For the questions below, consider the following operations on a Queue data structure that stores int values.
Queue q = new Queue( );
q.enqueue(3);
q.enqueue(5);
q.enqueue(9);
System.out.println(q.dequeue( )); // d1
q.enqueue(2);
q.enqueue(4);
System.out.println(q.dequeue( )); // d2
System.out.println(q.dequeue( )); // d3
q.enqueue(1);
q.enqueue(8);
-If we replace the System.out.println statements (denoted in comments as d1, d2 and d3) with the statement q.enqueue(q.dequeue( )); q would contain which order of int values after all instructions have executed?
A) 3, 5, 9, 2, 4, 1, 8
B) 3, 5, 9, 1, 8, 2, 4
C) 5, 9, 2, 4, 1, 8, 3
D) 3, 2, 4, 5, 9, 1, 8
E) 2, 4, 1, 8, 3, 5, 9

Question

Quizplus · Accepted Answer

D) The original order of int values in q is 3, 5, 9. At d1, the first item is dequeued and then enqueued resulting in 5, 9, 3. Two more enqueues result in 5, 9, 3, 2, 4. At d2 and d3, the first two items are dequeued and then enqueued resulting in 3, 2, 4, 5, 9. Finally, 1 and 8 are enqueued leaving q as 3, 2, 4, 5, 9, 1, 8.

For the Questions Below, Consider the Following Operations on a Queue