Submission #521063

#	Time	Username	Problem	Language	Result	Execution time	Memory
521063		Jomnoi	Easter Eggs (info1cup17_eastereggs)	C++17	100 / 100	18 ms	464 KiB

eastereggs

#include <bits/stdc++.h>
#include "grader.h"
#define DEBUG 0
using namespace std;

const int MAX = 520;

int timer;
vector <int> adj[MAX];
int st[MAX];

void dfs(int u, int p) {
    st[++timer] = u;
    for(auto v : adj[u]) {
        if(v != p) {
            dfs(v, u);
        }
    }
}

int findEgg(int N, vector <pair <int, int>> bridges) {
    timer = 0;
    for(int i = 1; i <= N; i++) {
        adj[i].clear();
    }

    for(auto [u, v] : bridges) {
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    dfs(1, -1);

    int l = 1, r = N;
    while(l < r) {
        int mid = (l + r) / 2;

        vector <int> islands;
        for(int i = 1; i <= mid; i++) {
            islands.push_back(st[i]);
        }

        if(query(islands) == 1) {
            r = mid;
        }
        else {
            l = mid + 1;
        }
    }
    return st[l];
}

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