B-tree and 2-3 tree

Now I see.

As it turns out the operation of B-tree is probably much simpler than red-black tree. (In a way I think RB tree is actually more advanced).

You can also gauge the difficulty of the class by how much it discuss balanced trees.  In fact, most of the time, you will only see cursory description of them like insertion in an introductory class.

This is good.  That means if I review Chapter 16, I will probably know how to do all the problems in HW4.