Internal X-Sum Yin Yang
(Published on 10. May 2025, 01:40 by yttrio)
Rules:
Normal Sudoku rules apply.
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.
Small numbers in the corners of cells are internal X-Sum clues. The digit in a cell with a clue gives the total number of cells (including itself) of the same shading as itself seen in all horizontal/vertical directions combined (cells of the opposite shading block the vision). Those cells sum to the number given by the clue. Digits may repeat within a sum if allowed by other rules.
6x6 Example:
The image below shows a sample 6x6 puzzle and solution with the same rule set.
Play the example 6x6 in SudokuPad.
Solution code: Digits in cells that match the shading of r1c1 in row 8 (left to right) followed by digits in cells of that same shading in column 8 (top to bottom)
Comments
on 14. May 2025, 23:04 by Kawkaz
Great puzzle, enjoyable, challenging and highly rewarding.
on 14. May 2025, 09:00 by damo_89
After finishing the shading it did not look like there was enough information to finish the sudoku.. then the digits practically filled themselves in! Gorgeous
on 13. May 2025, 10:08 by StephenR
The best Internal X-Sum Yin Yang Sudoku I have done. Also the only Internal X-Sum Yin Yang Sudoku I have done. But this is not damning with faint praise - this is a great puzzle, thanks.
on 12. May 2025, 12:52 by Agent
Smooth and lovely!
on 11. May 2025, 16:50 by wuc
Took me a while to break in. Very smooth enjoyable puzzle thx.
on 11. May 2025, 16:31 by Blashyrkh
Fantastic!
on 11. May 2025, 08:08 by VitP
sort out row 1 to unlock
on 11. May 2025, 00:09 by Calvinball
That's a "wow" from me. Needed a yttrio yin yang, it's been too long!
on 10. May 2025, 23:59 by Exigus
Smooth puzzle with an interesting rule set, thanks
on 10. May 2025, 19:05 by Snookerfan
Gorgeous and smooth as butter! Thank you
on 10. May 2025, 16:33 by Franjo
Wonderful YY-cave-sudoku with incredibly good setting leading along the smooth solution path! Thank you very much for creating and sharing another one of your beautiful puzzles.
on 10. May 2025, 14:30 by Christounet
The combination of clues works wonders. Very enjoyable! Thanks :)
on 10. May 2025, 13:56 by LehanLehan
So much pleasure in solving as always, thanks a lot,yttrio.
on 10. May 2025, 13:53 by marcmees
Very nice. thanks
on 10. May 2025, 10:28 by Wuschel
Very cool and smooth. Thanks!
on 10. May 2025, 05:14 by rameshsrivats
Very nice
on 10. May 2025, 03:37 by Elliott810
Beautiful puzzle! Thank you:)
