Dividing a 9x9 2d array into 9 sub-grids (like in sudoku)? (C++)

Question

I\'m trying to code a sudoku solver, and the way I attempted to do so was to have a 9x9 grid of pointers that hold the address of \"set\" objects that posses either the solu

Answer 1

You could calculate a block number from row and column like this:

int block = (row/3)*3 + (col/3);

This numbers the blocks like this:

+---+---+---+
| 0 | 1 | 2 |
+---+---+---+
| 3 | 4 | 5 |
+---+---+---+
| 6 | 7 | 8 |
+---+---+---+