Python3实现的反转单链表算法示例

本文实例讲述了Python3实现的反转单链表算法。分享给大家供大家参考，具体如下：

反转一个单链表。

方案一:迭代

# Definition for singly-linked list.
# class ListNode:
#   def __init__(self, x):
#     self.val = x
#     self.next = None
class Solution:
  def reverseList(self, head):
    """
    :type head: ListNode
    :rtype: ListNode
    """
    cur, pre = head, None
    while cur:
      cur.next, pre, cur = pre, cur, cur.next
    return pre

方案二：递归

# -*- coding:utf-8 -*-
# class ListNode:
#   def __init__(self, x):
#     self.val = x
#     self.next = None
class Solution:
  # 返回ListNode
  def ReverseList(self, pHead):
    # write code here
    if not pHead or not pHead.next:
      return pHead
    else:
      newHead = self.ReverseList(pHead.next)
      pHead.next.next=pHead
      pHead.next=None
      return newHead

希望本文所述对大家Python程序设计有所帮助。