运行结果出现问题了，代码的头文件没有发出来的

Question

void SatisticsMenu() //统计功能
{       //排序子菜单

    printf("*****************************\n");
    printf("*\t\t1.平均数\t\t*\n");
    printf("*\t\t2.方差 \t\t*\n");
    printf("******************************\n");
}

 void Satistics()
 {
  double n;
  int MAX_NUM;
  double date[MAX_NUM],mean,variance,sum=0,sum_sq=0;
  int choice;
  printf("请输入您的选择：\n");
  scanf("%d",&choice);
  printf("请输入数据个数：\n");
  scanf("%lf",&n);

switch (choice)
{
   case 1:
   for(int i=0;i<n;i++)
  {
   printf("请输入数据：\n");
   scanf("%lf",&date[i]);
   sum+=date[i];
  }
  mean=sum/n;

  printf("平均值是：%lf\n",mean);
  break;
  case 2:
   for(int i=0;i<n;i++)
  {printf("请输入数据：\n");
   scanf("%lf",&date[i]);
   sum+=date[i];

  }
  int i;
  mean=sum/n;
  sum_sq+=(date[i]-mean)*(date[i]-mean);
  variance=sum_sq/n;
 printf("方差是：%lf\n",variance);

  break;
}

}

Answer 1

你啥也没输入？？？
int MAX_NUM;
double date[MAX_NUM],mean,variance,sum=0,sum_sq=0;
MAX_NUM没有赋值啊，date数组这要申请多大空间呢？