Sunday 29 May 2022

pzprRT slitherlink experiment

Perhaps I'll reflect more on this after I finish the experiment - but for the time being I'm going to live-blog a slitherlink puzzle setting process which relies entirely on the hugely impressive pzprRT project.  Let's see how many puzzles I can publish in the next 30 minutes...

UPDATE: The answer is 9 puzzles, which feels like a lot for 30 minutes worth of work.  I have now gone through and solved them all - they are unique and cover a surprising range of difficulty levels.  Some of them are more fun to solve than others!

Here are the puzzles:

Solved in 1'02.  The solve was a bit disjointed solving symmetric parts of the grid, but after that it was surprisingly smooth.  Not the ugliest looking puzzle in the world either.

Solved in 1'59.  A smooth enough start to the puzzle, it got a bit fiddly at the end.  Some interesting topological deductions in play here but it did feel somehow artificial.

Solved in 4'29.  I didn't want to have to guess to solve any of these puzzles, but I ended up doing so here.  There's probably a clever topological argument at play here, but this one definitely feels the most computer generated puzzle so far.

Solved in 3'13.  Again needed to guess to finish things off at the end, so pretty hard.  You can kind of see how I tried to build up a theme, and then compromised it quickly in order to get out the unique solution.  Not amazing either.

Solved in 1'54.  This one I remember trying to set by including a few patterns of clues I'm familiar with.  It kind of works, but not entirely successfully.  Definitely better than the previous two, but still with an undeniable artificial feeling to it.

Solved in 1'36.  This one is largely easy and with a smooth solve, except for a fiddly end which kind of ruins things a bit.  Again you can see how the initial visual theme got watered down a bit.  I suspect it wouldn't take that much work on this to keep the theme stronger and have a more consistent solve.

Solved in 1'20.  Basically a taburega puzzle for those familiar with the reference.  Solves smoothly and with a couple of interesting moments, but always with the sense that the thing is one big gimmick.

Solved in 2'16.  This one felt very computer generated.

Solved in 0'29.  Nice to have an easy one, although that was always going to be the case using patterns like this.  I suppose if I'm honest I'd have to say this one is fairly taburega-like as well.


  1. yay another post :) I was 10-20 seconds slower than you on most of them, but I didn't have to guess. I wonder at what point you got stuck on puzzle 3 because it didn't seem that hard to me? Here's what I did

    1. ps please ignore the mistake in the top left the rest of the solve still works oops...

    2. So I did find a convoluted topological argument to solve puzzle 3 - as it turns out it was totally unnecessary. I missed a couple of deductions implied by the clues in column 3, which improves my opinion of the puzzle no end!


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