Number of 9x9 Sudoku solution boards:
Number of different 9x9 Sudoku solution boards:
(eliminating symmetries such as rotations)
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
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.
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