Ruudukko

#include <array>
#include <iostream>
#include <vector>

int main()
{
	int n, m;
	std::cin >> n >> m;
	std::cin.ignore();

	std::vector<std::array<int, 4>> subs(m);

	for (auto& sub : subs)
	{
		std::cin >> sub[0] >> sub[1] >> sub[2] >> sub[3];
		sub[0]--;
		sub[1]--;
		sub[2]--;
		sub[3]--;
	}

	std::vector<int> ruudukko(n * n);

	for (const auto& sub : subs)
	{
		for (int i = 0; i < sub[2] - sub[0] + 1; ++i)
		{
			ruudukko[(sub[0] + i) * n + sub[1]]++;
			ruudukko[(sub[0] + i) * n + sub[3] + 1]++;
		}
	}

	/*for (int i = 0; i < n * n; ++i)
	{
		if (i % n == 0)
			std::cout << std::endl;
		std::cout << ruudukko[i] << " ";
	}

	std::cout << std::endl;*/

	int l = 0;
	std::string printtaus = "";
	for (int i = 0; i < n * n; ++i)
	{
		if (i % n == 0 && i != 0)
			printtaus += '\n';

		int ruutu = ruudukko[i];

		if (ruutu % 2 == 1)
			l++;
		printtaus += l % 2 == 0 ? '.' : '#';

	}


	std::cout << printtaus << std::endl;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 2, 3

Verdict: ACCEPTED

Test 4

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 3

Verdict: TIME LIMIT EXCEEDED