Logic Masters Deutschland e.V.

Shishi (Ichikara)

(Published on 20. December 2025, 08:15 by The Book Wyrm)

This puzzle was inspired by certain ideas that I discovered while solving Shintaro's brilliant puzzle, Rule of Thirds, along with some discussions I had with him afterwards.
Shintaro also gets further credit for testing this puzzle, and suggesting the name.

Note: This puzzle is very difficult, but it can be solved logically.
For easier puzzles with the same ruleset, some introductory puzzles (with an example) can be found here.

Rules:

  • Divide the grid into orthogonally connected regions.
    A region must contain the numbers from 1 to N once each, where N is the largest number in the region.
  • Regions may also contain empty cells.
  • A ? stands for an unknown number.

Penpa link: Click Here

Solution code: For each row of the grid, the number of vertical region borders in that row.


Solved by sfushidahardy, Andrewsarchus, MonsieurTRISTE, cyddrdrd, CutieRainbow
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Comments

Last changed on 23. December 2025, 16:51

on 23. December 2025, 16:51 by cyddrdrd
This is purely masterclass!

Last changed on 22. December 2025, 05:12

on 22. December 2025, 05:11 by MonsieurTRISTE
The fact this puzzle exists is a miracle.

on 21. December 2025, 14:42 by Andrewsarchus
Brilliant!

on 20. December 2025, 13:00 by sfushidahardy
Such a cool puzzle! It's different from anything else I've solved.

Difficulty:5
Rating:N/A
Solved:5 times
Observed:1 times
ID:000QMC

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Solution code:

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