The rules of X-Sudoku are exactly the same as a normal Sudoku puzzle, but there is one more rule
that you need to follow,
- Both the diagonals must contain the numbers 1-9 once and only once.
This is an example of a X-Sudoku puzzle. You can use all the normal techniques you would use to
solve a Sudoku puzzle, but you can also take the two diagonals in to account.