Nikoli Logic Puzzles

Nikoli are a Japanese firm who publish logic puzzles on paper,
such as the well-known sudoku puzzles. I don't enjoy sudoku very
much, but some of Nikoli's other puzzles are quite enjoyable.
They include kakuro (aka cross-sums in Dell / Penny Press magazines),
hashi, masyu, ripple effect, and slitherlink.

Nikoli Books at Sterling Publishing
Sterling publishes affordable spiral-bound books of Nikoli
puzzles. For instance, "Slitherlink and Sudoku" contains
96 slitherlinks and 48 sudoku, and costs $7.50 Cdn

Nikoli Company Website
Nikoli have an English-language website which describes their
puzzles and allows one to solve puzzles online if interested.
I've not tried online solving - I prefer to work on paper.

Wikipedia about Nikoli
The Wikipedia article about Nikoli has some interesting
background about the company, the origins of sudoku, etc.

The best source of kakuro puzzles that I've encountered
is from Penny Press / Dell Publishing. Their cross-sums
tend to have a nice cascading behaviour - once you fit a
digit in, there are implications that yield other digits.

On the other hand, the kakuro books published by Penguin
are not very good. I think the trouble is that they do not
have any cascading during the solving process. Determining
one digit does not lead to any interesting effects; their
kakoro are just a tedious slog. It is an illustration of
how important it is, in computer puzzle generation, to have
a good "interesting puzzle" identification algorithm.

The hitori books by Penguin is also not very good - they have
far too many unforced choices to be enjoyable to the solver.

However, the Penguin sudoku books are pretty good if you like
sudoku. And their nurikabe and masyu books are fine. Bottom
line: the same author can do a good job with one puzzle type,
an average job with others, and a poor job with still others.

Nikoli does a much better job of publishing enjoyable hitori.

Mindboggler.ca Home Page

If you have a favourite mind boggling puzzle or problem,
please tell me about it. If I enjoy it, I'll list it here.
Thanks! Ken Roberts