题解 | #反转链表#

#coding:utf-8
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param head ListNode类 
# @return ListNode类
#
class Solution:
    def ReverseList(self , head ):
        # write code here
       pre = None
       cur = head
       if head and head.next is None:
            return head
       else:
            while (cur):
                temp = cur.next
                cur.next = pre
                pre = cur
                cur = temp
       return pre

解题思路：

1.首先保存当前指向temp = cur.next

2.让当前指向指向前一个 cur.next = pre

3.右移前一个的位置 pre= cur

4.右移当前位置 cur = temp