剑指offer-题16：反转链表

题目描述

解决思路：

/*
public class ListNode {
int val;
ListNode next = null;

ListNode(int val) {
this.val = val;
}
}*/
public class Solution {
public ListNode ReverseList(ListNode head) {
ListNode pNode = head;
ListNode pPrev = null;
ListNode pNest = null;
ListNode pReversedHead = null;
while (pNode != null) {
pNest = pNode.next;
if (pNest == null) {
pReversedHead = pNode;
}
pNode.next = pPrev;
pPrev = pNode;
pNode = pNest;
}
return pReversedHead;
}
}

# -*- 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
pNode = pHead
pPrev = None
pReversedHead = None
while pNode is not None:
pNext = pNode.next
if pNext is None:
pReversedHead = pNode
pNode.next = pPrev
pPrev = pNode
pNode = pNext
return pReversedHead