//队列的链式存储
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

//结点的结构体
struct QueueNode
{
    struct QueueNode *next;
};

//队列结构体
struct LQueue
{
	struct QueueNode pHeader;
	int m_size;
	struct QueueNode * pTail;
};
typedef void * LinkQueue;

//初始化队列
LinkQueue init_LinkQueue(){
    struct LQueue * myQueue = malloc(sizeof(struct  LQueue));
	 if (myQueue == NULL)
	 {
		 return NULL;
	 }
    //结点赋初值
	 myQueue->pHeader.next = NULL;
	 myQueue->m_size = 0;
	 myQueue->pTail = &myQueue->pHeader;

	 return myQueue;
}

//入队
void push_LinkQueue(LinkQueue queue, void * data)
{
	if (queue == NULL)
	{
		return;
	}
	if ( data == NULL)
	{
		return;
	}

	//本质 尾插
	struct LQueue * myQueue = queue; 
	struct QueueNode * myNode = data; //取用户数据的前四个字节

	//更改指针指向
	myQueue->pTail->next = myNode;
	myNode->next = NULL;

	//更新新的尾节点
	myQueue->pTail = myNode;

	myQueue->m_size++;

}

//出队
void pop_LinkQueue(LinkQueue queue)
{
	if (queue == NULL)
	{
		return;
	}

	struct LQueue * myQueue = queue;

	//本质 头删

	if (myQueue->m_size == 0)
	{
		return;
	}

	if (myQueue->m_size == 1)
	{
		myQueue->pHeader.next = NULL;
		myQueue->pTail = &myQueue->pHeader;  //1个节点的时候，要将尾节点还原到头
		myQueue->m_size--;
		return;
	}

	//记录第一个有数据的节点
	struct QueueNode * pFirst = myQueue->pHeader.next;

	//更改指针指向
	myQueue->pHeader.next = pFirst->next;

	myQueue->m_size--;

}
//返回队列大小
int size_LinkQueue(LinkQueue queue)
{
	if (queue == NULL)
	{
		return -1;
	}

	struct LQueue * myQueue = queue;
	return myQueue->m_size;


}
//判断是否为空
int isEmpty_LinkQueue(LinkQueue queue)
{
	if (queue == NULL)
	{
		return -1;
	}

	struct LQueue * myQueue = queue;
	if (myQueue->m_size == 0)
	{
		return 1;
	}
	return 0;

}
//返回队头
void * front_LinkQueue(LinkQueue queue)
{
	if (queue == NULL)
	{
		return NULL;
	}

	struct LQueue * myQueue = queue;

	return myQueue->pHeader.next;

}
//返回队尾
void * back_LinkQueue(LinkQueue queue)
{
	if (queue == NULL)
	{
		return NULL;
	}

	struct LQueue * myQueue = queue;
	return myQueue->pTail;
}
//销毁队列
void destroy_LinkQueue(LinkQueue queue)
{
	if (queue == NULL)
	{
		return;
	}

	free(queue);
	queue = NULL;

}

int main()
{
    return 0;
}