#include <iostream.h>

#include <string.h>

class CStudent

{

public:

      CStudent(char *n, int a);

      ~CStudent();

      static void SetAge(int age);

private:

      char *name;

      int age;

      static int nTotalObj;

};

int CStudent::nTotalObj = 0;

CStudent::CStudent(char *n, int a)

:age(a)

{

      int nLen = strlen(n);

      name = new char[nLen+1];

      strcpy(name,n);

      name[nLen] = '\0';

      nTotalObj++;

}

CStudent::~CStudent()

{

      delete[] name;

      nTotalObj--;

}

void CStudent::SetAge(int age)

{

      this->age = age;

}

void main()

{

      CStudent stu1("张三",25);

      CStudent str2("李四",26);

      cout<<"CStudent::nTotalObj="<<CStudent::nTotalObj<<endl;

}

问题一：以上程序编译能通过吗，为什么？

问题二：成员变量nTotalObj在程序中起什么作用，它是如何实现的？

问题三：如果规定该程序的主函数和类CStudent中的成员变量的属性不允许改变，应该如何改正该程序？