AoC/2019/day8/day8.hs

{-# LANGUAGE LambdaCase #-}
import Data.List.Split
import Data.List

main = do
    content <- chunksOf (25*6) <$> head <$> lines <$> readFile "input"
    print (day8a content)
    putStrLn (day8b content)

count x = (length . filter (==x))

day8a xs = let l = toLayers xs in
    (count '2' l) * (count '1' l)
    where toLayers xs = snd $ minimum [(count '0' x, x) | x <- xs]

day8b xs = intercalate "\n" $ map (map (\case '0'->' ';'1'->'•')) $ chunksOf 25 img
    where img = map (head . filter (/='2')) $ transpose xs