Submission #3779083

---

Source Code Expand

import Data.List (sort)

main = do
    getLine
    putStr . unlines . solve . lines =<< getContents

-- |
-- >>> solve ["1148-1210","1323-1401","1106-1123","1129-1203"]
-- ["1105-1210","1320-1405"]
-- >>> solve ["0000-2400"]
-- ["0000-2400"]
-- >>> solve ["1157-1306","1159-1307","1158-1259","1230-1240","1157-1306","1315-1317"]
-- ["1155-1310","1315-1320"]

solve ss = map toString . reverse $ foldl f [t] ts
  where
    t:ts = sort $ map roundUp ss
    f acc x = merge (head acc) x ++ tail acc

merge t u
    | snd t < fst u = [u, t]
    | otherwise     = [(fst t, max (snd t) (snd u))]

roundUp s =
    let spanned = span (/= '-') s
        start = fst spanned
        end = tail $ snd spanned
    in  (backword start, forward end)

forward s =
    let hm = read s
        m  = ((hm `mod` 100) + 4) `div` 5 * 5
        m' = if m == 60 then 0 else m
        h  = hm `div` 100 + if m == 60 then 1 else 0
    in  h * 100 + m'

backword s =
    let hm = read s
        m = (hm `mod` 100) `div` 5 * 5
        h = hm `div` 100
    in  h * 100 + m

toString (st, et) =
    let s  = reverse . take 4 . (++ "000") . reverse $ show st
        e  = reverse . take 4 . (++ "000") . reverse $ show et
    in  s ++ "-" ++ e

Submission Info

Judge Result