제출 #558046

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
558046		aryan12	커다란 상품 (IOI17_prize)	C++17	20 / 100	43 ms	296 KiB

prize

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

const int MAXN = 450;
vector<array<int, 3> > results;
int N;

bool cmp(array<int, 3> a, array<int, 3> b)
{
	return ((a[0] + a[1]) > (b[0] + b[1]));
}

int DivideAndConquer(int l, int r)
{
	// cout << "l = " << l << ", r = " << r << "\n";
	if(l > r)
	{
		return -1;
	}
	if(l == 0 && r == N - 1)
	{
		int value1 = -1, value2 = -1;
		if(results[0][0] != 0)
		{
			value1 = DivideAndConquer(l, results[0][2] - 1);
		}
		if(results[0][1] != 0)
		{
			value2 = DivideAndConquer(results[0][2] + 1, r);
		}
		// cout << "value1 = " << value1 << ", value2 = " << value2 << "\n";
		if(results[0][0] == 0 && results[0][1] == 0)
		{
			return results[0][2];
		}
		if(value1 == -1)
		{
			return value2;
		}
		return value1;
	}
	int mid = (l + r) >> 1;
	vector<int> reply = ask(mid);
	if(reply[0] + reply[1] == 0)
	{
		// cout << "mid = " << mid << "\n";
		return mid;
	}
	int value1 = -1, value2 = -1;
	if(reply[0] != 0)
	{
		value1 = DivideAndConquer(l, mid - 1);
	}
	if(reply[1] != 0)
	{
		value2 = DivideAndConquer(mid + 1, r);
	}
	if(value1 == -1 && value2 == -1)
	{
		return -1;
	}
	if(value1 == -1)
	{
		return value2;
	}
	return value1;
}

int find_best(int n)
{
	N = n;
	int mid = n / 2;
	// results.push_back({2, 1, 4});
	for(int i = max(0, mid - MAXN / 2); i < min(n, mid + MAXN / 2 + 1); i++)
	{
		vector<int> reply = ask(i);
		if(reply[0] + reply[1] == 0)
		{
			return i;
		}
		results.push_back({reply[0], reply[1], i});
	}
	sort(results.begin(), results.end(), cmp);
	return DivideAndConquer(0, n - 1);
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 80