Sashikabe
Example puzzle and solution

Sashikabe Basically Sashigane and Nurikabe together. Shade some of the cells black so that the black cells form a Tapa wall (also known as a Nurikabe). The remaining white cells form several polyominoes each. Each polyomino must be of the shape of an L; formally, it is composed of an “elbow” of one square, with two “legs” of 1-cell width non-degenerate rectangles orthogonally adjacent to the elbow and are perpendicular to each other.

There are clues on the grid in form of arrows and circles; these squares must remain white. An arrow marks the end of some leg and shows the direction where the corresponding elbow is; for example, a left arrow means that a leg ends there and the elbow of that leg is located to the left of the square. A circle marks an elbow; a number inside a circle means that the polyomino containing that elbow has exactly that many squares.

Expected difficulty Hard • Answer • Comment/E-mail if you want a solution to be published

Puzzle 69: Foxger’s Hybrid
Sashikabe

Yay, a puzzle! It’s rated hard solely because it’s a rather unusual genre.

So… What’s with the title? This genre is invented by Grant Fikes aka glmathgrant, and is pretty obviously a hybrid. In addition, Grant’s online persona (Grant Badger Fox) is also a hybrid (fox and badger), so you can call “Foxger [is] Hybrid”, using “hybrid” as an adjective. So, yeah, lame title. I can’t think of a better one though.

Also, as you can see, I attempted a perfectly symmetrical clue arrangement. Turns out I need to use a single circle there (luckily still preserving symmetry of layout, but not the contents), but I’m quite happy with the result as the solution itself is satisfying.

Why do I construct this? A request by mathgrant, of course! He made a Sashikabe puzzle and challenged me to make one too, so here it is. Turns out constructing these is a pain. Perhaps because I put the condition of making the clues perfectly symmetric, but hey, I tend to like perfect layouts.

Anyway. TVC XIV and CTC 2013 on Logic Masters India are going on! If you like Tapa, you should give both a try. The latter needs a consistent online schedule if you want to score high, but if you’re not into competitive stuff, you can still solve them for fun. They are pretty amazing puzzles. On the other hand, the former is part of TVC 2013, a 4-part contest of Tapa variations that has run since 2010. So yeah, two big events are running now.

On a more personal note. I’m currently in KAIST, as you should have known if you read this blog regularly (the latest post about my experience in KAIST has been up for about 4 days now). My Orientation Week has just ended, and seems like it’s not too busy…yet. The first academic week will start next Monday, so let’s see whether I still have time to construct puzzles or not…

Well, that’s all for now. Stay tuned!

EDIT 27 September 2013: Grant Fikes got his Sashikabe puzzle published! I’ve testsolved it and it’s a very nice puzzle. Also, this is one part of my thanks to Grant due to a certain personal problem that I prefer not to be shared with general public, but basically Grant helped me with my problem. A lot of help. Next part will come later. :3