Submission #1148575

#	Time	Username	Problem	Language	Result	Execution time	Memory
1148575		adlin	Valley (BOI19_valley)	C++20	0 / 100	38 ms	9028 KiB

valley

#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define all(v) v.begin(),v.end()

using namespace std;

typedef long long ll;

const int maxn = 1e5 + 5;

int n,s,q,e,a[maxn],x[maxn],y[maxn],z[maxn],c[maxn],z1[maxn],z2[maxn];

vector <pair<int,int>> g[maxn];

int d[maxn];

int xx;

void dfs(int v, int u){
	for(auto i : g[v]){
		if(i.F == u) continue;
		if(min(i.F,v) == x[z1[xx]] && max(i.F,v) == y[z1[xx]]){
			continue;
		}
		d[i.F] = d[v] + i.S;
		dfs(i.F,v);
	}
}

int main(){
	
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> s >> q >> e;
	
	for(int i = 1; i < n; i++){
		cin >> x[i] >> y[i] >> z[i];
		if(x[i] > y[i]) swap(x[i],y[i]);
		g[x[i]].pb({y[i],z[i]});
		g[y[i]].pb({x[i],z[i]});
	}
	
	for(int i = 1; i <= s; i++){
		cin >> c[i];
	}
	
	for(int i = 1; i <= q; i++){
		cin >> z1[i] >> z2[i];
	}
	
	if(n <= 1000 && q <= 1000){
		for(int i = 1; i <= q; i++){
			for(int j = 1; j <= n; j++) d[j] = -1;
			xx = i;
			d[z2[i]] = 0;
			dfs(z2[i],z2[i]);
			if(d[e] != -1){
				cout << "escaped\n";
			}
			else {	
				int mn = 1e9;
				for(int j = 1; j <= s; j++){
					if(d[c[j]] != -1) mn = min(mn, d[c[j]]); 
				}
				if(mn == 1e9) cout << "oo\n";
				else cout << mn << '\n';
			}
		}	
	}
	
	return 0;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 27
• Subtask 3: 0 / 23
• Subtask 4: 0 / 41