Ruudukko

#include <iostream>
#include <vector>
using namespace std;   



int main() {
    int n;
    int m;

    cin >> n;
    cin >> m;

    vector<vector<bool>> table(n + 1, vector<bool>(n + 1, false));
    
    for ( int i = 0; i < m; i++ ) {
        int x1;
        int y1;
        int x2;
        int y2;
        cin >> x1 >> y1 >> x2 >> y2;


        table[x1 -1 ][y1 -1] = !table[x1 -1 ][y1 -1];
        table[x1 -1][y2] = !table[x1 -1 ][y2];
        table[x2][y1 -1] = !table[x2][y1 -1];
        table[x2][y2] = !table[x2][y2];
    }

    for ( int y = 1; y < n; y++ ) {
        table[0][y] = table[0][y] != table[0][y - 1];
        table[y][0] = table[y][0] != table[y - 1][0];
    }

    for ( int x = 1; x < n; x++ ) {
        for ( int y = 1; y < n; y++ ) {
            table[x][y] = (table[x][y] != table[x - 1][y]) != (table[x][y - 1] != table[x - 1][y - 1]);
        }
    }


    for ( int x = 0; x < n; x++ ) {
        for ( int y = 0; y < n; y++ ) {
            if ( table[x][y]) {
                cout << "#";
            } else {
                cout << ".";
            }    
        }

        cout << "\n";
    }
    
    return 0;
}

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