Anti-knight Anti-king: The Pattern
(Published on 27. November 2021, 03:15 by DiMono)
Standard sudoku rules apply.
Anti-king: diagonally adjacent cells may not contain the same digit.
Anti-knight: cells a chess knight's move away from each other may not contain the same digit.
Solve on f-puzzles
Solve on CTC
Solution code: Row 5, column 5
Comments
on 24. July 2025, 10:14 by Klook
Thanks for the explanation. Now anti-king, anti-knight sudoku puzzles are dead to me. For example, https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=000O6U. Instead of spending several hours pencil-marking and eliminating candidates, it takes 10 minutes and you’re done. :)
on 23. July 2025, 16:45 by Klook
On the Sudokupad timer, I spent six hours on this. I had to start over three times. I thought I wouldn’t make it. But after all that, I can’t imagine how it’s possible to solve it in two minutes. I see the pattern (anti-king, anti-knight Sudoku grids), but I don’t understand how to use it for a fast solution.
@Klook - I have added a hidden comment that explains the fast solution path. Thank you for sticking with it through the long way! I'm glad you made it, and hopefully enjoyed it.
on 28. November 2021, 08:32 by Gullie
Hmm, after taking the difficult path I now seem to know things about anti-king anti-knight sudokus. Nice! I wonder if it can be proven that this holds for all anti-king anti-knights?
@Gullie: Yes, it is true for all anti-king anti-knight sudoku. I've posted an in-depth proof of one of the properties of these puzzles in the #theory-and-programming channel of the Cracking the Cryptic discord server.
