LeetCode -- Add Two Numbers

Add Two Numbers

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)

Output: 7 -> 0 -> 8

/**
* Definition for singly-linked list.
* struct ListNode {
*     int val;
*     ListNode *next;
*     ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
ListNode *newNode = new ListNode(0);
ListNode *resultNode = newNode;
int carry = 0;

while(l1!=NULL||l2!=NULL){
int v = 0;
if(l1!=NULL){
v = l1->val;
l1 = l1->next;
}
if(l2!=NULL){
v +=l2->val;
l2 = l2->next;
}
resultNode->next = new ListNode((v+carry)%10);
carry = (v+carry)/10;
resultNode = resultNode->next;
}
if(carry>0){
resultNode->next = new ListNode(1);
}

return newNode->next;
}
};