循环链表的C风格实现（单向）

头文件：

#ifndef _CIRCLELIST_H_#define _CIRCLELIST_H_typedef void CircleList;//typedef struct _tag_CircleListNode{struct _tag_CircleListNode* next;}CircleListNode;//创建一个循环链表CircleList* CircleList_Create();//删除一个循环链表void CircleList_Destroy(CircleList* list);//清空一个循环链表void CircleList_Clear(CircleList* list);//返回链表的长度int CircleList_Length(CircleList* list);//在POS位置插入一个节点int CircleList_Insert(CircleList* list, CircleListNode* node, int pos);//获取POS位置节点的信息CircleListNode* CircleList_Get(CircleList* list, int pos);//删除POS位置的节点CircleListNode* CircleList_Delete(CircleList* list, int pos);////与游标相关的函数//删除游标所指的位置节点CircleListNode* CircleList_DeleteNode(CircleList* list, CircleListNode* node);//重置游标位置CircleListNode* CircleList_Reset(CircleList* list);//当前游标位置CircleListNode* CircleList_Current(CircleList* list);//游标的NEXT域CircleListNode* CircleList_Next(CircleList* list);#endif

//Cpp

#include "circleList.h"#include <iostream>using namespace std;//这个为头链表头typedef struct _tag_CircleList{CircleListNode header;CircleListNode* slider;int length;}tagCircleList;//创建一个循环链表CircleList* CircleList_Create(){tagCircleList* ret = (tagCircleList*)malloc(sizeof(tagCircleList));  //分配内存if (ret == NULL){return NULL;}//初始化ret->header.next = NULL;ret->length = 0;ret->slider = NULL;return ret;}//删除一个循环链表void CircleList_Destroy(CircleList* list){if (list = NULL){return;}//释放内存free(list);return;}//清空一个循环链表void CircleList_Clear(CircleList* list){tagCircleList* sList = NULL;sList = (tagCircleList*)list;if (sList == NULL){return ;}//重置为初始化状态sList->header.next = NULL;sList->length = 0;sList->slider = NULL;return;}//返回链表的长度int CircleList_Length(CircleList* list){tagCircleList* sList = NULL;sList = (tagCircleList*)list;int ret = -1;//异常处理if (list == NULL){return ret;}return sList->length;}//在POS位置插入一个节点int CircleList_Insert(CircleList* list, CircleListNode* node, int pos){tagCircleList* sList = NULL;sList = (tagCircleList*)list;int ret = -1;//异常处理if(list == NULL || node == NULL || pos<0){return ret;}//临时变量CurrentCircleListNode* Current = (CircleListNode*)sList;for(int i = 0; (i < pos) && (Current->next != NULL); i++){Current = Current->next;}node->next = Current->next;Current->next = node;//当长度为0时 游标指向nodeif (sList->length == 0){sList->slider = node;}sList->length++;//如果current 依旧指向链表头 证明没跳走 是从0开始插入的 需要头插法if (Current == (CircleListNode*)sList){//定义一个辅助last 变量来获取尾部节点的信息CircleListNode* last = (CircleListNode*)CircleList_Get(sList, sList->length - 1);//将尾部节点的NEXT域存为当前节点（头节点）last->next = Current->next;}return 0;}//获取POS位置节点的信息CircleListNode* CircleList_Get(CircleList* list, int pos){tagCircleList* sList = (tagCircleList*)list;CircleListNode* ret = NULL;int i = 0;if (list == NULL || pos < 0){return NULL;}CircleListNode* Current = (CircleListNode*)sList;for(i = 0; i < pos; i++){Current = Current->next;} ret = Current->next;return ret;}//删除POS位置的节点CircleListNode* CircleList_Delete(CircleList* list, int pos){tagCircleList* sList = (tagCircleList*)list;CircleListNode* ret = NULL;if ((sList != NULL) && (pos >=0) && (sList->length > 0)){//将Current指向表头CircleListNode* Current = (CircleListNode*)(&(sList->header));//辅助节点last 进行头节点的删除使用 存取最后一个元素CircleListNode* last = NULL;for(int i = 0; i < pos; i++){Current = Current->next;}//删除头结点if ( Current == (CircleListNode*)sList){last = (CircleListNode*)CircleList_Get(sList, sList->length - 1);}//要删除的元素ret = Current->next;Current->next = ret->next;sList->length--;//判断链表非空if( last != NULL){//sList->header.next = ret->next;Current->next = ret->next;last->next = ret->next;}//若删除的元素为游标所指的元素if(sList->slider = ret){sList->slider = ret->next;}//若删除元素后 链表长度为0 做处理if (sList->length == 0){sList->header.next = NULL;sList->slider = NULL;}}return ret;}////与游标相关的函数//删除游标所指的位置节点CircleListNode* CircleList_DeleteNode(CircleList* list, CircleListNode* node){tagCircleList* sList = (tagCircleList*)list;CircleListNode* ret = NULL;int i = 0;if (sList != NULL){CircleListNode* Current = (CircleListNode*)sList;//循环查找node 在链表中的位置for (i = 0; i < sList->length; i++){if (Current->next == node){ret = Current->next;break;}Current = Current->next;}//找到了 使用CircleList_Delete 删除if(ret != NULL){CircleList_Delete(list, i);}}return ret;}//重置游标位置CircleListNode* CircleList_Reset(CircleList* list){tagCircleList* sList = (tagCircleList*)list;CircleListNode* ret = NULL;//如果不为空if (sList != NULL){sList->slider = sList->header.next;ret = sList->slider;}return ret;}//当前游标位置CircleListNode* CircleList_Current(CircleList* list){tagCircleList* sList = (tagCircleList*)list;CircleListNode* ret = NULL;//如果不为空if (sList != NULL){ret = sList->slider;}return ret;}//把游标位置返回，游标下移CircleListNode* CircleList_Next(CircleList* list){tagCircleList* sList = (tagCircleList*)list;CircleListNode* ret = NULL;//如果不为空if((sList != NULL) && (sList->slider != NULL)){ret = sList->slider;sList->slider = ret->next;}return ret;}

测试框架如下：

#include "circleList.h"#include <iostream>using namespace std;typedef struct _Temp_Test{CircleListNode node;int temp;char temp2;}TempTast;int main(){CircleList* circlelist = NULL;circlelist = CircleList_Create();//异常处理if (circlelist == NULL){cout << "Create Err "  << endl;return -1;}TempTast t1, t2, t3, t4, t5;t1.temp = 1;t2.temp = 2;t3.temp = 3;t4.temp = 4;t5.temp = 5;//插入元素CircleList_Insert(circlelist, (CircleListNode*)(&t1), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t2), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t3), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t4), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t5), 0);//测试功能cout << "Length: " << CircleList_Length(circlelist) << endl;//遍历两次cout << "遍历两次:" << endl;for(int i = 0; i < 2*CircleList_Length(circlelist); i++){cout <<"Node:" << ((TempTast*)CircleList_Get(circlelist, i))->temp << endl;}cout << endl;//删除第一个节点cout <<"Node:" << ((TempTast*)CircleList_Delete(circlelist, 0))->temp << endl;//清空CircleList_Clear(circlelist);cout << "After Clear Length: " << CircleList_Length(circlelist) << endl;//插入元素CircleList_Insert(circlelist, (CircleListNode*)(&t1), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t2), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t3), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t4), 0);CircleList_Insert(circlelist, (CircleListNode*)(&t5), 0);//删除指定元素cout << "Delete Node :" << ((TempTast*)CircleList_DeleteNode(circlelist, (CircleListNode*)(&t1)))->temp << endl;//显示游标当前位置cout << "Silder Now :" << ((TempTast*)CircleList_Current(circlelist))->temp << endl;//移动后CircleList_Next(circlelist);cout << "Silder After Next :" << ((TempTast*)CircleList_Current(circlelist))->temp << endl;//重置后CircleList_Reset(circlelist);cout << "Silder After Reset :" << ((TempTast*)CircleList_Current(circlelist))->temp << endl;cout << endl;//销毁CircleList_Destroy(circlelist);cout << "circle has been Destroied" << endl;system("pause");return 0;}