63 lines
1.5 KiB
C++
63 lines
1.5 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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typedef pair<int, int> PII;
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const int INF = 0x3f3f3f3f;
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const int M = 2e5 + 5, N = 1005;
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// 存图
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int idx, h[N], e[M], w[M], ne[M];
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void add(int a, int b, int c) {
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e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx++;
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}
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int n, m; // n个点，m条边
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int S; // 出发点
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int dis[N]; // 距离数组
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bool st[N]; // Dijkstra是不是入过队列
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void dijkstra() {
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priority_queue<PII, vector<PII>, greater<PII>> q;
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q.push({0, S});
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dis[S] = 0;
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while (q.size()) {
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auto t = q.top();
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int u = t.second;
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q.pop();
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if (st[u]) continue;
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st[u] = true;
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for (int i = h[u]; ~i; i = ne[i]) {
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int j = e[i];
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if (dis[j] > dis[u] + w[i]) {
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dis[j] = dis[u] + w[i];
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q.push({dis[j], j});
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}
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}
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}
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}
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int main() {
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while (cin >> n >> m >> S) {
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// 初始化
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memset(st, 0, sizeof st);
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memset(h, -1, sizeof h);
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memset(dis, 0x3f, sizeof dis);
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idx = 0;
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int ans = INF;
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while (m--) {
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int a, b, c;
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cin >> a >> b >> c;
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add(b, a, c); // 反向建边
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}
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// 最短路
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dijkstra();
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int T; // T个终点
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int x; // 终点ID
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cin >> T;
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while (T--) {
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cin >> x;
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ans = min(ans, dis[x]);
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}
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printf("%d\n", ans == INF ? -1 : ans);
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}
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return 0;
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}
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