What is the cost of ContainsAll in Java?

Question

I discovered containsAll() (a List interface method) during some coding today, and it looks pretty slick. Does anyone know how much this costs in

Answer 1

consider

n.ContainsAll(m)

the best possible case scenario is O(m), and that's if n is a perfect hash set.

considering unsorted lists, i can come up with an O(n*log(n) + m*log(m)) algorithm