PlaySudoku.us
Hard · Puzzle #347
1
5
2
3
4
2
4
9
6
4
7
2
6
3
7
5
4
3
2
4
7
8
3
7
2
5
The hardest Sudoku puzzles require techniques equivalent to propositional logic — the same foundation used in computer proofs.
The hardest Sudoku puzzles require techniques equivalent to propositional logic — the same foundation used in computer proofs.
A Sudoku grid is a special case of a Latin square: a 9×9 grid where each symbol appears exactly once in each row and column.
A Sudoku grid is a special case of a Latin square: a 9×9 grid where each symbol appears exactly once in each row and column.