Sudoku Variants Series (314) - Chess Pairs Sudoku
(Published on 31. March 2021, 00:00 by Richard)
Chess Pairs Sudoku
Inspiration for this type comes from Genomico.
Solve online in F-Puzzles (thx Ryx!)
Apply classic sudoku rules.
Two cells containing the same digit form a ‘chess pair’ if they are a (chess)knight’s or a bishop’s move away from each other. Each cell must be part of at least one chess pair.
Solution code: Row 3, followed by row 9.
Comments
on 4. September 2022, 07:38 by Richard
Added link and tag for online solving. Thx Ryx!
on 2. April 2021, 13:58 by Ryx
@Dandelo - Thank you, I did not know that about hidden comments. And I am switching my position and agree with you. It kept me up this morning thinking about this topic.
For this puzzle, I found "a solution", but as it did not fulfill all the constraints, I should consider that itself a constraint and fall back, regroup and find "the solution".
Thanks to Richard for providing me a challenging puzzle and a learning opportunity, in several aspects.
on 2. April 2021, 09:28 by Dandelo
The hidden comment is viewable for the author and those, who have already solved it.
It is (by far) not the only puzzle in the portal, where the solution code is chosen bad in this respect. IMO it is not that important. In a championship ok, but here the fun is to solve the puzzle and not to find the solution code.
on 2. April 2021, 04:09 by Ryx
@henrypijames
@Dandelo - I get what you are saying, but agree with henrypijames, that the solution code should require the correct puzzle configuration.
And how do you guys see my hidden comment?
And thanks to you both, I see where I went wrong. In my 3rd or 4th attempt at this puzzle (this time coloring all the satisfied cells) I placed a 5 where it was still ambiguous (thought it could only be satisfied by one chess move, where it could have been either of two moves). From there, the rest "solved", but I was left with one digit at the end that could not find a chess pair :-(
on 1. April 2021, 21:49 by Dandelo
If you construct (or test) with penpa+, you have the option to save the undo-history, which is helpful anyway, but also stores the construction or solution path, e.g. for such purposes.
on 1. April 2021, 20:46 by filuta
thank you for the puzzle, very nice concept
on 31. March 2021, 20:48 by Richard
I test solved this one a few weeks ago, but didn't make notes which row/column was last in the solve. So when I installed this puzzle in the portal, I based the code on my own scribblings, but didn't resolve it to have the best feeling regarding the code...
on 31. March 2021, 17:32 by glum_hippo
This certainly requires some very sharp-eyed checking, but I had fun!
on 31. March 2021, 15:34 by henrypijames
@Ryx: Your "solution" is indeed incorrect - in boxes 5, 7 and 8.
But this does show there should be a better choice for the solution code.
on 31. March 2021, 15:32 by Dandelo
@Ryx: But then this is not the solution, since the rule is not fulfilled...
on 31. March 2021, 14:24 by Genomico
Beautiful construction and fun to solve!
on 31. March 2021, 05:24 by henrypijames
Penpa+: https://git.io/JYEp6
on 31. March 2021, 03:37 by Ryx
F-puzzles link to solve:
https://f-puzzles.com/?id=yguee85t
