At the moment I’m tinkering with a little Java puzzle from our local CJUG that centres around Sudoku Solving. If you check out that link you can download Matt’s harness to try your skills. Subclass the base solver and implement the abstract solve() method and you’re in business. The harness will fire a bunch of sample Sudokus of varying difficulty at your class and tell you what you’re missing.
Crushingly after two hours I can only manage to solve two of the easy and two of the mild problems. Maybe I should submit it as a TabloidSolver?
Try your hand if you’re feeling game… And you have too much time on your hands…