Sudoku command line solver Files

1) All files of this software package under MIT License (Expat):

Copyright (c) 2018 Steffen Illhardt

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


2) Usage of the command line utility.

The tool expects the Sudoku puzzle to be solved as strings of nine
lines with a length of nine characters each read from stdin.
Valid characters are 1-9. Empty values are represented by space
characters. The zip archive in the bin folder contains some example
grids besides of the binary for Windows and a Batch script for
testing. Of course the nine lines each can be entered in the console
window as well by hand. However, the C source code in the src folder
can be compiled for POSIX-compliant target platforms, too.


3) Additional information.

The doc folder contains two PDF files in German or in English. They
give some information about the used algorithm and its implementation.
A few figures should be helpful to understand the bitwise operations
used and the program flow.