Nikoli is a Japanese company that publishes pencil puzzles (Sudoku, Fillomino, Slitherlink, and Kakuro, to name a few of very many). Their logic puzzles have a worldwide audience, owing partly to their culture-independence: if you know how to count, you can understand the rules of pretty much any Nikoli puzzle (and sometimes you don’t even need that!)

Nikoli-style puzzles are also very fun to design. Here I’ve collected some Nikoli-style puzzles that I’ve created.

Hikkosu

Probably my favorite thing that I created for my CS Puzzles class – Hikkosu is a brain-bending fusion of Shikaku and Numberlink style puzzles!

Example Puzzles

[Solution] [For pros who don't need no stinkin' instructions]*


Assets

If you'd like to make your own Hikkosu puzzles, here are the assets I used to make these.


*You see, one of the lessons in our class involved us solving Nikoli puzzles whose instructions were in Japanese – but since I know a fair amount of Japanese, the professor had to redact them… so, I decided to give him a taste of his own medicine :)

Hikkosu Solver & Generator

If I didn’t write a Hikkosu solver, nobody was going to.

[Download]

Included in the download is:

  • A portable installation of PyPy 3 for Windows (Mac and Linux distributions can be found at pypy.org). Running with PyPy is completely unnecessary, but probably advisable if you value your time.
  • HikkosuSolver.py, a Python 3 program. Run with the command “HikkosuSolver.py filename.txt solve” to solve a puzzle, or “HikkosuSolver.py filename.txt generate” to generate a puzzle. Note that the file format is different for solving and generating.
  • Three puzzle files containing the program-compatible versions of the included puzzles: easy.txt, medium.txt, and hard.txt
  • Three generator files containing the input used to generate those files: gen_easy.txt, gen_medium.txt, and gen_hard.txt

Pillars

Unfortunately, I can’t seem to find who invented this style of puzzle – it was somebody else in my Spring 2020 CS Puzzles class, I know that much! If you know who invented these, please get in touch.

The rules of Pillars puzzles are as follows:

  1. Mark some tiles, leaving the rest empty.
  2. Some tiles have numbers in them. This corresponds to the number of marked tiles that tile can see (ie, the number of marked tiles in that tile's row or column).
  3. Tiles can see through marked and unmarked tiles, but cannot see through numbered tiles.
  4. You cannot mark tiles with a number in them.
Example Puzzles
(Note: These example puzzles were created by the inventor of Pillars, not by me!)
[Solution]


Friendly Puzzles

[Solution]