Extended traffic

传送门

#include <iostream>
#include <map>
#include <queue>
#include <cstring>
#include <algorithm>
using namespace std;

const int N = 1010, INF = 0x3f3f3f3f;
struct Edge{
	int u, v, w, next;
}edge[4e5 + 10];
bool vis[N], flag = false;
int tot = 1, head[N], n, q, a[N], cnt[N], dist[N];
void add(int u, int v, int w){
	edge[tot].w = w;
	edge[tot].v = v;
	edge[tot].next = head[u];
	head[u] = tot ++;
}
int cal(int x){
	return x * x * x;
}

bool spfa(int s){
	queue<int> qq;
	memset(cnt, 0, sizeof cnt);
	memset(dist, INF, sizeof dist);
	memset(vis, 0, sizeof vis);
	dist[s] = 0;
	qq.push(s);
	vis[s] = 1;
	while(qq.size()){
		int t = qq.front();
		qq.pop();
		vis[t] = 0;
		for(int i = head[t]; i; i = edge[i].next){
			int w = edge[i].w;
			int to = edge[i].v;
			if(dist[to] > w + dist[t]){
				dist[to] = w + dist[t];
				cnt[to] = cnt[t] + 1;    //change 
				if(cnt[to] >= n)
					return true;
				if(!vis[to]){
					vis[to] = true;
					qq.push(to);
				}
			}
		}
	}
}
int main(){
	int t, k = 0;
	cin >> t;
	while(t --){
		memset(head, 0, sizeof head);
		cout << "Case " << ++ k << ":" << endl;
		cin >> n;
		for(int i = 1; i <= n; i ++)
			cin >> a[i];
		cin >> q;
		while(q --){
			int x, y;
			cin >> x >> y;
			add(x, y, cal(a[y] - a[x]));
		}
		spfa(1);
		int query;
		cin >> query;
		while(query --){
			int des;
			cin >> des;
			if(dist[des] >= INF / 2 || dist[des] < 3)
				cout << '?' << endl;
			else
				cout << dist[des] << endl; 
		}
	}	
	
	return 0;
}