All scripts in this directory use a simple text board format,
consisting of one line for each row, with the digits 1 through 9
representing values, and either 0 or '-' representing a blank cell.

In general, cells must be separated by blanks.  Extra blanks are
ignored, as are blank lines and lines beginning with '#'.

This directory contains the following Perl scripts:

 ** build_sudoku -- Script for constructing a new Sudoku board.  This
    		    uses the solve_sudoku script to analyze the
    		    partially built boards as it goes, and determine
    		    what values are legal for each cell.
			 
 ** build_sudoku_to_spec -- Script which runs build_sudoku repeatedly
		    (and in several instances, in parallel) until it
		    produces a board with the desired characteristics,
		    which are set by command arguments. The output is
		    raw text; use make_sudoku_board to convert it to a
		    form which can be printed.
			 
 ** find_sudoku_errors -- If you really mess up a board, and you want
    		    back up and try again, use this.
		    It takes two arguments:  The file name of the
    		    initial board, and the file name of the partially
    		    solved thing you've messed up.  When run, it tells
    		    you each cell where the partial solution is
    		    *wrong*.  It doesn't print anything else (like,
    		    the solution) so you can white out the mistakes
    		    and try again.

		    (Obviously you have to type in both the starting
    		    board and the partial solution, if the sudoku was
    		    from a book or newspaper, but that's easy enough
    		    to do, compared with figuring out where your
    		    mistakes were by trial and error!)

		    Internally, this runs the solver script on the
    		    initial board, and then compares the results with
    		    the partial board.

 ** make_sudoku_board -- Script to read a raw text board layout and
    		      	 emit a .svg file for that board.

 ** score_puzzle -- Run the solver on a puzzle and extract the
    		    difficulty level information into an easy to read
		    form.  This does not print the solution to the board.

 ** solve_sudoku -- Solver for sudoku puzzles.  It normally runs in several
    		    passes, in order to provide a reasonable estimate
    		    of how difficult the puzzle was to solve.  It also
    		    has some features for partially solving boards or
    		    for just determining the initial possibilities;
    		    these are used by the board builder (which calls
    		    this script, often many times, in the course of
    		    building a board).

In addition, it contains a number of blank boards and patterns which
are for use with the scripts:

    blank-board.txt -- Totally blank, used as a seed board for the generator

    blank-sudoku-2-X.svg -- Used by make_sudoku_board to construct the
    			    svg file.

    Patterns, used for building a board with values in a specific layout:    

	pattern-blank-rows-3.txt
	pattern-blank-rows.txt
	pattern-four-corners-5.txt
	pattern-four-corners.txt
	pattern-slashes.txt

And last but not least, the md5sums for all files in this directory
are here in the file "md5sums".