dijkstra无论怎么调都是20分，蒟蒻求助！

#include<bits/stdc++.h>
using namespace std;
struct edge
{
	int len,end,up;
}edge[500010];
int head[100010];
long long v[100010],dis[100010],minn;
int main()
{
	int n,m,s,a,b,c,t;
	long long inf;
	inf=99999999999999;
	cin>>n>>m>>s;
	for(int i=1;i<=m;i++)
	{
		cin>>a>>b>>c;
		if(a==s) dis[b]=c;
		if(head[a]==0) edge[i].up=0;
        else edge[i].up=head[a];
        head[a]=i;
        edge[i].len=c;
        edge[i].end=b;
	}
	for(int i=1;i<=n;i++) 
	{
	   if(dis[i]==0) dis[i]=inf;
    }
	dis[s]=0;
	t=s;
	while(1)
	{
		minn=inf;
		for(int i=1;i<=n;i++)
		{
			if(dis[i]<minn && v[i]==0 && i!=s)
			{
				t=i;
                minn=dis[i];
			}
		}
		v[t]=1;
		if(minn==inf) break; 
		for(int i=head[t];i!=0;i=edge[i].up)
		{
			if(dis[edge[i].end]>dis[t]+edge[i].len)
			{
				v[edge[i].end]=1;
				dis[edge[i].end]=dis[t]+edge[i].len;
			}
		}
	}
	for(int i=1;i<=n;i++) 
	{
	  if(dis[i]==inf) cout<<"2147483647 ";
	  else cout<<dis[i]<<" ";
    }
	return 0;
}