LeetCode 2. Add Two Numbers

non-empty

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)

Output:

answer:

class Solution {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
        ListNode * resultP = new ListNode(0) ;
        ListNode * head = resultP;
        ListNode * pre ;
        
        while((l1 != NULL) && (l2 != NULL)){
            int jinwei = resultP->val;
            int sum = l1->val + l2->val + jinwei;
            jinwei = sum / 10;
            sum = sum % 10;
            pre = resultP;
            resultP->val = sum;
            resultP->next = new ListNode(jinwei);
            resultP = resultP->next;
            l1 = l1->next;
            l2 = l2->next;
        }
        ListNode * temp =NULL;
        if(l1 != NULL)  temp = l1;
        if(l2 != NULL)  temp = l2;
        while(temp != NULL){
            int jinwei = resultP->val;
            int sum = temp->val + jinwei;
            jinwei = sum / 10;
            sum = sum % 10;
            pre = resultP;
            resultP->val = sum;
            resultP->next = new ListNode(jinwei);
            resultP = resultP->next;
            temp = temp->next;
        }
        if(resultP->val == 0)
            pre->next = NULL;
        return head;
    }
};