제출 #496390

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
496390		armashka	Valley (BOI19_valley)	C++17	0 / 100	81 ms	22084 KiB

valley

#include <bits/stdc++.h>
 
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#define fast ios_base::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
#define all(v) v.begin(),v.end()
#define pb push_back
#define sz size()
#define ft first
#define sd second
 
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef unsigned long long ull;
 
const int N = 5e5 + 5;
const ll M = 1e8;
const ll inf = 1e18;
const ll mod = 1e9;
const double Pi = acos(-1); 
 
ll binpow(ll x, ll ti) { ll res = 1;while (ti){if(ti & 1)res *= x;x *= x;ti >>= 1; x %= mod; res %= mod;} return res;}
ll binmul(ll x, ll ti) { ll res = 0;while (ti){if(ti & 1)res += x;x += x;ti >>= 1; x %= mod; res %= mod;} return res;}
ll nok(ll a, ll b) { return (a*b)/__gcd(abs(a),abs(b)) * (a*b > 0 ? 1 : -1); }
bool odd(ll n) { return (n % 2 == 1); }
bool even(ll n) { return (n % 2 == 0); }            

ll n, s, q, e, a[N], in[N], out[N], timer;
vector <pll> g[N];
pll edge[N];
bool used[N]; 

void dfs(ll v) {
	used[v] = 1;
	in[v] = ++ timer;
	for (auto [to, w] : g[v]) {
		if (!used[to]) {	
			dfs(to);
		}
	}	
	out[v] = ++ timer;
}

bool check(ll u, ll v) {
	return (in[u] > in[v] && out[u] < out[v]);
}

const void solve(/*Armashka*/) {
	cin >> n >> s >> q >> e;
	for (int i = 1; i < n; ++ i) {
		ll w;
		cin >> edge[i].ft >> edge[i].sd >> w;
		ll u = edge[i].ft, v = edge[i].sd;
		g[u].pb({v, w});
		g[v].pb({u, w});
	}
	for (int i = 1; i <= s; ++ i) cin >> a[i];
	
	if (s == n) {
	    dfs(e);
		for (int i = 1; i <= q; ++ i) {
			ll num, start;
			cin >> num >> start;
			ll u = edge[num].ft, v = edge[num].sd;
			if (start == e) cout << "escaped\n";
			else if (check(start, u) && check(start, v)) cout << "0\n";
			else cout << "escaped\n";
		}
		return;
	}

	for (int i = 1; i <= q; ++ i) {
		ll num, start;
		cin >> num >> start;
		pll bl = {edge[num].ft, edge[num].sd};
		queue <ll> qq; 
		vector <ll> d(n + 5, inf);
		qq.push(start);
		d[start] = 0;
		while (qq.sz) {
			ll v = qq.front();
			qq.pop();
			for (auto [to, w] : g[v]) {
				if (bl == make_pair(to, v) || bl == make_pair(v, to)) continue;
				if (d[to] > d[v] + w) {
	            	d[to] = d[v] + w;
					qq.push(to);
				}
			}
		}
		if (d[e] != inf) cout << "escaped\n";
		else {
			ll mn = inf;
			for (int i = 1; i <= s; ++ i) mn = min(mn, d[a[i]]);
			if (mn == inf) cout << "oo\n";
			else cout << mn << "\n";
		}
	}
}
            
signed main() {
    fast;
    //freopen("divide.in", "r", stdin);
    //freopen("divide.out", "w", stdout);
    int tt = 1;
    //cin >> tt;
    while (tt --) {
        solve();
    }
}
 
/*
5 4 4
1 2
3 1
3 4
5 3
4 5 2 3
2 1 3 1
1 3 5
2 3 4 5
2 1 3 1
*/

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