'commit'

TangDou/Topic/HuanGenDp/1073_1.cpp

@@ -0,0 +1,41 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+const int INF = 0x3f3f3f3f;
+const int N = 10010, M = N << 1;
+int n;
+int ans;
+int res = INF;
+
+// 邻接表
+int e[M], h[N], idx, w[M], ne[M];
+void add(int a, int b, int c = 0) {
+    e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
+}
+
+void dfs(int u, int fa, int sum) {
+    for (int i = h[u]; ~i; i = ne[i]) {
+        int v = e[i];
+        if (v == fa) continue;
+        dfs(v, u, sum + w[i]);
+    }
+    ans = max(ans, sum);
+}
+
+int main() {
+    memset(h, -1, sizeof h);
+    cin >> n;
+    for (int i = 1; i < n; i++) {
+        int a, b, c;
+        cin >> a >> b >> c;
+        add(a, b, c), add(b, a, c);
+    }
+    // 暴力换根
+    for (int i = 1; i <= n; i++) {
+        ans = 0;
+        dfs(i, 0, 0);
+        res = min(res, ans);
+    }
+    printf("%d\n", res);
+    return 0;
+}