1 #include "stdafx.h"
2 #include <iostream>
3 /*
4 题目:在O(1)时间删除链表结点
5 给定单向链表的头指针和一个结点指针，定义一个函数在O(1)时间删除该结点。链表结点与函数定义如下:
6 struct ListNode
7 {
8 int m_nValue;
9 ListNode *m_pNext;
10 };
11 void DeleteNode(ListNode** pListHead,ListNode* pToBeDeleted);
12 */
13 using namespace std;
14 struct ListNode
15 {
16 int m_nValue;
17 ListNode *m_pNext;
18 };
19 void DeleteNode(ListNode** pListHead,ListNode* pToBeDeleted)
20 {
21 if (pListHead ==NULL||pToBeDeleted==NULL)
22 {
23 return;
24 }
25 //删除的不是尾结点
26 if(pToBeDeleted->m_pNext!=NULL)
27 {
28 ListNode* pNext = pToBeDeleted->m_pNext;
29 pToBeDeleted->m_nValue=pNext->m_nValue;
30 pToBeDeleted->m_pNext=pNext->m_pNext;
31 delete pNext;
32 pNext=NULL;
33 }
34 //链表只有一个结点
35 else if(*pListHead==pToBeDeleted)
36 {
37 delete pToBeDeleted;
38 pToBeDeleted=NULL;
39 *pListHead = NULL;
40 }
41 //如果要删除的是尾结点
42 else
43 {
44 ListNode* pNode = *pListHead;
45 while(pNode->m_pNext!=pToBeDeleted)
46 pNode=pNode->m_pNext;
47 pNode->m_pNext = NULL;
48 delete pToBeDeleted;
49 pToBeDeleted=NULL;
50 }
51 }
52
53
54 int _tmain(int argc, _TCHAR* argv[])
55 {
56
57 return 0 ;
58 }
