码迷,mamicode.com
首页 > 其他好文 > 详细

[LintCode] Reverse Linked List 倒置链表

时间:2016-10-12 00:14:21      阅读:149      评论:0      收藏:0      [点我收藏+]

标签:

 

Reverse a linked list.

Example

For linked list 1->2->3, the reversed linked list is 3->2->1

Challenge 

Reverse it in-place and in one-pass

 

LeetCode上的原题,请参见我之前的博客Reverse Linked List

 

解法一:

class Solution {
public:
    /**
     * @param head: The first node of linked list.
     * @return: The new head of reversed linked list.
     */
    ListNode *reverse(ListNode *head) {
        if (!head) return NULL;
        ListNode *dummy = new ListNode(-1), *cur = head;
        dummy->next = head;
        while (cur->next) {
            ListNode *t = cur->next;
            cur->next = t->next;
            t->next = dummy->next;
            dummy->next = t;
        }
        return dummy->next;
    }
};

 

解法二:

class Solution {
public:
    /**
     * @param head: The first node of linked list.
     * @return: The new head of reversed linked list.
     */
    ListNode *reverse(ListNode *head) {
        if (!head || !head->next) return head;
        ListNode *t = head;
        head = reverse(t->next);
        t->next->next = t;
        t->next = NULL;
        return head;
    }
};

 

[LintCode] Reverse Linked List 倒置链表

标签:

原文地址:http://www.cnblogs.com/grandyang/p/5951061.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!