P3371 【模板】单源最短路径（弱化版）[70' Code]

R53520699 #Unaccepted

Luogu/problem/P3371/P3371.cpp

@@ -2,33 +2,41 @@
 
 using namespace std;
 
-int n, m, s;
-long long u, v, w, f[10005][10005];
+int n, m, s, x, y, z, g[10005][10005], dist[10005];
+bool st[10005];
 
-int main() {
-    scanf("%d%d%d", &n, &m, &s);
-    for (int i = 1; i <= n; i++) {
+void diskstra() {
+    memset(dist, 0x3f, sizeof(dist));
+    dist[s] = 0;
+    for (int i = 0; i < n - 1; i++) {
+        int t = -1;
         for (int j = 1; j <= n; j++) {
-            f[i][j] = i == j ? 0 : INT_MAX;
-        }
-    }
-    for (int i = 0; i < m; i++) {
-        scanf("%d%d%d", &u, &v, &w);
-        f[u][v] = min(f[u][v], w);
-    }
-    for (int k = 1; k <= n; k++) {
-        for (int i = 1; i <= n; i++) {
-            for (int j = 1; j <= n; j++) {
-                if (i == k || f[i][k] == INT_MAX) {
-                    continue;
-                }
-                f[i][j] = min(f[i][j], f[i][k] + f[k][j]);
+            if (!st[j] && (t == -1 || dist[t] > dist[j])) {
+                t = j;
             }
         }
+        for (int j = 1; j <= n; j++) {
+            dist[j] = min(dist[j], dist[t] + g[t][j]);
+        }
+        st[t] = true;
     }
+}
+
+int main() {
+    cin >> n >> m >> s;
     for (int i = 1; i <= n; i++) {
-        printf("%d ", f[s][i]);
+        for (int j = 1; j <= n; j++) {
+            g[i][j] = i == j ? 0 : 0x3f3f3f3f;
+        }
     }
-    printf("\n");
+    for (int i = 1; i <= m; i++) {
+        cin >> x >> y >> z;
+        g[x][y] = min(g[x][y], z);
+    }
+    diskstra();
+    for (int i = 1; i <= n; i++) {
+        cout << (dist[i] == 0x3f3f3f3f ? INT_MAX : dist[i]) << ' ';
+    }
+    cout << endl;
     return 0;
 }