spfa关于INF设置值的问题

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;

const int N = 10010, M = 50010 * 2,INF = 1000000010; //为啥这里INF = 2000000010就会wa掉两个样例呀？？？

int h[N],e[M],ne[M],w[M],f[M],idx;
int price[N];
void add(int a,int b,int c)
{
    e[idx] = b,ne[idx] = h[a],w[idx] = c,h[a] = idx ++;
}
int dist[N],q[M * 10];
bool st[N];
int n,m,k;

bool check(int mid)
{
    int hh = 0, tt = 0;
    memset(st,false,sizeof st);
    for(int i = 0; i <= n; i ++) dist[i] = INF;
    dist[1] = 0;
    q[0] = 1;

    while(hh <= tt)
    {
        int t = q[hh ++];

        st[t] = false;

        for(int i = h[t]; ~ i; i = ne[i])
        {
            int j = e[i];
            if(price[j] <= mid && dist[j] > dist[t] + w[i])
            {
                dist[j] = dist[t] + w[i];
                if(! st[j])
                {
                    st[j] = true;
                    q[++ tt] = j;
                }
            }
        }
    }
    if(dist[n] > k || dist[n] >= INF / 2) return false;
    // spfa 在判断是否可达的时候，不能直接使用INF判断，会出错
    return true;
}

// bool check(int mid)
// {
//     for(int i = 0; i < idx; i ++)
//         if(w[i] > mid) f[i] = INF;
//         else f[i] = w[i];
//     return spfa();
// }

int main()
{
    scanf("%d%d%d",&n,&m,&k);
    int l = 0, r = 0;
    memset(h,-1,sizeof h);
    for(int i = 1; i <= n; i ++)
    {
        scanf("%d",&price[i]);
        r = max(r,price[i]);
    }
    int t = r + 1;
    r = t;
    for(int i = 1; i <= m ; i ++)
    {
        int a,b,c;
        scanf("%d%d%d",&a,&b,&c);
        add(a,b,c);
        add(b,a,c);
    }

    while(l < r)
    {
        int mid = l + r >> 1;
        if(check(mid)) r = mid;
        else l = mid + 1;
    }
    if(r == t) puts("AFK");
    else printf("%d",r);

}