问题：主要是队列为空和满的条件.

         为空：cqueue->front==cqueue->rear  为满(cqueue->rear+1)==cqueue->front

 

代码:

#include 
     
      #include 
      
       using namespace std;#define MAXSIZE 20typedef struct CQueue{	int front;	int rear;	int data[MAXSIZE];}*CirQueue;void initCQueue(CirQueue &cqueue){	cqueue=(CirQueue)malloc(sizeof(struct CQueue));	if(!cqueue)	{		cout<<"allocate fail"<
       
        front=cqueue->rear=0;	}}void enCQueue(CirQueue cqueue,int elem){	if((cqueue->rear+1)%MAXSIZE==cqueue->front)	{		cout<<"循环队列已满"<
        
         data[cqueue->rear%MAXSIZE]=elem;		cqueue->rear++;	}}int deCQueue(CirQueue cqueue){	int elem;	if(cqueue->front==cqueue->rear)	{		cout<<"队列已空"<
         
          data[cqueue->front%MAXSIZE];		cqueue->front++;	}	return elem;}int main(){	CirQueue cqueue;	int arr[]={1,2,3,4,5,6,7,9,0};	initCQueue(cqueue);	cout<<"循环队列入队:1 2 3 4 5 6 7 9 0:"<
          
           front!=cqueue->rear) { cout<
           
            <<" "; } cout<
           
          
         
        
       
      
     

运行结果: