Submission #915167

#	Time	Username	Problem	Language	Result	Execution time	Memory
915167		Pikachu	Easter Eggs (info1cup17_eastereggs)	C++17	87 / 100	13 ms	1244 KiB

eastereggs

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

using namespace std;

const int maxn = 520, oo = 1e9;
int n;
vector<int> adj[maxn];
vector<int> pos;

int findEgg (int N, vector<pair<int,int> > bridges)
{
    ::n = N;
    pos.clear();
    for (int i = 1; i <= n; i++) adj[i].clear();
    for (pair<int,int> p : bridges) {
        adj[p.first].push_back(p.second);
        adj[p.second].push_back(p.first);
    }

    auto DFS = [&] (auto DFS, int u, int par) -> void {
        pos.push_back(u);
        for (int v : adj[u]) {
            if (v == par) continue;
            DFS(DFS, v, u);
        }
    };

    DFS(DFS, 1, -1);

    int l = 0, r = n - 1, ans = r;
    while (l <= r) {
        int mid = (l + r) >> 1;
        if (query(vector<int>(pos.begin(), pos.begin() + mid + 1))) {
            ans = mid;
            r = mid - 1;
        }
        else l = mid + 1;
    }
    
    return pos[ans];
}

• Subtask 1: 32 / 40
• Subtask 2: 40 / 40
• Subtask 3: 15 / 20