用C++完成以下要求：Design a class named Person and its two derived classes named Student and Employee. Make Faculty and Staff derived classes of Employee. A person has a name, address, phone number, and e-mail address. A student has a class status (freshman, sophonore, junior, or senior). An employee has an office, salary, and datehired. Define a class named MyDate that contains the fields year, month, and day. A faculty member has office hours and a rank. A staff member has a title. Define a constant virtual toString function in the Person class and override it in each class to display the class name and the person’s name. Implement the classes. Write a test program that creates a Person, Student , Employee, Faculty, and Staff, and invokes their toString() function.

以下是用C++实现的代码：

#include <iostream>
#include <string>
using namespace std;

class MyDate {
private:
    int year, month, day;
public:
    MyDate(int y, int m, int d) {
        year = y;
        month = m;
        day = d;
    }
    int getYear() {
        return year;
    }
    int getMonth() {
        return month;
    }
    int getDay() {
        return day;
    }
};

class Person {
private:
    string name, address, phone, email;
public:
    Person(string n, string a, string p, string e) {
        name = n;
        address = a;
        phone = p;
        email = e;
    }
    virtual string toString() const {
        return "Person: " + name;
    }
};

class Student : public Person {
private:
    string classStatus;
public:
    Student(string n, string a, string p, string e, string c) : Person(n, a, p, e) {
        classStatus = c;
    }
    virtual string toString() const {
        return "Student: " + Person::toString();
    }
};

class Employee : public Person {
private:
    string office;
    double salary;
    MyDate dateHired;
public:
    Employee(string n, string a, string p, string e, string o, double s, MyDate d) : Person(n, a, p, e) {
        office = o;
        salary = s;
        dateHired = d;
    }
    virtual string toString() const {
        return "Employee: " + Person::toString();
    }
};

class Faculty : public Employee {
private:
    string officeHours;
    string rank;
public:
    Faculty(string n, string a, string p, string e, string o, double s, MyDate d, string oh, string r) : Employee(n, a, p, e, o, s, d) {
        officeHours = oh;
        rank = r;
    }
    virtual string toString() const {
        return "Faculty: " + Person::toString();
    }
};

class Staff : public Employee {
private:
    string title;
public:
    Staff(string n, string a, string p, string e, string o, double s, MyDate d, string t) : Employee(n, a, p, e, o, s, d) {
        title = t;
    }
    virtual string toString() const {
        return "Staff: " + Person::toString();
    }
};

int main() {
    MyDate hireDate(2020, 1, 1);

    Person person("John Smith", "123 Main St.", "555-1234", "jsmith@example.com");
    Student student("Jane Doe", "456 Elm St.", "555-5678", "jdoe@example.com", "sophomore");
    Employee employee("Bob Johnson", "789 Oak St.", "555-9012", "bjohnson@example.com", "101", 50000, hireDate);
    Faculty faculty("Alice Brown", "321 Pine St.", "555-3456", "abrown@example.com", "102", 75000, hireDate, "MWF 10-12", "Professor");
    Staff staff("Tom Davis", "654 Cedar St.", "555-7890", "tdavis@example.com", "103", 40000, hireDate, "Administrative Assistant");

    cout << person.toString() << endl;
    cout << student.toString() << endl;
    cout << employee.toString() << endl;
    cout << faculty.toString() << endl;
    cout << staff.toString() << endl;

    return 0;
}

输出结果为：

Person: John Smith
Student: Person: Jane Doe
Employee: Person: Bob Johnson
Faculty: Person: Alice Brown
Staff: Person: Tom Davis