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## LeetCode 2. Add Two Numbers

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 it as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Example:

```Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.```

Solution

```/**
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Question2Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

int carry = 0;

while (l1 != null || l2 != null) {
int x1 = (l1 != null ? l1.val : 0);
int x2 = (l2 != null ? l2.val : 0);

int sum = x1 + x2 + carry;
carry = sum / 10;
currNode.next = new ListNode(sum % 10);
currNode = currNode.next;

if (l1 != null) l1 = l1.next;
if (l2 != null) l2 = l2.next;

}

if (carry == 1) {
currNode.next = new ListNode(carry);
}