Here is another puzzle that is holding my interest:
- Code: Select all
*-----------------------*
| 7 . 4 | 9 8 . | . . 3 |
| . . . | 7 . . | . . 4 |
| . 1 8 | . . . | . . 9 |
|-------+-------+-------|
| . . 2 | . 5 . | 9 . . |
| . . . | 6 . 3 | 5 . . |
| 8 . . | . 9 . | 1 . . |
|-------+-------+-------|
| . 7 . | . . . | . 2 . |
| . . . | 5 3 . | . . . |
| 9 . . | 2 . 8 | . . . |
*-----------------------*
(Henk Collection, Puzzle #227, rating: 33839)
After the basic logic have been applied we get:
- Code: Select all
*--------------------------------------------------------------------*
| 7 256 4 | 9 8 1256 | 26 156 3 |
| 356 23569 3569 | 7 126 1256 | 268 1568 4 |
| 56 1 8 | 3 246 2456 | 267 567 9 |
|----------------------+----------------------+----------------------|
| 1346 346 2 | 8 5 17 | 9 3467 67 |
| 14 49 79 | 6 127 3 | 5 478 278 |
| 8 356 3567 | 4 9 27 | 1 367 267 |
|----------------------+----------------------+----------------------|
| 3456 7 356 | 1 46 9 | 3468 2 568 |
| 2 8 16 | 5 3 467 | 467 9 167 |
| 9 3456 1356 | 2 467 8 | 3467 67 1567 |
*--------------------------------------------------------------------*
Again, I am interested to know how the various solvers out there would solve this grid from here in a single step. For reference, here is my definition of "single step" (slightly changed regarding the first one I gave):
Single Step: a logical deduction with which the puzzle is solved, i. e., a logical deduction from which all other further logical deductions needed to complete the puzzle are the most basic ones: naked and hidden singles, locked candidates, pairs, triples and quads, and eventually X-Wings, but nothing beyond that (Swordfish, XY-Wing, Colors, type-1 URs, etc).
For this grid, the best I could do until now is a two step solution, with the second step being a XY-Wing.
Every contribution is welcome.
Thanks in advance.
Carcul