循环队列，求助大佬：为什么显示的运行结果不对

distanthusk 2023-03-23 13:49:35

#include<stdio.h>
#include<stdlib.h>
#define MAXLEN 10
typedef struct
{
int data[MAXLEN];
int front,rear;
}Csequeue;
Csequeue *q;

void InitQueue(Csequeue *q) //初始化
{
q->front=q->rear=0;
}

int IsEmpty(Csequeue * q) {
return q->front == q->rear;
}

int EnterQueue(Csequeue *q,int x) //入队
{
   if((q->rear+1)%MAXLEN==q->front)
   {
   printf("队列已经满！\n");
   return 0;
}
else
{
   q->rear=(q->rear+1)%MAXLEN;
   q->data[q->rear]=x;
   printf("%d入队成功!\n",x);
   return 1;
   }
}

int Delete(Csequeue *q,int *x) //出队
{
   if(q->rear==q->front)
   {
       printf("队列中无元素，出队失败！\n");
       return 0;
   }
   else
   {
       *x=q->data[q->front];
       q->front=(q->front+1)%MAXLEN;
       printf("出队成功！\n");
       return 1;
   }
}

void Showqueue(Csequeue *q) //展示
{
    if(q->rear==q->front)
    {
        printf("队列为空，显示失败！");
   }
   else
   { printf("队列中元素为：\n");
      while(q->front!=q->rear)
      {
          printf("%5d",q->front );
          q->front=(q->front+1)%MAXLEN;
       }
       printf("\n");
       printf("显示完毕\n");
   }
}

int Lenqueue(Csequeue *q) //求表长
{
    return (q->rear - q->front + MAXLEN) % MAXLEN;
}

int main()
{
    Csequeue q;
    InitQueue(&q);
    int choise,x;
    printf("选择操作：\n");
printf("1. 入队\n");
printf("2. 出队\n");
printf("3. 显示队列中所有元素\n");
printf("4. 求队列长度\n");
printf("0. 退出\n");
    do
    {
printf("请输入您的选择：\n");
scanf("%d",&choise);
switch(choise)
{
   case 1:
       printf("请输入要入队的元素：\n");
       scanf("%d",&x);
       EnterQueue(&q,x);
       break;
       case 2:
           Delete(&q,&x);
           break;
           case 3:
               Showqueue(&q);
               break;
               case 4:
                   printf("队长为：%d",Lenqueue(&q));
                   break;
                   default:
                       printf("无效输入！\n");
                       break;
                       case 0:
                           printf("已退出！\n");
                           break;
       }
   }while(choise!=0);
}