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The Miracle Sudoku [video]

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Re: The Miracle Sudoku [video]

#21
post #11

Earlier quoted context omitted.

I wonder how much of that is programmed/automated and how much work is still being done manually... Backtracking and eliminating numbers can be easily automated.

I made a sudoku solver back when I was in school. It's quite simple and almost a textbook case for backtracking. Even brute-force algorithms are instantaneous on the hardest puzzles.

I'm still mesmerized by the 15-line prolog sudoku solver: http://programmablelife.blogspot.com/2012/07/adventures-in-d...

Re: The Miracle Sudoku [video]

#23
post #18

"Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." Impressive work from a board that initially appears too open-ended to solve but turns out to have sufficient constraints. Well worth watching. (Aside: the solver reminded me oddly of Professor Falcon.)

Oh my gosh Professor Falcon!!! You reminded me of those times when as a kid i wad so excited and inspired by that movie!

Re: The Miracle Sudoku [video]

#24
I almost didn’t watch that’s because who cares about someone solving a sudoku puzzle, but that was brilliant.

That’s one happy solver; it was worth it just for the absolute joy he gets from it. Amazingly quick solving too. Good to watch him develop extra strategies during the process.

Re: The Miracle Sudoku [video]

#25
post #9

Earlier quoted context omitted.

I was discussing this with a friend. I too made a brute force sudoku solver. It was somewhat smart since it was keeping track of what options are available for each cell and updates those options as it puts/removes digits. The friend told me he was working on a sudoku solver and was trying to explain his non-brute force algorithm. I told him I did a solver back in collage and it was basically instant even though it i…

Amazing. I got down voted for my story. HackerNews does not like Mediocre Programmers I guess lol. I bet I could write a better algorithm today if I was motivated. Back then I was not as experienced in programming, and I struggled with even figuring out how to represent the data and the state. Its all about learning from where you were at the time.

It's more that solving Sudoku by Brute Force is easy.

But the trouble with brute force sudoku solvers is you can't use them to create sudokus solveable by humans with a unique solution.

That's the fun stuff in writing a sudoku solver/generator.

Re: The Miracle Sudoku [video]

#26
In case anybody sees this comment before the video: I'd highly recommend trying to solve the puzzle yourself. After you see the rules stated in the video, click the link in the info. It took me a bit longer than this guy, but it was a very fun puzzle.

Re: The Miracle Sudoku [video]

#27
post #3

Earlier quoted context omitted.

You can also if you want turn the playback rate up of the video and have the same satisfaction in half the time :)

I recently started increasing playback speed on many videos I watch. It's really hard at first, but I quickly got used to it, to the point where I now use an addon to increase playback speed to 3-6x where appropriate. When there's something complicated, or something I want to enjoy and savior, I jump back and slow down. This is an incredible time saver. I got inspired to do this by observing a blind programmer use a…

I only recently discovered this, too. I was complaining about how I preferred reading than watching videos, partly because I can read a lot faster than someone can narrate, and because I can "skim-read" text. They suggested playing the video back at a higher speed, and it works fine. Still haven't quite solved the "skim-read" thing - guessing where the narrator stops the "welcome to my channel, smash subscribe and like, etc" bit is tricky.

Re: The Miracle Sudoku [video]

#29
post #3

Earlier quoted context omitted.

You can also if you want turn the playback rate up of the video and have the same satisfaction in half the time :)

I recently started increasing playback speed on many videos I watch. It's really hard at first, but I quickly got used to it, to the point where I now use an addon to increase playback speed to 3-6x where appropriate. When there's something complicated, or something I want to enjoy and savior, I jump back and slow down. This is an incredible time saver. I got inspired to do this by observing a blind programmer use a…

which addon are you using for speedup?

Re: The Miracle Sudoku [video]

#30
post #25

Earlier quoted context omitted.

Amazing. I got down voted for my story. HackerNews does not like Mediocre Programmers I guess lol. I bet I could write a better algorithm today if I was motivated. Back then I was not as experienced in programming, and I struggled with even figuring out how to represent the data and the state. Its all about learning from where you were at the time.

It's more that solving Sudoku by Brute Force is easy. But the trouble with brute force sudoku solvers is you can't use them to create sudokus solveable by humans with a unique solution. That's the fun stuff in writing a sudoku solver/generator.

Sure you can, just brute force your way to ensure there is only a single solution. You can try all combinations and count how many reached to the end and check if count == 1.

Generating sudokus while all you have a sudoku solver seems an interesting challenge. Sounds like it can be done though, just a matter of creating random boards by adding one digit at a time that doesn't break rules and check if # of solutions is 1. I imagine even that would be fast enough, at least enough to create sudokus at a reasonable rate that can supply entire human population.

You can do anything given enough brute force!

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