Logic Masters Deutschland e.V.

Chaos Construction: Position Sums (9x9)

(Published on 12. October 2021, 20:35 by Jesper)


Rules

1. Divide the grid into nine orthogonally connected regions, each containing nine cells.

2. Each row, column and region must contain the digits 1 to 9.

3. Let A and B be the digits in the first and second cells of the grid from any direction
a) Unshaded clues outside the grid indicate the sum of A and B
b) Shaded clues indicate the sum of the digits in positions A and B from that direction

4. If a clue is circled, the cells that are part of its sum belong to the same region. If a clue is not circled, the cells that are part of its sum belong to different regions.

5. A question mark can stand for any positive integer.



Example (7x7):


Penpa+: Example (7x7)




The puzzle follows:



Penpa+: Chaos Construction: Position Sums (9x9)
The Penpa solution check requires digits + green edges.

SudokuPad: Chaos Construction: Position Sums (9x9)


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Solution code: Row 6 followed by row 7. For each boundary edge within a row, intersperse the capital letter I. For the example puzzle, the solution code would be 67I53I2I147214I35I6.

Last changed on on 7. September 2023, 15:51

Solved by polar, Vebby, marcmees, Mark Sweep, Playmaker6174, SirWoezel, abed hawila, harrison, PixelPlucker, Bobby, PulverizingPancake, SudokuExplorer, ogi.djukovic, udukos, DamnedLight, bigger, AnnaTh, ... misko, akamchinjir, Jaych, guihori, h5663454, shangchenxi123, Piatato, Tom-dz, dennischen, Lyun Licuss, lerroyy, dogfarts, Agent, StephenR, Kavman15, Tacosian, zakkai, Myxo, wullemuus, Unknown
Full list

Comments

on 12. February 2024, 16:25 by Myxo
Just amazing, and super smooth solve!

on 1. January 2024, 02:15 by Kavman15
Just incredible setting, enjoyed every step!

on 21. November 2023, 09:30 by StephenR
So there I was coasting along nicely wondering why everyone had said this was so hard when suddenly I broke it. Backtracked and then broke it again. Both times I had overlooked region building possibilities. Anyway, a mindblowingly good puzzle. Despite my problems I loved every second of it, thanks Jesper.

on 10. November 2023, 05:08 by Agent
Exceptional puzzle, the clues work together very nicely! I had the same mistake as SirWoezel and Christounet, this was a well-designed trap :D

on 22. March 2023, 00:54 by Piatato
Wonderful! Really smooth and fun puzzle throughout!

on 17. October 2022, 03:07 by ONeill
Wow. I'm in the same boat as Christounet and SirWoezel. I'm glad I finally caught my mistake. Great puzzle, thank you :)

on 25. July 2022, 17:02 by Christounet
Very nice puzzle which caused me trouble because I made a mistake in the midgame (exactly the same one as SirWoezel described in his hidden comment by the way, which led me to think you might have designed it on purpose as an intended evil trap !) Very enjoyable puzzle nonetheless, as all your CC puzzles ! Thanks a lot !!

on 25. June 2022, 22:54 by Niverio
Very cool puzzle, fantastic!

on 12. May 2022, 01:25 by Gnosis66
One of the most enjoyable puzzles I've done on the site.

on 15. January 2022, 22:43 by glum_hippo
The hottest tears are the ones I didn't cry because I managed to finish this one. But I think I broke it a prime number of times. A really tough and rewarding challenge!!

on 6. December 2021, 14:36 by Statistica
Ganz klasse!

on 6. November 2021, 22:31 by Phistomefel
Wow, what a puzzle! Every time I began to feel a little bit stuck, there always came a clue around that helped. Thanks for the wonderful creation, Jesper! :)

on 20. October 2021, 15:42 by AnnaTh
Mega Rätsel! Wenn man den Anfang gefunden hat, geht es Stückchen für Stückchen weiter. Hat unglaublich viel Spaß gemacht.

on 14. October 2021, 18:30 by udukos
Fantastic puzzle! This was such a joy to solve. Thanks for this beauty, Jesper!

on 14. October 2021, 17:47 by SudokuExplorer
The 7x7 puzzle was a great warm-up to this lovely ruleset. The main puzzle was extraordinary! The variety of logic from how the clues interact was simply stunning. Thanks for the two treats! :-)

on 13. October 2021, 22:49 by PixelPlucker
Absolutely loved it, as always with your puzzles! Such a pleasant solve path. :)

on 13. October 2021, 19:30 by abed hawila
Wow! What a gem this is! Absolutely fantastic puzzle. Thank you, Jesper!

on 13. October 2021, 18:34 by Jesper
@polar @Vebby @marcmees @Mark Sweep @Playmaker6174 @SirWoezel: thanks for the wonderful comments! It really made my day :)

on 13. October 2021, 17:16 by SirWoezel
Absolutely stunning puzzle! Filling in the solution code (after penpa told me it was right...) was quite a challenge too ;), but that was all my own fault. While solving this puzzle I also drew edges all around the grid. Oh well, thanks for this gem!

Last changed on 13. October 2021, 16:43

on 13. October 2021, 16:41 by Playmaker6174
Oh my goodness, I finally finished this puzzle, what a magnificent and wonderful puzzle!
The clues in this one must've been chosen precisely because every clue felt so necessary at certain points, yet it didn't change the fact that it's so consistent till the end. It's somehow lucky that I did it in only one go, but I loved every second of the solve! ;)

on 13. October 2021, 16:05 by Mark Sweep
Wonderful! The idea of the circles adds a nice touch to Position Sums. The puzzle was consistently challenging until the end in a smooth manner.

on 13. October 2021, 14:01 by marcmees
brilliant. Had to return on my steps several times. Very tricky construction. thanks.

Last changed on 13. October 2021, 00:55

on 13. October 2021, 00:51 by Vebby
Brilliant puzzle! Very enjoyable to solve. Had to restart a couple times due to silly errors but the solution path is not too difficult if you wrap your head around the clues.
Was really happy to see this new one after your brief hiatus, Jesper! :) I received an email thanks to LMD's new Follow List feature, which is pretty handy for solvers.

on 12. October 2021, 22:46 by polar
Wonderful! There's a lovely interaction between both rulesets throughout the puzzle and they work together beautifully. Very clear and smooth solving path. Thank you for setting this :)

Difficulty:5
Rating:100 %
Solved:55 times
Observed:6 times
ID:0007WQ

Variant combination Online solving tool

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Solution code:

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