## Classic Sudoku(nightmare）

(Eingestellt am 1. September 2020, 12:23 Uhr von cdwg2000)

Sudoku

Rules: Classic Sudoku rules apply.

The author of the puzzle is my friend 胡蒙汀(Hu Meng Ting) from China. I hope you like it and would appreciate any feedback.

Special note: To complete this nightmare level puzzle, you need to use an intuitive skill (SK-Loop) of Classic Sudoku. Even if you are familiar with the skill, it is difficult to observe, so the difficulty is set as 5 stars. If you can't find a solution, I suggest you check the 5 previously published puzzles, they also apply the intuitive skills of problem Sk-Loop.

Hint has:

Key Hint：

1)Row: 13579 rows are more than 2468 rows {123456789}; Columns: 13579 columns are more than 2468 columns {123456789}; 2)we find that R2468C2468 has 12 cells {135745674567} and 4 unknowns cells; 3)R13579C13579 has 8 cells {12891289} and 17 unknowns cells; 4)after equivalent complementary replacement, {1289} writes R2468C2468 unknowns 4 cells, {134567} complements writes R13579C13579 unknowns 17 cells; 5)the conclusion of complementary replacement is that the remaining blank cells of R2468C2468 can only be filled in {1289}, R13579C13579 remaining blank cells can only be filled in {4567};

Catalogue of Hu Meng Ting（胡蒙汀）'s problems:

https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=00046K

https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=00046V

https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=000473

https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=000474

https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=00047K

Lösungscode: Row 7, followed by coloum 2.

Zuletzt geändert am 17. Oktober 2020, 04:17 Uhr

Gelöst von zorant, NikolaZ, Rollo, SKORP17, Dandelo, MumboJumbo, saskia-daniela, rimodech, MavericksJD, skywalker, Realshaggy, panthchesh, Imperial Marcher, glum_hippo, Nothere, Puzzle_Maestro, kerry, rob, Nusi, Zzzyxas, katch, PixelPlucker, Tigerhu, zhergan, Ours brun
Komplette Liste

### Kommentare

am 18. Oktober 2020, 04:36 Uhr von cdwg2000
@glum_hippo@detuned@Puzzle_Maestro@Realshaggy@Dandelo

I am very glad that you can evaluate this problem!

It is true that problems like this will not appear in official competitions, and there will not be many Sudoku fans who will try to complete them. However, if there are some special structures that can make them easy to solve, for such special structures , I personally think you can let Sudoku lovers know. Therefore, this is the original intention of publishing this problem.

am 17. Oktober 2020, 04:17 Uhr von cdwg2000
repair title

am 20. September 2020, 17:31 Uhr von cdwg2000
Modify format

am 13. September 2020, 18:12 Uhr von Dandelo
Yes. And I can't understand why people are changing the puzzles after a few days. Both ratings are useless after adding a hint.

If there is mistake, it's ok. But just because of the small number of users? You don't know how many users have solved it without registering.

But if some authors often change their puzzles (by adding hints) I will ignore their puzzles in future. If you want the users to notice the intended solution path, why not to describe it in a hidden comment?

I think generally such analyses (and maybe even such puzzles) are not suited best for the portal. It would be perfect for the NED, our (printed) club magazine, which is fallen asleep in the past years. This would be the right place IMO. We have so many new authors here, so many discussions. There would be enough material to revitalise the NED, I suppose.

I will copy this comment to the forum. This would be a better place for this discussion.

am 13. September 2020, 16:00 Uhr von Realshaggy
Almost all solvers solved it when there were no hints at all. I agree that this is a general problem of the rating system, but it's a hard one to fix.
This is the equivalent of a very hard chess study you only understand after it is explained by a GM.
It breaks with the right guess, but before, even Andrew Stuarts solver throws the towel and can't calculate a difficulty rating because it can't find a path.

am 13. September 2020, 12:21 Uhr von Puzzle_Maestro
I have to say that I am very much disappointed by the low rating on this sudoku. The key idea is a very beautiful one!

am 11. September 2020, 17:50 Uhr von cdwg2000
Increase problem solving tips

am 10. September 2020, 17:25 Uhr von detuned
Absolutely fascinating - this puzzle breaks scanraid. I'm not sure I've fully understood what is going on, but it's clear this puzzle is a gateway into previously poorly understood structures woven into the fabric of Sudoku. Thanks for sharing!

am 3. September 2020, 19:27 Uhr von glum_hippo
'Add prompt information' ist irgendwie kein mir bekanntes Tag

am 1. September 2020, 13:09 Uhr von cdwg2000
@Phistomefel

Thanks.

am 1. September 2020, 13:08 Uhr von cdwg2000