
     vl val() const { return dist; }
 };

From 18167379ac80730fc8df75199840be40510b92bd Mon Sep 17 00:00:00 2001
From: manoflearning <77jwk0724@gmail.com>
Date: Sun, 4 Jan 2026 03:33:38 +0900
Subject: [PATCH 6/6] common

---
 README.md                                       | 4 ++--
 src/{common => 0-common}/common.hpp             | 0
 src/1-ds/erasable_pq.cpp                        | 2 +-
 src/1-ds/fenwick_tree.cpp                       | 2 +-
 src/1-ds/li_chao_tree.cpp                       | 2 +-
 src/1-ds/merge_sort_tree.cpp                    | 2 +-
 src/1-ds/pbds.cpp                               | 2 +-
 src/1-ds/segment_tree.cpp                       | 2 +-
 src/1-ds/union_find.cpp                         | 2 +-
 src/2-graph/bcc.cpp                             | 2 +-
 src/2-graph/euler_circuit.cpp                   | 2 +-
 src/2-graph/kth_shortest_path.cpp               | 2 +-
 src/2-graph/offline_dynamic_connectivity.cpp    | 2 +-
 src/2-graph/scc_2_sat.cpp                       | 2 +-
 src/2-graph/shortest_path.cpp                   | 2 +-
 src/3-tree/centroid_decomp.cpp                  | 2 +-
 src/3-tree/lca_sparse_table.cpp                 | 2 +-
 src/3-tree/tree_composition.cpp                 | 2 +-
 src/3-tree/tree_exchange_argument.cpp           | 2 +-
 src/4-optimizations/flow.cpp                    | 6 +-----
 src/4-optimizations/hungarian.cpp               | 2 +-
 src/5-string/aho_corasick.cpp                   | 3 +--
 src/5-string/kmp_algorithm.cpp                  | 2 +-
 src/5-string/manachers_algorithm.cpp            | 2 +-
 src/5-string/rabin_karp_algorithm.cpp           | 3 +--
 src/5-string/suffix_array.cpp                   | 2 +-
 src/5-string/trie.cpp                           | 3 +--
 src/5-string/z_algorithm.cpp                    | 2 +-
 src/6-geometry/geom_base.cpp                    | 2 +-
 src/7-math/conv_fft.cpp                         | 2 +-
 src/7-math/linalg_mat.cpp                       | 2 +-
 src/7-math/misc_sqrt.cpp                        | 2 +-
 src/7-math/modint.hpp                           | 8 --------
 src/7-math/nt_sieve.cpp                         | 2 +-
 src/7-math/num.hpp                              | 2 +-
 src/8-misc/dp_opt.cpp                           | 2 +-
 src/8-misc/fraction_data_type.cpp               | 3 +--
 src/8-misc/kitamasa.cpp                         | 2 +-
 src/8-misc/lis_in_o_nlogn.cpp                   | 2 +-
 src/8-misc/random.cpp                           | 2 +-
 src/8-misc/simd.cpp                             | 2 +-
 src/8-misc/sqrt_decomposition_mos_algorithm.cpp | 3 +--
 src/8-misc/system_of_difference_constraints.cpp | 2 +-
 src/8-misc/ternary_search.cpp                   | 2 +-
 44 files changed, 43 insertions(+), 60 deletions(-)
 rename src/{common => 0-common}/common.hpp (100%)

diff --git a/README.md b/README.md
index 574e904..5741a94 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,8 @@
 My implementations of various data structures and algorithms for competitive programming.
 
 ## Contents (GitHub links, `main`)
+- [0-common](https://github.com/manoflearning/cp-reference-codes/tree/main/src/0-common)
+  - [`common.hpp`](https://github.com/manoflearning/cp-reference-codes/blob/main/src/0-common/common.hpp)
 - [1-ds](https://github.com/manoflearning/cp-reference-codes/tree/main/src/1-ds)
   - [`erasable_pq.cpp`](https://github.com/manoflearning/cp-reference-codes/blob/main/src/1-ds/erasable_pq.cpp)
   - [`fenwick_tree.cpp`](https://github.com/manoflearning/cp-reference-codes/blob/main/src/1-ds/fenwick_tree.cpp)
@@ -69,5 +71,3 @@ My implementations of various data structures and algorithms for competitive pro
   - [`stress_test.py`](https://github.com/manoflearning/cp-reference-codes/blob/main/src/8-misc/stress_test.py)
   - [`system_of_difference_constraints.cpp`](https://github.com/manoflearning/cp-reference-codes/blob/main/src/8-misc/system_of_difference_constraints.cpp)
   - [`ternary_search.cpp`](https://github.com/manoflearning/cp-reference-codes/blob/main/src/8-misc/ternary_search.cpp)
-- [common](https://github.com/manoflearning/cp-reference-codes/tree/main/src/common)
-  - [`common.hpp`](https://github.com/manoflearning/cp-reference-codes/blob/main/src/common/common.hpp)
diff --git a/src/common/common.hpp b/src/0-common/common.hpp
similarity index 100%
rename from src/common/common.hpp
rename to src/0-common/common.hpp
diff --git a/src/1-ds/erasable_pq.cpp b/src/1-ds/erasable_pq.cpp
index 10f972e..bec5c49 100644
--- a/src/1-ds/erasable_pq.cpp
+++ b/src/1-ds/erasable_pq.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: priority queue that supports deleting arbitrary values via lazy deletion.
 // time: push/pop/erase O(log n); memory: O(n)
diff --git a/src/1-ds/fenwick_tree.cpp b/src/1-ds/fenwick_tree.cpp
index cbdf86a..0dd3f3c 100644
--- a/src/1-ds/fenwick_tree.cpp
+++ b/src/1-ds/fenwick_tree.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: maintain prefix sums with point updates and range sum queries.
 // time: build O(n), update/query O(log n); memory: O(n)
diff --git a/src/1-ds/li_chao_tree.cpp b/src/1-ds/li_chao_tree.cpp
index 9b498c8..3e3ffce 100644
--- a/src/1-ds/li_chao_tree.cpp
+++ b/src/1-ds/li_chao_tree.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: maintain max of lines on a fixed x-range with online add + point query.
 // time: add/query O(log X); memory: O(n)
diff --git a/src/1-ds/merge_sort_tree.cpp b/src/1-ds/merge_sort_tree.cpp
index 2f9f3b7..e3f3f61 100644
--- a/src/1-ds/merge_sort_tree.cpp
+++ b/src/1-ds/merge_sort_tree.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 constexpr int MAX_MST = 1 << 17;
 
 // what: static range count queries by storing sorted lists on a segment tree.
diff --git a/src/1-ds/pbds.cpp b/src/1-ds/pbds.cpp
index f7a1ef5..2fae294 100644
--- a/src/1-ds/pbds.cpp
+++ b/src/1-ds/pbds.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 #include <ext/pb_ds/assoc_container.hpp>
 #include <ext/pb_ds/tree_policy.hpp>
 using namespace __gnu_pbds;
diff --git a/src/1-ds/segment_tree.cpp b/src/1-ds/segment_tree.cpp
index 06d0775..760e9fc 100644
--- a/src/1-ds/segment_tree.cpp
+++ b/src/1-ds/segment_tree.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: point update + range sum on a fixed-size array using a tree.
 // time: build O(n), update/query O(log n); memory: O(n)
diff --git a/src/1-ds/union_find.cpp b/src/1-ds/union_find.cpp
index e8355bc..aca213c 100644
--- a/src/1-ds/union_find.cpp
+++ b/src/1-ds/union_find.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: maintain dynamic connectivity with union-find and size queries.
 // time: init O(n), join/find amortized a(n); memory: O(n)
diff --git a/src/2-graph/bcc.cpp b/src/2-graph/bcc.cpp
index c7ce283..376ea63 100644
--- a/src/2-graph/bcc.cpp
+++ b/src/2-graph/bcc.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: find biconnected components and articulation points/bridges in an undirected graph.
 // time: O(n+m); memory: O(n+m)
diff --git a/src/2-graph/euler_circuit.cpp b/src/2-graph/euler_circuit.cpp
index 7552b2f..9f67492 100644
--- a/src/2-graph/euler_circuit.cpp
+++ b/src/2-graph/euler_circuit.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: build an Eulerian circuit in an undirected multigraph (adjacency matrix).
 // time: O(n^2+m); memory: O(n^2)
diff --git a/src/2-graph/kth_shortest_path.cpp b/src/2-graph/kth_shortest_path.cpp
index 4986635..69bc605 100644
--- a/src/2-graph/kth_shortest_path.cpp
+++ b/src/2-graph/kth_shortest_path.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: enumerate k-th shortest walk from s to t with non-negative weights (Eppstein-style).
 // time: O((n+m)log m + klog k); memory: O(n+m+heap)
diff --git a/src/2-graph/offline_dynamic_connectivity.cpp b/src/2-graph/offline_dynamic_connectivity.cpp
index a875c73..75a7270 100644
--- a/src/2-graph/offline_dynamic_connectivity.cpp
+++ b/src/2-graph/offline_dynamic_connectivity.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: answer edge add/remove connectivity queries offline using segment tree + rollback DSU.
 // time: O((n+q)log q); memory: O(n+q)
diff --git a/src/2-graph/scc_2_sat.cpp b/src/2-graph/scc_2_sat.cpp
index bf0e64d..fa036e4 100644
--- a/src/2-graph/scc_2_sat.cpp
+++ b/src/2-graph/scc_2_sat.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: compute SCCs in a directed graph using Kosaraju's algorithm.
 // time: O(n+m); memory: O(n+m)
diff --git a/src/2-graph/shortest_path.cpp b/src/2-graph/shortest_path.cpp
index c929df3..918118a 100644
--- a/src/2-graph/shortest_path.cpp
+++ b/src/2-graph/shortest_path.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: compute single-source shortest paths with non-negative edges (Dijkstra).
 // time: O((n+m)log n); memory: O(n+m)
diff --git a/src/3-tree/centroid_decomp.cpp b/src/3-tree/centroid_decomp.cpp
index c58f79b..a773275 100644
--- a/src/3-tree/centroid_decomp.cpp
+++ b/src/3-tree/centroid_decomp.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: centroid decomposition for tree, builds centroid parent/children for path queries.
 // time: O(n log n); memory: O(n)
diff --git a/src/3-tree/lca_sparse_table.cpp b/src/3-tree/lca_sparse_table.cpp
index f9ebd7c..eb73f14 100644
--- a/src/3-tree/lca_sparse_table.cpp
+++ b/src/3-tree/lca_sparse_table.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: LCA via binary lifting for rooted tree.
 // time: build O(n log n), query O(log n); memory: O(n log n)
diff --git a/src/3-tree/tree_composition.cpp b/src/3-tree/tree_composition.cpp
index b599728..a252db8 100644
--- a/src/3-tree/tree_composition.cpp
+++ b/src/3-tree/tree_composition.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: virtual tree builder for subset DP using LCA and dfs order.
 // time: build O(n log n), make O(k log k); memory: O(n log n)
diff --git a/src/3-tree/tree_exchange_argument.cpp b/src/3-tree/tree_exchange_argument.cpp
index 005f6c3..dd673a9 100644
--- a/src/3-tree/tree_exchange_argument.cpp
+++ b/src/3-tree/tree_exchange_argument.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: maximize sum w[i]*completion_time[i] under precedence "parent before child" on rooted tree.
 // time: O(n log n); memory: O(n)
diff --git a/src/4-optimizations/flow.cpp b/src/4-optimizations/flow.cpp
index 0a4c17c..781ee85 100644
--- a/src/4-optimizations/flow.cpp
+++ b/src/4-optimizations/flow.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: collection of flow solvers (max flow, min-cost flow, matching, bounds).
 // time: see each struct; memory: O(E)
@@ -82,7 +82,6 @@ struct dinic {
         }
         return 0;
     }
-
     ll max_flow(int s, int t, ll limit = INF) {
         if (s == t) return 0; // edge: no flow needed
         ll flow = 0;
@@ -160,7 +159,6 @@ struct hk {
         dist[v] = -1;
         return false;
     }
-
     int max_matching() {
         // goal: compute maximum matching size
         fill(all(match_l), -1);
@@ -356,7 +354,6 @@ struct lr_dinic {
         for (auto ref : aux) mf.clear_edge(ref);
         return flow == total;
     }
-
     pair<bool, ll> max_flow(int s, int t) {
         if (s == t) return {feasible(), 0}; // edge: trivial s == t
         vector<dinic::edge_ref> aux;
@@ -442,7 +439,6 @@ struct lr_mcmf {
         if (res.fr != total) return {false, 0};
         return {true, res.sc + base_cost};
     }
-
     pair<bool, pll> max_flow(int s, int t, bool init_pot = true) {
         if (s == t) {
             auto r = feasible(init_pot);
diff --git a/src/4-optimizations/hungarian.cpp b/src/4-optimizations/hungarian.cpp
index 2339241..fa438ca 100644
--- a/src/4-optimizations/hungarian.cpp
+++ b/src/4-optimizations/hungarian.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: solve rectangular assignment problem (min-cost matching) via Hungarian.
 // time: O(n m^2); memory: O(n+m)
diff --git a/src/5-string/aho_corasick.cpp b/src/5-string/aho_corasick.cpp
index e935927..c90a738 100644
--- a/src/5-string/aho_corasick.cpp
+++ b/src/5-string/aho_corasick.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: build automaton to find many lowercase patterns inside a text.
 // time: add O(|p|), build O(nodes*ALPHA), query O(|t|); memory: O(nodes*ALPHA)
@@ -34,7 +34,6 @@ struct aho_corasick {
         out[v]++;
         return v;
     }
-
     void build() {
         // goal: compute failure links and output counts.
         queue<int> q;
diff --git a/src/5-string/kmp_algorithm.cpp b/src/5-string/kmp_algorithm.cpp
index ad167d3..876fb25 100644
--- a/src/5-string/kmp_algorithm.cpp
+++ b/src/5-string/kmp_algorithm.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: find all occurrences of a pattern using prefix-function (KMP).
 // time: O(|t|+|p|); memory: O(|p|)
diff --git a/src/5-string/manachers_algorithm.cpp b/src/5-string/manachers_algorithm.cpp
index d728426..c8e1a9b 100644
--- a/src/5-string/manachers_algorithm.cpp
+++ b/src/5-string/manachers_algorithm.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: compute longest palindrome radius at every center (odd/even).
 // time: O(n); memory: O(n)
diff --git a/src/5-string/rabin_karp_algorithm.cpp b/src/5-string/rabin_karp_algorithm.cpp
index 66974ed..4e94dcf 100644
--- a/src/5-string/rabin_karp_algorithm.cpp
+++ b/src/5-string/rabin_karp_algorithm.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: probabilistic substring matching using double rolling hash.
 // time: build O(n), get O(1), match O(n); memory: O(n)
@@ -25,7 +25,6 @@ struct rabin_karp {
             h2[i + 1] = (h2[i] * BASE + x) % MOD2;
         }
     }
-
     pll get(int l, int r) const { // [l, r)
         // result: hash of s[l..r).
         ll x1 = (h1[r] - h1[l] * p1[r - l]) % MOD1;
diff --git a/src/5-string/suffix_array.cpp b/src/5-string/suffix_array.cpp
index 10257f5..5852516 100644
--- a/src/5-string/suffix_array.cpp
+++ b/src/5-string/suffix_array.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: build lexicographic suffix order and LCP for fast substring comparisons.
 // time: build_sa O(n log n), build_lcp O(n); memory: O(n)
diff --git a/src/5-string/trie.cpp b/src/5-string/trie.cpp
index 723470e..a274f21 100644
--- a/src/5-string/trie.cpp
+++ b/src/5-string/trie.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: store a set of lowercase strings for fast prefix traversal and lookup.
 // time: add/has O(|s|); memory: O(nodes*ALPHA)
@@ -32,7 +32,6 @@ struct trie {
         term[v] = 1;
         return v;
     }
-
     bool has(const string &s) const {
         // result: true if s exists as a full word.
         int v = 0;
diff --git a/src/5-string/z_algorithm.cpp b/src/5-string/z_algorithm.cpp
index 7ae1048..0eb8cd6 100644
--- a/src/5-string/z_algorithm.cpp
+++ b/src/5-string/z_algorithm.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: compute prefix match lengths for each position in a string.
 // time: O(n); memory: O(n)
diff --git a/src/6-geometry/geom_base.cpp b/src/6-geometry/geom_base.cpp
index 85fb905..eb6bc47 100644
--- a/src/6-geometry/geom_base.cpp
+++ b/src/6-geometry/geom_base.cpp
@@ -1,5 +1,5 @@
 #pragma once
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: 2D primitives and orientation/intersection helpers for integer and double points.
 // time: O(1) per op; memory: O(1)
diff --git a/src/7-math/conv_fft.cpp b/src/7-math/conv_fft.cpp
index 671cf6b..f8fdefd 100644
--- a/src/7-math/conv_fft.cpp
+++ b/src/7-math/conv_fft.cpp
@@ -1,5 +1,5 @@
 #pragma once
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 #include "num.hpp"
 
 // what: multiply integer sequences using FFT (optionally via split for mod).
diff --git a/src/7-math/linalg_mat.cpp b/src/7-math/linalg_mat.cpp
index c886336..c136edc 100644
--- a/src/7-math/linalg_mat.cpp
+++ b/src/7-math/linalg_mat.cpp
@@ -1,5 +1,5 @@
 #pragma once
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: small matrix helper for modular multiply and fast exponentiation.
 // time: multiply O(n*m*k); power O(log e * n^3); memory: O(n*m)
diff --git a/src/7-math/misc_sqrt.cpp b/src/7-math/misc_sqrt.cpp
index 8a96a0b..1a7c7de 100644
--- a/src/7-math/misc_sqrt.cpp
+++ b/src/7-math/misc_sqrt.cpp
@@ -1,5 +1,5 @@
 #pragma once
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: list all divisors and prime factors of a single integer by sqrt trial division.
 // time: O(sqrt x); memory: O(1) extra
diff --git a/src/7-math/modint.hpp b/src/7-math/modint.hpp
index f82c697..04eba61 100644
--- a/src/7-math/modint.hpp
+++ b/src/7-math/modint.hpp
@@ -18,7 +18,6 @@ struct modint {
         return x;
     }
     static ll mul(ll a, ll b) { return (ll)((__int128)a * b % MOD); }
-
     modint(ll x = 0) : v(norm(x)) {}
     static ll mod() { return MOD; }
     modint &operator+=(const modint &o) {
@@ -36,7 +35,6 @@ struct modint {
         return *this;
     }
     modint &operator/=(const modint &o) { return (*this) *= o.inv(); }
-
     modint operator-() const { return modint(v ? MOD - v : 0); }
     friend modint operator+(modint a, const modint &b) { return a += b; }
     friend modint operator-(modint a, const modint &b) { return a -= b; }
@@ -45,10 +43,8 @@ struct modint {
 
     bool operator==(const modint &o) const { return v == o.v; }
     bool operator!=(const modint &o) const { return v != o.v; }
-
     modint pow(ll e) const { return pow_mod(v, e, MOD); }
     modint inv() const { return euclid::inv_mod(v, MOD); }
-
     explicit operator ll() const { return v; }
     friend ostream &operator<<(ostream &os, const modint &x) { return os << x.v; }
     friend istream &operator>>(istream &is, modint &x) {
@@ -75,7 +71,6 @@ struct dyn_modint {
         return x;
     }
     static ll mul(ll a, ll b) { return (ll)((__int128)a * b % mod_); }
-
     dyn_modint(ll x = 0) : v(norm(x)) {}
     static void set_mod(ll m) { mod_ = m; }
     static ll mod() { return mod_; }
@@ -94,7 +89,6 @@ struct dyn_modint {
         return *this;
     }
     dyn_modint &operator/=(const dyn_modint &o) { return (*this) *= o.inv(); }
-
     dyn_modint operator-() const { return dyn_modint(v ? mod_ - v : 0); }
     friend dyn_modint operator+(dyn_modint a, const dyn_modint &b) { return a += b; }
     friend dyn_modint operator-(dyn_modint a, const dyn_modint &b) { return a -= b; }
@@ -103,10 +97,8 @@ struct dyn_modint {
 
     bool operator==(const dyn_modint &o) const { return v == o.v; }
     bool operator!=(const dyn_modint &o) const { return v != o.v; }
-
     dyn_modint pow(ll e) const { return pow_mod(v, e, mod_); }
     dyn_modint inv() const { return euclid::inv_mod(v, mod_); }
-
     explicit operator ll() const { return v; }
     friend ostream &operator<<(ostream &os, const dyn_modint &x) { return os << x.v; }
     friend istream &operator>>(istream &is, dyn_modint &x) {
diff --git a/src/7-math/nt_sieve.cpp b/src/7-math/nt_sieve.cpp
index d2d2a47..3883342 100644
--- a/src/7-math/nt_sieve.cpp
+++ b/src/7-math/nt_sieve.cpp
@@ -1,5 +1,5 @@
 #pragma once
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: precompute primality table and prime list with Eratosthenes sieve.
 // time: O(n log log n); memory: O(n)
diff --git a/src/7-math/num.hpp b/src/7-math/num.hpp
index e0456a9..054b77d 100644
--- a/src/7-math/num.hpp
+++ b/src/7-math/num.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: gcd/egcd/inverse helpers and modular exponentiation.
 // time: O(log n); memory: O(1)
diff --git a/src/8-misc/dp_opt.cpp b/src/8-misc/dp_opt.cpp
index ed1b76a..96d02b4 100644
--- a/src/8-misc/dp_opt.cpp
+++ b/src/8-misc/dp_opt.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: collection of DP optimizations (CHT, Knuth, DnC, slope trick).
 // time: see each component; memory: see each component.
diff --git a/src/8-misc/fraction_data_type.cpp b/src/8-misc/fraction_data_type.cpp
index 3d9f6b6..fa93f51 100644
--- a/src/8-misc/fraction_data_type.cpp
+++ b/src/8-misc/fraction_data_type.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: normalized rational type with exact arithmetic and comparisons.
 // time: O(log max(|n|,|d|)) per op; memory: O(1)
@@ -38,7 +38,6 @@ struct fraction {
     bool operator>(const fraction &rhs) const { return rhs < *this; }
     bool operator<=(const fraction &rhs) const { return !(rhs < *this); }
     bool operator>=(const fraction &rhs) const { return !(*this < rhs); }
-
     fraction operator+(const fraction &rhs) const {
         fraction ret;
         ret.n = n * rhs.d + rhs.n * d;
diff --git a/src/8-misc/kitamasa.cpp b/src/8-misc/kitamasa.cpp
index a095943..edc5a77 100644
--- a/src/8-misc/kitamasa.cpp
+++ b/src/8-misc/kitamasa.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: compute n-th term of a linear recurrence using Kitamasa.
 // time: O(k^2 log n); memory: O(k^2)
diff --git a/src/8-misc/lis_in_o_nlogn.cpp b/src/8-misc/lis_in_o_nlogn.cpp
index 9e35eef..84ad0a6 100644
--- a/src/8-misc/lis_in_o_nlogn.cpp
+++ b/src/8-misc/lis_in_o_nlogn.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: compute LIS length and reconstruct one increasing subsequence.
 // time: O(n log n); memory: O(n)
diff --git a/src/8-misc/random.cpp b/src/8-misc/random.cpp
index 12700bd..56b0bb9 100644
--- a/src/8-misc/random.cpp
+++ b/src/8-misc/random.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: mt19937_64 quick usage snippet (time-seeded + rand range + shuffle).
 // time: O(1) per draw; memory: O(1)
diff --git a/src/8-misc/simd.cpp b/src/8-misc/simd.cpp
index d7600bb..3f65d75 100644
--- a/src/8-misc/simd.cpp
+++ b/src/8-misc/simd.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 #include <immintrin.h>
 
 // what: AVX2 usage snippets (i32 add/sum/min/count, f32 dot/add).
diff --git a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
index cdfeac5..a97a932 100644
--- a/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
+++ b/src/8-misc/sqrt_decomposition_mos_algorithm.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: reorder offline range queries to minimize add/del operations (Mo's algorithm).
 // time: O((n+q) * sqrt(n)); memory: O(q)
@@ -20,7 +20,6 @@ struct mo {
         q.clear();
     }
     void add_query(int l, int r, int idx) { q.pb({l, r, idx}); }
-
     template <class Add, class Del, class Out>
     void run(Add add, Del del, Out out) {
         // goal: process queries in Mo order with callbacks.
diff --git a/src/8-misc/system_of_difference_constraints.cpp b/src/8-misc/system_of_difference_constraints.cpp
index 7820813..6aa7d0a 100644
--- a/src/8-misc/system_of_difference_constraints.cpp
+++ b/src/8-misc/system_of_difference_constraints.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: solve difference constraints x_v - x_u <= w with Bellman-Ford.
 // time: O(nm) via Bellman-Ford; memory: O(n+m)
diff --git a/src/8-misc/ternary_search.cpp b/src/8-misc/ternary_search.cpp
index 4ebb003..d744f02 100644
--- a/src/8-misc/ternary_search.cpp
+++ b/src/8-misc/ternary_search.cpp
@@ -1,4 +1,4 @@
-#include "../common/common.hpp"
+#include "../0-common/common.hpp"
 
 // what: maximize/minimize a unimodal function with ternary search (int/real).
 // time: int O(log range); real O(it); memory: O(1)