Submission #964458

#	Time	Username	Problem	Language	Result	Execution time	Memory
964458		irmuun	Valley (BOI19_valley)	C++17	36 / 100	3035 ms	12248 KiB

valley

#include<bits/stdc++.h>

using namespace std;

#define ll long long
#define pb push_back
#define ff first
#define ss second
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    ll n,s,q,e;
    cin>>n>>s>>q>>e;
    vector<array<ll,3>>adj[n+5];
    vector<pair<ll,ll>>edge;
    for(ll i=1;i<n;i++){//edge
        ll a,b,w;
        cin>>a>>b>>w;
        adj[a].pb({b,w,i});
        adj[b].pb({a,w,i});
    }
    vector<bool>shop(n+5,0);
    for(ll i=1;i<=s;i++){//shop
        ll c;
        cin>>c;
        shop[c]=true;
    }
    while(q--){
        ll I,r;
        cin>>I>>r;
        bool can=false;
        ll mn=1e18,dist=0;
        function <void(ll,ll)> dfs=[&](ll x,ll p){
            if(x==e){
                can=true;
                return;
            }
            if(shop[x]==true){
                mn=min(mn,dist);
            }
            for(auto [y,w,j]:adj[x]){
                if(j!=I&&y!=p){
                    dist+=w;
                    dfs(y,x);
                    dist-=w;
                }
            }
        };
        dfs(r,-1);
        if(can){
            cout<<"escaped\n";
        }
        else if(mn<1e18){
            cout<<mn<<"\n";
        }
        else{
            cout<<"oo\n";
        }
    }
}

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