The easy solving of Sudoku.

I’m not one for Sudoku puzzles. It’s not because I don’t like puzzles, but no one ever explained how logical they are. I know all puzzles can be solved with logic, but they just seemed so ridiculously hard that I didn’t want to spend the time to figure out how to do it. This is the same reason I don’t try Rubix Cubes.

This last Wednesday, for my Introduction to Artificial Intelligence class, the class was given the task to write a console application in C++ to solve the Easy Sudoku puzzles. I spent a large part of the day doing this. I had figured I’d fail and try to finish it up on the day it was due, but I just kept at it, and was able to write it all in just 126 lines of code.

The application reads a comma-delineated text file broken into nine values on nine lines (like a 9×9 Sudoku grid) and loops over each value until it figures out what the proper value is. I played one on Easy this morning and figured out the three rules the Easy puzzles use. Following the normal rules of having the values 1-9 appear only once in a horizontal line, vertical line, and 3×3 box, I just wrote out loops to look up, down, and through those other boxes for each space and widdle away at the possible answers. I surprised myself, as my logic was generally correct as I wrote it.

I also spent a little time making the output look pretty (in Console terms), check it out:

Easy Sudoko Solved.

I looked over it, and it seemed to be right, but if you happen to notice something wrong, let me know!

This entry was posted on Saturday, August 25th, 2007 at 8:12 pm and is filed under Ramblings. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.

  1. Tyler Sticka says:
    August 25, 2007 at 8:51 pm

    I think it’s interesting that, although C++ is an incredibly powerful language and I’m sure there are some neat things going on behind the scenes, the output reminds me most of all of the QBASIC apps I used to write and compile years and years ago.

  2. peterwooley says:
    August 25, 2007 at 9:19 pm

    It’s funny how ridiculous console apps look at this point in Computing history. I like that you can quickly print out values without having to design and code an interface, but at least there could be a shnazzy-looking console, with a well thought-out monospace font (that’s actually anti-aliased).

    I’d suggest we’ll get there in the future, but I have a feeling bulky grey text on a black background is going to stay around for a while.

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