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) {
if(l1==NULL||NULL==l2)
return NULL;
ListNode *head=new ListNode(0),*pNode=head,*p=NULL;
int carryNum=0;
while(l1!=NULL||l2!=NULL)
{
int s=0;
if(l1!=NULL)
s=l1->val,l1=l1->next;
if(l2!=NULL)
s+=l2->val,l2=l2->next;
pNode->next=new ListNode((s+carryNum)%10);
carryNum=(s+carryNum)/10;
pNode=pNode->next;
}
if(carryNum!=0)
pNode->next=new ListNode(carryNum);
p=head->next;
delete head;
return p;
}
};