顺序循环队列
基本操作
1.初始化
2.入队
3.出队
4.取对头元素
5.遍历

#include<iostream>
using namespace std;
#define ok 1
#define error 0
#define MAXSIZE 100

//定义循环队列结构
struct SqQueue {
	int *base;
	int front;
	int rear;
}; 

//初始化循环队列 
int Init(SqQueue &Q){
	Q.base = new int[MAXSIZE];
	if(!Q.base){
		exit(error);
	} 
	Q.front = Q.rear = 0;
	return ok;
}

//求循环队列长度
int QueueLength(SqQueue Q){
	return (Q.rear - Q.front + MAXSIZE) % MAXSIZE;
}

//入队
int Insert(SqQueue &Q , int e){
	//队列已满，不能入队 
	if((Q.rear + 1) % MAXSIZE == Q.front){
		return error;
	}
	Q.base[Q.rear] = e;
	Q.rear =(Q.rear + 1) % MAXSIZE;
	return ok;
} 

//出队,引用e接收出队的数据 
int DeQueue(SqQueue &Q, int &e){
	//队空 
	if(Q.rear == Q.front){
		return error;
	} 
	e = Q.base[Q.front];
	//队头指针+1 
	Q.front = (Q.front + 1) % MAXSIZE;
	return ok; 
} 

//取对头
int GetHead(SqQueue Q){
	if(Q.front != Q.rear){
		return Q.base[Q.front];
	}
} 

//遍历循环队列
void print(SqQueue Q){
	while(Q.front != Q.rear){
		cout<<Q.base[Q.front]<<",";
		Q.front = (Q.front + 1) % MAXSIZE;
	}
} 


int main(){
	int data;
	SqQueue Q;
	Init(Q);
	cout<<"----------入队---------------\n";
	for(int i=1; i<=5; i++){
		Insert(Q,i);
	}
	print(Q);
	cout<<"\n----------出队---------------\n";
	DeQueue(Q,data);
	cout<<"出队元素为: "<<data<<endl;
	print(Q);
	cout<<"\n----------取对头元素---------------\n";
	cout<<"对头元素为："<<GetHead(Q)<<endl; 
	return 0;
}