fgl VS AoC2021

Your names are good, I reckon it is Martin Erwig's fgl stuff and Andrey Mokhov's algebraic-graphs that you have in mind.

I am about to start a new project in Haskell, model checking with (new) tree-like data structures. I think it is best to start building on a library such that i can already have elegant base functions, yet i am wondering what library is currently the standard? I read about fgl ( https://hackage.haskell.org/package/fgl ), yet it is a very old library.

Couple of approaches to graphs that are state-free: functional graphs and algebraic graphs

Using fgl but only as a data structure this time, with edge labels denoting whether the target is a big room. Not using any of its algorithms as it doesn't have anything built-in for "traversal with re-visiting".

For part 2, instead of trying to union-merge from the lowest points, I simply found all connected regions of <9. I say "simply" because I just threw things at fgl, but setting the graph up first took a bit of work. buildGr is fast but picky about the exact order things come in with.

Interesting approach. I did away with a recursive function, Array.transpose and a bit of copypasta ...

I think my solution should be easy to understand - (you can ignore the getEdges for now, it's just a function that generates a Map of -> )

F#

Any help appreciated, current (spaghetti) code is in my GitHub

In the end it turned out pretty nice

So pretty compared to my spaghetti

So much more elegant than my solution

Your solution is so much cleaner than mine

+1, Quite similar to my solution

Here is link number 1 - Previous text "F#"