Submission #918577

#	Time	Username	Problem	Language	Result	Execution time	Memory
918577		vjudge1	Easter Eggs (info1cup17_eastereggs)	C++17	100 / 100	13 ms	1248 KiB

eastereggs

#include <bits/stdc++.h>
#include "grader.h"
using namespace std;
vector<vector<int>> ve;
vector<int> w;
void dfs(int x, int p){
    w.push_back(x);
    for (auto el : ve[x]){
        if (el != p){
            dfs(el, x);
        }
    }
}
int findEgg (int N, vector < pair < int, int > > bridges)
{
    w.clear();
    ve.clear();
    ve.resize(N + 1);
    for (auto el : bridges){
        ve[el.first].push_back(el.second);
        ve[el.second].push_back(el.first);
    }
    dfs(1, -1);
    int l = 1, r = N;
    while (l <= r){
        if (l == r){
            return w[l - 1];
        }
        int mid = (l + r) / 2;
        vector<int> rec;
        for (int i = 0; i < mid; i++){
            rec.push_back(w[i]);
        }
        bool a = query(rec);
        if (a){
            r = mid;
        }
        else{
            l = mid + 1;
        }
    }
    return w[l - 1];
}

• Subtask 1: 40 / 40
• Subtask 2: 40 / 40
• Subtask 3: 20 / 20