Sudoku solver

A simple sudoku problem solver because I got bored of solving them manually.

WASM Adaptation

This branch has been specially adapted to work with WebAssembly: specifically, Emcripten. To compile, simply run emcc main.c board.c -s WASM=1 -o sudoku.html and then open the generated html file in a browser that supports WASM. NOTE: Emscripten has a terrible default stdin, so to enter a board into the program, one must enter it as one line, press OK, then, when the second input text box appears, press Cancel.

File format

The sudoku solver accepts a file for the following format:

• Each row consists of 9 characters (+ newline)

• Each character on a row (aside from newline) must be '0'-'9' or ' ' (if value is unknown)

• There must be a total of 9 rows

For example, a file might look as follows:

 23456789
2 4567891
34 678912
456 89123
5678 1234
67891 345
789123 56
8912345 7
91234567 

or

123456789
2 456 891
3456789  
456 89123
5678 12 4
6  91 345
789123456
8 12345 7
912345678

Optimization

An optimization directive has been included in board.c to allow for the near complete removal of boundary checks and error conditions. To enable this optimization, simply add -DOPTIMIZE to your compiler flags.

TODO

• Optimizations

  • Packed structures

  • Better structure layouts

  • Optimize speculative value placement error-condition checks

• Cleaner code

  • Move printing to separate file

  • Move board solver algorithm to separate file

• Better error messages

• Makefile