From bdfd09400742be9be45359d69d2dc98aa55e86b9 Mon Sep 17 00:00:00 2001
From: "ACHERONMIRROR\\ArtemiszeN" <artemiszenn@gmail.com>
Date: Sat, 10 Feb 2024 15:04:35 +0800
Subject: [PATCH] Add min cost flow functionality to ch9/mcmf.cpp Param
 flow_limit can be ignored for normal mcmf usage.

---
 ch9/mcmf.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/ch9/mcmf.cpp b/ch9/mcmf.cpp
index 9335e78..dda5971 100644
--- a/ch9/mcmf.cpp
+++ b/ch9/mcmf.cpp
@@ -82,11 +82,11 @@ class min_cost_max_flow {
     if (!directed) add_edge(v, u, w, c);         // add again in reverse
   }
 
-  pair<ll, ll> mcmf(int s, int t) {
+  pair<ll, ll> mcmf(int s, int t, ll flow_limit = (ll)1e18) {
     ll mf = 0;                                   // mf stands for max_flow
-    while (SPFA(s, t)) {                          // an O(V^2*E) algorithm
+    while (SPFA(s, t) && mf < flow_limit) {      // an O(V^2*E) algorithm
       last.assign(V, 0);                         // important speedup
-      while (ll f = DFS(s, t))                   // exhaust blocking flow
+      while (ll f = DFS(s, t, flow_limit - f))   // exhaust blocking flow
         mf += f;
     }
     return {mf, total_cost};