队列基本操作

基于c语言实现的队列基本操作，包括：

• 创建
• 入队
• 出队
• 判断是否为空

代码如下（gcc编译器）：

#include <stdlib.h>
#include <stdio.h>

typedef struct node
{
	int nValue;
	struct node *pNext;
}Node;

typedef struct queue
{
	int nCount;
	Node *pHead;
	Node *pTail;
}Queue;

void Init(Queue **pQueue)
{
	
	*pQueue = (Queue*)malloc(sizeof(Queue));
	(*pQueue)->pHead = NULL;
	(*pQueue)->pTail = NULL;
	(*pQueue)->nCount = 0;
}

void Push(Queue *pQueue, int nValue)
{
	if(pQueue == NULL) exit(1);
	Node *pTemp = NULL;
	pTemp = (Node*)malloc(sizeof(Node));
	pTemp->nValue = nValue;
	pTemp->pNext = NULL;
	if(pQueue->pHead == NULL)
	{
		pQueue->pHead = pTemp;
	}
	else
	{
		pQueue->pTail->pNext = pTemp;
	}
	pQueue->pTail = pTemp;
	pQueue->nCount++;	
}

int Pop(Queue *pQueue)
{
	if(pQueue == NULL) exit(1);
	if(pQueue->nCount == 0) return -1;
	Node *pDel = NULL;
	int nNum;
	pDel = pQueue->pHead;
	nNum = pQueue->pHead->nValue;
	pQueue->pHead = pQueue->pHead->pNext;
	free(pDel);
	pDel = NULL;
	pQueue->nCount--;
	if(pQueue->nCount == 0)
	{
		pQueue->pTail = NULL;
	}
	return nNum;
}

int IsEmpty(Queue *pQueue)
{
	if(pQueue == NULL) exit(1);
	return pQueue->nCount==0? 1:0;
}
int main()
{
	Queue *pQueue = NULL;
	Init(&pQueue);
	Push(pQueue, 1);
	Push(pQueue, 2);
	Push(pQueue, 3);
	Push(pQueue, 4);
	printf("%d\n", Pop(pQueue));
	printf("%d\n", Pop(pQueue));
	printf("%d\n", Pop(pQueue));
	printf("%d\n", Pop(pQueue));
	return 0;
}