Cinte's Leetcode Record
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面试题 02.05. 链表求和

Posted on Edited on In Disqus:
Symbols count in article: 752 Reading time ≈ 1 mins.

面试题 02.05. 链表求和

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/**
 * 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)
            return l2;
        if(!l2)
            return l1;
        int c = 0;
        ListNode* ret = l1;
        ListNode* pre = nullptr;
        while(l1 && l2)
        {
            l1->val += l2->val + c;
            c = l1->val / 10;
            l1->val %= 10;
            pre = l1;
            l1 = l1->next;
            l2 = l2->next;
        }
        if(l2)
        {
            pre->next = l2;
            l1 = l2;
        }
        while(c)
        {
            if(l1)
            {
                l1->val += c;
                c = l1->val / 10;
                l1->val %= 10;
                pre = l1;
                l1 = l1->next;
            }else
            {
                pre->next = new ListNode(c);
                break;
            }
        }
        return ret;
    }
};

还可以新建个链表直接递归

不想写