Consider the following definitions for a reference-based linked list: public cla
ID: 3848989 • Letter: C
Question
Consider the following definitions for a reference-based linked list: public class MyListNode { public object item: public MyListNode next;} public class MyList { private MyListNode head: private int numNodes: ..} Implement the method pop for the class MyList in order to include in this class the functionality of a stack. Please consider the first node of the reference-based linked list as the top of the stack. //Removes and returns the object at the top of this stack. //Returns null if this stack is empty. public object pop() {....} Assume you have a queue Q that has already been populated with data. What does the following code fragment do to the queue Q? Stack S = new Stack(): while (!Q.isEmpty()) { S.push(Q.dequeue());} while(!S.isEmpty()) { Q.enqueue(S. pop());}Explanation / Answer
Assume the queue Q contains elements 1,2,3,4,5 in sequence (where 1 being the first inserted elememt and 5 being last inserted element).
Stack S = new Stack() - Now an empty stack is created.
The next line while( !Q.isEmpty()....... dequeues the elements from the queue Q in FIFO(First In First Out) order and pushes into the Stack S until the queue gets complemely dequeued or empty. So now the elements present in stack will be 1,2,3,4,5 in sequence (where 1 being the first inserted elememt and 5 being last inserted element).
Now 3rd line while(!S.isEmpty()...... pops out each element from the stack in pushes it to the empty queue Q. Popping out elements from the stack is FILO(First In Last Out) order. So elements gets inserted in queue Q in this order 5,4,3,2,1. So at the end of day, this code snippet actually reverses the elements present in queue where stack is being used as an intermediate.