RT 91分代码，思路是题解第一篇，第四个测试点错误，求大佬找错，第一次求助链接here

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<queue>
using namespace std;
struct edge
{
	int f,t,v,n;
}e[10000000];
struct gl
{
	int i;
	int sum;
}poi;
bool operator < (gl a,gl b)
{
	return a.sum>b.sum;
}
priority_queue < gl > q;
int head[10000000];
bool vis[10000000];
int city[10000000],s[10000000];
int dis[10000000];
int n,m,b,top,k,f,t,v,mid,l,r,ans;
bool Dijstra(int x)
{
	if(x<city[1]||x<city[n])return false;
	memset(vis,0,sizeof(vis));
	for(int i=1;i<=n;i++)
	{
        if(city[i]>x)vis[i]=1;
        else vis[i]=0;
    }
	poi.i=1;
	poi.sum=0;
	q.push(poi);
	for(int i=1;i<=n;i++)dis[i]=2147483647;
	dis[1]=0;
	while(!q.empty())
	{
		k=q.top().i;
		q.pop();
		if(vis[k])continue;
		vis[k]=1;
		for(int i=head[k];i;i=e[i].n)
		{
			if(dis[e[i].t]>dis[k]+e[i].v)
			{
				dis[e[i].t]=dis[k]+e[i].v;
				poi.i=e[i].t;
				poi.sum=dis[e[i].t];
				q.push(poi);
			}
		}
	}
	if(dis[n]<=b)return true;
    else return false;
}
void add_edge(int f,int t,int v)
{
	top++;
	e[top].f=f;
	e[top].t=t;
	e[top].v=v; 
	e[top].n=head[f];
	head[f]=top;
}
int main()
{
	cin>>n>>m>>b;
	for(int i=1;i<=n;i++)
	{
		cin>>city[i];
		s[i]=city[i];
	}
	for(int i=1;i<=m;i++)
	{
		cin>>f>>t>>v;
		if(f==t)continue;
		add_edge(f,t,v);
		add_edge(t,f,v);
	}
	sort(s+1,s+1+n);
	if(!Dijstra(s[n]))
	{
		cout<<"AFK"<<endl;
		return 0;
	}
	ans=s[n];
	l=1;
	r=n;
	while(l<=r)
	{
		mid=l+r>>1;
		if(Dijstra(s[mid]))
		{
			ans=s[mid];
			r=mid-1;
		}
		else l=mid+1;
	}
	cout<<ans;
	return 0;
}