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.

Click to increase the number in a square and right-click to decrease it. Click Solve to find the solutions.