增加一个fun函数，使用对象的引用作为形参（第三章第八题）

#include <iostream>using namespace std;class Student{public:Student(int n,float s):num(n),score(s){}void change(int n,float s) {num=n;score=s;}void display() {cout<<num<<" "<<score<<endl;}private:int num;float score;};int main(){Student stud(101,78.5);void fun(Student&);fun(stud);return 0;}void fun(Student &stu){stu.display();stu.change(101,80.5);stu.display();}