Submission #1019310

#	Time	Username	Problem	Language	Result	Execution time	Memory
1019310		j_vdd16	Counting Mushrooms (IOI20_mushrooms)	C++17	84.01 / 100	5 ms	604 KiB

mushrooms

#include "mushrooms.h"

#include <algorithm>
#include <bitset>
#include <cstdint>
#include <cstring>
#include <iostream>
#include <limits.h>
#include <math.h>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

//#define int long long
#define loop(X, N) for(int X = 0; X < (N); X++)
#define all(V) V.begin(), V.end()
#define rall(V) V.rbegin(), V.rend()

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;

//int use_machine(vi x);

int count_mushrooms(int n)
{
	if (n < 10) {
		int As = 1;
		for (int i = 1; i < n; i++) {
			if (!use_machine({ 0, i })) As++;
		}
		return As;
	}

	vi a = { 0 };
	vi b;

	int i = 1;
	if (use_machine({ 0, 1 }) == 1)
	{
		b.push_back(1); 
		if (use_machine({ 0, 2 }))
			b.push_back(2);
		else
			a.push_back(2);

		i += 2;
	}
	else
	{
		a.push_back(1);
		i++;
	}

	int result = a.size();
	while (i < n)
	{
		if (a.size() > b.size())
		{
			int sq = a.size();
			
			vi ask;
			int asked;
			if (i <= 164 && i + 1 < n)
			{
				asked = 2;
			}
			else if (i <= 300 && i + 2 < n && a.size() >= 3)
			{
				asked = 3;
			}
			else
			{
				asked = min(sq, n - i);
			}

			loop(j, asked)
			{
				ask.push_back(a[j]);
				ask.push_back(i++);
			}

			int res = use_machine(ask);
			result += asked - res / 2 - res % 2;
			if (res % 2)
				b.push_back(i - 1);
			else
				a.push_back(i - 1);

			int others = (res - res % 2) / 2;
			if (others == asked - 1)
			{
				loop(j, asked - 1)
					b.push_back(i - 2 - j);
			}
			else if (others == 0)
			{
				loop(j, asked - 1)
					a.push_back(i - 2 - j);
			}
		}
		else
		{
			int sq = b.size();

			vi ask;
			int asked;

			if (i <= 164 && i + 1 < n)
			{
				asked = 2;
			}
			else if (i <= 300 && i + 2 < n && b.size() >= 3)
			{
				asked = 3;
			}
			else
			{
				asked = min(sq, n - i);
			}

			loop(j, asked)
			{
				ask.push_back(b[j]);
				ask.push_back(i++);
			}

			int res = use_machine(ask);
			result += res / 2 + res % 2;
			if (res % 2)
				a.push_back(i - 1);
			else
				b.push_back(i - 1);

			int others = (res - res % 2) / 2;
			if (others == asked - 1)
			{
				loop(j, asked - 1)
					a.push_back(i - 2 - j);
			}
			else if (others == 0)
			{
				loop(j, asked - 1)
					b.push_back(i - 2 - j);
			}
		}
	}

	return result;
}

• Subtask 1: 84.0149 / 100