Entroparity Loop
(Published on 13. December 2025, 01:20 by yttrio)
Rules:
Normal Sudoku rules apply.
Draw a one-cell-wide loop of orthogonally connected cells. The loop may not touch itself, not even diagonally.
The loop acts as both an entropic line and a parity line.
- Entropic line: Each set of three adjacent digits along the loop must be one low [123], one medium [456], and one high digit [789].
- Parity line: Digits along the loop must alternate between even and odd.
Digits in cells with arrows count how many loop cells are in the indicated direction (not including the cell itself).
Solution code: Digits on the loop in row 7 (left to right) followed by digits on the loop in column 7 (top to bottom)
Comments
on 10. January 2026, 12:38 by bboom
Very cool. I re-read the rules about 4 times at the start, because it felt like there was just too little to go on. But once I started to understand the implications for the loop it was really smooth.
on 15. December 2025, 17:52 by madhupt
A very very smooth puzzle!
on 14. December 2025, 12:07 by Exigus
Another really nice loop with bafflingly little clues but still a smooth solve. Thanks!
on 14. December 2025, 06:46 by Xazzops
Super fun loop logic!
on 13. December 2025, 15:04 by Franjo
The combination of the two line rules here leads to some interesting deductions about the loop straight away. But there’s more … So thank you very much again for creating and sharing another beautiful loop-puzzle.
on 13. December 2025, 14:36 by Snookerfan
Always happy to play an yttrio loop puzzle and this was top quality as usual. Thanks!
on 13. December 2025, 02:05 by rysmyth240
Amazing puzzle!
