Reverse Revisited

When writing a method to reverse a linked list, there is great efficiency in having a "helper method" that returns a node. This is true whether the reverse method is iterative or recursive.

Write methods reverseIterative() and reverseRecursive() that can be added to this implementation for a linked list that will both reverse the list, but do so without any helper methods and where neither method returns anything but void. Naturally, given the names of the methods, the first should employ an iterative (non-recursive) algorithm, while the second should employ a recursive one.