Thursday, 11 September 2025

Freddie Hand

The instructions booklet for this year's World Puzzle Championship has been released! You can find it linked here. Hitori (Fillomino) is one of the variants appearing in the Hitori round, which should really only have one puzzle.

Rules: Shade some cells so that no two shaded cells are orthogonally adjacent and the remaining unshaded cells form one orthogonally connected area. No two cells in the same row or column containing the same number may both be unshaded.

Then, divide the remaining unshaded cells into regions of orthogonally connected cells. Two regions of the same size cannot share an edge. Clues in unshaded cells must belong to a region containing the indicated number of cells. Clues in shaded cells convey no information.

Notation note: Unfortunately a bit fiddly. I recommend alternating between shading mode (for the Hitori part) and edgesub (for the Fillomino part).

Answer check note: The answer checker requires both shaded cells and edges to be drawn. It draws implicit borders between adjacent cells with different shading, so you won't have to draw all of the edges around shaded cells for answer check to pop up, but you will need to colour all unshaded cells in green for this to work. There is no number checking.

In case you need a refresher on how Hitori/Fillomino work, here's a couple past ones in GAPP.
Hitori - Archive: Sunday, 21 January 2024 by Menderbug
Fillomino - Archive: Tuesday, 23 January 2024 by Walker

Acquire a Speedy Sloth 🦥 by solving in 4:30 or less!
Obtain a Quick Crab 🦀 by solving in 9:00 or less!
And all solvers who complete the puzzle will be rewarded with a Hybrid Highland Elaenia 🐦

Example (Penpa+): https://tinyurl.com/282pygfk
Puzzle (Penpa+): https://tinyurl.com/278fyvyo