Problem A 你会定义类吗？

Description

定义一个类Demo，有构造函数、析构函数和成员函数show()，其中show()根据样例的格式输出具体属性值。该类只有一个int类型的成员。

Input

输入只有一个整数，int类型范围内。

Output

见样例。

Sample Input

-100

Sample Output

A data 10 is created! A data 0 is created! A data -100 is created! This is data 10 This is data 0 This is data -100 A data -100 is erased! A data 0 is erased! A data 10 is erased!

HINT

Append Code

append.cc,

int main()

{

    Demo tmp(10), tmp2;

    int d;

    cin>>d;

    Demo tmp3(d);

    tmp.show();

    tmp2.show();

    tmp3.show();

    return 0;

}

代码

#include <iostream>

using namespace std;
class Demo
{
    int a;
public:
    Demo(int x=0):a(x)
    {
        cout<<"A data "<<a<<" is created!"<<endl;
    }
   ~Demo(){cout<<"A data "<<a<<" is erased!"<<endl;}
    void show()
    {
        cout<<"This is data "<<a<<endl;
    }
};

int main()
{
    Demo tmp(10), tmp2;
    int d;
    cin>>d;
    Demo tmp3(d);

tmp.show();
    tmp2.show();
    tmp3.show();
    return 0;
}