The New Sudoku Players' Forum

[urhegyi]

Normally windokus published on this site have always a clear and logical solvepath. Today it has a rating of SE9.5 by sudokuexplainer. I can't find any logical way to solve it. Is it because sudokuexplainer is missing some new techniques? Anyone can try this windoku? The only single I can find is R9C8=5. Then i'm totally blocked.

Code: Select all

005200700900000000000060091000006000700050002000700000430010000000000009007002400

update: when assuming R1C9=4 and R7C9=7 it can be solved.

[urhegyi]

I found out when R1C9=4 and R7C9=7 it can be solved.
Does anyone see a possible logical solvepath without trial and error?
Here I am stuck:

Code: Select all

+----------------------+----------------------+----------------------+
| 138    18     5      | 2      3489   1389   | 7      368    3468   |
| 9      124678 123468 | 1358   3478   13478  | 2358   2348   3458   |
| 238    2478   2348   | 358    6      34578  | 2358   9      1      |
+----------------------+----------------------+----------------------+
| 2358   2589   2389   | 1389   2348   6      | 1358   13478  34578  |
| 7      4689   3468   | 13489  5      1389   | 13689  1368   2      |
| 23568  124568 124689 | 7      238    3489   | 35689  348    3568   |
+----------------------+----------------------+----------------------+
| 4      3      2689   | 5689   1      589    | 268    2678   678    |
| 2568   2568   268    | 468    378    3478   | 12368  12368  9      |
| 168    1689   7      | 3689   389    2      | 4      5      368    |
+----------------------+----------------------+----------------------+

[m_b_metcalf]

The only single I can find is R9C8=5. Then i'm totally blocked.

Same is true for my program, which then goes to brute force.

Note that r5c1 and r5c9 are, individually, redundant.

Mike

[creint]

SukakuExplainer gives SE 9.0
My solver can solve it too with nets.