Since I discovered a new Sudoku variant called Windoku I went looking for some online Windoku puzzles to solve.
The rules for solvinh a Windoku, every number from 1 to 9 must appear in:
– Each of the nine vertical columns
– Each of the nine horizontal rows
– Each of the nine 3 x 3 boxes
– Each of the four 3 x 3 window panes