854. Floyd求最短路

https://www.acwing.com/problem/content/submission/code_detail/6498911/

AcWing/854/854.cpp

@@ -0,0 +1,34 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, m, k, x, y, z, f[205][205];
+
+int main() {
+    cin >> n >> m >> k;
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= n; j++) {
+            f[i][j] = i == j ? 0 : 0x3f3f3f3f3f;
+        }
+    }
+    for (int i = 1; i <= m; i++) {
+        cin >> x >> y >> z;
+        f[x][y] = min(f[x][y], z);
+    }
+    for (int k = 1; k <= n; k++) {
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= n; j++) {
+                f[i][j] = min(f[i][j], f[i][k] + f[k][j]);
+            }
+        }
+    }
+    for (int i = 1; i <= k; i++) {
+        cin >> x >> y;
+        if (f[x][y] > 0x1fffffff) {
+            cout << "impossible" << endl;
+        } else {
+            cout << f[x][y] << endl;
+        }
+    }
+    return 0;
+}