int puzzle[9][9]={{1, 0, 0, 0, 0, 0, 4, 9, 0},
                  {0, 0, 0, 0, 0, 0, 7, 0, 0},
                  {3, 9, 6, 0, 5, 0, 0, 0, 0},

                  {6, 0, 0, 9, 0, 0, 0, 0, 0},
                  {0, 0, 0, 0, 7, 0, 0, 0, 0},
                  {0, 4, 9, 0, 0, 1, 8, 2, 0},

                  {4, 0, 0, 0, 8, 7, 0, 0, 0},
                  {0, 0, 3, 0, 0, 2, 0, 0, 5},
                  {0, 0, 0, 0, 0, 0, 0, 0, 0}};

int puzzle[9][9]{};
for (int i{}; i != 9; ++i) {
    for (int j{}; j != 9; ++j) {
        file >> puzzle[i][j];
    }
}