One queue implementation discussed in this chapter dedicated an unused cell before the front of the queue to distinguish between a full queue and an empty queue. Write another queue implementation that keeps track of the length of the queue in a data member length.

1. Write the class definition for this implementation.

2. Implement the member functions for this implementation. (Which of the member functions have to be changed and which do not?)

3. Compare this new implementation with the previous one in terms of Big-O notation.