Submission #546806

#	Time	Username	Problem	Language	Result	Execution time	Memory
546806		LucaDantas	Counting Mushrooms (IOI20_mushrooms)	C++17	79.30 / 100	14 ms	600 KiB

mushrooms

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

mt19937 rng(random_device{}());

vector<int> color[2];

int count_mushrooms(int N) {
    int cnt[2]{};
    color[0] = {0};
    
    vector<int> unknown(N-1);
    iota(unknown.begin(), unknown.end(), 1);
    shuffle(unknown.begin(), unknown.end(), rng);
    
    // umas queries qqr aleatorias ai
        for(int i = 0; i < 5; i++) {
        vector<int> qr(N);
        iota(qr.begin(), qr.end(), 0);
        shuffle(qr.begin(), qr.end(), rng);
        while(qr.size() > N/4 && qr.size() > 10) qr.pop_back();
        use_machine(qr);
    }

    while(unknown.size()) {
        int usar = color[1].size() > color[0].size(); // escolho o grupo que tem mais gente pra usar
        int sz = color[usar].size();

        vector<int> qr;
        for(int i = 0; i < sz && unknown.size(); i++, unknown.pop_back())
            qr.push_back(color[usar][i]), qr.push_back(unknown.back());

        int resp = use_machine(qr);

        color[usar ^ (resp&1)].push_back(qr.back());

        cnt[usar^1] += resp/2;
        cnt[usar] += (qr.size() / 2 - 1) - resp/2;
    }

    return cnt[0] + color[0].size();
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:22:25: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   22 |         while(qr.size() > N/4 && qr.size() > 10) qr.pop_back();
      |               ~~~~~~~~~~^~~~~

• Subtask 1: 79.2982 / 100