Submission #1306592

#	Time	Username	Problem	Language	Result	Execution time	Memory
1306592		sophiaeternalia	Valley (BOI19_valley)	C++20	23 / 100	87 ms	10972 KiB

valley

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

vector<vector<pair<int, int>>> g;
vector<pair<int, int>> ra;
int in;

void dfs(int v, int la){
    ra[v].first=in++;
    for (auto u: g[v]){
        if (u.first!=la){
            dfs(u.first, v);
        }
    }
    ra[v].second=in++;
}

int main() {
    cin.tie(0); ios_base::sync_with_stdio(NULL);

    int n, s, q, e;
    cin>>n>>s>>q>>e;
    e--;
    vector<pair<int, int>> ed(n-1);
    g.resize(n);
    //cout<<'a'<<endl;
    for (int i=0; i<n-1; i++){
        int a, b, w;
        cin>>a>>b>>w;
        a--;
        b--;
        ed[i]={a, b};
        g[a].push_back({b, w});
        g[b].push_back({a, w});
    }
    //cout<<'b'<<endl;
    ra.resize(n);
    in=0;
    dfs(e, -1);
    vector<int> sh(s);
    for (int i=0; i<s; i++){
        cin>>sh[s];
    }
    /*for (auto u: ra){
        cout<<u.first<<" "<<u.second<<"\n";
    }*/
    for (int i=0; i<q; i++){
        int e0, v;
        cin>>e0>>v;
        e0--;
        v--;
        int a=ed[e0].first, b=ed[e0].second;
        if (ra[a].first<ra[b].first){
            swap(a, b);
        }
        //cout<<ra[a].first<<" "<<ra[a].second<<" "<<ra[b].first<<" "<<ra[b].second<<" "<<ra[v].first<<" "<<ra[v].second<<"\n";
        if (ra[a].first<=ra[v].first and ra[v].second<=ra[a].second){
            cout<<0<<"\n";
        } else {
            cout<<"escaped"<<"\n";
        }
    }
}

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