#include<stdio.h>
#include<stdlib.h>
#define MAXSIZE 100
#define OK 1
#define OVERFLOW -1
typedef struct{
	int *base;
	int front;
	int rear;
}SqQueue;
typedef int Status;
//初始化
Status InitQueue(SqQueue *Q)
{
	Q->base=(int *)malloc(MAXSIZE*sizeof(int));
	if(!(Q->base))
		exit(OVERFLOW);
	Q->front=Q->rear=0;
	return OK;
}
//佇列的長度
int QueueLength(SqQueue Q)
{
	return (Q.rear-Q.front+MAXSIZE)%MAXSIZE;
}
//入隊
Status EnQueue(SqQueue *Q,int e)
{
	if((Q->rear+1)%MAXSIZE==Q->front)
		return -1;
	Q->base[Q->rear]=e;
	Q->rear=(Q->rear+1)%MAXSIZE;
	return OK;
}
//出隊
Status DeQueue(SqQueue *Q,int *e)
{
	if(Q->front==Q->rear)
		return -1;
	*e=Q->base[Q->front];
	Q->front=(Q->front+1)%MAXSIZE;
	return OK;
}
void main()
{
	int ch=1;
	SqQueue Q;
	InitQueue(&Q);
	while(ch!=0)
	{
		system("cls");
		printf("1.佇列長度\t2.進隊\t3.出隊\n");
		printf("請選擇:\n");
		scanf("%d",&ch);
		switch(ch)
		{
		case 0:printf("byebye!\n");
			break;
		case 1:
			{
				int len;
				len=QueueLength(Q);
				printf("長度為:%d\n",len);
				break;
			}
		case 2:
			{
				int e;
				printf("請輸入你要入隊的數值:\n");
				scanf("%d",&e);
				if(EnQueue(&Q,e)==OK)
					printf("入隊成功\n");
				else
					printf("入隊失敗\n");
				break;
			}
		case 3:
			{
				int e;
				DeQueue(&Q,&e);
				printf("%d\n",e);
				break;
			}
		default:
			printf("輸入錯誤，請重新輸入\n");
			break;
		}
		system("pause");
	}
}