AoC_2022/day1/Main.hs
2022-12-04 23:15:09 +01:00

51 lines
1.3 KiB
Haskell

{-# LANGUAGE LambdaCase #-}
module Main where
import Data.List as L
import Data.Maybe
import Safe
data InputOptions = Elf1
| Elf3
| Quit
getInput :: IO InputOptions
getInput = do
putStrLn "Only get top Elf or sum of top 3 Elf? (1/3/q)"
getLine >>= \case
"1" -> return Elf1
"3" -> return Elf3
"q" -> return Quit
_ -> putStrLn "not understood" >> getInput
main :: IO ()
main = getInput >>= \case
Quit -> putStrLn "bye!"
Elf1 -> interact $
(<>"\n")
. show
. maximum
. fmap (sum . mapMaybe (readMay :: String -> Maybe Integer))
. splitOn ""
. lines
Elf3 -> interact $
(<>"\n")
. show
. sum
. take 3
. sortOn negate
. fmap (sum . mapMaybe (readMay :: String -> Maybe Integer))
. splitOn ""
. lines
-- | Split a list into sublists delimited by the given element.
--
-- From: https://hackage.haskell.org/package/haskell-gi-0.26.2/docs/src/Data.GI.CodeGen.Util.html#splitOn
splitOn :: Eq a => a -> [a] -> [[a]]
splitOn x xs = go xs []
where go [] acc = [reverse acc]
go (y : ys) acc = if x == y
then reverse acc : go ys []
else go ys (y : acc)