alt Hacker NewsBecause there's already another 6 on the same main diagonal. This is an "X Sudoku" puzzle, which means that each main diagonal must have all 9 different numbers.
Because there's already another 6 on the same main diagonal. This is an "X Sudoku" puzzle, which means that each main diagonal must have all 9 different numbers.
All I've never done the diagonals before... oops.
https://imgur.com/a/Dfxf9CJ (before picking 2 / 6 / 7.)