Description
学校是老师和学生组成的。现在定义Student、Teacher和School三个类来模拟一个学校。
Student类只有一个int类型的数据成员，表示学生的年级；Teacher类只有一个double类型的数据成员，表示该教师的工资；School类是由1个Student类的对象、1个Teacher类的对象组合而成。定义它们的构造函数和析构函数，使程序能产生样例所示的输出。
Input
输入4行，第1行和第3行是2个int类型的正整数；第2行和第4行是double类型的正数。
Output
见样例。
Sample Input
3 1600.31 4 2451.34
Sample Output
A student grade 3 is created.
A teacher with salary 1600.
31 is created.
A school is created.
A student grade 4 is created.
A teacher with salary 2451.
34 is created.
A student grade 4 is created.
A teacher with salary 2451.
34 is created.
A school is created.
A school is erased.
A teacher with salary 2451.
34 is erased.
A student grade 4 is erased.
A teacher with salary 2451.
34 is erased.
A student grade 4 is erased.
A school is erased.
A teacher with salary 1600.
31 is erased.
A student grade 3 is erased.
HINT
Append Code
#include<iostream>
#include <cstring>
using namespace std;
class Student
{
friend class School;
private:
int st;
public:
Student(int _st):st(_st){cout<<"A student grade "<<st<<" is created."<<endl;}
~Student(){cout<<"A student grade "<<st<<" is erased."<<endl;}
};
class Teacher
{
friend class School;
private:
double te;
public:
Teacher(double _te):te(_te){cout<<"A teacher with salary "<<te<<" is created."<<endl;}
~Teacher(){cout<<"A teacher with salary "<<te<<" is erased."<<endl;}
};
class School
{
private:
Student a;
Teacher b;
public:
School(int _a,double _b):a(_a),b(_b){cout<<"A school is created."<<endl;}
~School(){cout<<"A school is erased."<<endl;}
};
int main()
{
int g;
double s;
cin>>g>>s;
School sch(g, s);
cin>>g;
Student stu(g);
cin>>s;
Teacher tea(s);
School(g, s);
return 0;
}