C语言队列（排队）先进先出.实现全部函数

#include 
#include 





#define QUEUE_CAPACITY 3    //队列容量

typedef struct tag_queue
{
	int *pQueue;   //队列内存指针
	int head;      //队列头
	int tail;      //队列尾
	int length;    //元素个数
}LineQueue;

int InitQueue(LineQueue **myQueue);               //InitQueue(&Q)             创建队列
void DestroyQueue(LineQueue *myQueue);           //DestroyQueue(&Q)          销毁队列
void ClearQueue(LineQueue *myQueue); //已有的元素清空掉            //ClearQueue(&Q)            清空队列
int QueueEmpty(LineQueue *myQueue);              //QueueEmpty(&Q)            判空队列
int QueueFull(LineQueue *myQueue);               //QueueFull(&Q)             判满队列
int QueueLength(LineQueue *myQueue);             //QueueLength(&Q)           队列长度
int EnQueue(LineQueue *myQueue, int element);    //EnQueue(&Q, element)      新元素入队
int DeQueue(LineQueue *myQueue, int *element);   //DeQueue(&Q, &element)     首元素出队
void QueueTraverse(LineQueue *myQueue);          //QueueTraverse(Q, visit()) 遍历队列

int InitQueue(LineQueue **myQueue)
{
	(*myQueue) = (LineQueue *)malloc(sizeof(LineQueue));//申请内存.强制转换，不然会为void无类型。分配结构体内存
	//printf("queue1 = %pn", (*myQueue));
	if(myQueue == NULL)
	{
		return 0;
	}
	(*myQueue)->pQueue = (int *)malloc(sizeof(int) * QUEUE_CAPACITY);//分配队列内存
	if((*myQueue)->pQueue == NULL)
	{
		return 0;
	}
	(*myQueue)->head = 0;
	(*myQueue)->tail = 0;
	(*myQueue)->length = 0;

	return 1;
}

void DestroyQueue(LineQueue *myQueue)
{
	free(myQueue->pQueue);
	myQueue->pQueue = NULL;
	free(myQueue);
	myQueue = NULL;
}

void ClearQueue(LineQueue *myQueue)//把队列里面所有的元素删除掉
{
	myQueue->length = 0;
	myQueue->tail = 0;
}

int QueueEmpty(LineQueue *myQueue)
{
	if(myQueue->length == 0)
	{
		return 1;
	}
	return 0;
}

int QueueFull(LineQueue *myQueue)
{
	if(myQueue->length >= QUEUE_CAPACITY)//#define QUEUE_CAPACITY 3    //队列容量
	{
		return 1;
	}
	return 0;
}

int QueueLength(LineQueue *myQueue)
{
	return myQueue->length;
}

int EnQueue(LineQueue *myQueue, int element)
{
	if(QueueFull(myQueue))//判断他是否为满的操作，满了就不能进队列了
	{
		return 0;
	}
	myQueue->pQueue[myQueue->tail] = element;//把元素放入队尾
	myQueue->tail++;//因为进队列，所以++1
	myQueue->length++;//大小++1
	return 1;
}

int DeQueue(LineQueue *myQueue, int *element)//取出来，是从head开始取出的啦
{
	int i = 0;
	if(QueueEmpty(myQueue))
	{
		return 0;
	}
	*element = myQueue->pQueue[myQueue->head];

	for(i = 1; i < myQueue->length; i++)
	{
		myQueue->pQueue[i-1] = myQueue->pQueue[i];//所有元素往前靠一步
	}
	myQueue->length--;//因为少了一个，所以--
	myQueue->tail--;//因为所有元素往前移动一位了，所以--1
	return 1;
}

void QueueTraverse(LineQueue *myQueue, int flag)
{
	int i = 0;
	if(flag == 0)  //从头到尾
	{
		for(i = 0; i < myQueue->length; i++)
		{
			printf("%d ", myQueue->pQueue[i]);
		}
	}
	
	if(flag == 1)  //从尾到头
	{
		for(i = myQueue->length - 1; i >= 0; i--)
		{
			printf("%d ", myQueue->pQueue[i]);
		}
	}
}

int main(void)
{
	int elem = 0;
	LineQueue *queue = NULL;
	InitQueue(&queue);

	if(QueueEmpty(queue))
	{
		printf("当前队列为空n");
	}

	EnQueue(queue, 2);
	EnQueue(queue, 4);
	EnQueue(queue, 5);

	if(QueueFull(queue))
	{
		printf("当前队列为满n");
	}

	QueueTraverse(queue, 0);

	printf("n-----------------------n");

	
	

	printf("queueLength = %dn", QueueLength(queue));

	ClearQueue(queue);

	if(QueueEmpty(queue))
	{
		printf("当前队列为空n");
	}

	//QueueTraverse(queue, 1);

	//printf("queue2 = %pn", queue);
	DestroyQueue(queue);

	system("pause");
	return 0;
}