2018/Day2/Day2A.hs

19 lines
501 B
Haskell

module Day2A where
import qualified Data.IntMap as IM
import Data.Char (ord)
out :: String -> Int -> Int
out id' n = min (length $ IM.filter (==n) counts) 1
where counts = foldr (\c -> IM.insertWith (+) (ord c) 1) IM.empty id'
handleId :: String -> (Int, Int)
handleId id' = (out id' 2, out id' 3)
add2 :: Num a => (a, a) -> (a, a) -> (a, a)
add2 (a, b) (x, y) = (a + x, b + y)
main :: IO ()
main = interact $ show . uncurry (*) . counts . lines
where counts = foldr (add2 . handleId) (0, 0)