关于#c++#的问题，请各位专家解答！

#include<iostream>
#include <string>
using namespace std;
class Date{
    private:
        int year;
        int month;
        int day;
    public:
        Date(int _year,int _month,int _day):year(_year),month(_month),day(_day){
        }
        Date(){
        }
        Date(Date& a){
            this->year =a.year ;
            this->month =a.month ;
            this->day =a.day ;
        }
        void setyear(int year1){
            this->year =year1;
        }
        void setmonth(int month1){
            this->month =month1;
        }
        void setday(int day1){
            this->day =day1;
        }
        int getyear(){
            return this->year ;
        }
        int getmonth(){
            return this->month ;
        }
        int getday(){
            return this->day ;
        }
};
class Cstudent{
    private:
        string name;
        int num;
        char sex;
        int age;
        string major;
        Date enroll;
        int Math,English,program;
        static double TotalMath;
        static double TotalEnglish;
        static double Totalprogram;
        static int TotalNum;
        static double TotalAge;
    public:
        Cstudent(string  _name,int _num,char _sex,int _age,string _major,Date _enroll,int _Math,int _English,int _program
        ):name(_name),num(_num),sex(_sex),age(_age),major(_major),enroll(_enroll),Math(_Math),English(_English),program(_program){
        TotalNum++;
        TotalMath+=TotalMath;
        TotalEnglish+=TotalEnglish;
        Totalprogram+=Totalprogram;
        TotalAge+=TotalAge;    
        }
        Cstudent(){
        }
        Cstudent(Cstudent& c){
            this->name =c.name ;
            this->num =c.num ;
            this->sex =c.sex ;
            this->age =c.age ;
            this->major =c.major ;
            this->enroll =c.enroll ;
            this->Math =c.Math ;
            this->English =c.English ;
            this->program =c.program ;
            TotalNum++;
            TotalMath+=TotalMath;
            TotalEnglish+=TotalEnglish;
            Totalprogram+=Totalprogram;
            TotalAge+=TotalAge;    
        }

你自己看看帖的代码，怎么看啊