24-Oct-2010

# Sudoku Puzzles

Number of 9x9 Sudoku solution boards:
6,670,903,752,021,072,936,960

Number of different 9x9 Sudoku solution boards:
(eliminating symmetries such as rotations)
5,472,730,538

Sudoku rules are simple enough. Arrange the numbers such that the 1 to 9 appear in each of the nine:

• 3x3 regions as delineated by the light blue and green shading
• rows
• columns

Completing the Sudoku board is not so simple. Trial and error is one approach that may or may not solve Sudoku puzzles. However, trying that approach may lead you to see patterns or to develop your own insights and strategies for solving Sudoku puzzles. Beyond that, there are books and many articles on the Internet explaining how to solve Sudoku puzzles.

Sudoku Puzzles to Solve is my implementation for generating Sudoku puzzles. The program to generate Sudoku solution boards is written in the C programming language and runs on my local computer. The program generated Sudoku boards provide all the data I need to generate Sudoku puzzles in the web application.

The C program was actually written to solve Sudoku puzzles. The generation of Sudoku puzzles is just a by-product (having the program solve a blank puzzle generates solution boards). The program execution is a combinatorial exercise which is very computationally-intensive. On my computer, with my present recursive algorithm (with backtracking), I am able to solve up to 16x16 Sudoku boards.

Sudoku Abuse!

## How to achieve high ranking in search results

Blog Entries Listing
2010  Aug  Sep  Oct  Nov  Dec
2011  Jan  Feb  Mar  Apr  Jun  Sep  Oct  Dec
2012  Jan  Feb  Apr  May  Jun  Oct  Nov  Dec
2013  Jan  Feb  Mar  May  Jun  Dec
2014  Jan  Mar  Jun  Jul  Aug  Oct  Nov  Dec
2015  Jan  Feb  Mar  Apr  May  Jun  Oct  Nov  Dec
2016  Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec
2017  Jan  Feb  Apr  Oct
2018  Jan  Feb  Mar

## Collection of Celtic Woman (Christmas Songs) YouTube Videos

Visit the Camera Guy
to shoot your photos and videos.

Luxury Boat

If you make customers unhappy in the physical world, they might each tell 6 friends. If you make customers unhappy on the Internet, they can each tell 6,000 friends. – Jeff Bezos