SUDOKU PLACE SOLVER

This excel based solver is, truly, the heart of my entire sudoku enterprise. A "souped-up" version of it is what allowed me to semi-automate the production of puzzles.

Now, I believe that sudoku puzzles ought to be solved by pencil and paper (or by pen and paper if you're very sure of yourself). But I also understand that sometimes, you just get stuck. And that can be frustrating. So I figured I should make this solver available for such times.

You should be warned however: this solver may not work for all puzzles! Not that the solver is defective, but the puzzle might be. I am refering here to puzzles which come from other sudoku writers, some of whom have no scrupples about requiring "brute force" approaches to solving their puzzles. Brute force searches are not fun! Thus, none of my puzzles ever require brute force. The solver should work fine for any sudoku which is solvable by pure logical deduction.

If you encounter a puzzle that you are convinced does not require brute force, but for which this solver does not work, please let me know! It has happened at least once, and as I result I re-wrote the solver to make it smarter. Thanks.

Instructions

1. This Excel module uses macros! If you have your security setting at the most paranoid level, Excel will automatically disable macros, and the solver will do nothing at all. Go to Tools>Options>Security>Macro Security and drop the level to "Medium".
2. The "Solve It!" button will solve the whole puzzle. Please use this just as a last resort, and try to solve the puzzle yourself, first!
3. The "Remember" button stores the current state of the board -- very useful in combination with the "Recall" button if you want to "test something out".
4. Be warned that the "Recall" button will erase the board if you haven't used the "Remember" button first.
5. The "Clear Board" button will erase the whole board.
6. If you have an old copy (prior to May 2009) of this module around, you might want to upgrade. The new version is much, much faster.