CodinGame - Temperatures

temps.hs

import System.IO
import Data.List
import Data.Ord

main = do
    hSetBuffering stdout NoBuffering
    n <- fmap read getLine
    if n == 0
        then print 0
        else getLine >>= print . head . sortOn abs . reverse . sort . map read . words

-- Pasted from Data.List because it's missing in the (outdated?) version here.
sortOn f = map snd . sortBy (comparing fst) . map (\x -> let y = f x in y `seq` (y, x))