LeetCode 2 Add Two Numbers 模拟,读题 难度:0

https://leetcode.com/problems/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) {}
 * };
 */
class Solution {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
        ListNode* res = new ListNode(0);
        int tmp = 0,cnt = 0;
        ListNode * result = res;
        while(l1||l2||cnt){
            tmp = cnt;
            tmp += (l1?l1->val:0) + (l2?l2->val:0);
            cnt = tmp / 10;
            tmp %= 10;
            if(l1)l1=l1->next;
            if(l2)l2=l2->next;
            res->val = tmp;
            if(l1||l2||cnt){
                res->next = new ListNode(0);
                res = res->next;
            }
        }
        return result;
    }
};