A puzzle I created a couple of months ago but forgot to post here earlier. It looks like a killer sudoku but it's really about the anti-king constraint. Without it, this puzzle has over 5000 solutions. This is where I stopped counting; if someone can tell me how many solutions there are to this puzzle without the anti-king rule, I'd be very grateful! The lay-out is inspired by Joseph Nehme's excellent VXX-XVX-XXV puzzle, featured on Cracking the Cryptic.
You can play this puzzle online using f-puzzles: https://f-puzzles.com/?id=y4h8avc6.
Good luck!
Solution code: Columns 1 and 9. I.e. the 9 digits in column 1 from top to bottom, followed by the 9 digits in column 9 from top to bottom, for example: 123456789123456789
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