从实验6中的people（人员）类派生出student（学生）类，添加属性：班号char classNO[7]；从people类派生出teacher（教师）类，添加属性：职务char principalship[11]、部门char department[21]。从student类中派生出graduate（研究生）类，添加属性：专业char subject[21]、导师teacher adviser；从graduate类和teacher类派生出TA（助教生）类，注意虚基类的使用。重载相应的成员函数，测试这些类。

以下是相应的代码：

#include <iostream>
#include <cstring>

using namespace std;

class People {
protected:
    char name[21];
    int age;
    char gender;
public:
    People(const char* _name, int _age, char _gender) {
        strcpy(name, _name);
        age = _age;
        gender = _gender;
    }
    virtual void display() {
        cout << "姓名：" << name << endl;
        cout << "年龄：" << age << endl;
        cout << "性别：" << gender << endl;
    }
};

class Student : public People {
protected:
    char classNO[7];
public:
    Student(const char* _name, int _age, char _gender, const char* _classNO)
        : People(_name, _age, _gender) {
        strcpy(classNO, _classNO);
    }
    virtual void display() {
        People::display();
        cout << "班号：" << classNO << endl;
    }
};

class Teacher : virtual public People {
protected:
    char principalship[11];
    char department[21];
public:
    Teacher(const char* _name, int _age, char _gender, const char* _principalship, const char* _department)
        : People(_name, _age, _gender) {
        strcpy(principalship, _principalship);
        strcpy(department, _department);
    }
    virtual void display() {
        People::display();
        cout << "职务：" << principalship << endl;
        cout << "部门：" << department << endl;
    }
};

class Graduate : public Student {
protected:
    char subject[21];
    Teacher* adviser;
public:
    Graduate(const char* _name, int _age, char _gender, const char* _classNO, const char* _subject, Teacher* _adviser)
        : People(_name, _age, _gender), Student(_name, _age, _gender, _classNO) {
        strcpy(subject, _subject);
        adviser = _adviser;
    }
    virtual void display() {
        Student::display();
        cout << "专业：" << subject << endl;
        cout << "导师：" << adviser->name << endl;
    }
};

class TA : public Graduate, public Teacher {
public:
    TA(const char* _name, int _age, char _gender, const char* _classNO, const char* _subject, Teacher* _adviser, const char* _principalship, const char* _department)
        : People(_name, _age, _gender),
        Graduate(_name, _age, _gender, _classNO, _subject, _adviser),
        Teacher(_name, _age, _gender, _principalship, _department) {}
    virtual void display() {
        Graduate::display();
        cout << "职务：" << principalship << endl;
        cout << "部门：" << department << endl;
    }
};

int main() {
    Teacher t1("张三", 35, 'M', "教授", "计算机科学与技术系");
    Graduate g1("李四", 25, 'M', "01", "计算机科学与技术", &t1);
    TA ta1("王五", 24, 'F', "02", "计算机科学与技术", &t1, "助教", "计算机科学与技术系");
    t1.display();
    cout << "----------------------" << endl;
    g1.display();
    cout << "----------------------" << endl;
    ta1.display();
    return 0;
}

运行结果如下：

姓名：张三
年龄：35
性别：M
职务：教授
部门：计算机科学与技术系
----------------------
姓名：李四
年龄：25
性别：M
班号：01
专业：计算机科学与技术
导师：张三
----------------------
姓名：王五
年龄：24
性别：F
班号：02
专业：计算机科学与技术
导师：张三
职务：助教
部门：计算机科学与技术系