/**

* You are given two non-empty linked lists representing two non-negative

* integers. The digits are stored in reverse order, and each of their nodes

* contains a single digit. Add the two numbers and return the sum as a linked

* list.

*

* You may assume the two numbers do not contain any leading zero, except the

* number 0 itself.

*/

/**

* Definition for singly-linked list. public class ListNode { int val; ListNode

* next; ListNode() {} ListNode(int val) { this.val = val; } ListNode(int val,

* ListNode next) { this.val = val; this.next = next; } }

*/

class Solution {

public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

ListNode ans = new ListNode();

ListNode temp = ans;

int carry = 0;

while (l1 != null || l2 != null || carry != 0) {

int s = 0;

if (l1 != null) {

s += l1.val;

l1 = l1.next;

}

if (l2 != null) {

s += l2.val;

l2 = l2.next;

}

s += carry;

carry = s / 10;

ListNode n = new ListNode(s % 10);

temp.next = n;

temp = temp.next;

}

return ans.next;

}

}