【模板】迪杰斯特拉的优先队列优化

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
using namespace std;
const int SIZE=100010;
int head[SIZE],n,m,s,ecnt,dis[SIZE];
bool vis[SIZE];
struct node
{
int id,w;
};
struct edge
{
int v,nxt,dist;
}e[SIZE];
bool operator <(node a,node b)
{
return (a.w>b.w);
}
void add_edge(int from,int to,int dis)
{
e[++ecnt]=(edge){to,head[from],dis};
head[from]=ecnt;
}

void dijkstra(int u)
{
memset(dis,0x3f,sizeof(dis));
memset(vis,0,sizeof(vis));
priority_queue<node>q;
dis[u]=0;
q.push((node){u,0});
while(!q.empty())
{
node flag=q.top();
q.pop();
int v=flag.id;

4000
if(vis[v]) continue;
vis[v]=1;
for(int i=head[v];i;i=e[i].nxt)
{
int to=e[i].v;
if(dis[to]>dis[v]+e[i].dist)
{
dis[to]=dis[v]+e[i].dist;
q.push((node){to,dis[to]});
}
}
}
}
int main()
{
scanf("%d%d%d",&n,&m,&s);
for(int i=1,x,y,z;i<=m;i++)
{
scanf("%d%d%d",&x,&y,&z);
add_edge(x,y,z);
add_edge(y,x,z);
}
dijkstra(s);
for(int i=1;i<=n;i++)
printf("%d ",dis[i]);
return 0;
}