제출 #1297709

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1297709		kawhiet	버섯 세기 (IOI20_mushrooms)	C++20	85.28 / 100	13 ms	572 KiB

mushrooms

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

constexpr int lim = 50;

mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());

int count_mushrooms(int n) {
	vector<int> a = {0}, b, s;
	for (int i = 1; i < n; i++) {
		s.push_back(i);
	}
	while (max(a.size(), b.size()) < lim && s.size() > 1) {
		shuffle(s.begin(), s.end(), rng);
		int x = s.back(); s.pop_back();
		int y = s.back(); s.pop_back();
		int ret = use_machine({0, x, y});
		if (ret == 0) {
			a.push_back(x);
			a.push_back(y);
		} else if (ret == 2) {
			a.push_back(y);
			b.push_back(x);
		} else {
			b.push_back(y);
			s.push_back(x);
		}
	}
	int res = a.size();
	while (!s.empty()) {
		vector<int> k = (a.size() > b.size() ? a : b);
		int m = min(k.size(), s.size());
		vector<int> t, v;
		for (int i = 0; i < m; i++) {
			t.push_back(k[i]);
			t.push_back(s.back());
			v.push_back(s.back());
			s.pop_back();
		}
		int cnt = use_machine(t);
		if (a == k) {
			if (cnt & 1) {
				b.push_back(v.back());
			} else {
				a.push_back(v.back());
			}
			res += m - (cnt + 1) / 2;
		} else {
			if (cnt & 1) {
				a.push_back(v.back());
			} else {
				b.push_back(v.back());
			}
			res += (cnt + 1) / 2;
		}
	}
	return res;
}

• Subtask 1: 85.283 / 100