quicksort.hs

-- http://www.thedotpost.com/2015/11/francesc-campoy-flores-functional-go
-- https://youtu.be/ouyHp2nJl0I?t=85
quicksort [] = []
quicksort (x:xs) =
  let smaller = quicksort [a | a <- xs, a <= x]
      bigger = quicksort [a | a <- xs, a > x]
  in smaller ++ [x] ++ bigger