利用二级指针删除单向链表节点

// testPPointer.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include <stdlib.h>typedef struct tagNode{struct tagNode* m_next;int m_nVal;}Node, *PNode;// 通过二级指针方式删除节点void DelNode_Val2(PNode* ppHead, int nVal);void DelNode_Val2(PNode* ppHead, int nVal){ for (PNode* ppCurr = ppHead; *ppCurr != NULL;) { PNode pEntry = *ppCurr; if (pEntry->m_nVal == nVal) {*ppCurr = pEntry->m_next;free(pEntry); } else {ppCurr = &pEntry->m_next; } }}void DelNode_Val(PNode* ppHead, int nVal);void DelNode_Val(PNode* ppHead, int nVal){for (PNode pPre = NULL, pCurr = *ppHead; pCurr != NULL;){PNode pNext = pCurr->m_next;if (pCurr->m_nVal == nVal){if (pPre == NULL){*ppHead = pNext;}else{pPre->m_next = pNext;}free(pCurr);}else{pPre = pCurr;}pCurr = pNext;}}void OutPut(PNode pHead);void OutPut(PNode pHead){for (PNode pCurr = pHead; pCurr != NULL; pCurr = pCurr->m_next){printf("address:%d, val:%d\r\n", pCurr, pCurr->m_nVal);}}int _tmain(int argc, _TCHAR* argv[]){PNode pnode1 = (PNode)malloc(sizeof(Node));pnode1->m_nVal = 1;PNode pnode2 = (PNode)malloc(sizeof(Node));pnode2->m_nVal = 2;PNode pnode3 = (PNode)malloc(sizeof(Node));pnode3->m_nVal = 3;PNode pnode4 = (PNode)malloc(sizeof(Node));pnode4->m_nVal = 4;PNode pnode5 = (PNode)malloc(sizeof(Node));pnode5->m_nVal = 5;PNode pnode6 = (PNode)malloc(sizeof(Node));pnode6->m_nVal = 6;pnode1->m_next = pnode2;pnode2->m_next = pnode3;pnode3->m_next = pnode4;pnode4->m_next = pnode5;pnode5->m_next = pnode6;pnode6->m_next = NULL;PNode pHead = pnode1;OutPut(pHead);printf("*******************************\r\n");DelNode_Val(&pHead, 3);OutPut(pHead);printf("*******************************\r\n");DelNode_Val2(&pHead, 4);OutPut(pHead);return 0;}