编程实现一个简单的大学人员管理程序，该程序可以管理大学的一些基本人员：学生、教师、职工。首先设计一个抽象类person。通过该类保存人员的最基本信息：姓名（name）、年龄（age）和性别（sex），同时定义一个静态数据成员用来统计人数（sum）。然后使用该类派生出学生类、教师类和职工类，在其中添加各自的特性，如在学生类中添加如下信息：专业（speciality），在教师类中添加院系（department），在职工类中添加部门和职务等信息。为每个类定义一个输出函数print()，输出该类相关信；定义一个保存函数保存相关信息到文件。

以下是一个简单的实现，仅供参考：

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

class Person {
public:
    Person(string n, int a, string s) : name(n), age(a), sex(s) { sum++; }
    virtual void print() { cout << "Name: " << name << ", Age: " << age << ", Sex: " << sex << endl; }
    static int getSum() { return sum; }
    static void saveToFile(string filename) {
        ofstream outfile(filename);
        outfile << "Total Number of Persons: " << sum << endl;
        outfile.close();
    }
protected:
    string name;
    int age;
    string sex;
    static int sum;
};

int Person::sum = 0;

class Student : public Person {
public:
    Student(string n, int a, string s, string sp) : Person(n, a, s), speciality(sp) {}
    virtual void print() { Person::print(); cout << "Speciality: " << speciality << endl; }
    static void saveToFile(string filename) {
        Person::saveToFile(filename);
        ofstream outfile(filename, ios::app);
        outfile << "Number of Students: " << getSum() << endl;
        outfile.close();
    }
private:
    string speciality;
};

class Teacher : public Person {
public:
    Teacher(string n, int a, string s, string d) : Person(n, a, s), department(d) {}
    virtual void print() { Person::print(); cout << "Department: " << department << endl; }
    static void saveToFile(string filename) {
        Person::saveToFile(filename);
        ofstream outfile(filename, ios::app);
        outfile << "Number of Teachers: " << getSum() << endl;
        outfile.close();
    }
private:
    string department;
};

class Worker : public Person {
public:
    Worker(string n, int a, string s, string d, string p) : Person(n, a, s), department(d), position(p) {}
    virtual void print() { Person::print(); cout << "Department: " << department << ", Position: " << position << endl; }
    static void saveToFile(string filename) {
        Person::saveToFile(filename);
        ofstream outfile(filename, ios::app);
        outfile << "Number of Workers: " << getSum() << endl;
        outfile.close();
    }
private:
    string department;
    string position;
};

int main() {
    Person* p1 = new Student("Tom", 20, "Male", "Computer Science");
    Person* p2 = new Teacher("Lily", 35, "Female", "Mathematics");
    Person* p3 = new Worker("John", 25, "Male", "HR", "Manager");
    p1->print();
    p2->print();
    p3->print();
    Person::saveToFile("personnel.txt");
    Student::saveToFile("personnel.txt");
    Teacher::saveToFile("personnel.txt");
    Worker::saveToFile("personnel.txt");
    delete p1;
    delete p2;
    delete p3;
    return 0;
}

运行结果：

Name: Tom, Age: 20, Sex: Male
Speciality: Computer Science
Name: Lily, Age: 35, Sex: Female
Department: Mathematics
Name: John, Age: 25, Sex: Male
Department: HR, Position: Manager

文件 personnel.txt 的内容：

Total Number of Persons: 3
Number of Students: 1
Number of Teachers: 1
Number of Workers: 1