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

  • @LeixB
    1•1 day ago

    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