提交了20遍了，所有spfa都是CE,求大神

#include<iostream>
#include<cstring>
using namespace std;
int u[10001],v[10001],w[10001],first[10001],next[10001];
int dis[10001],book[10001];
int que[10001],head=1,tail=2;
int n,m;
int s,e,k;
int spfa()
{
    que[head]=s;
    book[s]=1;
    while(head<tail)
    {
        k=first[que[head]];
        while(k!=-1)
        {
            if(dis[v[k]]>dis[u[k]]+w[k])
            {
                dis[v[k]]=dis[u[k]]+w[k];
                if(book[v[k]]==0)
                {
                    que[tail]=v[k];
                    tail++;
                    book[v[k]]=1;
                }
            }
            k=next[k];
        }
        book[que[head]]=0;
        head++;
    }
}
int main()
{
    cin>>n>>m>>s>>e;
    memset(dis,0x7f,sizeof(dis));
    memset(first,-1,sizeof(first));
    dis[s]=0;
    for(int i=1;i<=2*m;i=i+2)
    {
        cin>>u[i]>>v[i]>>w[i];
        next[i]=first[u[i]];
        first[u[i]]=i;
        next[i+1]=first[v[i]];
        first[v[i]]=i+1;
    }
    spfa();
    cout<<dis[e]<<endl;
    return 0;
}