循环链表（循环链表图解）

优点缺点:

无需一次性定制链表的容量

插入和删除操作无需移动数据元素

缺点:

数据元素必须保存后继元素的位置信息

获取指定数据的元素操作需要顺序访问之前的元素

struct Value
{
	CircleListNode circlenode;
	int v;
};

int main(int argc,char *argv[])
{
	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;

	int i = 0;
	v1.v = 1;
	v1.v = 2;
	v1.v = 3;
	v1.v = 4;
	v1.v = 5;
	v1.v = 6;
	v1.v = 7;
	v1.v = 8;

	CircleList_Insert(list, (CircleListNode*)&v1, 0);
	CircleList_Insert(list, (CircleListNode*)&v2, 0);
	CircleList_Insert(list, (CircleListNode*)&v3, 0);
	CircleList_Insert(list, (CircleListNode*)&v4, 0);

	for (i = 0; i < 2 * CircleList_Length(list); i++)
	{
		struct Value*pv = (struct Value*)CircleList_Get(list, i);
		printf("%d\n", pv->v);
	}
	while(CircleList_Length(list)>0)
	{
		CircleList_Delete(list, 0);
	}
	CircleList_Destory(list);
	system("pause");
	return 0;
}

typedef  struct  _tag_CircleList
{
	CircleListNode   header;
	CircleListNode*  slider;
	int length;
}TCircleList;

CircleList* CircleList_Create()
{
	TCircleList* ret = (TCircleList*)malloc(sizeof(TCircleList));
	if (ret == NULL)
	{
		return NULL;
	}
	ret->length = 0;
	ret->header.next = NULL;
	ret->slider = NULL;
	return ret;
}

void CircleList_Destroy(CircleList* list)
{
	if (list == NULL)
	{
		return;
	}
	free(list);
}

void CircleList_Clear(CircleList* list)
{
	TCircleList* list = (TCircleList*)list;
	if (sList == NULL)
	{
		return;
	}
	sList->length = 0;
	sList->header.next = NULL;
	sList->slider = NULL;
}

int  CircleList_Length(CircleList* list)
{
	TCircleList* sList = (TCircleList*)list;
	int ret = -1;
	if (list == NULL)
	{
		return ret;
	}
	ret = sList->length;
	return ret;
}

int CircleList_Insert(CircleList* list, CircleListNode* node, int pos)
{
	int ret = 0, i = 0;
	TCircleList* sList = (TCircleList*)list;
	if (list == NULL || node == NULL || pos < 0)
	{
		return -1;
	}

	{
		CircleListNode* current = (CircleListNode*)sList;
		for (i = 0; (i < pos) && (current->next != NULL); i++)
		{
			current = current->next;
		}
		node->next = current->next;
		current->next = node;
		//若第一次插入节点
		if (sList->length == 0)
		{
			sList->slider = node;
		}
		sList->length++;
		//
		if (current == (CircleListNode*)sList)
		{
			//获取最后一个元素
			CircleListNode* last = CircleList_Get(sList, sList->length - 1);
			last->next = current->next;
		}
	}
	return ret;
}

CircleListNode* CircleList_Get(CircleList* list, int pos)
{
	TCircleList* sList = (TCircleList*)list;
	CircleListNode* ret = NULL;
	int i = 0;
	if (list == NULL || pos < 0)
	{
		return NULL;
	}
}
int main(int argc,char *argv[])
{
	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;

	int i = 0;
	v1.v = 1;
	v1.v = 2;
	v1.v = 3;
	v1.v = 4;
	v1.v = 5;
	v1.v = 6;
	v1.v = 7;
	v1.v = 8;

	CircleList_Insert(list, (CircleListNode*)&v1, 0);
	CircleList_Insert(list, (CircleListNode*)&v2, 0);
	CircleList_Insert(list, (CircleListNode*)&v3, 0);
	CircleList_Insert(list, (CircleListNode*)&v4, 0);

	for (i = 0; i < 2 * CircleList_Length(list); i++)
	{
		struct Value*pv = (struct Value*)CircleList_Get(list, i);
		printf("%d\n", pv->v);
	}
	while(CircleList_Length(list)>0)
	{
		CircleList_Delete(list, 0);
	}
	CircleList_Destory(list);
	system("pause");
	return 0;
}