有F :: * -> *,iterate' :: Ord a => (a -> a) -> a -> F a并elem' :: Ord a => Int -> a -> F a -> Bool具有以下属性?
elem x (take n (iterate f y))⇒ elem' n x (iterate' f y)⇒elem x (iterate f y)
elem' n x (iterate' f y)在O(n * log n)时间和O(n)空间上运行
elem' n x xs在O(log n)时间和O(1)空间上运行