sudoku solver
Solve sudoku's using two strategies: constraint propagation and search. Sudoku's represented as a 2D array of cell objects. Each cell tracks "constraints"; cells remember which numbers are eliminated from checking rows, columns and grids.
Cell.java - Cell object. Sudoku.java - Sudoku object. Solve.java - Easy puzzle that can be solved through constraints only. Solve2.java - Difficult puzzle.