首页 > 代码库 > [leetcode]Swap Nodes in Pairs @ Python
[leetcode]Swap Nodes in Pairs @ Python
原题地址:http://oj.leetcode.com/problems/swap-nodes-in-pairs/
Given a linked list, swap every two adjacent nodes and return its head.
For example,
Given 1->2->3->4, you should return the list as 2->1->4->3.
Your algorithm should use only constant space. You may not modify the values in the list, only nodes itself can be changed.
题意:将链表中的节点两两交换。Given 1->2->3->4
, you should return the list as 2->1->4->3
.
解题思路:这题主要涉及到链表的节本操作。加一个头结点,操作起来会很方便。另外配了一个示意图 [本图是我asrman原创]
代码:
# Definition for singly-linked list.# class ListNode:# def __init__(self, x):# self.val = x# self.next = Noneclass Solution: # @param a ListNode # @return a ListNode def swapPairs(self, head): pre = ListNode(0) pre.next = head curr = head head = pre while curr and curr.next: # curr =1, curr.next =2 pre.next = curr.next # 0 --> 2 curr.next = pre.next.next # 1 --> 3 # curr.next.next pre.next.next = curr # 3 --> 1 pre = curr # pre = 1 curr = curr.next # curr= 3 return head.next
参考:
https://oj.leetcode.com/discuss/3608/seeking-for-a-better-solution
[leetcode]Swap Nodes in Pairs @ Python
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。