在本科生类基础上怎么再派生一个研究生类

#include<iostream>
#include<fstream>
#include<iomanip>
#include<stdlib.h>
#include<Windows.h>
#include<conio.h>
using namespace std;

#define HEADER1 "     ----------------------------学生成绩---------------------------------------------- \n"
#define HEADER2 "     |   学号   |   姓名    |    性别   |    年龄   |   学院    |    品牌   |    补贴   |\n"
#define HEADER3 "     |----------|-----------|-----------|-----------|-----------|-----------|-----------|\n"

int num; //学生总数
class Student             //定义学生类
{
public:
    char id[20];//学号 
    char name[20];//名字
    char sex[5];//性别
    int age;//年龄
    char xibie[20];//系别
    char yimiao[20];
    Student* next;
    virtual void input();//输入函数
    virtual void ReadFile(istream& in);//读取文件
    virtual void show();//显示方法
};
void Student::input()     //输入学生信息函数
{
    cout << "\t\t学号：";
    cin >> id;
    cout << "\t\t姓名：";
    cin >> name;
    cout << "\t\t性别：";
    cin >> sex;
    cout << "\t\t年龄：";
    cin >> age;
    cout << "\t\t学院：";
    cin >> xibie;
    cout<<"\t\t品牌：";
    cin>> yimiao; 
}
void Student::ReadFile(istream& in)        //读取文件
{
    in >> id >> name >> sex >> age >> xibie >> yimiao;
}
void Student::show()          //输出学生信息
{
    cout << "     |" << setw(5) << id << "     |" << setw(9) << name << "  |" << setw(7) << sex << "    |" << setw(7) << age << "    |" << setw(8) << xibie << "   |" << setw(7) << yimiao << "    |" << endl;
    cout << "     |----------|-----------|-----------|-----------|-----------|-----------|-----------|\n";
}
class Stduenty:public Student
{public:
    int butie;
    void input();
    void show();
    void ReadFile(istream& in);
};
void Stduenty::input()
{
    cout << "\t\t学号：";
    cin >> id;
    cout << "\t\t姓名：";
    cin >> name;
    cout << "\t\t性别：";
    cin >> sex;
    cout << "\t\t年龄：";
    cin >> age;
    cout << "\t\t学院：";
    cin >> xibie;
    cout << "\t\t品牌：";
    cin >> yimiao; 
    cout << "\t\t补贴：";
    cin >> butie; 
}
void Stduenty::show()
{
    cout << "     |" << setw(5) << id << "     |" << setw(9) << name << "  |" << setw(7) << sex << "    |" << setw(7) << age << "    |" << setw(8) << xibie << "   |" << setw(7) << yimiao << "    |" << setw(7) << butie << "    |" << endl;
    cout << "     |----------|-----------|-----------|-----------|-----------|-----------|-----------|\n";
}
void Stduenty::ReadFile(istream& in)
{
        in >> id >> name >> sex >> age >> xibie >> yimiao>>butie;
}
class StudentMassage      //定义学生信息类，包含各项处理功能
{
public:
    StudentMassage();
    ~StudentMassage();
    void ShowMenu();
    void Display();
    void AddItem();
    void Find();
    void save();
    void ModifyItem();
    void RemoveItem();
    void Swap(Student* p1, Student* p2);
    void Sort();
    int ListCount();
    int Count();
private:
    Student* Head, * End;
    Studenty* Head1,* End1;
    ifstream in;
    ofstream out;
    Student* FindId(char* name);
    Student* FindYm(char* yimiao);
};
Student* StudentMassage::FindId(char* name)
{
    Student* p;
    for (p = Head; p->next != End; p = p->next)
        if (!strcmp(p->next->name, name))
            return p;
    return NULL;
}
Student* StudentMassage::FindYm(char* yimiao)
{
    Student* p;
    for (p = Head; p->next != End; p = p->next)
        if (!strcmp(p->next->yimiao, yimiao))
            return p;
    return NULL;
}
StudentMassage::StudentMassage()   //构造函数
{
    Head = new Student;
    Head->next = new Student;
    End = Head->next;
    in.open("学生成绩.txt");
    if (!in)
        cout << "\n\t\t这是一个新系统，无学生信息，请先输入。" << endl;
    else
    {
        while (!in.eof())
        {
            End->ReadFile(in);
            if (End->name[0] == '\0')
                break;
            End->next = new Student;
            End = End->next;
        }
        in.close();
        cout << "\n\t\t读取学生信息成功！" << endl;
    }
}
StudentMassage::~StudentMassage()       //析构函数
{
    Student* temp;
    save();
    for (temp; Head->next != End; )
    {
        temp = Head->next;
        Head->next = Head->next->next;
        delete temp;
    }
    delete Head, End;
}

void StudentMassage::ShowMenu()                      //显示菜单
{
    cout << "\n\n\t\t\t\t 主菜单" << endl << endl << endl;
    cout << "\t\t****************************************" << endl << endl;
    cout << "\t\t1、录入学生信息          2、修改学生信息" << endl << endl;
    cout << "\t\t3、删除学生信息          4、学生信息查找" << endl << endl;
    cout << "\t\t5、统计学生信息          ***************" << endl << endl;
    cout << "\t\t0、系统安全退出                         " << endl << endl;
    cout << "\t\t****************************************" << endl << endl << endl;
    cout << "\t\t请选择：";
}

void StudentMassage::Display()            //显示学生信息
{
    Student* p;
    cout << endl << HEADER1 << HEADER2 << HEADER3;
    for (p = Head->next; p != End; p = p->next)
        p->show();
    cout << "\n\n输入任意字符，继续......";
    getch();
}

void StudentMassage::AddItem()      //添加学生信息
{
    int n;
    cout<<"Enter n:"<<endl;
    cin>>n;
    switch(n)
    {
        case 1:
            End->input();
            End->next = new Student;
            End = End->next;
            cout << "\n\t\t添加成功！" << endl;
            cout << "\n输入任意字符，继续......";
            getch();
        case 2:
            End1->input();
            End1->next = new Student;
            End1 = End1->next;
            cout << "\n\t\t添加成功！" << endl;
            cout << "\n输入任意字符，继续......";
            getch();
    }
}

void StudentMassage::Find()    //查找函数
{
    Student *p=NULL; 
    char yimiao[20]; 
    cout << "\n\t\t请输入要查找的疫苗的品牌：";
    cin >> yimiao;
    if (p = FindYm(yimiao))
    {
        cout << endl << HEADER1 << HEADER2 << HEADER3;
        p->next->show();
        cout << "\n请输入任意字符，继续......";
        getch();
    }
    else
    {
        cout << "\n\t\t没有找到接种该品牌疫苗的学生！" << endl << endl;
        cout << "请输入任意字符，继续......";
        getch();
    }
}
void StudentMassage::ModifyItem()     //修改学生信息
{
    char name[20];
    Student* p = NULL;
    cout << "\n\t\t请输入要修改的学生的姓名：";
    cin >> name;
    if (p = FindId(name))
    {
        cout << "\n\t\t已找到该学生，请输入新的信息！" << endl;
        p->next->input();
        cout << "\n\t\t修改成功！" << endl;
        Display();
    }
    else
    {
        cout << "\n\t\t没有找到！" << endl;
        cout << "\n输入任意字符！继续.......";
        getch();
    }
}

void StudentMassage::RemoveItem()      //删除学生信息
{
    char name[20];
    Student* p = NULL, * temp = NULL;
    cout << "\n\t\t请输入要删除的学生的姓名：";
    cin >> name;
    if (p = FindId(name))
    {
        temp = p->next;
        p->next = p->next->next;
        delete temp;
        cout << "\n\t\t删除成功！" << endl;
        Display();
    }
    else
    {
        cout << "\t\t没有找到！" << endl;
        cout << "输入任意字符！继续......";
        getch();
    }
}

int StudentMassage::ListCount()   //返回记录的学生总数
{
    Student* p;
    int n = 0;
    if (!Head)
        return 0;
    for (p = Head->next; p != End; p = p->next)
        n++;
    num = n;
    return num;
}

int StudentMassage::Count()         //成绩统计
{
    Student* p;
    int x, count = 0;
    if (!Head)
    {
        cout << "\n\t\t没有资料可以统计！" << endl;
        return 0;
    }
}

void StudentMassage::Swap(Student* p1, Student* p2)       //交p1,p2学生信息
{
    Student* temp = new Student;
    strcpy(temp->name, p1->name);
    strcpy(temp->id, p1->id);
    strcpy(p1->name, p2->name);
    strcpy(p1->id, p2->id);
    strcpy(p2->name, temp->name);
    strcpy(p2->id, temp->id);
}

void StudentMassage::save()                    //存入文件
{
    out.open("学生成绩.txt");
    for (Student* p = Head->next; p != End; p = p->next)
        out << p->id << "\t" << p->name << "\t" << p->sex << "\t" << p->age << "\t" << p->xibie << "\t" << '\n';
    out.close();
    cout << "\n\t\t学生成绩文件保存成功！" << endl;
    cout << "\n输入任意字符，继续......";
    getch();
}
int main(
)
{
    int x;
    bool quit = false;
    cout << "\n\n\n\n\n\n\n\n";
    cout << "\t\t********************************************" << endl;
    cout << "\t\t         欢迎使用学生信息管理系统！" << endl;
    cout << "\t\t********************************************" << endl;
    StudentMassage Grade;
    Sleep(1000);
    while (!quit)
    {
        system("cls");
        Grade.ShowMenu();
        cin >> x;
        switch (x)
        {
        case 0:quit = 1; break;
        case 1:Grade.AddItem(); break;//添加信息 
        case 2:Grade.ModifyItem(); break;//修改信息 
        case 3:Grade.RemoveItem(); break;//删除信息 
        case 4:Grade.Find(); break;//查找信息 
        case 5:Grade.Display(); break;//显示信息 
        case 6:Grade.Count(); break;//
        }
    }
    return 0;
}

如何再其中再派生出一个研究生类（Stduenty），使其可以实现与本科生（Student）类实现同样的功能；

不知道你这个问题是否已经解决, 如果还没有解决的话:

• 关于该问题，我找了一篇非常好的博客，你可以看看是否有帮助，链接：继承与派生的基本知识

如果你已经解决了该问题, 非常希望你能够分享一下解决方案, 以帮助更多的人 ^-^