Anti3sis (Yin Yang Doubler Sudoku)
(Published on 8. November 2022, 09:00 by Agent)
Going back in time with a variation of my first ever Yin Yang hybrid, Antithesis. Many puzzles later, it remains one of my favourite rulesets to work with as a constructor. I'm hoping to recreate a similar solving experience, but with enough novelty to justify making a new puzzle. I hope you will enjoy! The puzzle can be a bit confusing at first, due to the complexity of rules, but it should be quite approachable once you wrap your head around it.
Rules
- Normal sudoku rules apply.
- Normal Yin Yang rules almost apply. Shade some cells in the grid such that all shaded cells are connected and all unshaded cells are connected. No 2x2 box may be fully shaded or fully unshaded.
- Each row, each column and each box must contain exactly one hole, which is neither shaded nor unshaded. Holes block the path of shaded and unshaded cells. (i.e. shaded cells and unshaded cells cannot connect through holes, they must connect around them)
- Holes must contain the digits 1 to 9 exactly once each.
- Digits in cages cannot repeat and must sum to the small clue in the upper left corner. For this purpose:
- Digits in unshaded cells are unchanged.
- Digits in shaded cells are treated as negative.
- Digits in holes are doubled.
Puzzle links
Solution code: Row 7 (left to right) then row 9 (left to right)
Comments
on 14. August 2024, 14:42 by ibag
Very nice!
on 29. March 2024, 08:08 by Piatato
Lovely!
on 13. October 2023, 14:58 by codewizard
Very nice, very nice indeed. Lovely in fact. It is rare for me to find a puzzle that feels quite challenging while not getting stuck. This was very even and flowy, and full of surprises (that you could make deductions where it appeared too complicated).
on 28. August 2023, 20:37 by StephenR
Very nicely engineered, thanks. Once I got my head out of normal yin-yang mode I found it surprisingly smooth.
on 1. December 2022, 15:56 by Niverio
This puzzle had some solid railroading ;) Pretty enjoyable, thank you a lot for setting this Agent!
-- Thank you @Niverio!
on 13. November 2022, 01:10 by cdwg2000
Very nice!
-- Thank you cdwg2000!
on 12. November 2022, 02:36 by wenchang
Very nice and very hard.
Spoiler Alert!
https://youtu.be/KPRHTfoLF5k
-- Thank you wenchang! Always fun to watch your solution videos.
on 11. November 2022, 17:31 by Hareeb
Interesting puzzle in that the solution path is pretty clearly laid out on rails, but the logic at each stop is good enough that I didn't mind. Well done.
-- Thank you @Hareeb! I believe this is the power of Yin Yang / Killer hybrids :p
on 10. November 2022, 14:19 by Christounet
Wow ! Very cool !
At first sight, it might look like that there's gonna be some head-scratching arithmetic involved with the presence of doublers and negatives, but you somehow managed to let the solver focus on the interesting geometry by selecting very approchable cage sums to deal with. Great stuff as always ! Thanks.
-- Thank you @Christounet! Indeed I'm sure it would be possible to make puzzles with very complicated arithmetic with this ruleset, but it wasn't my goal. What I really like with this sort of Yin Yang / killer ruleset is that you can have many deductions that are surprising and simple at the same time.
on 9. November 2022, 21:08 by Al Fresco
Very creative use of doublers and fun to solve. Thanks Agent
-- Thank you Al Fresco, glad you liked this new twist on doublers!
on 9. November 2022, 19:51 by KNT
really fun and fresh, thanks agent!
-- Thanks KNT! Really glad you enjoyed the puzzle!
on 9. November 2022, 17:57 by madhupt
An absolutely delightful puzzle! Such a neat flow of logic! Great setting.
-- Thank you madhupt for the solve and very encouraging feedback!
on 9. November 2022, 12:05 by marcmees
the values choosen make for a smooth fun solve, but one can see that this variation has the potential to get more difficult. Thanks
-- Thank you marcmees! I agree with you, my goal with this puzzle was to make the Sudoku effortless.
on 9. November 2022, 11:18 by peacherwu2
Very creative rules!
-- Thank you peacherwu2!
on 9. November 2022, 02:49 by kjholt
Loved this puzzle, definitely loved the logic the holes presented, and would love more :)
-- Thank you kjholt! I do think there's room for many other Yin Yang puzzles with holes. And other shading puzzle types as well, for that matter.
on 9. November 2022, 00:14 by kjholt
So another way of saying it would be that holes are neither shaded nor unshaded. Would that be easier for people to visualize?
-- You can think of it that way, the key point is that holes are obstacles for the connectivity of Yin Yang.
on 8. November 2022, 23:32 by Jesper
Lovely, really enjoyed it, thanks!
-- Thank you Jesper! I'm really glad to hear this!
on 8. November 2022, 16:06 by Agent
@henrypijames It means that shaded cells and unshaded cells cannot connect through holes, they must connect around them. Updated the rules.
on 8. November 2022, 15:21 by henrypijames
"Block the path"? What does that mean? What's "path" in the first place?
on 8. November 2022, 14:50 by MagnusJosefsson
Fantastic! The holes adds complexity to the shading logic which is great now that Yin-Yang has become so commonplace. Overall a very smooth and enjoyable puzzle with a well thought-out solution path.
-- Thank you Magnus! I agree with you that Yin Yang shading logic can become one-dimensional once you know the basics, but I'm glad you found the addition of holes refreshing!
on 8. November 2022, 13:41 by ONeill
Very enjoyable and smooth. It’s always fun to wrap your head around a new ruleset. Thanks! :)
-- Thank you ONeill, I'm glad you enjoyed this Yin Yang variant!
