Question

use intellij idea

main java

wp the professor. Please make sure to only implement what is asked for. You may not add any instance variables to any class, though you may create local variables inside of a method to accomplish its task. No other methods should be created other than the ones listed here. Step 1 Develop the following interface: Interface Name: Queue Interface<T> Access Modifier: public Methods Name: isEmpty Access modifier: public Parameters: none Return type: boolean Name: dequeue Access modifier: public Parameters: none Return type: T (parameterized type) Name: enqueue Access modifier: public Parameters: element (data type T, parameterized type) Return type: void Step 2 Develop the following class: Class Name: Queue Node <T> Access Modifier: public Linkedlist.png

Answer 1

// QueueInterface.java

public interface QueueInterface<T> {
    public boolean isEmpty();

    public T dequeue();

    public void enqueue(T type);
}

// QueueNode.java

public class QueueNode<T> {
    private T info;
    private QueueNode<T> link;

    public QueueNode(T info) {
        this.info = info;
        this.link = null;
    }

    public void setInfo(T info) {
        this.info = info;
    }

    public T getInfo() {
        return info;
    }

    public void setLink(QueueNode<T> link) {
        this.link = link;
    }

    public QueueNode<T> getLink() {
        return link;
    }
}

// ImprovedQueue.java

public class ImprovedQueue<T> implements QueueInterface<T> {

    private QueueNode<T> front;

    public ImprovedQueue() {
        front = null;
    }

    @Override
    public boolean isEmpty() {
        return front == null;
    }

    @Override
    public T dequeue() {
        if (isEmpty()) {
            return null;
        } else {
            QueueNode<T> temp = front;
            front = front.getLink();
            return temp.getInfo();
        }
    }

    @Override
    public void enqueue(T type) {
        QueueNode<T> newNode = new QueueNode(type);
        if(isEmpty()) {
            front = newNode;
        } else {
            QueueNode<T> temp = front;
            while(temp.getLink() != null) {
                temp = temp.getLink();
            }
            temp.setLink(newNode);
        }
    }
}

// QueueDemo.java

public class QueueDemo {
    public static void main(String args[]) throws Exception {
        QueueInterface<String> myQueue = new ImprovedQueue<String>();

        myQueue.enqueue("A");
        myQueue.enqueue("B");
        myQueue.enqueue("C");
        myQueue.enqueue("D");

        String discard = myQueue.dequeue();

        while(!myQueue.isEmpty()) {
            String front = myQueue.dequeue();
            System.out.println("Front = " + front);
        }
    }
}