Another nice mess ... nonconsecutive circles
(Published on 21. September 2023, 09:18 by Fool on Hill)
Puzzle rules
Normal Sudoku rules apply.
If a digit n is in a circle, then precisely n circles contain the digit n
Orthogonally adjacent digits may not be consecutive.
This is a puzzle which has a tricky step or two to unlock it: possibly a harder 4* puzzle? I liked the purity of a puzzle with just circles and no extra clues and pretty much any way I bypassed the difficulties ruined some of the logic I wanted to keep. With a constraint which applies across the whole grid, like the circle constraint, logic sometimes appears in unexpected places.
Here is the Cracking the Cryptic link: Another nice mess
Here are some notes and hints on solving strategy, including a specific hint for the trickiest part of the solve. They do not give everything away, but do try seeing it yourself.
Widen your view
In circle puzzles both high digits and low digits can be constrained - but in different ways - keep a careful count of the places where key digits are present in circles (low digits) or absent from circles (high digits)
Clue interactions
Consider the configurations of circles and the placement of digits in relation to the nonconsecutive constraint. This can be useful with consecutive triples like 234 or 678
Specific hints
You should be able to constrain places for 8s and 9s and also for some 7s - 7 in box 5 is much more constrained than you might imagine
A key step
There are two options for 8 in box 2. One of these obviously forces a 7 in box 5. The other forces 8s across the whole grid - what does that do to to 7 in boxes 6 and 5?
And again
That does something to 3. Then consider that you have a consecutive triple to fit into circles in box 9, and that affects 8 in box 6. Now revert to the options for 8, and that should unlock things a bit.
Solution code: The digits in the circles in rows 1 and 4 (9 digits)
Comments
on 15. November 2023, 23:48 by Krokant
Stunning puzzle. Really fun. :)
on 25. October 2023, 08:22 by marty_sears
This was very hard, but an absolutely stunning and pure circles puzzle; one of the best I've seen. Delightful and satisfying deductions throughout.
on 17. October 2023, 16:33 by yuanbangod
good
on 1. October 2023, 15:14 by 5Head
Very nice, pretty hard but managable once you get used to the variant. Fantastically creative aswell. Thank you for setting this!
Glad you enjoyed it - thank you for the comment
on 29. September 2023, 05:01 by wenchang
very tricky! VERY NICE! Spoiler alert! https://youtu.be/i-hhSDnI5UI
Thank you so much for solving it, and for appreciating the logic in the puzzle. I think there is just one thing you nearly spotted which would have made life a bit easier for you. I have loved watching your solves occasionally since I first watched your video of Jay Dyer's puzzle Shockwaves.
Have put a hidden comment to highlight the point in question.
on 22. September 2023, 14:42 by Snookerfan
Excellent and brutally hard! Thank you
I think that means you may have enjoyed solving - thanks so much for the comment.
