Ruudukko

#include <bits/stdc++.h>

using namespace std;

int sum[2222][2222];

int main () {
    int n, m;
    cin>>n>>m;
    for (int i = 0; i < m; i++) {
        int x1, y1, x2, y2;
        cin>>y1>>x1>>y2>>x2;
        sum[y1][x1]++;
        sum[y2 + 1][x2 + 1]++;
        sum[y2 + 1][x1]--;
        sum[y1][x2 + 1]--;
    }
    for (int i = 0; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            sum[i][j] += sum[i][j - 1];
        }
    }
    for (int j = 0; j <= n; j++) {
        for (int i = 1; i <= n; i++) {
            sum[i][j] += sum[i - 1][j];
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            if (sum[i][j] % 2 == 1) cout<<'#';
            else cout<<'.';
        }
        cout<<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: ACCEPTED

Test 5

Group: 3

Verdict: ACCEPTED