Leetcode Problem.2—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) {}
 * };
 */

My C++ solution!

 ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) 
    {
    ListNode *result=new ListNode(0);
	ListNode *s=result;
	bool jinwei=false;
    int temp;
    if(l1==NULL&&l2==NULL)
		return result->next;
    while(l1!=NULL||l2!=NULL)
        {
            if(l1==NULL)
                temp=l2->val+jinwei;
            else if(l2==NULL)
                temp=l1->val+jinwei;
            else
                temp=l1->val+l2->val+jinwei;
			jinwei=(temp>=10)?true:false;
            temp=temp%10;
            s->next=new ListNode(temp);  //这两步的逻辑很容易写错
			s=s->next;
	      if(l1!=NULL)
		  {
            l1=l1->next;
		  }
		  if(l2!=NULL)
		  {
            l2=l2->next;
		  }
        }
        if(jinwei)
        {
            s->next=new ListNode(1);
        }
		return result->next;
    }