Question

Implement and test a "contains" method for the LinkedStack class in the following UML. Your method should return True if the item is found in the LinkedStack. Also, make sure that your method is a helper method. Design and implement a VectorStack using the UML in question 12. You must figure out which instance variables and methods your class should have at first place. Draw the UML diagram of your VectorStack, place it in the correct spot in the UML Class Diagram given in Question 12. Do not forget to draw the relations between your VectorStack and other classes (arrows).

Answer 1

//LinkedStackImplements.java

import java.util.NoSuchElementException;

/*Node class represent each node of linked stack */

class Node

{

protected int data; //data value in stack node

protected Node link; //next node link in stack

//default constructor

public Node() {

link = null;

data = 0;

}

//argument constructor

public Node(int data, Node link) {

this.data = data;

this.link = link;

}

public int getData() {

return data;

}

public void setData(int data) {

this.data = data;

}

public Node getLink() {

return link;

}

public void setLink(Node link) {

this.link = link;

}

}

class LinkedStack {

protected Node top;

public LinkedStack() {

top = null;

}

public void push(int data)

{

Node nptr = new Node (data, null);

if (top == null)

top = nptr;

else

{

nptr.setLink(top);

top = nptr;

}

}

public void pop()

{

if (isEmpty() )

throw new NoSuchElementException("Underflow Exception") ;

Node ptr = top;

top = ptr.getLink();

}   

/* Function to check the top element of the stack */

public int top()

{

if (isEmpty() )

throw new NoSuchElementException("Underflow Exception") ;

return top.getData();

}

  

/* Function to check if stack is empty */

public boolean isEmpty()

{

return top == null;

}

/*helper function to check for data contains or not*/

public boolean contains(int data)

{

if(top == null)

{

return false;

}

else

{

Node ptr = top;

while (ptr != null)

{

if(ptr.getData() == data )

return true;

ptr = ptr.getLink();

}

}

return false;

}

}

public class LinkedStackImplements

{

public static void main(String[] args) {

LinkedStack stack = new LinkedStack();

stack.push(4);

stack.push(6);

stack.push(16);

stack.push(9);

stack.push(8);

if(stack.contains(88))

System.out.println("Stack contains data");

else

System.out.println("Stack does not contains data");

}

}

//output:

* Project ▼ File ▼ Edit 에〉 codinggrou COMPILE AND EXECUTE JAVA-8 ONLINE >Share Code LinkedStacklmplementsj ava x compile l Execute 186 187 188 109 110 *New Project-201708172다+《 stack.push (16) stack.push (9); stack.push(8) 曰 root LinkedStacklmplements.java f(stack.contains (88)) System.out.println("Stack contains data" 112 113 114 115 116 else System.out.println( "Stack does not contains data"); 118 Default Term +Browser sh-4.3$ javac LinkedStackImplements.java sh-4.3 java LinkedStackImplements Stack does not contains data sh-4.3$ Activate Go to Settin

codingground COMPILE AND EXECUTE JA VA 8 o NLINE rojec *New Project-20170817日다+ 白a root ,Compile ! Execute ! >Share Code LinkedStacklmplementsjavat 186 107 188 189 110 stack.push (16); stack.push (9); stack.push (8); LinkedStacklmplements.java if(stack.contains(16)) System.out.println("Stack contains data"); 112 113 114 115 116 else System.out.println("Stack does not contains data"); 118 Default Term +Browser sh-4.3$ javac LinkedStackImplements.java sh-4.3$ java LinkedStackImplements Stack contains data sh-4.3$

13.

We need to use vector as member variable and use it as a stack.Add elements as end always and remove from end also.

//VectorStackImplements.java

import java.util.NoSuchElementException;

import java.util.Vector;

class VectorStack {

Vector myvector;

public VectorStack() {

myvector = new Vector();

}

public void push(Object obj)

{

myvector.addElement(obj);

}

public void pop()

{

if(myvector.size()>0)

{

myvector.removeElementAt(myvector.size()-1);

}

else

System.out.println("Stack Underflow");

  

}   

/* Function to check the top element of the stack */

public Object top()

{

Object obj = null;

if(myvector.size()>0)

obj=(int) myvector.elementAt(myvector.size()-1);

else

System.out.println("Stack Underflow");

return obj;

}

  

/* Function to check if stack is empty */

public boolean isEmpty()

{

return myvector.size() == 0;

}

}

public class VectorStackImplements

{

public static void main(String[] args) {

VectorStack stack = new VectorStack();

stack.push(4);

System.out.println("Added... "+stack.top());

stack.push(6);

System.out.println("Added... "+stack.top());

stack.push(16);

System.out.println("Added... "+stack.top());

stack.push(9);

System.out.println("Added... "+stack.top());

stack.push(8);

System.out.println("Added... "+stack.top());

System.out.println();

System.out.println("The top of stack now is... "+stack.top());

stack.pop();

System.out.println("The top of stack now is... "+stack.top());

stack.pop();

System.out.println("The top of stack now is... "+stack.top());

stack.pop();

System.out.println("The top of stack now is... "+stack.top());

stack.pop();

}

}

//output:

14.

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