一、CircleList.h
#ifndef _CIRCLELIST_H_
#define _CIRCLELIST_H_
typedef void CircleList;
typedef struct _tag_CircleListNode CircleListNode;
struct _tag_CircleListNode
{
CircleListNode* next;
};
CircleList* CircleList_Create(); //創建循環鏈表
void CircleList_Destroy(CircleList* list);
void CircleList_Clear(CircleList* list);
int CircleList_Length(CircleList* list);
int CircleList_Insert(CircleList* list, CircleListNode* node, int pos);
CircleListNode* CircleList_Get(CircleList* list, int pos);
CircleListNode* CircleList_Delete(CircleList* list, int pos);
CircleListNode* CircleList_DeleteNode(CircleList* list, CircleListNode* node); //直接刪除某個元素
CircleListNode* CircleList_Reset(CircleList* list); //將遊標重置指向系統的一個元素
CircleListNode* CircleList_Current(CircleList* list); //獲取當前遊標指向的第一個元素
CircleListNode* CircleList_Next(CircleList* list); //將遊標指向系統的下一個元素
#endif
二、CircleList.c
#include <stdio.h>
#include <malloc.h>
#include "CircleList.h"
typedef struct _tag_CircleList
{
CircleListNode header;
CircleListNode* slider;
int length;
} TCircleList; //創建一個循環鏈表的結構體
CircleList* CircleList_Create() // O(1)
{
TCircleList* ret = (TCircleList*)malloc(sizeof(TCircleList)); //內存動態分配
if( ret != NULL ) //判斷是否分配到內存
{
ret->length = 0; //初始化循環鏈表當前的長度爲0
ret->header.next = NULL; //初始化循環鏈表的頭結點
ret->slider = NULL; //初始化循環鏈表的遊標
}
return ret;
}
void CircleList_Destroy(CircleList* list) // O(1)
{
free(list); //銷燬線性表
}
void CircleList_Clear(CircleList* list) // O(1)
{
TCircleList* sList = (TCircleList*)list;
if( sList != NULL ) //判斷線性表是否合法
{
sList->length = 0; //重置線性表當前長度爲0
sList->header.next = NULL; //初始化頭結點
sList->slider = NULL; //重置遊標的地址
}
}
int CircleList_Length(CircleList* list) // O(1)
{
TCircleList* sList = (TCircleList*)list; //通過強制轉化獲取TCircleList類型的線性表
int ret = -1;
if( sList != NULL ) //判斷循環鏈表是否合法
{
ret = sList->length;
}
return ret;
}
int CircleList_Insert(CircleList* list, CircleListNode* node, int pos) // O(n)
{
TCircleList* sList = (TCircleList*)list; //獲取TCircleList類型的循環鏈表
int ret = (sList != NULL) && (pos >= 0) && (node != NULL);
int i = 0;
if( ret ) //判斷鏈表循環鏈表是否合法,獲取位置是否存在,插入元素是否存在
{
CircleListNode* current = (CircleListNode*)sList; //將當前元素的指針指向頭結點
for(i=0; (i<pos) && (current->next != NULL); i++) //遍歷要插入元素的位置
{
current = current->next;
}
node->next = current->next; //將插入元素的指針域指向當前元素的下一個結點
current->next = node; //而當前元素的指針指向插入當前元素
if( sList->length == 0 ) //若插入的位置爲第一個元素
{
sList->slider = node; //遊標指向第一個元素
node->next = node;//插入的元素要指向本身
}
sList->length++;
}
return ret;
}
CircleListNode* CircleList_Get(CircleList* list, int pos) // O(n)
{
TCircleList* sList = (TCircleList*)list;
CircleListNode* ret = NULL;
int i = 0;
if( (sList != NULL) && (pos >= 0) )
{
CircleListNode* current = (CircleListNode*)sList;
for(i=0; i<pos; i++)
{
current = current->next;
}
ret = current->next;
}
return ret;
}
CircleListNode* CircleList_Delete(CircleList* list, int pos) // O(n)
{
TCircleList* sList = (TCircleList*)list; //創建一個TCrcleListNode類型的新鏈表
CircleListNode* ret = NULL;
int i = 0;
if( (sList != NULL) && (pos >= 0) ) //判斷循環鏈表是否合法,刪除的元素位置是否合法
{
CircleListNode* current = (CircleListNode*)sList; //將當前的指針指向循環鏈表的頭結點地址
CircleListNode* first = sList->header.next;//初始化frist爲頭結點指向的下一個元素
CircleListNode* last = (CircleListNode*)CircleList_Get(sList, sList->length - 1);//last初始化爲最後倒數第二個元素
for(i=0; i<pos; i++) //通過遍歷,獲取我們要刪除元素的前一個
{
current = current->next;
}
ret = current->next; //ret理解爲要刪除的元素
current->next = ret->next; //current,直接指向刪除元素的下一個元素
sList->length--;
if( first == ret ) //當刪除的是第一個元素時
{
sList->header.next = ret->next; //頭結點指針指向第二個元素
last->next = ret->next; //最後一個元素也指向第二個元素
}
if( sList->slider == ret ) //如果遊標指向爲要刪除的元素時,遊標應下移一位
{
sList->slider = ret->next;
}
if( sList->length == 0 ) //當刪除的元素爲最後一個元素時要初始化
{
sList->header.next = NULL;
sList->slider = NULL;
}
}
return ret;
}
CircleListNode* CircleList_DeleteNode(CircleList* list, CircleListNode* node) // 直接刪除某個元素
{
TCircleList* sList = (TCircleList*)list;
CircleListNode* ret = NULL;
int i = 0;
if( sList != NULL )
{
CircleListNode* current = (CircleListNode*)sList;
for(i=0; i<sList->length; i++) //通過遍歷,當current指向我們要刪除的元素時,停止遍歷,獲取刪除元素的位置
{
if( current->next == node )
{
ret = current->next;
break;
}
current = current->next;
}
if( ret != NULL )
{
CircleList_Delete(sList, i); //通過元素的位置進行刪除
}
}
return ret;
}
CircleListNode* CircleList_Reset(CircleList* list) // 將遊標重置到循環鏈表的第一個數據元素
{
TCircleList* sList = (TCircleList*)list;
CircleListNode* ret = NULL;
if( sList != NULL )
{
sList->slider = sList->header.next;
ret = sList->slider;
}
return ret;
}
CircleListNode* CircleList_Current(CircleList* list) // 獲取遊標指向的位置的元素
{
TCircleList* sList = (TCircleList*)list;
CircleListNode* ret = NULL;
if( sList != NULL )
{
ret = sList->slider;
}
return ret;
}
CircleListNode* CircleList_Next(CircleList* list) // 將遊標指向鏈表的下一個元素
{
TCircleList* sList = (TCircleList*)list;
CircleListNode* ret = NULL;
if( (sList != NULL) && (sList->slider != NULL) )
{
ret = sList->slider;
sList->slider = ret->next;
}
return ret;
}
三、main.c
#include <stdio.h>
#include <stdlib.h>
#include "CircleList.h"
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
struct Value
{
CircleListNode header;
int v;
};
int main(int argc, char *argv[])
{
int i = 0;
CircleList* list = CircleList_Create();
struct Value v1;
struct Value v2;
struct Value v3;
struct Value v4;
struct Value v5;
struct Value v6;
struct Value v7;
struct Value v8;
v1.v = 1;
v2.v = 2;
v3.v = 3;
v4.v = 4;
v5.v = 5;
v6.v = 6;
v7.v = 7;
v8.v = 8;
CircleList_Insert(list, (CircleListNode*)&v1, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v2, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v3, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v4, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v5, 5);
CircleList_Delete(list, 0);
for(i=0; i<2*CircleList_Length(list); i++)
{
struct Value* pv = (struct Value*)CircleList_Get(list, i);
printf("%d\n", pv->v);
}
printf("\n");
while( CircleList_Length(list) > 0 )
{
struct Value* pv = (struct Value*)CircleList_Delete(list, 0);
printf("%d\n", pv->v);
}
printf("\n");
CircleList_Insert(list, (CircleListNode*)&v1, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v2, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v3, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v4, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v5, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v6, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v7, CircleList_Length(list));
CircleList_Insert(list, (CircleListNode*)&v8, CircleList_Length(list));
for(i=0; i<CircleList_Length(list); i++)
{
struct Value* pv = (struct Value*)CircleList_Next(list);
printf("%d\n", pv->v);
}
printf("\n");
CircleList_Reset(list);
while( CircleList_Length(list) > 0 )
{
struct Value* pv = NULL;
for(i=1; i<3; i++)
{
CircleList_Next(list);
}
pv = (struct Value*)CircleList_Current(list);
printf("%d\n", pv->v);
CircleList_DeleteNode(list, (CircleListNode*)pv);
}
CircleList_Destroy(list);
return 0;
}