双向循环链表简单实现

#include <iostream>

using namespace std;

struct Info

{

int nNo;

char szNo[20];

};

struct InfoListNode

{

Info info;

InfoListNode *next;

InfoListNode *prev;

};

InfoListNode *g_list = NULL;

//插入队首

void insertBegin(InfoListNode *pList)

{

g_list->next->prev = pList;

pList->next = g_list->next;

pList->prev = g_list;

g_list->next = pList;

}

//插入队尾

void insertEnd(InfoListNode *pList)

{

g_list->prev->next = pList;

pList->prev = g_list->prev;

g_list->prev = pList;

pList->next = g_list;

}

//删除某个元素

void deleteItem(InfoListNode *pList)

{

pList->next->prev = pList->prev;

pList->prev->next = pList->next;

delete pList;

pList = NULL;

}

void LoopPrint(int n)

{

printf("%d time\n", n);

InfoListNode *pList = g_list->next;

while(pList != g_list)

{

printf("%d ", pList->info.nNo);

pList = pList->next;

}

printf("\n");

}

void InitList()

{

if (g_list == NULL)

{

g_list = new InfoListNode;

g_list->next = g_list;

g_list->prev = g_list;

}

else

{

InfoListNode *pList = g_list->next;

while(pList != g_list)

{

InfoListNode *tmp = pList;

pList = pList->next;

deleteItem(tmp);

}

}

}

int main()

{

g_list = new InfoListNode;

g_list->next = g_list;

g_list->prev = g_list;

int iCount = 0;

InfoListNode* pTmp = new InfoListNode;

pTmp->info.nNo = 0;

insertBegin(pTmp);

LoopPrint(iCount++);

InfoListNode* pTmp1 = new InfoListNode;

pTmp1->info.nNo = 1;

insertBegin(pTmp1);

LoopPrint(iCount++);

InfoListNode* pTmp2 = new InfoListNode;

pTmp2->info.nNo = 2;

insertBegin(pTmp2);

LoopPrint(iCount++);

InfoListNode* pTmp3 = new InfoListNode;

pTmp3->info.nNo = 3;

insertEnd(pTmp3);

LoopPrint(iCount++);

deleteItem(pTmp1);

LoopPrint(iCount++);

InitList();

LoopPrint(iCount++);

InfoListNode* pTmp4 = new InfoListNode;

pTmp4->info.nNo = 4;

insertBegin(pTmp4);

LoopPrint(iCount++);

system("pause");

return 0;

}