Day 1: Historian Hysteria
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)
- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://blocks.programming.dev if you prefer sending it through a URL
FAQ
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/22323136
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
You are viewing a single thread.
View all comments 1 point
Haskell
import Control.Arrow
import Control.Monad
import Data.List
import Data.Map
part1 [a, b] = sum $ abs <$> zipWith (-) (sort a) (sort b)
part2 [a, b] = sum $ ap (zipWith (*)) (fmap (flip (findWithDefault 0) (freq b))) a
where
freq = fromListWith (+) . fmap (,1)
main = getContents >>= (print . (part1 &&& part2)) . transpose . fmap (fmap read . words) . lines