解题思路:
传送门
AC代码：
1 #include<iostream>
2 #include<cstdio>
3 #include<cstring>
4
5 using namespace std;
6
7 struct kkk {
8 int from,to,v,next;
9 }e[500001];
10 int n,m,s,head[500001],q,w,p,tot,ans[500001];
11 bool vis[500001];
12
13 void add(int q,int w,int p) {
14 e[++tot].from = q;
15 e[tot].to = w;
16 e[tot].v = p;
17 e[tot].next = head[q];
18 head[q] = tot;
19 }
20
21 void dijkstra(int s) {
22 memset(vis,0,sizeof(vis));
23 ans[s] = 0;
24 for(int i = 1;i <= n; i++) {
25 int id = 0,sum = 0x3f3f;
26 for(int j = 1;j <= n; j++)
27 if(!vis[j] && sum >= ans[j])
28 sum = ans[j],id = j;
29 vis[id] = 1;
30 for(int j = head[id];j;j = e[j].next)
31 ans[e[j].to] = min(ans[e[j].to],ans[id] + e[j].v);
32 }
33 }
34
35 int main() {
36 scanf("%d%d%d",&n,&m,&s);
37 for(int i = 1;i <= n; i++)
38 ans[i] = 0x3f3f3f3f;
39 for(int i = 1;i <= m; i++) {
40 scanf("%d%d%d",&q,&w,&p);
41 add(q,w,p);
42
43 }
44 dijkstra(s);
45 for(int i = 1;i <= n; i++) {
46 if(ans[i] == 0x3f3f3f3f) printf("2147483647 ");
47 else
48 printf("%d ",ans[i]);
49 }
50 return 0;
51 }