c++城西：分别定义Person类、Employee类、Student类以及在职研 究生类PartTime_Graduate_Student，并且画出相应的继承层 次图

以下是相应的代码和继承层次图：

class Person {
protected:
    string name;
    int age;
public:
    Person(string n, int a) : name(n), age(a) {}
    virtual void show() {
        cout << "Name: " << name << endl;
        cout << "Age: " << age << endl;
    }
};

class Employee : public Person {
protected:
    double salary;
public:
    Employee(string n, int a, double s) : Person(n, a), salary(s) {}
    void show() {
        Person::show();
        cout << "Salary: " << salary << endl;
    }
};

class Student : public Person {
protected:
    string major;
public:
    Student(string n, int a, string m) : Person(n, a), major(m) {}
    void show() {
        Person::show();
        cout << "Major: " << major << endl;
    }
};

class PartTime_Graduate_Student : public Employee, public Student {
protected:
    string research;
public:
    PartTime_Graduate_Student(string n, int a, double s, string m, string r) : Employee(n, a, s), Student(n, a, m), research(r) {}
    void show() {
        Employee::show();
        cout << "Major: " << major << endl;
        cout << "Research: " << research << endl;
    }
};

继承层次图：

        +-----------+
        |   Person  |
        +-----------+
              |
              |
        +-----------+
        |  Student  |
        +-----------+
              |
              |
        +-----------+
        |  Employee |
        +-----------+
              |
              |
+---------------------------+
| PartTime_Graduate_Student |
+---------------------------+