2 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

My Submissions

/**
* 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* resHead = NULL;
ListNode* curNode = resHead;

int carry = 0;

while(l1!=NULL||l2!=NULL||carry>0)
{
int num1 = 0;
if(l1!=NULL)
{
num1 = l1->val;
l1 = l1->next;
}

int num2 = 0;
if(l2!=NULL)
{
num2 = l2->val;
l2 = l2->next;
}

int sum = num1+num2+carry;

ListNode* tempNode = (ListNode*)malloc(sizeof(ListNode));
tempNode->val = sum%10;
tempNode->next = NULL;
carry = sum/10;

if(curNode == NULL)
{
curNode = tempNode;
resHead = curNode;
}
else
{
curNode->next = tempNode;
curNode = tempNode;
}
}

return resHead;
}
};