Computational complexity of TreeSet operations in Java?

Question

I am trying to clear up some things regarding complexity in some of the operations of TreeSet. On the javadoc it says:

\"This implementation provides

Answer 1

According to this blog post:
http://rgrig.blogspot.com/2008/06/java-api-complexity-guarantees.html
it's O(n log n). Because the documentation gives no hints about the complexity, you might want to write your own algorithm if the performance is critical for you.