1245. Tree Diameter

Author: amitbansal7

tree-diameter.cpp

@@ -0,0 +1,33 @@
+// Runtime: 52 ms
+// Memory Usage: 20.3 MB
+class Solution {
+public:
+  int mdepth = 0;
+  int node = 0;
+
+  void dfs(vector<vector<int> > &adj, vector<bool> &vis, int src, int depth) {
+    vis[src] = true;
+    for (int a : adj[src]) {
+      if (!vis[a]) {
+        dfs(adj, vis, a, depth + 1);
+      }
+    }
+    if (depth > mdepth) {
+      mdepth = depth;
+      node = src;
+    }
+  }
+
+  int treeDiameter(vector<vector<int>>& edges) {
+    vector<vector<int> > adj(edges.size() + 1, vector<int>());
+    for (auto a : edges) {
+      adj[a[0]].push_back(a[1]);
+      adj[a[1]].push_back(a[0]);
+    }
+    vector<bool> vis(edges.size() + 1, 0);
+    dfs(adj, vis, 0, 0);
+    vis = vector<bool>(edges.size() + 1, 0);
+    dfs(adj, vis, node, 0);
+    return mdepth;
+  }
+};