注意点：
- 源点需要设置初始距离（0）.
- 优先队列默认是从大到小排序，因此需要重载运算符.
#include<cstdio>
#include<iostream>
#include<queue>
using namespace std;
const int MAXN=1000010,MAXM=1000010;
struct Edge{
int from,to,w,nxt;
}e[MAXM];
int head[MAXN],edgeCnt=1;
void addEdge(int u,int v,int w){
e[++edgeCnt].from=u;
e[edgeCnt].to=v;
e[edgeCnt].w=w;
e[edgeCnt].nxt=head[u];
head[u]=edgeCnt;
}
int s;
struct Node{
int nowPoint,dis;
bool operator <(Node another)const{
return dis>another.dis;
}
};
int dis[MAXN];
void dijkstra(){
priority_queue<Node> q;
q.push(Node{s,0});
dis[s]=0;
while(!q.empty()){
Node nowNode=q.top();q.pop();
int nowPoint=nowNode.nowPoint,nowDis=nowNode.dis;
if(nowDis>dis[nowPoint])continue;
for(int i=head[nowPoint];i;i=e[i].nxt){
int nowV=e[i].to;
if(dis[nowPoint]+e[i].w<dis[nowV]){
q.push(Node{nowV,dis[nowPoint]+e[i].w});
dis[nowV]=dis[nowPoint]+e[i].w;
}
}
}
}
const int INF=2e9;
int main(){
int n,m;
scanf("%d%d%d",&n,&m,&s);
for(int i=1;i<=n;i++)dis[i]=INF;
for(int i=1;i<=m;i++){
int u,v,w;
scanf("%d%d%d",&u,&v,&w);
addEdge(u,v,w);
}
dijkstra();
for(int i=1;i<=n;i++){
printf("%d ",dis[i]);
}
printf("
");
return 0;
}