队列实现

#include <iostream>
#include <cstdlib>
#include <cstdio>
using namespace std;
typedef char QueueElemType;

typedef struct LinkQueueNode
{
	QueueElemType data;
	struct LinkQueueNode *next;
}LinkQueueNode;

typedef struct LinkQueue
{
	LinkQueueNode *front;
	LinkQueueNode *rear;
}LinkQueue;

int EnterQueue(LinkQueue *Q, QueueElemType x)
{
	LinkQueueNode *NewNode;
	NewNode = (LinkQueueNode *)malloc(sizeof(LinkQueueNode));
	if(NewNode != NULL)
	{
		NewNode->data = x;
		NewNode->next = NULL;
		Q->rear->next = NewNode;
		Q->rear = NewNode;
		return true;
	}
	else
	{
		return false;
	}
}

int DeleteQueue(LinkQueue *Q, QueueElemType *x)
{
	LinkQueueNode *p;
	if(Q->front == Q->rear)
	{
		return false;
	}
	p = Q->front->next;
	Q->front->next = p->next;
	if(Q->rear == p)
	{
		Q->rear = Q->front;
	}
	*x = p->data;
	free(p);
	return true;
}

int scan()
{
	int n;
	cout << "1、入队       2、出队" << endl;
	cin >> n;
	return n;
}

int main()
{
	int quit = 0;
	QueueElemType x;
	LinkQueue *queue = (LinkQueue *)malloc(sizeof(LinkQueue));

	queue->front = (LinkQueueNode *)malloc(sizeof(LinkQueueNode));
	queue->rear = queue->front;
	queue->front->next = NULL;
	while(!quit)
	{
		switch(scan())
		{
		case 1 :  cin >> x; EnterQueue(queue, x); break;
		case 2 : if(DeleteQueue(queue, &x) == true) cout << x << "元素已出队" << endl; else cout << "队列为空，请输入要入队的元素" << endl; break;
		default : quit = 1;
		}
	}
	return 0;
}