Question

I have added a little Code but I need help with the rest.

/**

A class of stacks whose entries are stored in a chain of nodes.

Implement all methods in MyStack class

Main Reference : text book or class notes

Do not change or add data fields

*/

package PJ2;

public class MyStack<T> implements StackInterface<T>

{

   // Data fields

   private Node<T> topNode; // references the first node in the chain

   private int numberOfEntries;

  

   public MyStack()

   {

topNode = new Node<T>();

numberOfEntries = 0;

// add stataments

   } // end default constructor

  

   public void push(T newEntry)

   {

if(empty()){topNode.setData(newEntry); // add stataments

numberOfEntries++;

}

Node<T>nextNode = new Node<T>();

//set data

//attach it to top node

//increment numberOfEntries

   } // end push

   public T peek()

   {

// add stataments

return null;

   } // end peek

   public T pop()

   {

return null;

   } // end pop

   public boolean empty()

   {

   if(numberOfEntries == 0){return true;

   }

   else{return false;}

     

     

// add stataments

   } // end empty

   public int size()

   {

// add stataments

return 0;

   } // end isEmpty

   public void clear()

   {

// add stataments

   } // end clear

   public String toString()

   {

// add stataments

return "";

   }

   /****************************************************

Do not modify: Stack test

Expected output:

   OK: stack is empty

   Push 3 data: 10, 30, 50

   Print stack [50,30,10,]

   OK: stack size is 3

   OK: peek stack top is 50

   OK: stack is not empty

   Pop 2 data: 50, 30

   Print stack [30,10,]

   Print stack [10,]

   OK: stack pop data is 30

   Clear stack

   Print stack []

   ******************************************************/

   public static void main (String args[])

   {

   MyStack<Integer> s = new MyStack<Integer>();

   if (s.empty())

System.out.println("OK: stack is empty");

else

System.out.println("Error: stack is not empty");

   s.push(10);

   s.push(30);

   s.push(50);

System.out.println("Push 3 data: 10, 30, 50");

System.out.println("Print stack " + s);

   if (s.size() == 3)

System.out.println("OK: stack size is 3");

else

System.out.println("Error: stack size is " + s.size());

   if (s.peek() == 50)

System.out.println("OK: peek stack top is 50");

else

System.out.println("Error: peek stack top is " + s.size());

   if (!s.empty())

System.out.println("OK: stack is not empty");

else

System.out.println("Error: stack is empty");

System.out.println("Pop 2 data: 50, 30");

s.pop();

System.out.println("Print stack " + s);

   int data=s.pop();

System.out.println("Print stack " + s);

   if (data == 30)

System.out.println("OK: stack pop data is 30");

else

System.out.println("Error: stack pop data is " + data);

System.out.println("Clear stack");

s.clear();

System.out.println("Print stack " + s);

   }

} // end Stack