The theory/algorithm for creating a Sudoku puzzle

Here ya go.

Well, I like it. I'm surprised, it a kind of brute force system rather than some formulas. Have you looked into whether any "formula methods" exist ? Has anyone who has looked into this looked back to what Euler had to say ? If so, in what papers and where are they located ? Any other general approaches to programming a sudoku solution known to anyone else ? Thanks for this start, but we're still a long way from a fully researched conclusion for me. (BTW what programming language is being used, my first interest was the flowchart, now I have to go further with what was provided.)

Geez! You live in the city of Will Shortz and you're looking here for Sudoku help. Isn't that "hauling coals to Newcastle"?

But, no, I don't know of any algorithim. I'm just addicted to the puzzles. Interestingly enough, I can't do either the very difficult OR the very easy ones, so I'm probably missing something (other than a few bricks) about how they work anyway.

Can you reverse engineer the way some of these handhelds that make sudokus are set up ? Or is there a way to check patents for some proprietary method thats patented, if any ? Also, rather than the time it takes, have you done any analysis of how many times it goes how far (i.e. how many steps ) back to complete one that it started ? or how many total steps are involved ? I think those would make interesting graphs, and much richer (i.e. many more dimensions) than just 1000ths of a second. (Perhaps a 6x6, would be interesting, too. Any experience with them ?) HN