Loopy Entropic X-Sums
(Published on 24. May 2025, 01:34 by yttrio)
This puzzle is the third I've created using the idea of loop-based X-sums, with difficulty estimated between 2 and 3 stars. The previous puzzles are linked to below:
Loopy Whisper X-Sums
Loopy Parity X-Sums
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 an entropic line. Each set of three adjacent digits along the loop must be one low [123], one medium [456], and one high digit [789].
Clues outside the grid are loop-cell X-sums. They indicate the sum of the first X digits on the loop in the row or column, where X is the digit next to the clue (and not necessarily on the loop). X cannot be larger than the number of loop cells in the row/column.
Solution code: Digits on the loop in row 8 (left to right)
Comments
on 2. June 2025, 10:15 by takeponmaki
yttrio's puzzles are always great. thank you.
on 25. May 2025, 00:01 by cam
Very cool puzzle :)
on 24. May 2025, 18:22 by Franjo
Again a beautiful loop-puzzle with perfect setting. Thank you very much for creating and sharing this gem. And now I have to try the whispers variant …
on 24. May 2025, 18:18 by Exigus
Very well set. For some time the break in seemed impossible to me and then it clicked and flowed nicely from there.
on 24. May 2025, 17:33 by thoughtbyte
Masterful setting here, as always with a yttrio loop puzzle. And this one is nice and approachable. Thanks!
on 24. May 2025, 17:23 by wuc
Another brilliant loop puzzle. Thanks yttrio. Great break in. Very smooth solve. Great setting.
on 24. May 2025, 12:27 by damo_89
Working out how to get started took almost as long as the rest of the puzzle. Really nice flow.
on 24. May 2025, 10:35 by Wuschel
Very nice!
on 24. May 2025, 05:19 by Chaossudokusplease
Loved this one, lots of great clue interactions (including one that tripped me up very early and helped me reevaluate my assumptions haha!)
on 24. May 2025, 03:23 by sasheo
Thanks for the puzzle! Loved it when the 24 clue kicked in!
