Sudoku Solver

The script on this page uses recursive backtracking to solve a sudoku puzzle.  For further information on recursion, see the recursion page in the Programming section.  There is also a Python version of the Sudoku solver, which contains only the code required to solve the problem and is thoroughly commented - it also shows multiple solutions (where they exist) but isn't as easy to use.

If you're interested in recursive backtracking solutions then you might also want to check out the word ladder page.