题目:P4779 【模板】单源最短路径

#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<queue>
const int MaxN=100010;
int last[MaxN],dis[MaxN],cnt;
bool vis[MaxN];
int n,m,s;
struct edge
{
    int dis,to,next;
}e[MaxN*5];
struct node
{
    int dis;
    int pos;
    bool operator < (const node &x)const
    {
        return x.dis < dis;
    }
};
std::priority_queue<node> q;
void add(int u,int v,int d)
{
    cnt++;
    e[cnt].dis=d;
    e[cnt].to=v;
    e[cnt].next=last[u];
    last[u]=cnt;
}
void dijkstra()
{
    dis[s]=0;
    q.push((node){0,s});
    while(!q.empty())
    {
        node tmp=q.top();
        q.pop();
        int x=tmp.pos,d=tmp.dis;
        if(vis[x]) continue;
        vis[x]=1;
        for(int i=last[x];i;i=e[i].next)
        {
            int y=e[i].to;
            if(dis[y]>dis[x]+e[i].dis)
            {
                dis[y]=dis[x]+e[i].dis;
                if(!vis[y])
                {
                    q.push((node){dis[y], y});
                }
            }
        }
    }
}
int main()
{
    scanf("%d%d%d", &n, &m, &s);
    for(int i=1;i<=n;++i)dis[i]=0x7fffffff;
    for(int i=0;i<m;++i)
    {
        int u,v,d;
        scanf("%d%d%d",&u,&v,&d);
        add(u,v,d);
    }
    dijkstra();
    for(int i=1;i<=n;i++)
        printf("%d ",dis[i]);
    return 0;
}