思路 二分+spfa，感觉没大问题？

#include<bits/stdc++.h>
using namespace std;

#define int long long
const int maxn=1e4+5;
const int maxx=1e18;
int n,m,b;
int cost[maxn],v[maxn],d[maxn];
vector< pair<int,int> > g[maxn];
void add(int u,int v,int w){g[u].push_back(make_pair(v,w));}
void spfa(int c)
{
	fill(v+1,v+n+1,0);
	fill(d+1,d+n+1,maxx);
	queue<int>q;
	d[1]=0,v[1]=1;q.push(1);
	while(!q.empty())
	{
		int x=q.front();q.pop();
		//if(cost[x]>c)continue;
		for(int i=0;i<g[x].size();++i)
		{
			int y=g[x][i].first;
			int z=g[x][i].second;
			if(cost[y]>c)continue;
			if(d[y]>d[x]+z)
			{
				d[y]=d[x]+z;
				if(!v[y])q.push(y),v[y]=1;
			}
		}
	}
}
bool check(int x)
{
	spfa(x);
	for(int i=1;i<=n;++i)cout<<d[i]<<' ';
	cout<<endl;
	//getchar();
	return d[n]<=b;
}
signed main()
{
	f//reopen("data.in","r",stdin);
	cin>>n>>m>>b;
	int l=maxx,r=0;
	for(int i=1;i<=n;++i)cin>>cost[i],l=min(l,cost[i]),r=max(r,cost[i]);
	for(int i=1;i<=m;++i)
	{
		int x,y,z;
		cin>>x>>y>>z;
		if(x==y) continue;
		add(x,y,z);
		add(y,x,z);
	}
	int ans=0;
	if(!check(r))
	{
		cout<<"AFK";
		return 0;
	}
	while(l<=r)
	{
		int mid=(l+r)>>1;
		//cout<<l<<' '<<r<<endl;
		if(check(mid))ans=mid,r=mid-1;
		else l=mid+1;
	}
	cout<<ans<<endl;

}