C数据结构与算法-基础整理-线性表-02：双向链表操作集

0x01.结构

typedef struct SLIST
{
	int data;
	struct SLIST * next;
	struct SLIST* front;
}SLIST;

SLIST* head=NULL;//全局指针
SLIST* end = NULL;

0x02.创建

void CreateList()
{
	head = (SLIST*)malloc(sizeof(SLIST));
	head->next = head->front = NULL;
	end = NULL;
}

0x03.增

void AddData(int m)
{
	if (head == NULL)
	{
		printf("头结点为空，无法插入！！！");
		return;
	}
	SLIST* tmphead = head;
	if (tmphead->next == NULL)//当只有一个头结点的时候
	{
		SLIST* pnew = (SLIST*)malloc(sizeof(SLIST));
		pnew->data = m;
		pnew->next = tmphead->next;//核心代码
		tmphead->next = pnew;
		pnew->front = tmphead;
		end=pnew;
	}
	else
	{
		SLIST* pnew = (SLIST*)malloc(sizeof(SLIST));
		pnew->data = m;
		/*tmphead->next->front = pnew;//核心代码
		pnew->front = tmphead;
		pnew->next = tmphead->next;
		tmphead->next = pnew;
		*/
		end->next = pnew;
		pnew->front = end;
		pnew->next = NULL;
		end=end->next;	
		
	}
}

0x04.删

void DeleteData(int m)
{
	if (head == NULL)
	{
		printf("链表为空！！！");
		return;
	}
	SLIST* tmphead = head;
	while (tmphead->next != NULL)
	{
		tmphead = tmphead->next;
		if (tmphead->data == m)
		{
			tmphead->front->next = tmphead->next;//核心代码
			tmphead->next->front = tmphead->front;//
			break;
		}
	}
	free(tmphead);
	return;
}

0x05.遍历

void PrintData()
{
	if (head == NULL)
	{
		printf("链表为空！！！");
		return;
	}
	SLIST* tmphead = head;
	printf("正向输出结果：\n");
	while (tmphead->next != NULL)
	{
		tmphead = tmphead->next;
		printf("%d\n", tmphead->data);
	}
	//从尾开始遍历
	printf("反向输出结果：\n");
	while (tmphead->front->front != NULL)
	{
		printf("%d\n", tmphead->data);
		tmphead = tmphead->front;
	}
	printf("%d\n", tmphead->data);
	return;
}

0x06.主函数测试

int main()
{
	int n,i,m;
	CreateList();
	printf("你想为双向链表添加几个元素？？？");
	scanf("%d", &n);
	for (i = 0; i < n; i++)
	{
		printf("\n添加第 %d 个元素: 为多少？",i+1);
		scanf("%d", &m);
		AddData(m);
	}
	printf("添加完毕！！！\n");
	PrintData();
	printf("你想删除的元素的值为多少？");
	scanf("%d", &m);
	DeleteData(m);
	PrintData();

}