About My Book (2)

In About My Book (1) I explained how to preview and/or purchase my book.

On this page I will explain how I produced the book and how you can solve the puzzles. If you are reading this page on my blog, it has several hyperlinks to explain terms which may be new to you. If you are reading this page on a printout you can either visit my blog on the Internet to use these hyperlinks or simply Google the terms yourself.

I wrote a C program to create sudoku puzzles in 2012. It uses a natural order tree search as described in Computer Science: A First Course, by Forsythe, Keenan, Organick, and Stenberg.

Using a Linux shell script I ran this program repeatedly and graded each puzzle using Hodoku. I saved puzzles with a Hodoku grade between Hard (1000) and Hard (1999) and rejected the rest. I ran my program just over 8000 times to create the 400 puzzles which appear in my book.

I then wrote a Python  program to put the puzzles into a PDF, which Amazon print for me through KDP. This has allowed me to publish my book with no up-front costs. Copies of my book are printed on demand so I do not have to hold any stock either.

The puzzles all have a similar level of difficulty, which I describe as Tough. This is a subjective term, especially when applied to sudoku puzzles. To quantify it, I would say that they are somewhere between the tough and diabolical sudokus which you may have tried in the Daily Telegraph.

If you are unfamiliar with the techniques required to solve these puzzles you can find  them at several places on the Internet. https://www.sudokuwiki.org/sudoku.htm is my favourite.

This site was created by somebody called Andrew Stuart. By a strange coincidence my full name is Andrew Stuart Reid. This has caused some confusion in the past but we are two different people with no connection.

When you visit this page it looks like this:

Experiment with the Clear, Save and Reload links then read and understand strategies 1 through 13. These should allow you to solve most of the puzzles in my book. If you get stuck, key the offending puzzle into the left hand box and click on Solve Path.