Magnetic Field
(Published on 30. September 2025, 07:36 by cygne)
Magnetic Field by Cygne
Rules
- Normal Sudoku rules apply.
- Digits appearing in quad circles must be placed in at least one of the four surrounding cells.
- Digits on a red parity line (whether in a cell or a quad circle) alternate between odds and evens. See below for an example.
Play in SudokuPad
Been playing with quad circles being used on lines in an as yet unfinished puzzle, so I put this together as a bit of a proof of concept. Hope you enjoy!
Parity Line Quad Example
In this example, the cell highlighted in blue is connected via a red parity line to a quad circle containing the digit 1. Because 1 is odd, and quad circles count as values along parity lines in this puzzle, the highlighted cell must be even.
Solution code: Row 9, left to right
Comments
on 8. October 2025, 08:04 by cygne
Added example of parity quad circle interaction
on 2. October 2025, 15:42 by cygne
Fix typo
on 1. October 2025, 13:44 by cygne
Thanks for all the comments and feedback all!
Sorry for the eye strain and parsing difficulty! I may take it as a challenge to take this concept into a more minimalistic and visually gentle puzzle.
@ViTP, the parity alternates between the digit in the cell and the digit in the circle. I thought the way I phrased it in the rules made that clear, but open to any suggested change in the wording.
@DiMono, thanks for catching that. I always copy the html for formatting from one of my other puzzles and must have missed to update the description after copying. That's fixed now.
on 1. October 2025, 13:39 by cygne
Fixed description
on 1. October 2025, 07:50 by Mozart40
Took me ages to find and arange all the bits and pieces. Nevertheless great fun.
on 1. October 2025, 01:23 by dzamie
Fun to look at without solving, but my eyes hurt a bit now.
Neat concept, though!
on 30. September 2025, 18:33 by Karitsu
I really enjoyed this. Definitely a 2* for me, but difficult to determine whether that was because of logic deductions or parsing the many quad circles. Overall, very nice!
To VitP’s comment, the rules pretty clearly state the parity exists between cells and circles. If a circle reads 3, the other end of the parity line must be 2, 4, 6, or 8. I took no issue with this.
on 30. September 2025, 17:09 by DiMono
Interesting idea, but I found it more tedious than anything else.
Why does the description talk about a disjoint group puzzle?
on 30. September 2025, 15:30 by TeddieMilo
It's interesting.. Not very difficult but need some patience.
Not very eye-friendly for old folk like me :D
Thanks a lot though.
on 30. September 2025, 15:14 by VitP
first of all, this is NOT a level 1 puzzle.
perhaps more important, what does "parity line" even mean when all of the "lines" exist only in SINGLE cells ?
on 30. September 2025, 10:43 by flutchman
Nice concept! Bit hard to parse, but I guess there is not much to be done about that.
Thanks for setting.
