Once Or Twice
(Published on 15. September 2026, 21:18 by sujoyku)
I am thanking all who tested the puzzle and wish you joyful solving!
Rules:
- Normal sudoku rules apply, i.e. each Row, Column, and 3x3 region has to contain the digits from 1 to 9 once each.
- Yin Yang: Shade some cells such that all shaded cells are orthogonally connected, all unshaded cells are orthogonally connected, and no 2x2 area is fully shaded or fully unshaded.
The value of a shaded cell is double its digit. The value of an unshaded cell equals its digit.
- Target Sums: A clue X outside the grid indicates the sum of all the values that (seen from the clue) appear in its row or column before reaching the first instance of the target value X.
- Region Sum Lines: Box borders divide the blue lines into segments with the same sum of values. (Different lines may have different sums.)
Here you can solve the puzzle online:
Solution code: Values in Row 5 from left to right
Comments
on 18. September 2026, 05:25 by Norkas
This was a lot of fun and I ended up liking the ruleset a lot. Thanks for settings.
**
You are much welcome, Norkas, thank you for your comment! I am glad that you liked the puzzle.
Kind regards, sujoyku
on 16. September 2026, 17:39 by KeenanN
Very fun and smooth. Thank you for sharing this puzzle!
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You are much welcome, KeenanN, thank you for your comment! I am glad that you had a fun and smooth solve.
Kind regards, sujoyku
on 16. September 2026, 17:18 by polcat
Beautiful!
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Thank you, polcat!
Kind regards, sujoyku
on 16. September 2026, 17:06 by GeorgeTheToad2
Excellent yin yang, quite hard for me but I got there in the end!
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Congratulations, GeorgeTheToad2, and thank you for commenting! I am glad that you enjoyed this Yin Yang.
Kind regards, sujoyku
on 16. September 2026, 16:15 by Franjo
Wow! Ich bin sprachlos. Vielen Dank für dieses wahre Kunstwerk. Ich bin total begeistert!
**
Sehr gern geschehen, Franjo, vielen Dank für deinen tollen Kommentar! Es freut mich, dass Dir das Rätsel so gut gefallen hat.
Herzliche Grüße, sujoyku
on 16. September 2026, 14:44 by marcmees
fun & smooth solve. delicious. Thanks
**
Thank you, marcmees! I am glad it was to your taste. :)
Kind regards, sujoyku
on 16. September 2026, 12:11 by Chaossudokusplease
Great fun YY puzzle, thanks for sharing! I had no idea where to start but when it clicked, it made so much sense, very smart puzzle!
**
Thank you for your comment, Chaossudokusplease! I am glad that it clicked with you and you enjoyed the solve.
Kind regards, sujoyku
on 16. September 2026, 09:46 by Snookerfan
Gorgeous and really intuitive, 2 stars by solve time. Thanks!
**
You are much welcome, Snookerfan, thank you for your comment! I am glad that you liked the puzzle. Considering difficulty, this is one of the rare times where I posted at 2* and solvers have it higher. :)
Kind regards, sujoyku
on 16. September 2026, 09:33 by Piatato
Great fun, thanks!
**
You are much welcome, Piatato, thank you for commenting! I am glad that you had a fun solve.
Kind regards, sujoyku
on 16. September 2026, 07:34 by Fizz
That was awesome and a lot of fun! Very nice flow from start to finish. Thanks!
**
You are much welcome, Fizz, thank you for your comment! I am glad that you enjoyed the flow of the puzzle.
Kind regards, sujoyku
on 16. September 2026, 06:14 by mihel111
I generally like YY. But this one is just splendid. A very good flow with a beautiful path. It is the most sujoyku-like puzzle.
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Thank you for your kind words, mihel111! It is great to hear that you liked the puzzle and found it to be in my style.
Kind regards, sujoyku
on 15. September 2026, 22:18 by Prof.Dori
I really like the twist on this puzzle of Target Sums with yin yang doublers. That is one of my favorite puzzles of yours!
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Thank you very much, Prof.Dori! It is great to hear you liked it, as you were the original inspiration coming up with the Target Sums constraint.
Kind regards, sujoyku
on 15. September 2026, 21:29 by Calvinball
Twice is the answer I solved it twice :P And I liked it so much I enjoyed each time!
**
Haha, I did not think of that meaning yet ... :)
Thank you for your lovely comment, Calvinball! And also thanks again for the double-testing!
Kind regards, sujoyku
