# Pastebin ijCxTrwy
type Range = (Int, Int)

type RangePair = (Range, Range)

getInput :: FilePath -> IO [RangePair]
getInput = parseFile (parseOne `endBy` "\n")
  where
    parseOne = ordered <$> range <* "," <*> range
    ordered a b = (min a b, max a b)
    range = (,) <$> L.decimal <* "-" <*> L.decimal

part1 :: IO Int
part1 = countIf contained <$> getInput "input/day4"
  where
    contained ((l1,h1), (l2,h2)) = h2 <= h1 || l1 == l2

part2 :: IO Int
part2 = countIf overlap <$> getInput "input/day4"
  where
    overlap ((_,h1), (l2,_)) = l2 <= h1