循环链表的操作

• 循环链表的创建
• 增加
• 插入
• 删除
• 完整代码

void create(int x)
{
	node* newnode = new node;
	newnode->v = x;
	head = tail = newnode;
	newnode->next = head;
	num++;
}

void add(int x)
{
	if (num == 0)
	{
		printf("链表为空n");
		return;
	}
	else
	{
		node* newnode = new node;
		newnode->v = x;
		newnode->next = head;
		tail->next = newnode;
		tail = newnode;
	}
	num += 1;
}

void Insert(int index,int x)
{
	if (num == 0)
	{
		node* newnode = new node;
		newnode->v = x;
		head = tail = newnode;
	}
	else
	{
		if (index<1 || index>num)
		{
			printf("越界n");
			return;
		}
		else
		{
			node* search = head;
			int j = 1;
			for (j = 1; j < index - 1; j++)
			{
				search = search->next;
				if (search == head)
				{
					break;
				}
			}
			if (j
				printf("越界n");
				return;
			}
			node* newnode = new node;
			node* t = search->next;
			newnode->v = x;
			newnode->next = t;
			search->next = newnode;
		}
	}
	num++;
}

void Delete(int index)
{
	if (index<1 || index>num)
	{
		printf("越界n");
		return;
	}
	else
	{
		if (index == 1)
		{
			node* t = head;
			head = head->next;
			tail->next = head;
			delete t;
		}
		else
		{
			node* search = head;
			for (int j = 1; j < index - 1; j++)
			{
				search = search->next;
				if (search == head)
				{
					break;
				}
			}
			if (search == head)
			{
				printf("越界n");
				return;
			}
			node* t = search->next;
			search->next = t->next;
			delete t;
		}
	}
	num--;
}

#include
using namespace std;
struct node
{
	int v;
	struct node* next;
};
node* head, * tail;
int num = 0;
void create(int x)
{
	node* newnode = new node;
	newnode->v = x;
	head = tail = newnode;
	newnode->next = head;
	num++;
}
void show(void)
{
	node* search = head;
	for (int i = 0; i < num; i++)
	{
		printf("%d ", search->v);
		search = search->next;
	}
	printf("n");
}
void Insert(int index,int x)
{
	if (num == 0)
	{
		node* newnode = new node;
		newnode->v = x;
		head = tail = newnode;
	}
	else
	{
		if (index<1 || index>num)
		{
			printf("越界n");
			return;
		}
		else
		{
			node* search = head;
			int j = 1;
			for (j = 1; j < index - 1; j++)
			{
				search = search->next;
				if (search == head)
				{
					break;
				}
			}
			if (j
				printf("越界n");
				return;
			}
			node* newnode = new node;
			node* t = search->next;
			newnode->v = x;
			newnode->next = t;
			search->next = newnode;
		}
	}
	num++;
}
void Delete(int index)
{
	if (index<1 || index>num)
	{
		printf("越界n");
		return;
	}
	else
	{
		if (index == 1)
		{
			node* t = head;
			head = head->next;
			tail->next = head;
			delete t;
		}
		else
		{
			node* search = head;
			for (int j = 1; j < index - 1; j++)
			{
				search = search->next;
				if (search == head)
				{
					break;
				}
			}
			if (search == head)
			{
				printf("越界n");
				return;
			}
			node* t = search->next;
			search->next = t->next;
			delete t;
		}
	}
	num--;
}
void add(int x)
{
	if (num == 0)
	{
		printf("链表为空n");
		return;
	}
	else
	{
		node* newnode = new node;
		newnode->v = x;
		newnode->next = head;
		tail->next = newnode;
		tail = newnode;
	}
	num += 1;
}
int main(void)
{
	create(5);
	add(6);
	add(7);
	show();
	Insert(2, 8);
	show();
	Delete(3);
	show();
	return 0;
}