题目：输入一个链表的头结点，反转该链表，并返回反转后链表的头结点。

题目：输入一个链表的头结点，反转该链表，并返回反转后链表的头结点。链表结点定义如下：
struct ListNode

{

    int       m_nKey;

    ListNode* m_pNext;

};
c语言实现
/*
File : rlink.c
Author :
Date : 2015/4/4
platform : windows7 x86_64
version : 1.0
Function : 反转一个链表
*/

#include <stdio.h>
#include <stdlib.h>
typedef struct _LinkNode
{
int m_nKey;
struct _LinkNode* m_npNext;
}LinkNode , *pLinkNode;
/*
创建链表 以0结尾
*/
pLinkNode create()
{
pLinkNode pHead = NULL , pCur , pNext;
int nData;
if(scanf("%d" , &nData) , nData)
{
pHead = (pLinkNode)malloc(sizeof(LinkNode));
pCur = pNext = pHead;
pHead->m_nKey = nData;
pNext->m_npNext = NULL;
}
else
{
return NULL;
}
while(scanf("%d" , &nData) , nData)
{
pNext = (pLinkNode)malloc(sizeof(LinkNode));
pNext->m_nKey = nData;
pCur->m_npNext = pNext;
pCur = pNext;
pNext->m_npNext = NULL;
}
return pHead;
}
void showLink(pLinkNode pHead)
{
while(pHead)
{
printf("%d " , pHead->m_nKey);
pHead = pHead->m_npNext;
}
printf("\n");
}
pLinkNode reverseLink(pLinkNode pHead)
{
pLinkNode pCur , prHead ;
pCur = pHead->m_npNext;
if(!pHead)
{
return NULL;
}
prHead = pHead;
while(pCur)
{
pHead->m_npNext = pCur->m_npNext; // A->B->C->D->NULL pHead = prHead = A
pCur->m_npNext = prHead; //pCur->m_npNext变为新的头节点
prHead = pCur;
pCur = pHead->m_npNext; //pCur始终是pHead->m_npNext
}
return prHead;
}
int main(int argc , char *argv[])
{
pLinkNode pHead = create();
showLink(pHead);
pHead = reverseLink(pHead);
showLink(pHead);
return 0;
}