From 37c129a99dfb2c5392caccaec0a80b9118bc4c36 Mon Sep 17 00:00:00 2001
From: chayan das <110921638+Chayandas07@users.noreply.github.com>
Date: Tue, 24 Dec 2024 23:02:49 +0530
Subject: [PATCH] Create 3203. Find Minimum Diameter After Merging Two Trees

---
 ...d Minimum Diameter After Merging Two Trees | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 3203. Find Minimum Diameter After Merging Two Trees

diff --git a/3203. Find Minimum Diameter After Merging Two Trees b/3203. Find Minimum Diameter After Merging Two Trees
new file mode 100644
index 0000000..ef144d9
--- /dev/null
+++ b/3203. Find Minimum Diameter After Merging Two Trees	
@@ -0,0 +1,51 @@
+class Solution {
+public:
+    void dfs(int node, int par, int dis, int &maxi, vector<vector<int>>&adj, int &far){
+        if(dis>maxi){
+            maxi = dis;
+            far = node;
+        }
+        for(auto it:adj[node]){
+            if(it!=par){
+                dfs(it, node, dis+1, maxi, adj, far);
+            }
+        }
+    }
+
+    int minimumDiameterAfterMerge(vector<vector<int>>& edges1, vector<vector<int>>& edges2) {
+        int n = edges1.size()+1;
+        int m = edges2.size()+1;
+        vector<vector<int>>adj1(n);
+        vector<vector<int>>adj2(m);
+        for(auto it: edges1){
+            adj1[it[0]].push_back(it[1]);
+            adj1[it[1]].push_back(it[0]);
+        }
+
+        int maxi1 = 0;
+        int far = 0;
+        dfs(0, -1, 0, maxi1, adj1, far);
+
+        maxi1 = 0;
+        int far1 = 0;
+        dfs(far, -1, 0, maxi1, adj1, far1);
+
+        for(auto it: edges2){
+            adj2[it[0]].push_back(it[1]);
+            adj2[it[1]].push_back(it[0]);
+        }
+
+        int maxi2 = 0;
+        far = 0;
+        dfs(0, -1, 0, maxi2, adj2, far);
+
+        maxi2 = 0;
+        int far2 = 0;
+        dfs(far, -1, 0, maxi2, adj2, far2);
+
+        int tmp1 = (maxi1+1)/2;
+        int tmp2 = (maxi2+1)/2;
+        int mrg = tmp1+tmp2+1;
+        return max(maxi1, max(mrg, maxi2));
+    }
+};