제출 #668009

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
668009		finn__	Easter Eggs (info1cup17_eastereggs)	C++17	100 / 100	18 ms	464 KiB

eastereggs

#include <bits/stdc++.h>
#include "grader.h"
using namespace std;

void get_preorder(vector<vector<int>> const &g, int u, int p, vector<int> &trav)
{
    trav.push_back(u + 1);

    for (int const &v : g[u])
        if (v != p)
            get_preorder(g, v, u, trav);
}

int findEgg(int n, vector<pair<int, int>> edges)
{
    vector<vector<int>> g(n);
    for (auto const &[u, v] : edges)
    {
        g[u - 1].push_back(v - 1);
        g[v - 1].push_back(u - 1);
    }

    vector<int> preorder;
    get_preorder(g, 0, -1, preorder);

    size_t a = 0, b = n - 1;
    while (a < b)
    {
        size_t mid = (a + b + 1) / 2;
        if (query(vector<int>(preorder.begin(), preorder.begin() + mid)))
            b = mid - 1;
        else
            a = mid;
    }

    return preorder[a];
}

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