CodeForces_1208_C

void solve() {
    int magic[4][4] = {{ 8,  9,  1, 13},
                       { 3, 12,  7,  5},
                       { 0,  2,  4, 11},
                       { 6, 10, 15, 14}};

    int n, N;
    cin >> n;
    N = n / 4;

    int square[n + 1][n + 1];

    for (int i = 0; i < n; i += 4) {
        for (int j = 0; j < n; j += 4) {
            int I = i / 4;
            int J = j / 4;
            for (int k = 0; k < 4; ++k) {
                for (int l = 0; l < 4; ++l) {
                    square[i + k][j + l] = 16 * (I * N + J) + magic[k][l];
                }
            }
        }
    }

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            cout << square[i][j] << ' ';
        }
        cout << '\n';
    }
}