Question

Implement a class for a stack and a queue. Implement as a parent a superclass called “ Container and two subclasses called “ Stack and Queue” How would you use templates on these classes to make in generic?

please I need step by step

Answer 1

class Node<T>{
   T data;
   Node<T> next;
   Node(T val){
       this.data=val;
       this.next=null;
   }
}
class Container<T>{
   Node<T> n;
   Container(){
       this.n=null;
   }
  
}
class Queue<T> extends Container<T>{
  
   Node<T> front, rear;
  
    public Queue() {
        this.front = this.rear = null;
    }
     
    // Method to add an key to the queue.
    void enqueue(T key)
    {
        
        Node<T> temp = new Node<T>(key);
    
        if (this.rear == null)
        {
           this.front = this.rear = temp;
           return;
        }
     
        this.rear.next = temp;
        this.rear = temp;
    }
     
    // Method to remove an key from queue.
    Node<T> dequeue()
    {
        //return null if queue is empty
        if (this.front == null)
           return null;
     
        // Store previous front and move front one node ahead
        Node<T> temp = this.front;
        this.front = this.front.next;
     
        // If front becomes NULL, then change rear also as NULL
        if (this.front == null)
           this.rear = null;
       // System.out.println(temp);
        return temp;
    }
  
}
class Stack<T> extends Container<T>{
   Node<T> Top;
   Stack(){
       this.Top=null;
   }
  
   //Function to check stack is empty or not
    public boolean isEmpty()
    {
        return this.Top == null;
    }
    //Function to get the top element in stack
    public Node<T> peek()
    {
        // check for empty stack
        if (!isEmpty()) {
            return this.Top;
        }
        else {
            System.out.println("Stack is empty");
            return null;
        }
    }
   public void push(T x) // insert at the beginning
    {
        // create a temp node
        Node<T> temp = new Node<T>(x);

        //if heap is not full insert the node
        if (temp != null) {
            temp.next = Top;
            Top = temp;
          
        } else {
           System.out.println("\nOverflow!!!!!! Can't insert into stack");
        }
     
    }
    // Function to pop top element from the stack
    public void pop() {
        // check for stack underflow
        if (Top != null) {
           Top = Top.next;
         
        } else {
           System.out.println("\nUnderflow!!!!!! Cant pop element from stack");
        }
    }
}
//main class to test queue and stack
public class TemplateClass {

   public static void main(String[] args) {
       //creating queue object
       Queue<Integer> q1=new Queue<Integer>();
       q1.enqueue(4);
       q1.enqueue(6);
       q1.enqueue(1);
       System.out.println(q1.dequeue().data);
      
       //creating stack object
       Stack<Character> s1=new Stack<Character>();
       s1.push('d');
       s1.push('a');
       s1.push('i');
       System.out.println(s1.peek().data);

   }

}

//############################### PGM END #############################
OUTPUT
##########

<terminated> Templat 4 1