マンガ版「エンジニアでも恋がしたい！」〜転職初日にぶつかった女の子が同僚だった件〜｜paizaオンラインハッカソン4 Lite https://paiza.jp/poh/enkoi-ending/fe7cbf79

hackason4_3.hs

import Control.Applicative
import Control.Monad
import Data.IntMap

diffRange :: IntMap Int -> Int -> Int -> Int
diffRange xs t d = l - h
    where
        h = xs ! (d)
        l = xs ! (d + t)

main = do
    [t, n] <- Prelude.map read . words <$> getLine
    ls <- replicateM n readLn
    let psum = scanl (+) 0 ls
        p = fromList . zip [0..] $ psum
        calc = diffRange p t
        count = n - t
    print $ maximum . fmap calc $ [0..count]