問題「砂漠の公園」 | エンジニアが死滅シタ世界 〜アンドロイドとふたりぼっちで生きろ〜

desert_park.hs

import Data.List  (elemIndex)
import Data.Maybe (fromJust, isJust)

p :: [String] -> [[Maybe Int]]
p = fmap (fmap d)
    where
        d 'W' = Just 2
        d 'D' = Just 1
        d 'L' = Just 0
        d _   = Nothing

f :: String -> String
f input = unwords . fmap show $
    let scores = p . drop 1 . lines $ input
        s = fromJust . (elemIndex =<< maximum) . fmap (sum . fmap fromJust . filter isJust) $ scores
        t = sum . fmap fromJust . filter isJust . (!! s) $ scores
        w = length . filter (== Just 2) . (!! s) $ scores
        d = length . filter (== Just 1) . (!! s) $ scores
        l = length . filter (== Just 0) . (!! s) $ scores
    in [s + 1, t, w, d, l]

main :: IO ()
main = interact f

test1 :: String
test1 = "3\n-DW\nD-D\nLD-\n"

test2 :: String
test2 = "10\n-WLDWWDWWW\nL-WDWWWLWW\nWL-LWWLWWD\nDDW-WWDWWW\nLLLL-LLLWW\nLLLLW-WLLL\nDLWDWL-WLW\nLWLLWWL-WW\nLLLLLWWL-W\nLLDLLWLLL-\n"