Logic Masters Deutschland e.V.

Sudocyclic Groups

(Published on 9. September 2021, 22:42 by SirSchmoopy)

There have been a lot of 1-5-9 puzzles and I thought I would try a generalization of this idea. Thanks to fjam from the CTC discord server for helping test this.

Please let me know if you have any feedback or if you need any additional clarification of the rules.

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Standard Rules:
  • Normal Sudoku rules apply.
  • Digits do not repeat along the indicated diagonal.

Cycle Definitions:

1. Let a horizontal cycle be defined as follows:

  • For a digit A in column X, look to the digit in the Ath Column.
  • For this digit B in the Ath column, look to the digit in the Bth column.
  • For this digit C in the Bth column, look to the digit in the Cth column...
  • Repeat this process until you are back to the digit A (e.g. eventually you will get to column Z which contains X as its digit, and this points back to the Xth column where you started with the digit A).

  • The horizontal cycle is then (A -> B -> C -> ...->Z)

2. Let a vertical cycle be defined similarly, but progressing vertically along rows rather than horizontally across columns as above.

3. Let the order of a cycle be defined as the number of unique digits appearing in a given horizontal or vertical cycle

n.b. - the 'start' of a cycle is completely arbitrary, and the order of any cycle is identical regardless of the chosen starting cell.

Cycle rules:

  • Green shaded cells have a horizontal cycle with order equal to the digit in that cell.
  • Blue cells similarly have a vertical cycle with order equal to the digit in that cell.
  • R9C9's digit contains the order of that cell's horizontal AND vertical cycle. (it would be valid either if it were shaded blue or if it was shaded green)
  • Digits in cages form a single, complete horizontal or vertical cycle. (e.g. there is a vertical 3-cycle consisting of R3C4,R4C4,and R5C5 in some order).

(Poorly) Illustrated 6x6 Example:

Shaded cells in the below 6x6 are all valid using the above rules. I've illustrated the cycles for R6C1, so you can see the order 3 vertical cycle (R6C1 -> R3C1 -> R4C1) and order 3 horizontal cycle (R6C1-> R6C3 -> R6C5)

Solution code: Row 8 from left to right (e.g. 123456789)


Solved by Arashdeep Singh, kublai, Morla, PrimeWeasel, Droi, Jakhob, wooferzfg, sandmoppe, starwarigami
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Comments

on 15. February 2022, 05:47 by Jakhob
Great puzzle love the colored cells and how they interact with the diagonal and the cage constraints!

on 16. September 2021, 11:00 by PrimeWeasel
Enjoyed this a lot! More of a 3 star I'd say though!

Last changed on 12. September 2021, 20:26

on 10. September 2021, 23:45 by Morla
Very nice rule set, indeed. Thank you for the puzzle. Because the colours are sort of arbitrary, I kept messing up the orientation, though. You should consider using inner cell arrows or alike for indication; at least that would've helped me.

Sir Schmoopy: That's a great idea! I think i might make another puzzle with this set of rules, and when I do I'll definitely use arrows or something similarly meaningful rather than just color.

on 10. September 2021, 18:22 by SirSchmoopy
You might ask how this is a generalization of a 1-5-9 puzzle.

You can think of a 1-5-9 puzzle as a puzzle where the order of the horizontal cycle of digits in columns 1, 5, and 9 is always exactly 2!

on 10. September 2021, 11:35 by Arashdeep Singh
Very innovative idea. Loved it.

Difficulty:2
Rating:N/A
Solved:9 times
Observed:9 times
ID:0007K2

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