#11. 开会还是逛街

https://sjzezoj.com/submission/35071

S2OJ/11/11.cpp

@@ -0,0 +1,30 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, m, x, u, v, w, g[1005][1005], ans;
+
+int main() {
+    cin >> n >> m >> x;
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= n; j++) {
+            g[i][j] = i == j ? 0 : 0x3f3f3f3f;
+        }
+    }
+    for (int i = 1; i <= m; i++) {
+        cin >> u >> v >> w;
+        g[u][v] = min(g[u][v], w);
+    }
+    for (int k = 1; k <= n; k++) {
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= n; j++) {
+                g[i][j] = min(g[i][j], g[i][k] + g[k][j]);
+            }
+        }
+    }
+    for (int i = 1; i <= n; i++) {
+        ans = max(ans, g[i][x] + g[x][i]);
+    }
+    cout << ans << endl;
+    return 0;
+}