用的dijkstra+二分，蒟蒻实在想不到哪里丢分了

#include<iostream>
#include<algorithm>
#include<queue>
#include<cstring>
#define ll long long
using namespace std;

const int N = 10010, M = 50010;
int head[N], s[N], f[N], tot, vis[N];
ll dis[N];
int n, m, b;

struct Node {
	int v, edge, next;
}arr[M << 1];

struct City {
	int x;
	ll dis;
	City(int X, int DIS) : x(X), dis(DIS) {}
	bool operator > (const City& o) const { return dis > o.dis; }
};
priority_queue< City, vector<City>, greater<City> > q;

void insert(int a, int b, int c) {
	arr[++tot].v = b;
	arr[tot].edge = c;
	arr[tot].next = head[a];
	head[a] = tot;
}

void dij(int md) {
	memset(dis, 0x3f3f3f3f3f3f3f3f, sizeof(dis));
	memset(vis, 0, sizeof(vis));
	if (f[1] > md) { return; }
	dis[1] = 0;
	q.push(City(1, 0));
	while (!q.empty()) {
		City cur = q.top(); q.pop();
		vis[cur.x] = 1;
		for (int i = head[cur.x]; i != 0; i = arr[i].next) {
			if (dis[arr[i].v] > cur.dis + arr[i].edge && f[arr[i].v] <= md && !vis[arr[i].v]) {
				dis[arr[i].v] = cur.dis + arr[i].edge;
				q.push(City(arr[i].v, dis[arr[i].v]));
			}
		}
	}

}

int main() {
	ios::sync_with_stdio(false);
	cin >> n >> m >> b;
	for (int i = 1; i <= n; ++i) {
		cin >> f[i];
		s[i] = f[i];
	}
	sort(s + 1, s + n + 1);

	for (int i = 1; i <= m; ++i) {
		int a, b, c;
		cin >> a >> b >> c;
		insert(a, b, c);
		insert(b, a, c);
	}

	dij(s[n]);
	if (dis[n] > b) {
		cout << "AFK";
		return 0;
	}


	int l = 1, r = n;
	while (l < r) {
		int mid = (l + r) >> 1;
		dij(s[mid]);
		if (dis[n] > b) { l = mid + 1; }
		else { r = mid; }
	}
	cout << s[l];
	return 0;
}