Flolac week of code 1: nub

nub.hs

nub' :: [Int] -> [Int]
nub' = foldr f [] where
  f x xs
    | x `elem` xs = xs
    | otherwise   = x:xs
    
-- without using `elem`
nub'' :: [Int] -> [Int]
nub'' = foldr f [] where
 f x xs
  | length (filter (x ==) xs) > 0 = xs
  | otherwise                     = x:xs