Submission #240818

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Source Code Expand

import Data.List
import Text.Printf

main :: IO ()
main = getContents >>= mapM_ print . solve . map read . tail . lines

data Range = Range Int Int deriving Eq

instance Show Range where
  show (Range s e) = printf "%04d-%04d" s e

instance Read Range where
  readsPrec _ s = [(Range (read $ take 4 s) (read $ drop 5 s), "")]

instance Ord Range where
  (<=) (Range _ x) (Range _ y) = (<=) x y

roundRange :: Range -> Range
roundRange (Range s e) = Range s' e''
  where s' = 5 * (s `div` 5)
        e' = -5 * ((-e) `div` 5)
        e'' = if e' `mod` 100 == 60 then e' + 40 else e'

solve :: [Range] -> [Range]
solve = foldr go [] . sort . map roundRange
  where go r [] = [r]
        go r@(Range s e) rs'@(Range s' e':rs)
          | s' < s = rs'
          | e < s' = r:rs'
          | otherwise = Range s e':rs

Submission Info

Judge Result