Advent Of Code

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An unofficial home for the advent of code community on programming.dev!

Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.

AoC 2023

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☃️ - 2023 DAY 11 SOLUTIONS - ☃️ (programming.dev)

submitted 11 months ago* (last edited 11 months ago) by [email protected] to c/[email protected]

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Day 11: Cosmic Expansion

Megathread guidelines

Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
Code block support is not fully rolled out yet but likely will be in the middle of the event. Try to share solutions as both code blocks and using something such as https://topaz.github.io/paste/ , pastebin, or github (code blocks to future proof it for when 0.19 comes out and since code blocks currently function in some apps and some instances as well if they are running a 0.19 beta)

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[–] [email protected] 4 points 11 months ago

Uiua

As promised, just a little later than planned. I do like this solution as it's actually using arrays rather than just imperative programming in fancy dress. Run it here

Grid ← =@# [
  "...#......"
  ".......#.."
  "#........."
  ".........."
  "......#..."
  ".#........"
  ".........#"
  ".........."
  ".......#.."
  "#...#....."
]

GetDist! ← (
  # Build arrays of rows, cols of galaxies
  ⊙(⊃(◿)(⌊÷)⊃(⧻⊢)(⊚=1/⊂)).
  # check whether each row/col is just space
  # and so calculate its relative position
  ∩(\++1^1=0/+)⍉.
  # Map galaxy co-ords to these values
  ⊏:⊙(:⊏ :)
  # Map to [x, y] pairs, build cross product, 
  # and sum all topright values.
  /+≡(/+↘⊗0.)⊠(/+⌵-).⍉⊟
)
GetDist!(×1) Grid
GetDist!(×99) Grid