advent of code day 15 part 2
Funny enough I first attempted the efficient solution for part 1, completely misunderstood the rules of the "game" and came up with the monstrosity you can see above.
After being completely stumped by part 2 (I don't think I have enough RAM to use the part 1 solution), I looked at the sub for a hint and found this Numberphile video, and finally understood the rules well enough to make the part 2 solution.
I still wasted way too much time on off-by-one errors and squeezing the input into my algorithm but at least it's fast enough