大佬求助，Cpp作业，关于派生类和虚基类的代码

#include <iostream>
using namespace std;
class MyArray
{
public:
MyArray()
{
alist = NULL;
}
MyArray(int len)
{
alist = new int[len];
length = len;
}//初始化，动态申请存储空间
~MyArray()
{
delete[] alist;
}//对象结束时，释放所占用的存储空间
void Input()
{
cout << "请输入整数:" << endl;
for (int i = 0; i < length; i++)
{
cin >> alist[i];
}
}//输入数据
void Display()
{
{
for (int i = 0; i < length; ++i)
cout << alist[i] << " ";
}
cout << endl;
}//显示数据
protected:
int* alist; //指向动态申请的一组空间
int length; //整数的个数
};
//pai sheng lei
class SortArray : virtual public MyArray
{
public:
SortArray(int len) : MyArray(len) {}
void Sort()
{
for (int i = 0; i < length - 1; ++i)
{
for (int j = 0; j < length - i - 1; ++j)
{
if (alist[j] > alist[j + 1])
{
int temp = alist[j];
alist[j] = alist[j + 1];
alist[j + 1] = temp;
}
}
}
}
};
class ReArray : virtual public MyArray
{
public:
ReArray(int len) : MyArray(len) {}
void Reverse()
{
for (int i = 0; i < length / 2; ++i)
{
int temp = alist[i];
alist[i] = alist[length - i - 1];
alist[length - i - 1] = temp;
}
}
};
class AverArray : virtual public MyArray
{
public:
AverArray(int len) : MyArray(len) {}
double Aver() const
{
double sum = 0;
for (int i = 0; i < length; ++i)
{
sum += alist[i];
}
return sum / length;
}
};
class NewArray : public SortArray, public ReArray, public AverArray
{
public:
NewArray(int len) : SortArray(len), ReArray(len), AverArray(len) {}
};
int main()
{
int num = 0;
cin >> num;
NewArray newclass(num);
//newclass.Input();
//newclass.Sort();
//cout << "排序后的数组为：\n";
//newclass.Display();
//cout << endl;
return 0;
}