Are you a regular to that channel, or did you just happen to find the video? I didn’t know about the channel before, and I was surprised by how popular it is.
Not a regular. Saw the video in my feed and was intrigued thinking it was a new way to solve Sudoku puzzles. Once I figured out it was about a whole other kind of puzzle, I lost interest and stopped watching.
FWIW: That Tredoku post you wrote some time ago inspired me to write some code to solve "3D" Sudoku (or traditional ones), which was fun. I encountered a Sudoku puzzle on the 'web that called itself "the hardest" to solve — explicitly designed to be extraordinarily hard. My solver ran for almost a week without solving it. (It's ultimately a brute force solver, and it seems harder puzzles require stochastic methods of some kind, because brute force can take eons.)
Edit: I do watch other math channels but prefer the ones that are scripted and rehearsed and have excellent graphics. 3Blue1Brown is top of that list, but there are others.
Yeah, I got the sense that it was of mathematical interest but not really for most puzzle lovers. (And I’m not into Sudoku or puzzles in general. I just thought coding a solver sounded like fun. That’s my kind of puzzle.)
Yep. That Sudoku is hard because of combinatorial explosion. As you likely know, Sudoku has ~6.67×10²¹ possible arrangements. No brute force algorithm can solve for that size. My algorithm worked by seeing how many possibilities exist for blank squares, picking the square with the fewest (ideally only one), and proceeding from there. In that “hardest” puzzle, there were just too many possibilities to make any headway, even after a week of trying.
Ha, synchronicity. I just watched that video last night.
Are you a regular to that channel, or did you just happen to find the video? I didn’t know about the channel before, and I was surprised by how popular it is.
Not a regular. Saw the video in my feed and was intrigued thinking it was a new way to solve Sudoku puzzles. Once I figured out it was about a whole other kind of puzzle, I lost interest and stopped watching.
FWIW: That Tredoku post you wrote some time ago inspired me to write some code to solve "3D" Sudoku (or traditional ones), which was fun. I encountered a Sudoku puzzle on the 'web that called itself "the hardest" to solve — explicitly designed to be extraordinarily hard. My solver ran for almost a week without solving it. (It's ultimately a brute force solver, and it seems harder puzzles require stochastic methods of some kind, because brute force can take eons.)
Edit: I do watch other math channels but prefer the ones that are scripted and rehearsed and have excellent graphics. 3Blue1Brown is top of that list, but there are others.
Spiral Sudoku isn’t a fun game to play, although the underlying structure is appealing.
Is the Sudoku puzzle hard because of a computational complexity obstruction?
Yeah, I got the sense that it was of mathematical interest but not really for most puzzle lovers. (And I’m not into Sudoku or puzzles in general. I just thought coding a solver sounded like fun. That’s my kind of puzzle.)
Yep. That Sudoku is hard because of combinatorial explosion. As you likely know, Sudoku has ~6.67×10²¹ possible arrangements. No brute force algorithm can solve for that size. My algorithm worked by seeing how many possibilities exist for blank squares, picking the square with the fewest (ideally only one), and proceeding from there. In that “hardest” puzzle, there were just too many possibilities to make any headway, even after a week of trying.