Zip Zero (yin yang, fog, zipper)
(Published on 7. January 2024, 18:34 by gdc)
This puzzle was inspired by one of Simons remarks when he solved Schrödingers Zipperlein. "Even in this ludicrous puzzle we can't include minus digits on the other side of the zipper" (youtube link to this quote). I felt this is a beautiful thought that deserves more research.
- Normal Sudoku rules apply.
- Fog of War: The grid is covered in fog. Placing correct digits lifts it.
- Zipper: Values of cells with an equal distance to the circled center of a line sum to the value of the central cell.
- Yin Yang: Shade some cells orange such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected. No 2x2 area may be fully shaded or fully unshaded.
- Negativity: The value of a shaded cell is its digit. The value of an unshaded cell is zero minus its digit (a negative number).
Example Puzzle and Explanations
Here is a finished 4x4 grid that satisfies the constraints shown above. The shaded cells (orange) and unshaded cells (blue) are fully connected and each 2x2 part of the grid contains orange and blue cells. For the bottom-left line, 3 is the sum of 2 and 1, of 1 and 2, and also of 4 and -1. For the bottom-right line, -4 is the sum of -1 and -3 and also of -2 and -2 (-2 is counted twice).
Acknowledgements
The negativity part of the rules were taken from Subzero and I also used it for Sub Zero Nabner. Thanks Schwupel for this idea. Thanks to the CtC fan discord and the Skunkworks discord for testing and feedback. Thanks to marty sears and flinty for improving the rules wording.
Solution code: Row 9, left to right (9 digits)
Comments
on 10. October 2024, 06:21 by snn
Absolutely delightful, as to be expected from the talent and expertise of gdc!!
on 4. September 2024, 00:59 by annaswan
I really enjoyed this. The combination of rules is great, the break-in was really satisfying in that special fog-of-war way, and the solve was painless.
on 13. June 2024, 21:14 by randall
Glorious setting. Some absolute moments of joy in this one.
on 17. May 2024, 09:57 by gdc
@Sliark: I deliberately used a low-opacity color so solvers can color over r9c8 with other colors.
on 17. May 2024, 08:51 by Sliark
hmmm，I've gotten a little disappointed that there's no colour in CTC being same to the given shadded cell at R9C8.
on 7. March 2024, 22:46 by elpadrinoIV
Awesome puzzle!
I don't think the orange given is needed (I just realised that there was a given shaded :D)
Thanks for setting!
on 13. January 2024, 09:03 by Christounet
Great stuff ! Enjoyed it a lot. Thanks :)
on 11. January 2024, 16:21 by Suxamethonium
Absolute brilliance! Took me a very long time, but it was 141 minutes of pure fun!
on 11. January 2024, 08:24 by astronixia
The rules seem a little daunting at first, but it flows so well. Quite possibly the best zipper puzzle I have done.
on 11. January 2024, 07:35 by Kuraishi
I stumble even on some of the easier rated puzzles, but this flowed so well. Alternating between the math and coloring felt great, so much fun!
on 10. January 2024, 23:29 by ViKingPrime
There's nothing I can say here that hasn't already been said. Brilliant puzzle by a brilliant mind - do yourself a favour and get cracking, already!
on 10. January 2024, 10:26 by MagnusJosefsson
Wonderful puzzle!
on 9. January 2024, 19:10 by TheBestThatICouldDo
Wonderful - the break in feels like a real gem of a revelation. Not only is the flow really nice, but it takes you all the way through - ending up with almost no gaps left to fill in with sudoku at the end - very satisfying
on 9. January 2024, 16:09 by superfluid
My first 3* puzzle, and what a gem- thanks!
on 9. January 2024, 12:47 by gdc
Thanks everyone for those nice comments. When I posted this, I was a bit worried the rules might be too complex to get many solves. You proved me wrong :)
on 8. January 2024, 19:43 by madhupt
Beautiful puzzle! Very enjoyable! Thanks for sharing.
on 8. January 2024, 17:05 by patinthehat48
fantastic puzzle, loved the zipper and yin yang constraints working together
on 8. January 2024, 12:34 by samuel1997
Fabulous! Now should we investigate the combination of Schrodingers' cell and Negative number to create more ludicrous puzzles ^^?
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gdc: Thanks! Take a look at Schrödinger's Funhouse (000GHS). It does exactly that and deserves many more solves IMO.
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samuel1997: Thanks for the recommendation! I've had it a go and indeed that is another delighting puzzle!
on 8. January 2024, 12:10 by nordloc
This was magical all the way through.
on 8. January 2024, 12:07 by ademjaz
Lovely puzzle, one of the most enjoyable puzzles I have solved lately, absolutely brilliant!
on 8. January 2024, 09:37 by Snookerfan
Great puzzle and very smooth! Thank you
on 8. January 2024, 05:42 by rameshsrivats
Fantastic puzzle. Absolute pleasure from the beginning to the end.
on 8. January 2024, 03:41 by Calvinball
Such a delight from start to finish, some tricky parts in there but the entire puzzle was lovely and fair.
on 8. January 2024, 03:28 by ashisstuff
love this, all the deductions were so nice, and how the negatives interacted on zippers was so cool
on 8. January 2024, 03:23 by mathpesto
Brilliant idea AND execution!
on 8. January 2024, 03:14 by GentlemanJim
That was a great puzzle. I was a little intimidated at first but once I got the hang of the mechanic, it went very smoothly. I love yin yang puzzles too and this used that very nicely as well. Cool puzzle.
on 8. January 2024, 01:32 by Robbo
Not sure whether I just got lucky with the solution but I believe there is a section in the middle of the solution that is isolated from the other unshaded cells. Maybe I made a mistake but commenting on the off chance I am correct
Fun puzzle none the less
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gdc: Thanks Robbo. There is a unique way of resovlving the shading which satisfies all yin yang requirements. See my hidden comment.
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Ahh yes I see my mistake, thanks for clarifying!
on 8. January 2024, 00:29 by samuel1997
Is r9c8 shaded as Orange already, or is it just highlighted to spot the center of the Zipper line?
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gdc: it is shaded as orange.
on 7. January 2024, 23:41 by talia_fr0st
Fortunately for me, this puzzle was not as ludicrous as its inspiration. Nonetheless, an experiment worthy of more eyes.
on 7. January 2024, 19:42 by vitaminz
A worthy follow-up to Schrödingers zipperlein
on 7. January 2024, 19:15 by chameleon
Nice logic, especially the opening! :)
