Yin Yang on Arrows 3
(Published on 23. July 2023, 15:17 by farodin64)
A note based on some comments. In this puzzle, the Yin and Yang part is a jump-start for the following sandwich part, i.e. even if the YY flow is correct and unique, the entire YY flow is not necessary to fill in all digits. Of course you are still welcome to complete the YY flow.
Rules
- Normal sudoku rules apply.
- Yin Yang: Shade some cells such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected and no 2x2 area is fully shaded or unshaded (Yin Yang).
- Arrow: Digits on an arrow line sum to the digit in the attached circle. All circles are shaded and show the number of unshaded cells in the up to 8 surrounded cells. All arrow lines are unshaded.
- Sandwich: Numbers outside the grid are the sum of the digits between the 1's and 9's in the row/column.
Links
Solution code: Row 5 (left to right) plus Column 5 (topdown)
Comments
on 12. March 2024, 22:22 by emilyble21
This was quite challenging for me as a beginner, took almost 2 hours! The logic was beautiful, most of the challenge was figuring out which rule or clue would lead to the next deduction. It didn't help that I always exhausted every option before sandwich sums, I was dreading those! I learned a valuable lesson: if you are stuck for more than 5 minutes, it is time to look at a new clue. I am sure there was a much easier way to solve this, but I am pleased that I was able to at all!
on 10. September 2023, 20:44 by walaura
My first yinyang!! Really enjoyed the shading and all of the choke points
on 3. August 2023, 05:09 by KyleBaran
29 mins for me
I liked it, good hybrid
on 27. July 2023, 18:59 by puzzlepandit
This is a really good puzzle. I enjoyed it. Unlike few others I needed yin yang to complete the sudoku. In fact I was thinking there could be multiple paths possible for yin yang, but at the end, there was only one solution. That was satisfying.
But I think this is more than 2* difficulty. I am putting 3*.
on 27. July 2023, 00:46 by Ratfinkz
Well, another of yours I've broken multiple times, but as ever, I get there in the end! Thank you for another mind bending, thought provoking, sudoku improving puzzle! You are single handedly teaching me Yin -Yang!
on 25. July 2023, 14:08 by farodin64
Add text
on 24. July 2023, 21:50 by WithIceCream
Very nice puzzle from start to finish! I thoroughly enjoyed completing the yin yang logic, even if doing so was not required for the solution code.
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Thank you :-)
on 24. July 2023, 16:49 by topoi
Agree with the other commenters that the YY part was not as well-integrated as it could have been.
I did use YY logic to solve the puzzle, but I still ended up with 20+ cells unshaded; that's about a third of the puzzle where the YY logic doesn't matter at all.
IMO, it's not about whether the solution code asks for only shaded or only unshaded cells. It's that the YY logic should be more important to actually figuring out the solution of the puzzle.
on 24. July 2023, 10:04 by coreng
I love shading puzzles! This one was fantastic. I was a bit stumped for a while, after the break in the solve was smooth:)
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I'm glad you enjoyed it :-)
on 24. July 2023, 08:03 by Nordy
Beautiful and smooth interactions!
on 24. July 2023, 00:33 by HumanBirdsong
That was lovely. Great setting!
on 23. July 2023, 21:44 by Fizz
Another super fun puzzle! Thanks!
on 23. July 2023, 18:45 by tobymgk
Fun, although I ended up not needing to complete the yin-yang shading in order to solve the puzzle. Maybe I made a leap of logic somewhere that I wasn’t supposed to.
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@tobymgk: Hi, shading of a few cells may not be necessary to fill in all the digits. But the Yin Yang path is unique, that's important. In addition, the Yin Yang serves as a starting point for the second part of the puzzle. I hope you still enjoyed it.
OK, a harder solution code check would be possible e.g. using only digits of unshaded cells. I think about that next time...
on 23. July 2023, 18:25 by jorgenunez
Very enjoyable. Thanks for the puzzle.
on 23. July 2023, 16:24 by Aaronomys
Very cute and fun logic! Thanks for the puzzle.
