PlaySudoku.us
Evil · Puzzle #239
1
6
9
2
1
7
8
1
4
3
4
9
5
7
3
6
4
6
4
5
3
7
8
9
9
2
Techniques used
- Hidden Single
- Naked Pair
- Naked Triple
- Naked Single
- Naked Quad
- Hidden Pair
- XY-Chain
- UR Type 4
- Forcing Chains
- XY-Wing
- Skyscraper
Some hospitals use Sudoku as a cognitive exercise for patients recovering from strokes or brain injuries.
Some hospitals use Sudoku as a cognitive exercise for patients recovering from strokes or brain injuries.
Irregular Sudoku (also called Squiggly Sudoku) uses non-rectangular regions instead of 3×3 boxes, requiring different solving strategies.
Irregular Sudoku (also called Squiggly Sudoku) uses non-rectangular regions instead of 3×3 boxes, requiring different solving strategies.