/**
* 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) {
int sum=0;
ListNode* l3=new ListNode(0);
ListNode* l4=l3;
while(l1!=NULL||l2!=NULL||sum>0)
{
if(l1!=NULL)
{
sum+=l1->val;
l1=l1->next;
}
if(l2!=NULL)
{
sum+=l2->val;
l2=l2->next;
}
l4->next=new ListNode(sum%10);
l4=l4->next;
sum/=10;
}
return l3->next;
}
};