Submission #1042713

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042713		parsadox2	Counting Mushrooms (IOI20_mushrooms)	C++17	92.24 / 100	6 ms	600 KiB

mushrooms

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

using namespace std;

int n;
vector <int> vec[2];


int count_mushrooms(int nn) {
	n = nn;
	vec[0].push_back(0);
	if(n <= 179)
	{
		for(int i = 1 ; i < n ; i++)
		{
			int c = use_machine({0 , i});
			vec[c].push_back(i);
		}
		return vec[0].size();
	}
	vec[use_machine({0 , 1})].push_back(1);
	vec[use_machine({0 , 2})].push_back(2);
	if(vec[0].size() < vec[1].size())
		swap(vec[0] , vec[1]);
	int m = min(n , 179);
	for(int i = 3 ; i + 1 < m ; i += 2)
	{
		int c = use_machine({vec[0][0] , i , vec[0][1] , i + 1});
		vec[c % 2].push_back(i + 1);
		vec[c / 2].push_back(i);
	}
	if(vec[0].size() < vec[1].size())
		swap(vec[0] , vec[1]);
	vector <int> rem;
	for(int i = m ; i < n ; i++)
		rem.push_back(i);
	int cnt[2];
	cnt[0] = cnt[1] = 0;
	while(!rem.empty())
	{
		vector <int> m;
		int tmp = 0;
		for(auto u : vec[0])
		{
			m.push_back(u);
			if(!rem.empty())
			{
				m.push_back(rem.back());
				rem.pop_back();
				tmp++;
			}
		}
		int c = use_machine(m);
		int val = (c + 1) / 2;
		cnt[1] += val;
		cnt[0] += tmp - val;
		if(tmp == vec[0].size())
		{
			if(c % 2 == 0)
			{
				cnt[0]--;
				vec[0].push_back(m.back());
			}
			else
			{
				cnt[1]--;
				vec[1].push_back(m.back());
			}
		}
		if(vec[0].size() < vec[1].size())
		{
			swap(vec[0] , vec[1]);
			swap(cnt[0] , cnt[1]);
		}
	}
	if(vec[0][0] == 0)
		return cnt[0] + vec[0].size();
	else
		return cnt[1] + vec[1].size();
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:58:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |   if(tmp == vec[0].size())
      |      ~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 92.2449 / 100