洛谷 P3371 【模板】单源最短路径

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<queue>
 4 using namespace std;
 5 const int MAX_E = 500010, MAX_P = 10010, INF = 2147483647;
 6 typedef pair<int, int> pii;
 7 priority_queue<pii, vector<pii>, greater<pii> > q;
 8 struct edge {
 9     int v, w, next;
10 } e[MAX_E];
11 int head[MAX_P], dis[MAX_P], tot, n, m, s;
12 bool vis[MAX_P];
13 void add(int a, int b, int c) {
14     e[++tot].v = b;
15     e[tot].w = c;
16     e[tot].next = head[a];
17     head[a] = tot;
18 }
19 void init() {
20     int i;
21     for (i = 1; i <= n; i++) {
22         head[i] = -1;
23         dis[i] = INF;
24     }
25 } 
26 void  dijkstra(int s) {
27     int i;
28     dis[s] = 0;
29     q.push(make_pair(dis[s], s));
30     while (!q.empty()) {
31         pii tmp = q.top();
32         q.pop();
33         int x = tmp.second;
34         if(vis[x]) continue;
35         else {
36             vis[x] = true;
37             for(i = head[x]; i + 1; i = e[i].next) {
38                 if(dis[e[i].v] > dis[x] + e[i].w) {
39                     dis[e[i].v] = dis[x] + e[i].w;
40                     q.push(make_pair(dis[e[i].v], e[i].v));    
41                 }
42             }
43         }
44     }
45 }
46 int main() {
47     scanf("%d%d%d", &n, &m, &s);
48     int i, f, g, w;
49     init();
50     for (i = 1; i <= m; i++) {
51         scanf("%d%d%d", &f, &g, &w);
52         add(f, g, w);
53     }
54     dijkstra(s);
55     for (i = 1; i <= n; i++) 
56         printf("%d ", dis[i]);
57     return 0;
58 }