An iterator offers an easy way to traverse through a collection, add new elements, delete and modify existing elements. Iterators are widely supported by langauges like C++ and Java. However, C does not offer iterators. In this assignment your task is to implement two list iterators that allow the programmer to traverse the list in either direction, modify the list during iteration, and obtain the iterator's current position in the list.
A List Iterator has no current element; its cursor position always lies between the element that would be returned by a call to previous and the element that would be returned by a call to next. See sample test log on how it works....