Sum up two Node to one in java

Our Idea is to sum up each elements in the given two nodes and create a new node.

/**
 * Sum up two Node to one in java
 */
package com.leetcode.algorithms;

/**
 * @author Cfed kozhikode
 *
 */
public class MainClass {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

Solution s = new Solution();

System.out.println(989+989);

ListNode l1 = new ListNode(9);
l1.next = new ListNode(9);
l1.next.next = new ListNode(9);

ListNode l2 = new ListNode(1);
/* l2.next = new ListNode(8);
l2.next.next = new ListNode(9);*/

ListNode a = s.addTwoNumbers(l1, l2);

// System.out.println(a);

while(a!=null) {
System.out.print(a.val+" ");
a=a.next;
}

}

}

package com.leetcode.algorithms;

/**

 * 

 * @author Bithesh

 *

 */

class Solution {

private ListNode parentNode = null;

private int carryforward = 0;

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

int val1 = (null != l1) ? l1.val : 0;

int val2 = (null != l2) ? l2.val : 0;

int sum = val1 + val2 + carryforward;

carryforward = sum / 10;

int value = sum % 10;

parentNode = insertValue(parentNode, value);

ListNode n1 = (l1 == null || l1.next == null) ? null : l1.next;

ListNode n2 = (l2 == null || l2.next == null) ? null : l2.next;

if (n1 != null || n2 != null) {

addTwoNumbers(n1, n2);

}else if (carryforward > 0) {

parentNode = insertValue(parentNode, carryforward);

carryforward = 0;

}

return parentNode;

}

private ListNode insertValue(ListNode node, int data) {

if (node == null) {

return new ListNode(data);

} else {

node.next = insertValue(node.next, data);

}

return node;

}

}

/**

 * 

 */

package com.leetcode.algorithms;

/**

 * @author Bithesh

 *

 */

public class ListNode {

int val;

ListNode next;

ListNode(int x) {

val = x;

}

}