技術標籤：Daily Leetcode其他

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode() : val(0), next(nullptr) {}
 *     ListNode(int x) : val(x), next(nullptr) {}
 *     ListNode(int x, ListNode *next) : val(x), next(next) {}
 * };
 */
class Solution
 
 {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
        ListNode *result = new ListNode(0);
        ListNode *l3 = result;
        int agr = 0;
        while(nullptr != l1 && nullptr != l2){
            l3->next = new ListNode(0);//需要new的時候再new一個
            l3 = l3->next;
 

            l3->val = l1->val + l2->val + agr;
            agr = 0;
            if(l3->val > 9){
                l3->val = l3->val % 10;
                agr = 1;
            }
            l1 = l1->next;
            l2 = l2->next;
        }
        while(nullptr != l1 &&
 
 nullptr == l2){
            l3->next = new ListNode(0);
            l3 = l3->next;
            l3->val = l1->val + agr;
            agr = 0;
            if(l3->val > 9){
                l3->val = l3->val % 10;
                agr = 1;
            }
            l1 = l1->next;
        }
        while(nullptr == l1 && nullptr != l2){
            l3->next = new ListNode(0);
            l3 = l3->next;
            l3->val = l2->val + agr;
            agr = 0;
            if(l3->val > 9){
                l3->val = l3->val % 10;
                agr = 1;
            }
            l2 = l2->next;
        }
        if(agr){//最後一位如果進位
            l3->next = new ListNode(0);
            l3 = l3->next;
            l3->val = 1;
        }
        return result->next;
    }
};