CS 315 Assignment 4: Merging and Stacks  Due: September 28,
2011.  Files: Cons.java, Account.java  This assignment may be
done in Java or in Lisp (except item 2) .    1. Write the
functions union and setDifference, using the merge technique, to
perform these functions on sets represented as lists. You may
use the llmergesort function to sort the lists first. We will
assume that the elements of the lists support the operations
.compareTo() and .equals().    2. Write a function Cons
bank(Cons accounts, Cons updates) that uses the merge technique
to update a list of bank accounts. Both accounts and updates
have elements of type Account, with access functions String
name() and Integer amount(). We will assume that accounts is
already sorted by name, but updates is not sorted. A given name
will appear only once in accounts, but may have multiple entries
in updates.      The function bank should update a customer's
bank balance by adding the amount of each update to it. The
output should be a new sorted list of acc