单源最短路径

#include<iostream>

#include<vector>

#include<queue>

#include <climits>

using namespace std;

const int N=1e5+10;

long long dist[N];

typedef pair<int,int> PII;

vector<PII>graph[N];

priority_queue<PII,vector<PII>,greater<PII>>pq;

int n,m,s;

void dijkstra(){

for(int i=0;i<=n;++i)dist[i]=INT_MAX;

vector<bool>st(n,false);

dist[s]=0;

pq.push({0,s});

while(pq.size()){

auto e=pq.top();pq.pop();

int w=e.first,u=e.second;

if(st[u])continue;

st[u]=true;

for(auto &p:graph[u]){

int ww=p.second,v=p.first;

if(!st[v]&&dist[v]>dist[u]+ww){

dist[v]=dist[u]+ww;

pq.push({dist[v],v});

}

}

}

}

int main(){

cin>>n>>m>>s;

for(int i=0;i<m;++i){

int u,v,w;cin>>u>>v>>w;

graph[u].push_back({v,w});

}

dijkstra();

for(int i=1;i<=n;++i)cout<<dist[i]<<" ";

return 0;

}