Chaos Construction: X-Sums (9x9)
(Published on 21. June 2021, 08:34 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. A clue outside the grid indicates that the first X cells in the row/column from that direction are in the same region, with X being the digit in the first cell. Moreover, the next cell (the (X+1)th cell) is part of a different region.
4. The clue further indicates the sum of the digits in those X cells. In some cases, the clue has been replaced by a question mark, which stands for any single- or double-digit number.
Example (6x6):
The puzzle follows:
Penpa+: Chaos Construction: X-Sums (9x9)
SudokuPad: Chaos Construction: X-Sums (9x9) (thanks codewizard)
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Solution code: Row 1 followed by row 3. For each boundary edge within a row, intersperse the capital letter I. For the example puzzle, the solution code would be 34I265126I1534.
Comments
on 15. November 2023, 21:18 by StephenR
A total blast. Some way into it, this puzzle began to ring a vague bell and sure enough I had done it more than two years ago when it was featured on CTC. My verdict then that it was "an utter joy" hasn't changed. Thanks Jesper for double the pleasure!
on 20. October 2022, 17:35 by codewizard
A wonderful puzzle. As @peacherwu2 said, it got quite tricky towards the end :)
For those who prefer, CTC App link: https://app.crackingthecryptic.com/sudoku/3bJgQPpDdj
on 4. August 2022, 18:07 by peacherwu2
Dont be fooled by easy start. It quickly gets complicated, especially toward ending. Brilliant setup! Thank you so much, Jesper!!!
on 29. April 2022, 04:15 by thefallenrat
The trickiest CC X-Sums of them all!
on 9. October 2021, 11:05 by PixelPlucker
Working through your catalogue has been some of the most fun I've had in recent memory! I'm truly blown away by the quality of your puzzles - it is always clear to me that the solution paths have been crafted with utmost care, extracting an incredible variety of logic from the rules and packing it into a small space. The difficulty was always impeccably consistent and considerate towards the solver; I never felt frustrated when I got stuck, because I was always sure there would be a beautiful deduction around the corner.
I can confidently state that of the 25 puzzles you have published, there is not a single one - not one at all - that I did not thoroughly enjoy. A truly extraordinary collection. Thank you very much for the puzzles! :)
EDIT @PixelPlucker: Thank you so much for the wonderful comment! Your appreciation really means a lot to me. Kind of makes me want to set some more puzzles. Well done solving my catalogue, and who knows, maybe there will be more coming soon :) /Jesper
on 12. September 2021, 09:55 by Mody
Das war großartig und unheimlich gut konstruiert.
That was great and incredibly well constructed.
on 11. September 2021, 01:16 by Vebby
Very nice! I'm a big fan of chaos constructions, so I'm glad to finish solving your published puzzles to date on this note. Thank you for the brilliant puzzles Jesper! I hope there are many more to come. :)
PS for future solvers: Solution check on the Penpa+ link requires both numbers and green edges around the regions (I completed the puzzle using colouring instead of edges, which led to momentary alarm when the message didn't show, lol).
EDIT @Vebby: Thanks, Vebby! I can't believe you solved all my puzzles in about a week. Very impressive!
on 17. July 2021, 22:39 by udukos
Brilliant! Decoding the regions was such a joy.
on 16. July 2021, 13:48 by AnnaTh
Mit jedem neuen Versuch bin ich etwas weiter gekommen. Mit jedem neuen Versuch habe ich die Logik dieses Rätsels besser verstanden. Mit jedem neuen Versuch hat es mehr Spaß gemacht.
on 10. July 2021, 12:51 by Mark Sweep
Very fun challenge. Nicely constructed!
on 8. July 2021, 12:58 by Ragna
Vielen Dank für die Tipps, die probiere ich gleich mal aus. :-)
on 8. July 2021, 09:29 by Jesper
@Ragna: Hallo Ragna, ich habe leider keine deutsche Anleitung für Penpa, aber vielleicht sind die folgenden Tipps hilfreich:
1) Abhängig von der Bildschirmgröße/Auflösung, kann es sinnvoll sein, mit der "Resize" Taste (oben links) "Display size" anzupassen. Einfach ausprobieren welche Größe möglich ist, damit Rätsel + Menüleiste problemlos auf dem Bildschirm passen (damit kein Bildschirmrollen nach oben oder unten erforderlich ist)
2) Wenn unten "Tab/" in der Menüleiste, z.B. "Surface" und "Sudoku Normal" ausgewählt werden, kann relativ schnell und einfach mit der Tab Taste am Keyboard zwischen diese Modi gewechselt werden. Dann muss man nicht so oft mit dem Maus die Menüleiste bedienen.
Viele Grüße, Jesper
on 8. July 2021, 02:39 by Ragna
Hi Jesper, hi all other nice solvers.
I need your help!
I tried to solve this puzzle with penpa. And simultanly with Simon, to learn.
But I don't understand the "Syntax" of penpa. If you click on Sudoku, you have numbers but no colours, allways scroll high and low.
Surely there is better way to solve. Is'n it?
I am absolutly NO IT-Person, and not very familiar with englisch.
Can you give me a Link explaning "penpa" in german? Thank you very much.
on 25. June 2021, 01:21 by cam
Every chaos construction I do is just a little more fun than the last. This was awesome. I'm a big fan :)
EDIT @cam: Thanks! That is really nice to hear :)
on 22. June 2021, 13:32 by abed hawila
Excellent puzzle! Very clever and neat solving path, had fun solving it. Thank you Jesper! ;)
EDIT @abed hawila: Thank you Abed! I'm thrilled to hear that you enjoyed it!
on 22. June 2021, 07:05 by Playmaker6174
The difficulty of this puzzle was so consistent it melted my brain at one point, it took me way too long to realize the fatal mistake I made at the mid solve. But overall the logics were so brilliant and the interactions were just *gasp*, I enjoyed it a lot :O
EDIT @Playmaker6174: Good to hear you liked the puzzle! I hope your brain has recovered :-) Thanks for the nice comment!
on 21. June 2021, 23:37 by SudokuExplorer
Great puzzle with lovely logic! The difficulty remained consistent and the constraints interacted very well. Thanks a lot for setting this beauty, it was a lot of fun :-)
EDIT @SudokuExplorer: Thanks for solving, and for your nice comment! It means a lot to me.
on 21. June 2021, 23:17 by marcmees
very beautiful chaos construction. Thanks.
EDIT @marcmees: Thanks for the kind words!
on 21. June 2021, 15:17 by kolot
Thank you for this elegant construction. It was fun!
EDIT @kolot: It's good to hear that you enjoyed the puzzle! Thanks for solving!
on 21. June 2021, 15:06 by henrypijames
Only 3 stars difficulty for me. (I did do quite a few Chaos Constructions lately.)
on 21. June 2021, 14:28 by Statistica
Sehr trickreich. Vielen Dank!
on 21. June 2021, 12:26 by cdwg2000
It's incredible. The whole process is a challenge. The division of areas and the determination of numbers must be carried out simultaneously. The combination with X-sums is very good, thank you Jesper!
Difficulty:4-4.5:)
EDIT @cdwg2000: Thank you very much! For solving, and for your kind words!
on 21. June 2021, 11:01 by Lizzy01
there's a typo in rule 1
EDIT @Lizzy01: Thanks! Corrected.
