Ruudukko

input/code.cpp: In function 'int main()':
input/code.cpp:35:21: error: 'ruutu' was not declared in this scope
   35 |                 if (ruutu % 2 == 1)
      |                     ^~~~~

#include <unistd.h>
#include <string>
#include <iostream>
#include <vector>

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

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

	for (int i = 0; i < m; ++i)
	{
		int a, b, c, d;
		std::cin >> a >> b >> c >> d;
		a--; b--; c--; d--;

		for (int i = 0; i < c - a + 1; ++i)
		{
			ruudukko[(a + i) * n + b]++;
			ruudukko[(a + i) * n + d + 1]++;
		}
	}

	std::string printtaus;
	printtaus.reserve(n * n + n);
	char merkki = '.';
	for (int i = 0; i < n * n; ++i)
	{
		if (i % n == 0 && i != 0)
			printtaus += '\n';

		if (ruutu % 2 == 1)
			merkki = merkki == '.' ? '#' : '.';
		printtaus += merkki;
	}
	std::cout << printtaus << std::endl;
}