INGAR'S SUDOKU SOLVER
	
	I'm not a fervent sudoku solver but I always wanted to try implementing
	a program to solve the puzzles faster than I can. This is my first attempt.
	
	This program uses the Qt library for its user interface, you will need
	to have it installed to run the program.
	
BUILDING INSTRUCTIONS

	Basic building instructions

		autoreconf -i
		mkdir build
		cd build
		../configure
		make
			
	The binary will be called 'sudoku' and be located in the 'src' directory.
	You can run it from within the build directory:
	
		src/sudoku

USAGE

	Running the program will show the main window, which consists of a basic
	sudoku grid (9x9) and a number of buttons.

	The LOAD button allows you to load a previously loaded game.
	
	The SAVE button allows you to save the current sudoku puzzle to a file,
	like wise, the LOAD button allwos you to load a previously saved sudoko.

	The CLEAR button will clear all values.

	The STEP button will solve a single cell, but only applies the sudoko
	rules, it will not "guess".
	
	The SOLVE button will try to solve the puzzle without "guessing".
	
	The SEARCH button will try to solve the puzzle and 
	
SAVE GAME FILE FORMAT

	The file format is extremely simple: the files can be opened and edited
	with a text editor. Note that empty (unsolved) positions are saved as well.
	Value 0 indicates an empty cell.
	
	Example:
	
		0 0 0  8 0 2  9 0 0
		0 0 0  9 0 7  3 6 0
		4 0 9  0 0 0  0 0 7

		0 8 0  0 0 5  0 4 6
		1 3 0  0 7 8  0 0 0
		0 0 0  2 0 0  0 7 0

		3 4 6  1 2 0  7 0 0
		0 1 0  0 0 0  6 0 2
		0 5 0  0 8 0  0 0 0

	While the file format is optimized for readability, the program will
	actually ignore extra whitespace while loading a file. This allows you to
	load games from a simple file with numbers.
	
ALGORITHM

	The constraint solver will try to find a solution by applying
	two sets of sudoko constraints: the sudoku elimination rules, 
	where every number from 1 to 9 can only appear once in every row, column and subgrid,
	and the sudoko inclusion rules, where every number has to appear exactly once
	in every row, column and subgrid,
	
	The search solver will apply constraints until there no more cells left with just one possibility.
	From there, it will pick a random empty cell and fill it with one of the remaining possibilities.
	From there it recurses into the next iteration.
	
COPYRIGHT

	This sudoku solver was written by Stijn "Ingar" Buys and is available under
	the terms and conditions of the GNU Public License (GPL).
	
	Copyright (c) 2012-2013
	ingar@telenet.be
	htpt://ingar.satgnu.net