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Sudoku 17 Clues

I'm steadily making progress with my Sudoku game. I've become a little distracted with doing all the software things sudoku in the process.

I learned that it was proven in 2012 ( then published in 2014 ) that Sudoku puzzles require at least 17 clues in order to lead to a single unique solution. That's neat.

I learned also incredibly that only 49,158 such puzzles are currently known, and there has been barely any progress in finding more of them. So of course I am now digging down the rabbit hole of finding more.

The last new 17-clue puzzle was found in 2019, a full 7 years ago!

To aid in that process I have, of course, first grabbed the 49k puzzle data, and compressed it to less than 512kb, because, well, I wanted to. ( the download I got them from was a 69mb zip file! )

I also created a Sudoku puzzle canonicalizer. I can now create a c14n identifier for sudoku grids, so that I can tell if one puzzle is part of a group I already know about where all the puzzles in the group are transforms of each other.

I also created an improved sudoku solver intended for solving the 17-clue puzzles at maximal speed. On my mac mini m4 I can now solve all 49k puzzles in 1.2 seconds total using said solver.

Next I'll be creating the reverse, something that will take a solved grid and find the 17 minimal clues of it. I don't need to ensure I can do this 100% of the time. I just want to be able to do it for all 49k known ones as fast as possible.

Then I'll just iterate through random puzzles checking them for the maximal amount of time it takes to find the 17 clues for the 49k known ones and giving up if time goes beyond that.

Based on my rough calculations and knowledge about all this I should be able to find new 17 clue puzzles at a rate of roughly 1 per day. If I'm correct that will be neat, because I'll then have something to show for my various efforts that nobody else ( that I know of ) is doing currently.

Sudoku world: I'm on the job. Look out.