Copyright ©r; 2014 Bart Massey
This little chunk of Python code is a rewrite of my originally Nickle Sudoku generator / solver.
The solver is a graph-coloring solver that works pretty well.
The generator is an algorithm more-or-less taken from KSudoku: it starts by generating a random solved puzzle using the solver on an empty board with random choices, and then deletes squares in random order until it comes to a deletion that would make the solution ambiguous.
This program is licensed under the "MIT License". Please see the file COPYING in the source distribution of this software for license terms.