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