this post was submitted on 01 Dec 2023
15 points (100.0% liked)

NotAwfulTech

6 readers
1 users here now

a community for posting cool tech news you don’t want to sneer at

non-awfulness of tech is not required or else we wouldn’t have any posts

founded 1 year ago
MODERATORS
 

Rules: no spoilers.

The other rules are made up as we go along.

Share code by link to a forge, home page, pastebin (Eric Wastl has one here) or code section in a comment.

you are viewing a single comment's thread
view the rest of the comments
[–] gerikson@awful.systems 4 points 11 months ago (1 children)

Day 11: Cosmic Expansion

https://adventofcode.com/2023/day/11

discussion

After yesterday' fiddle-fest we are back with a straight-forward puzzle. Today we get the return of Manhattan distance, an AoC fav, but this time not spelled out to fool the crafty LLMs.

I made the initial decision not to "move" the galaxies in the initial map, but instead to store an offset that was increased whenever an empty row or column preceding the object was detected. This turned out to make part 2 really easy once I figured out the off-by-one error.

[–] zogwarg@awful.systems 2 points 11 months ago

discussionIn retrospect that would have been far better for runtime, my dist function ended up being a tad expensive.

I substituted the rows/columns, with multiplication by the expansion rate if they were all numbers. And then for each galaxy pair do a running sum by going “down” the “right” and adding the distance for each row and column crossed.

https://github.com/zogwarg/advent-of-code/blob/main/2023/jq/11-b.jq

transpose is nice to have in that approach.