YYX-Sums
(Eingestellt am 26. Mai 2025, 06:23 Uhr von oskode)
Rules:
- Sudoku: Fill every cell with a digit from 1-9 such that no digit repeats in any row, column or 3x3 box.
- Yin-Yang: Shade some cells such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected. No 2x2 area is entirely shaded or entirely unshaded.
- Modified X-Sums: A number outside the grid indicate the sum of the first X runs of alternating shading in that row/column from the direction of the clue, where X is the first digit seen from the direction of the clue.
Click here to play online!
Rule Clarification:
The modified X-sums rule is satisfied for each column displayed.
The 1 sees one run of shading with the sum:
(1+2+3+4)=10
The 2 sees two runs of shading with the sum:
(2+1)+(3+4)=10
The 3 sees three runs of shading with the sum:
(3)+(1+2)+(4)=10
The 4 sees four runs of shading with the sum:
(4)+(1)+(2)+(3)=10
Ratings and comments are very much appreciated. Thank you for playing!
Lösungscode: The digits in column 3 from top to bottom, with a "-" between digits of different shading
Kommentare
am 10. Mai 2026, 19:09 Uhr von ElenaMonteille
Enjoyed a 10-hour puzzle time XD
As a variant sudoku beginner, I think I am able to solve 2 star puzzles, and 3 star puzzles with more time, and this puzzle felt like a 3.8 star to me. Maybe because I'm not very familiar with the ying-yang rule. I tried this puzzle 4 times this weekend, each time for 2-3 hours, and was finally able to solve it. It felt so good making each small step of progress. Absolute masterpiece. This is the kind of sudoku which you want to play it again after solving it. And again.
Thank you so much for this puzzle!
am 5. Mai 2026, 18:47 Uhr von Niveous
Really enjoyed the puzzle - the interplay between the shading and the totals kept it entertaining throughout.
am 24. April 2026, 08:27 Uhr von amelia0
Very fun!
am 12. Februar 2026, 02:12 Uhr von digim
The puzzle is really fun! It’s the first time I solved a YY-type puzzle, so I discovered a lot of insights. The X-sum variant tripped me up a lot, my mind frequently defaulted to the regular X-sum.
Took me over an hour, but I feel great solving it! Thanks for the puzzle!
am 4. September 2025, 09:38 Uhr von billychop
I've never done one of these: I've started OK, but I immediately run into a problem understanding the rules: when you say that all shaded cells are orthogonally connected, do you mean ALL with EVERY other, such that you could run a continuous path touching every single shaded cell and no unshaded cells? And the same for the unshaded ones? Thanks!
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Pretty much! You can get from any shaded cell to any other shaded cell via an orthogonal path (moving only up/down and left/right), passing through only shaded cells. The same is true for unshaded cells. Let me know if you have further questions!
am 20. August 2025, 14:50 Uhr von jubengo
Wonderful puzzle :) Loved it
am 17. Juli 2025, 17:59 Uhr von yttrio
Incredibly fun puzzle with a cool twist on X-sums!
am 9. Juli 2025, 20:52 Uhr von rainbowroad
A further rule clarification question: when a number is outside the grid, must the first run it faces be shaded?
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The first run it faces can be either shaded or unshaded, no restrictions there!
am 13. Juni 2025, 19:26 Uhr von Jensa
I actually got the break in pretty fast but after that it still took me nearly an hour to complete it.
Simply wonderful!
am 2. Juni 2025, 21:13 Uhr von Possum
Took me so long to find the break in but once it clicked, it clicked hard. Very satisfying. Thank you!
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Thanks for the kind words and for solving!
am 31. Mai 2025, 15:32 Uhr von Uhu
@Suxamethonium: you made a colouring mistake in row 6.
am 29. Mai 2025, 04:34 Uhr von Agent
Great idea and execution, very smooth!
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Thank you very much Agent!
am 28. Mai 2025, 10:24 Uhr von Snue
Amazing puzzle - I loved every bit of it :)
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Thank you so much, I'm glad you enjoyed your solve!
am 27. Mai 2025, 18:33 Uhr von madhupt
This is a fantastic, fantastic puzzle! The clues and the constraints interact so wonderfully and everything falls into place so beautifully. One of the best puzzle I have ever done. Thanks for sharing this!
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Hearing this from someone with over 1800 solves is extremely heart warming, thank you so much @madhupt!
am 27. Mai 2025, 16:13 Uhr von Christounet
That YY/X-sum logic is super cool and well executed. Thanks :)
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Thank you Christounet, I'm glad you enjoyed!
am 27. Mai 2025, 15:00 Uhr von Franjo
Absolutely amazing! Solving this puzzle made my day. Thank you so much for creating and sharing this masterpiece.
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Thank you so much Franjo for the kind words, it means a lot to me!
am 26. Mai 2025, 21:02 Uhr von wuc
Clever puzzle with a refreshing rule for me. Great fun thx. 3.5* to me.
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Thank you very much @wuc!
am 26. Mai 2025, 17:51 Uhr von Exigus
Lovely puzzle even if I thought I was going mad for 15 min but it turned out I was trying to add to 13 when it was supposed to be 14.
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Been there, done that... Glad to hear you got there!
am 26. Mai 2025, 17:16 Uhr von cyddrdrd
Beautiful!
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Thank you!
am 26. Mai 2025, 09:35 Uhr von thrutch
That felt like assembling the parts of a beautiful machine, with a big rush at the end when all the parts suddenly started working together.
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What a lovely way of putting it, thanks for the kind words!
