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 the sum as a linked list.

class Solution {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
        ListNode*dummy = new ListNode();
        ListNode*temp = dummy;
        int carry = 0;

        while(l1!= NULL || l2!=NULL ||carry){
            int sum = 0;
            if(l1!=NULL){
                sum+=l1->val;
                l1=l1->next;
            }
            if(l2!=NULL){
                sum+=l2->val;
                l2=l2->next;
            }
            sum+=carry;
            carry = sum/10;
            ListNode*newnode = new ListNode(sum%10);
            temp->next = newnode;
            temp =temp->next;
        }
        return dummy->next;

        }



};