Submission #547737

#	Time	Username	Problem	Language	Result	Execution time	Memory
547737		LucaDantas	Counting Mushrooms (IOI20_mushrooms)	C++17	99.56 / 100	9 ms	520 KiB

mushrooms

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

constexpr int repeticoes = 50;
int qtd_min = 93;

vector<int> color[2];

int count_mushrooms(int N) {
	qtd_min = min(qtd_min, N);
	int cnt[2]{};
	color[0] = {0};
	
	vector<int> unknown(N-1);
	iota(unknown.begin(), unknown.end(), 1);
	
	bool foi = 0;
	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();

		if(sz == 2 && !foi) {
			foi = 1;
			for(; (max(color[0].size(), color[1].size()) < 3 || min(color[0].size(), color[1].size()) < 2)
					&& color[0].size() + color[1].size() < qtd_min && unknown.size() > 2;) {
				vector<int> qr;
				for(int i = 0; i < 2; 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());
				resp >>= 1;
				color[usar ^ (resp&1)].push_back(qr[1]);
			}

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

			// for(; color[0].size() + color[1].size() < qtd_min && unknown.size() >= 5;) {
			// for(; max(color[0].size(), color[1].size()) < qtd_min && unknown.size() >= 5;) {
			for(int sla = 0; sla < repeticoes && unknown.size() >= 5 && max(color[0].size(), color[1].size()) < qtd_min; sla++) {
				vector<int> qr;
				for(int i = 0; i < 3; 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());
				qr.pop_back(), qr.pop_back();
				resp >>= 1;

				if(resp&1) {
					// os dois são diferentes
					int x1 = qr[1], x2 = qr[3];
					int uk1 = unknown.back(); unknown.pop_back();
					int uk2 = unknown.back(); unknown.pop_back();

					qr.clear();
					qr = {color[usar^1][0], x1, color[usar^1][1], color[usar][0], x2, color[usar][1], uk1, color[usar][2], uk2};

					int resp = use_machine(qr);
					resp--; // removo a ligacao obrigatoria entre color[usar^1][1] e color[usar][0]
					
					color[usar^(resp&1)].push_back(uk2);

					resp>>=1;
					color[usar^(resp&1)].push_back(uk1);

					resp>>=1;
					color[usar^1^(resp&1)].push_back(x1);
					color[usar^(resp&1)].push_back(x2);
				} else {
					color[usar^(resp==2)].push_back(qr[1]), color[usar^(resp==2)].push_back(qr[3]);
				}
			}

			continue;
		}

		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:26:43: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   26 |      && color[0].size() + color[1].size() < qtd_min && unknown.size() > 2;) {
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~
mushrooms.cpp:44:102: warning: comparison of integer expressions of different signedness: 'const long unsigned int' and 'int' [-Wsign-compare]
   44 |    for(int sla = 0; sla < repeticoes && unknown.size() >= 5 && max(color[0].size(), color[1].size()) < qtd_min; sla++) {
      |                                                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~

• Subtask 1: 99.5595 / 100