Submission #498779

#	Time	Username	Problem	Language	Result	Execution time	Memory
498779		sireanu_vlad	Chessboard (IZhO18_chessboard)	C++14	16 / 100	92 ms	2316 KiB

chessboard

#include <iostream>
using namespace std;

long long n, x, x2;
int k, t;

void f()
{
	x = n*n/2;
	for(int i = n/2; i >= 1; --i)
		if(n % i == 0)
			x = min(x, i*i*((n/i)*(n/i)/2));
	cout << x;
}

bool isprime(long long x)
{
	if(x < 2) return 0;
	if(x == 2 || x == 3) return 1;
	if(x % 2 == 0 || x % 3 == 0) return 0;
	for(int i = 5; i * i <= n; i += 6)
		if(x % i == 0 || x % (i+2) == 0)
			return 0;
	return 1;
}

void f2()
{
	x = n*n/2;
	x2 = x + 1;
	for(int c = 0, i1, i2, j1, j2; c < k; ++c)
	{
		cin >> i1 >> j1 >> i2 >> j2;
		for(int i = i1; i <= i2; ++i)
			for(int j = j1; j <= j2; ++j)
			{
				if(i % 2 == j % 2) x++, x2--;
				if(i % 2 != j % 2) x2++, x--;
			}
	}
	
	cout << min(x, x2);
}

int main()
{
	cin >> n >> k;
	if(k == 0) f();
	else if(isprime(n)) f2();
	return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 0 / 15
• Subtask 4: 0 / 16
• Subtask 5: 0 / 23
• Subtask 6: 0 / 30