Majority element in an array

majority.hs

module Majority where

zeroCrossing :: Eq a => [a] -> [(a, Int)]
zeroCrossing [] = []
zeroCrossing (x:xs) =
  scanl f i xs
    where f (u, count) v | u /= v && count /= 0 = (u, count - 1)
                         | u /= v && count == 0 = (v, count + 1)
                         | otherwise = (u, count + 1)
          i = (x, 1)

findMajority :: Eq a => [a] -> Maybe a
findMajority [] = Nothing
findMajority (x:xs) = let (c, count) = foldl f i xs
                      in
                       if count == 0 then Nothing
                       else Just c
  where f (u, count) v | u /= v && count /= 0 = (u, count - 1)
                       | u /= v && count == 0 = (v, count + 1)
                       | otherwise = (u, count + 1)
        i = (x, 1)