The Sequence is described in chapter 4 of the book. here I give you the full implementation of a Sequence class, that I call MySequence. It is implemented using a doubly linked list of MyNode's

You will also find a driver program to test out the class methods. 

What I think is important to note is the constructor methods, the use of enumerations from a Vector, and, well, just how it all goes.

You can get all the files here