- Code: Select all
+-----------------------------------------------------------------------------+
| 68 4 7 | 5 39 1 | 3689 368 2 |
| 5 1 368 | 3689 2 36789 | 4 368 36789 |
| 9 268 2368 | 368 4 3678 | 36789 1 5 |
|-------------------------+-------------------------+-------------------------|
| 7 3 689 | 69 5 2 | 1 4 68 |
| 1 2689 2689 | 7 39 4 | 2368 5 368 |
| 4 256 256 | 1 8 36 | 2367 9 367 |
|-------------------------+-------------------------+-------------------------|
| 2 7 589 | 4 6 3589 | 389 38 1 |
| 68 5689 1 | 389 7 3589 | 3689 2 4 |
| 3 689 4 | 2 1 89 | 5 7 689 |
+-----------------------------------------------------------------------------+
Although there's a Locked Candidate (2) in [c8b3] for <6>, it doesn't help. Other than that, a contradiction chain is the best I have to offer. It took my solver to find it.
- Code: Select all
[r5c5]=3 =>[r1c5]=9 => [r2c9]=9 => [r459c9]={68} contradiction! => [r5c5]=9
Singles then complete the puzzle.
You might wish to look at these links for further discussions on this puzzle.
http://forum.enjoysudoku.com/viewtopic.php?p=39630#p39630http://forum.enjoysudoku.com/viewtopic.php?p=41461#p41461