Java

Program Specifications:

A queue is another ADT we see everywhere in the real world. Just like the stack, it is a fundamental data structure for computers as well - as processes and threads are often organized by queues so that the CPU organizes what instructions to execute.

Just as a stack is an intuitive way to organize card games, a queue could be an intuitive way to simulate anything where a line forms and there is a first in, first out order of operations.

Implement a queue using a circular array or doubly linked nodes to simulate a simple airport with the following rules:

There are 2 runways

Only one airplane can take off at any given turn

The airplanes alternate between runways - unless one runway is empty.

Secondly, write a brief justification (minimum 250 words) why you chose to use a circular array or doubly linked node implementation. Your justification should clearly explain your choice in terms of big O notation for the efficiency of storage, runtime, and/or major operations that occur in this program. Include references to specific line numbers in your code where appropriate.

Notes:

The driver class should include two queues - one for each runway

The program should be robust and correctly deal with an empty queue; in other words, you should not simply assume that there are equal number of airplanes in each queue

To Do:

Design and implement an Airplane class

Design and implement a driver class that simulates this airport

Write a justification of why you chose a circular array or doubly linked node implementation for the queue ADT

Please include the justification as a comment on the top of your driver class

Queue.java

public interface Queue { /** * Inserts the specified element into this queue. */ public void enqueue(T item); /** * Retrieves and removes the head of this queue, or returns null if this queue is empty. */ public T dequeue(); /** * Retrieves, but does not remove, the head of this queue, or returns null if this queue is empty. */ public T getFront(); /** * Retrieves, but does not remove, the tail of this queue, or returns null if this queue is empty. */ public T getBack(); /** * Checks if there are any elements in the queue. * @return true if, and only if, the queue is empty. */ public boolean isEmpty(); /** * @return appropriate string representing the queue */ @Override public String toString(); }