1128. 信使

https://www.acwing.com/problem/content/submission/code_detail/7846048/

AcWing/1128/1128.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, m, u, v, w, dist[105], ans;
+vector<pair<int, int>> g[105];
+bool vis[105];
+
+int main() {
+    cin >> n >> m;
+    for (int i = 0; i < m; i++) {
+        cin >> u >> v >> w;
+        g[u].push_back(make_pair(v, w));
+        g[v].push_back(make_pair(u, w));
+    }
+    memset(dist, 0x3f, sizeof(dist));
+    dist[1] = 0;
+    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
+    q.push(make_pair(0, 1));
+    while (!q.empty()) {
+        auto t = q.top();
+        q.pop();
+        if (vis[t.second]) continue;
+        for (auto i : g[t.second]) {
+            if (dist[i.first] > t.first + i.second) {
+                dist[i.first] = t.first + i.second;
+                q.push(make_pair(dist[i.first], i.first));
+            }
+        }
+        vis[t.second] = true;
+    }
+    for (int i = 1; i <= n; i++) {
+        if (dist[i] == 0x3f3f3f3f) {
+            cout << -1 << endl;
+            exit(0);
+        } else {
+            ans = max(ans, dist[i]);
+        }
+    }
+    cout << ans << endl;
+    return 0;
+}