Question

use intellij idea

main java

Step 3 Develop the following class: Class Name: ImprovedQueue<T> Access Modifier: public Implements: QueueInterface<T> Instance variables Name: front Access modifier: private Data type: Queue Node<T> Constructors: Name: ImprovedQueue Access modifier: public Parameters: none (default constructor) Task: sets the value of front to null Methods Name: isEmpty Access modifier: public Parameters: none Return type: boolean Task: returns true if the front is equal to null; otherwise return false Name: dequeue Access modifier: public Parameters: none Return type: T (parameterized type) Task: makes a call to the isEmpty method to see if the queue is empty and if it is return null without changing the queue; otherwise removes the front element from this queue and returns it.

Answer 1

// ImprovedQueue.java

public class ImprovedQueue<T> implements QueueInterface<T>
{
   private QueueNode<T> front; // first node of the queue
  
   // constructor to create an empty queue
   public ImprovedQueue()
   {
       front = null; // set front to null
   }
  
   // method that returns true if front is null else false
   public boolean isEmpty()
   {
       return(front == null);
   }
  
   // method that removes and returns the front element of the queue if queue is not empty, else return null
   public T dequeue()
   {
       if(isEmpty())
           return null;
      
       T element = front.getData(); // Assuming QueueNode class contains a method getData() that return the element of type T stored in this node
       // set front to node next to this node, thus removing the front element
       front = front.getNext(); // Assuming QueueNode class contains a method getNext() that returns the node next to this node
      
       return element;
   }
  
   // method to insert the element at the end of queue
   public void enqueue(T element)
   {
       // create a new node with data as element and next as null      
       QueueNode<T> newNode = new QueueNode<T>(element);
      
       // is the queue is empty, set front to newNode
       if(isEmpty())
           front = newNode;
       else
       {
           // non-empty queue
           // create currNode to front node of the queue
           QueueNode<T> currNode = front;
          
           // loop to get the last node of queue
           // Assuming getNext() is a method of QueueNode class that returns the node next to this node
           while(currNode.getNext() != null)
               currNode = currNode.getNext();
              
           // set next of last node to newNode to insert element at the end of queue  
           // Assuming setNext() is a method of QueueNode class that sets the next node of this node
           currNode.setNext(newNode);     
       }  
   }
  
}

//end of ImprovedQueue.java