定义一个学生类

#include <iostream>
#include<string>
using namespace std;
class student;
class teacher
{
float num;
string name;
public:
teacher(float num1,string name1);
void set(student &s);
void show();
};
class student
{
float num,score;
string name;
public:
student(string name1,float num1,float score1);
void show();
friend void teacher::set(student &s);
};

student::student(string name1,float num1,float score1)
{
name=name1;
num=num1;
score=score1;
}
void student::show()
{
cout<<"学生学号:"<<num<<endl;
cout<<"学生姓名:"<<name<<endl;
cout<<"学生成绩:"<<score<<endl;
}
teacher::teacher(float num1,string name1)
{
num=num1;
name=name1;
}
void teacher::show()
{
cout<<"教师职工号:"<<num<<endl;
cout<<"教师姓名:"<<name<<endl;
}
void teacher::set(student &s)
{
cout<<"请输入学号:"<<endl;
cin>>s.num;
cout<<"请输入姓名:"<<endl;
cin>>s.name;
cout<<"请输入成绩:"<<endl;
cin>>s.score;
}
int main()
{
student stu1("aaa",1,95);
student stu2("bbb",2,93);
stu1.show();
cout<<"***********************"<<endl;
stu2.show();
teacher t(11111,"tttt");
cout<<"***********************"<<endl;
t.show();
cout<<"***********************"<<endl;
t.set(stu2);
cout<<"***********************"<<endl;
stu2.show();
return 0;
}