# include & lt string & gt
# include & ltfstream & gt
# include & ltconio.h & gt
# include & ltwindows.h & gt
Use namespace std
/////////////////////////////////////
//abstract base class//
///////////////////////////////////
Category basis
{
Protected:
Int id// undergraduate, postgraduate appraisal
int num
char name[20]；
char sex[5]；
Double ch, en, ma; //result
int borth
Public:
base()；
virtual int getid()= 0； //Undergraduate, postgraduate appraisal
Virtual void set () = 0; //Pure virtual function, called in derived class
Virtual void display()= 0；;
double getsum()； //Take the total score
char * getsex()； //Take gender
double getch()； //Get grades in all subjects
double geten()；
double getma()；
int getborth()；
int getnum()； //Take the student number
char * getname()； //Take a name
};
Base::Base()// base class construction
{
num = 0；
Strcpy (name, "nameless");
ch = 0； en = 0； ma = 0；
borth = 1900；
}
int Base::getborth()
{return to borth}
double Base::getsum()
{ return ch+en+ma； }
double Base::getch()
{ return ch}
Double base:: geten ()
{ return en}
Double base:: getma ()
{Return the horse; }
int Base::getnum()
{Return number; }
char *Base::getsex()
{Reward; }
char * Base::getname()
{Return name; }
/////////////////////////////////////
//Undergraduate class//
///////////////////////////////////
Class institutions: public courses//undergraduate courses
{
Private:
Int id// undergraduate identification