Java Foundations

Hand trace a queue X through the following operations: By "hand-trace", we mean for each of the 10 lines of code, you should write a line of text that states the content of the queue X (front-to-back) as well as the value of its count, after that line of code runs.

X.enqueue(new Integer(4));

X.enqueue(new Integer(1));

Object Y = X.dequeue();

X.enqueue(new Integer(8));

X.enqueue(new Integer(2));

X.enqueue(new Integer(5));

X.enqueue(new Integer(3));

Object Y = X.dequeue();

X.enqueue(new Integer(4));

X.enqueue(new Integer(9));

Given the queue X that results from the above question, what would be the result of each of the following?

a.X.first();

b.Y = X.dequeue(); X.first();

c.Y = X.dequeue();

d.X.first();

To clarify, imagine that just after the code of the above question, there are 5 more lines of code to run (shown below). After line 1 below, after line 3 below, and after line 5 below, describe what is returned by each call to first

X.first();

Y = X.dequeue();

X.first();

Y = X.dequeue();

X.first();

What would be the time complexity of the size operation for each of the implementations if there were not a count variable?

Describe two different ways in which the isEmpty method of the LinkedQueue class could be implemented.