All tags/Sudoku
The hardest one
Arto Inkala's "world's hardest sudoku", written in nine lines and solved in a blink.
{sudoku '
8........
..36.....
.7..9.2..
.5...7...
....457..
...1...3.
..1....68
..85...1.
.9....4..
', solve, title='Arto Inkala, 2012'}| 8 | 1 | 2 | 7 | 5 | 3 | 6 | 4 | 9 |
| 9 | 4 | 3 | 6 | 8 | 2 | 1 | 7 | 5 |
| 6 | 7 | 5 | 4 | 9 | 1 | 2 | 8 | 3 |
| 1 | 5 | 4 | 2 | 3 | 7 | 8 | 9 | 6 |
| 3 | 6 | 9 | 8 | 4 | 5 | 7 | 2 | 1 |
| 2 | 8 | 7 | 1 | 6 | 9 | 5 | 3 | 4 |
| 5 | 2 | 1 | 9 | 7 | 4 | 3 | 6 | 8 |
| 4 | 3 | 8 | 5 | 2 | 6 | 9 | 1 | 7 |
| 7 | 9 | 6 | 3 | 1 | 8 | 4 | 5 | 2 |