Shady Circles
(Published on 19. January 2025, 15:30 by Ridhwan)
My first setting with yin yang constraint. Hope you enjoy it.
Shady Circles
Rules:
1. Normal sudoku rules apply.
2. 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.
3. A circled digit in the shaded cells indicates exactly how many circles contain that digit in that shaded cells and vice versa.
4. Digits along an arrow must sum to the digit on that arrow's circle. ADDITIONALLY, the arrow and its circle must have different shading, eg if r1c2 is shaded, then r1r2c1 must be unshaded.
Do have a go!
Link(with solution check): CTC
Solution code: The solution code is the popup message that appears when you solved the puzzle.
Comments
on 4. February 2025, 21:47 by Tank
are the arrow circles also included as counting circles?
yes it is :)
on 27. January 2025, 19:08 by Lias
Nice puzzle, like the solve.
+1 for goldennumbers comment on clarifying the rules about "the same holds for unshaded", that wasn't very clear to me.
on 25. January 2025, 01:22 by goldennumber
Very good - I think in the puzzle description it's worth clarifying in rule 3 saying "the same holds for unshaded" rather than vice versa, just to be super clear
on 21. January 2025, 22:36 by Chaka
Great puzzle! Definitely solvable, if you know about the special features of the Yin-Yang rule. Super fun solve that opened up some freh logic regarding circle countings! Thank you for this gift, Ridhwan!
on 21. January 2025, 03:26 by Titus Adduxas
Dry nice puzzle, definitely made easier if you knew the secrets of Yin-Yang
on 21. January 2025, 00:19 by Ridhwan
Thank you all for kind words!
on 20. January 2025, 22:57 by spatzle
super fun and engaging but not overly difficult! love this
on 20. January 2025, 15:21 by IveejNaris
Box 3 is beautiful
on 20. January 2025, 13:32 by Franjo
Very nice puzzle, and a pleasure to solve it! Thank you very much for creating and sharing.
on 19. January 2025, 22:38 by VitP
an excellent puzzle.
you need to be an expert in yin/yang procedures to even get started, and an expert in counting circles to continue. however, all those procedures can be learned in a few minutes, so this puzzle remains accessible to beginners.
watch out for an unexpected twist in cc.
on 19. January 2025, 20:40 by Qodec
Awesome puzzle, enjoyed that!
on 19. January 2025, 19:27 by LeaVulpina
Very, very, very nice! =D
on 19. January 2025, 16:03 by mathpesto
A fantastic puzzle! Super smooth, and some rather unique deductions with counting circles.
