Question

I’m trying to describe a Sudoku Board in C++ with a union statement:

union Board
{
    int board[9][9];
    int sec1[3][3];
    int sec2[3][3];
    int sec3[3][3];
    int sec4[3][3];
    int sec5[3][3];
    int sec6[3][3];
    int sec7[3][3];
    int sec8[3][3];
    int sec9[3][3];     
}

Would each section of the board correspond with the correct part of the array? IE,

Would sec4 correspond with board[4-6][0-3]? Is there a better way to do this sort of thing (specifically describing a sudoku board)?

Answer 1

You could achieve the effect you want by encapsulating it in a class:

class Board {
public:
    int& sec1(int r, int c) { return board[r][c]); }
    int& sec2(int r, int c) { return board[r][c+3]; }
    // etc.

private:
    int board[9][9];
};

but, I’m not sure this is the best way to represent a Sudoku board. You may find that once you start working on the logic, you’ll come up with a better representation.