Question

We have written the following Node class:

class Node {
    // instance variables
    private int value;
    private Node next;

    // constructor
    public Node(int value) {
        this.value = value;
    }
    
    // get the 'next' variable
    public Node getNext() {
        return this.next;
    }

    // get the 'value' variable
    public int getValue() {
        return this.value;
    }
    
    // set the 'next' variable
    public void setNext(Node next) {
        this.next = next;
    }
}

TASK: Create a class called List that has the following properties:

• It should have one private instance variable of type Node called head
• It should have a constructor with one parameter of type Node, which sets the head instance variable to the argument
• It should have a non-parametric public instance method called sum that returns the sum of head.value, head.next.value, head.next.next.value, etc.

EXAMPLE: If we run the following code:

Node node = new Node(1);
node.setNext(new Node(2));
node.getNext().setNext(new Node(3));
List list = new List(node);
System.out.println(list.sum());

We should print 1 + 2 + 3 = 6.

Sample Input:

1 2 3

Sample Output:

6

Answer 1

Explanation::

• Code in JAVA is given below
• Please read comments for better understanding of the code
• Output is given at the end of the code

Code in JAVA::

List.java Code:

public class List {
   private Node head;
  
   public List(Node newNode) {
       this.head = newNode;
   }
  
   public int sum() {
       /**
       *    An integer variable named total is declared and initialized to 0
       * We will store all the node values into it as summation and at the end return it
       * */
       int total = 0;
      
       /**
       * We iterate through nodes using while loop until current head is not null
       * */
       while(this.head!=null) {
           total = total + this.head.getValue();
           this.head = this.head.getNext();
       }
       return total;
   }
}

Test.java Code:

public class Test {

   public static void main(String[] args) {
       // TODO Auto-generated method stub
       Node node = new Node(1);
       node.setNext(new Node(2));
       node.getNext().setNext(new Node(3));
       List list = new List(node);
       System.out.println(list.sum());

   }

}

NOTE : Node.java code is present in question itself :)

OUTPUT:

6

Please provide the feedback!!

Thank You!!