Counting Circles in Circles
(Published on 16. April 2025, 04:43 by egubachu)
Rules
- Sudoku: Place the digits 1 to 9 once each in every row, column, and box.
- Region sum lines: Box borders separate a region sum line into segments that sum to the same total.
- Counting circles: A digit on a circle indicates the number of circles containing that digit.
Thanks
Thanks to blueberrypug, Garford, and Roger Wrightshoe for testing and their wonderful feedback!
Solution code: Row 9
Comments
on 24. June 2025, 23:14 by shteev
Enjoyed this a lot right up until the final disambiguation which was a nightmare! Too many places to look!!!
on 21. April 2025, 08:53 by Norkas
Very fun puzzle. It's rare that such a hard puzzle still feels very flowy to me, but a lot of the deductions were great. I had some trouble with the final big disambiguation where the simplest way I spotted still feels a bit bifurcatey, but maybe I missed something.
on 19. April 2025, 18:05 by skuntsel
This is one of the nicest and the cleverest puzzles I’ve ever solved. The break-in is really nice and populating half of the grid is relatively easy if you know what questions to ask. But the larger half was brutal, and getting rid of one option without bifurcating was extremely hard (but maybe I took the wrong path). I liked every minute solving it. The interplay of circles and region sum lines was absolutely amazing and very unexpected. Thank you for this construct, egubachu! Please keep the excellent puzzles coming!
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Thank you so much for your kind words skuntsel! The way I see it, is that after the break-in it becomes clearer and clearer with each microdeduction what needs to be done, but the puzzle is teasing you because going directly at it won't give you anything (unless you bifurcate). The breakthrough happens by finding something else, which happens to resolve the one option you were describing. This is probably also why this puzzle is quite hard. Congratulations on the solve, and thanks so much for your wonderful comment!
on 17. April 2025, 14:42 by BenTen
Very enjoyable puzzle with some beautiful logic. After a silly mistake, completed on my second try in two hours.
Thank you for setting.
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Thank you so much BenTen! That sounds like a big effort! Congrats on the solve, and I'm so happy that you enjoyed my puzzle!
on 17. April 2025, 09:25 by gdc
Very fun puzzle. I haven't seen counting circles used like this before. Definitely on the harder side but also very smooth.
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Thank you so much gdc! I am thrilled that you like this idea!
on 17. April 2025, 04:34 by Elliott810
Absolutely brilliant puzzle! For me 5* difficulty. The digit in R2C6 will be one of my all time favourites. Take a bow and thank you:)
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Wow, thank you for such a wonderful compliment, Elliott810! The moment you describe indeed feels like the waves that have been building up start crashing on the rocks.
on 17. April 2025, 02:26 by blueberrypug
beautiful logic imo. even though I never felt like there was a point where the logic didn't flow smoothly, it's not easy and is certainly still deserving of that 4-star rating. well done!!
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Thank you so much blueberrypug, I appreciated your feedback during testing, and thank you so much again for helping to make this puzzle happen!
on 16. April 2025, 16:53 by Snookerfan
Stunning puzzle! Gorgeous logic from start to finish. I found it very hard and fun. Thank you
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Thank you so much snookerfan! I'm thrilled that you found it so good! I agree that it is a tough puzzle, but very much worth it.
on 16. April 2025, 13:35 by by81996672
Very fun structure, thank you for designing the puzzle.
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Thank you so much by81996672! I'm glad that you enjoyed the puzzle!
