循环队列

源代码：

#include<iostream>
#define m 5
using namespace std;

int a[m],i=0;
int front,rear;

//初始化一个队列
void init(int &front,int &rear)
{
	front = rear = -1;
	cout<<"front = "<<front<<endl<<"rear = "<<rear<<endl;
} 

//队列是否为空
void empty(int front,int rear)
{
	if(front == rear)
		cout<<"队列为空!"<<endl;
	else
		cout<<"队列非空!"<<endl;
} 

//进队 
void add(int *a,int &rear,int &item)
{
	if((rear+1)%m == front)
		cout<<"队列已满!"<<endl;
	else
		a[++rear%m]=item;
}

//取当前队头元素 
void geta(int a[],int front,int rear,int &item)
{
	if(front == rear)
		cout<<"队列为空!"<<endl;
	else
	{
		item = a[front+1];
		cout<<"当前元素为:"<<item<<endl;
	}
}

void del(int a[],int &front,int rear,int &item)
{
	if(front == rear)
		cout<<"队列为空!"<<endl;
	else
	{
		front = (front+1)%m;
		item = a[front];
		cout<<"删除的元素为:"<<item<<endl;
	}
}

int main()
{
	int item;
	//初始化一个队列
	cout<<"初始化一个队列!"<<endl;
	init(front,rear);
	
	//队列是否为空
	cout<<endl<<"队列是否为空"<<endl;
	empty(front,rear); 
	
	//队列的插入
	cout<<endl<<"队列的插入!"<<endl<<"进队元素:"; 
	while(cin>>item)
	{
		if(item==-1)
			break;
		else
			add(a,rear,item);
	}
	
	//取当前队头元素
	cout<<endl<<"取当前队头元素!"<<endl; 
	geta(a,front,rear,item); 
	
	//队列的删除
	cout<<endl<<"队列的删除!"<<endl;
	del(a,front,rear,item); 
	
	//队列的插入
	cout<<endl<<"队列的插入!"<<endl<<"进队元素:"; 
	while(cin>>item)
	{
		if(item==-1)
			break;
		else
			add(a,rear,item);
	}
	
	//取当前队头元素
	cout<<endl<<"取当前队头元素!"<<endl; 
	geta(a,front,rear,item); 
	
	return 0;
}    

运行结果: