Posted:
Advent of Code Day 5: Cafeteria is complete!
Did AutoLISP on this one, and it sucked. I forgot to reason about how this works again, specifically that the real problem inputs contain big fat 64 bit ints, which aren't available in AutoLISP. So I had to perform the manual gradeschool arithmetic method on digit strings.
Then it turns out the sample input doesn't cover the edge cases in the real input. So I had to do a little squint-eyed search to find someone else's test case that I could run against.
I don't feel too bad tho, as the running joke on the subreddit for today is "system ran out of memory trying to store every number".