//=======================
//student.h
//========================
#ifdef HEADER_STUDENT
#define HEADER_STUDENT
#include<iostream.h>
class Student
{
 string name;
 int semesterhours;
 double average;
public:
 Student(string pname="noname"):name(pname),semesterhours(0),average(0){}
 void addcourse(int hours,double grade)
 {
  double allgrade=(semesterhours*average+grade);
  semesterhours+=hours;
  average=semesterhours?allgrade/semesterhours:0;
 }
 void display()
 {
  cout<<"name=\""<<name<<"\""<<","<<"semesterhours="<<semesterhours<<","<<"average="<<average<<endl;
 }
 int gethours(){return semesterhours;}
 double getaverage(){return average;}
};
#endif //HEADER_STUDENT
 
//=======================
//graduatestudent.h
//========================
#ifdef HEADER_GRADUATESTUDENT
#define HEADER_GRADUATESTUDENT
#include"student.h"
#include<iostream.h>
//---------------------
class Advisor
{
 int noofmeeting;
};
class Graduatestudent public:Student
{
 Advisor advisor;
 int qualifiergrade;
public:
 Graduatestudent(string pname="noname"):Student(pname),qualifiergrade(0){}
 int getqualifier(){return qualifiergrade;}
 void display()
 {
  Student::display();
  std::cout<<"qualifiergrade="<<qualifiergrade<<endl;
 }
};
#endif //HEADER_GRADUATESTUDENT
 
//===================
//inheritance & member override
//====================
#include"student.h"
#include"graduatestudent.h"
#include<iostream.h>
//------------------------
int main()
{
 Student ds("han yu hang");
 Graduatestudent gs;
 ds.addcourse(3,2.5);
 ds.display();
 gs.addcourse(3,3.0);
 gs.display();
}

这个用排除法一点一点的来就行了吧。。。
还有貌似楼主的宏语句用的不是很对啊
#ifdef HEADER_STUDENT    -------------------> 应该是#ifndef 吧
#define HEADER_STUDENT

版主不错

楼主眼力好