Submission #671514

#	Time	Username	Problem	Language	Result	Execution time	Memory
671514		wenqi	Easter Eggs (info1cup17_eastereggs)	C++17	100 / 100	25 ms	364 KiB

eastereggs

// trans rights
#include <bits/stdc++.h>
#include "grader.h"

using namespace std;

vector<int> adj[1069];
vector<int> H;

void dfs(int i, int p)
{
    H.push_back(i);
    for (int j : adj[i])
    {
        if (j == p) continue;
        dfs(j, i);
    }
}

bool within(int x)
{
    vector<int> q;
    for (int i = 0; i <= x; i++)
        q.push_back(H[i]);
    return query(q);
}

int findEgg(int N, vector<pair<int, int>> bridges)
{
    for (auto &a : adj)
        a.clear();
    H.clear();
    for (int i = 0; i < N - 1; i++)
    {
        int a = bridges[i].first;
        int b = bridges[i].second;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    dfs(1, 1);
    int a = 0;
    int b = N;
    while (b - a > 1)
    {
        int m = (a + b) / 2;
        if (within(m - 1)) b = m;
        else a = m;
    }
    return H[a];
}

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