Giulio Zambon's Website
Non-fiction - Books and manuals - 100 Challenging CalcuDokus
100 Challenging CalcuDokus
by Giulio Zambon

ISBN: 978-1-2911-6565-4
Publisher: Self-published with Lulu
Publication date: 2012-11-01. Pages: 106.
From 2012-11-01 on: Lulu for AUD 9.99 in print

ISBN: 978-1-3014-9731-7
Publisher: Self-published with Smashwords
Publication date: 2012-11-15.
Downloadable for USD 1.99 in several formats

This book contains 100 difficult CalcuDoku puzzles. CalcuDokus, introduced in 004 as KenKen® (a registered trademark of Nextoy LLC), is a 9x9 numeric puzzle similar to Sudoku. But, unlike Sudoku, CalcuDoku doesn't require you to learn complex strategies.

The first sixty puzzles of this book consist of randomly generated cages, like the following one:

Random CalcuDoku

They are difficult, but I limited their difficulty by setting to 2 the maximum number of cages admitting more than 200 combinations. Therefore, although I haven't tried them all, I'm pretty confident that they can be solved analytically. That is, without having to guess.

To create the other forty puzzles, I used a different strategy: instead of generating random cages, I arranged them in fixed patterns and only generated random digits, targets, and op-codes. Here is the type of puzzle you can expect:

Patterned CalcuDoku

These puzzles are in most (but not all) cases more difficult than the random ones. In fact some of them are quite diabolical. The first couple of patterned puzzles are easier than those that follow. Otherwise, the difficulty of the puzzles varies in no particular order.

Of the pattern-puzzles, I solved those numbered from 61 to 98. I haven't solved puzzle 99 but I believe it should be possible to complete it without having to guess (which I never do). Puzzle 100 is a different type of challenge: it admits two solutions, which differ in three cages. I could have removed the ambiguity by splitting one of affected cages, but I thought you might like to check it out, just for fun.

In case you are wondering, the shading of patterned CalcuDokus serves no practical purpose. It's only there because it makes them prettier.

Valid XHTML 1.0!   Valid CSS!