先定义一个Person类，包含数据成员姓名、性别和出生日期，以该类为基类，派生出学生类和职工类。在学生类中增加数据成员学号、成绩：在职工类中增加数据成员职工号和工资。其中，出生日期是日期类的对象。要求计算学生的平均成绩和职工的平均工资。

代码如下：

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

class Date{
public:
    Date(int y=1990,int m=1,int d=1):year(y),month(m),day(d){}
    void display(){
        cout<<year<<"-"<<month<<"-"<<day<<endl;
    }
private:
    int year,month,day;
};

class Person{
public:
    Person(string n="Tom",char s='M',int y=1990,int m=1,int d=1):
        name(n),sex(s),birthday(y,m,d){}
    void display(){
        cout<<"name:"<<name<<endl;
        cout<<"sex:"<<sex<<endl;
        cout<<"birthday:";
        birthday.display();
    }
private:
    string name;
    char sex;
    Date birthday;
};

class Student:public Person{
public:
    Student(string n="Tom",char s='M',int y=1990,int m=1,int d=1,int num=1001,float score=80):
        Person(n,s,y,m,d),num(num),score(score){}
    void display(){
        Person::display();
        cout<<"num:"<<num<<endl;
        cout<<"score:"<<score<<endl;
    }
    static void average_score(Student stu[],int n){
        float sum=0;
        for(int i=0;i<n;i++){
            sum+=stu[i].score;
        }
        cout<<"average score:"<<sum/n<<endl;
    }
private:
    int num;
    float score;
};

class Worker:public Person{
public:
    Worker(string n="Tom",char s='M',int y=1990,int m=1,int d=1,string id="0001",float salary=5000):
        Person(n,s,y,m,d),id(id),salary(salary){}
    void display(){
        Person::display();
        cout<<"id:"<<id<<endl;
        cout<<"salary:"<<salary<<endl;
    }
    static void average_salary(Worker worker[],int n){
        float sum=0;
        for(int i=0;i<n;i++){
            sum+=worker[i].salary;
        }
        cout<<"average salary:"<<sum/n<<endl;
    }
private:
    string id;
    float salary;
};

int main(){
    Student stu[3]={
        Student("Tom",'M',1990,1,1,1001,80),
        Student("Lily",'F',1991,2,2,1002,90),
        Student("Jack",'M',1992,3,3,1003,85)
    };
    Worker worker[3]={
        Worker("Bob",'M',1980,1,1,"0001",6000),
        Worker("Amy",'F',1981,2,2,"0002",8000),
        Worker("Lucy",'F',1982,3,3,"0003",7000)
    };
    for(int i=0;i<3;i++){
        stu[i].display();
    }
    Student::average_score(stu,3);
    for(int i=0;i<3;i++){
        worker[i].display();
    }
    Worker::average_salary(worker,3);
    return 0;
}

输出结果为：

name:Tom
sex:M
birthday:1990-1-1
num:1001
score:80
name:Lily
sex:F
birthday:1991-2-2
num:1002
score:90
name:Jack
sex:M
birthday:1992-3-3
num:1003
score:85
average score:85
name:Bob
sex:M
birthday:1980-1-1
id:0001
salary:6000
name:Amy
sex:F
birthday:1981-2-2
id:0002
salary:8000
name:Lucy
sex:F
birthday:1982-3-3
id:0003
salary:7000
average salary:7000