Description

定義一個Base類，包括1個int類型的屬性，以及滿足輸出格式要求的構造函數、拷貝構造函數和析構函數。

定義Base類的子類Derived，包括1個int類型的屬性， 以及滿足輸出格式要求的構造函數、拷貝構造函數和析構函數。

Input

第1行N>0表示測試用例個數。

每個測試包括2個int類型的整數。

Output

見樣例。

Sample Input

1
10 20

Sample Output

Base = 10 is created.
Base = 10 is copied.
Base = 10 is created.
Derived = 20 is created.
Base = 10 is copied.
Derived = 20 is copied.
Derived = 20 is erased.
Base = 10 is erased.
Derived = 20 is erased.
Base = 10 is erased.
Base = 10 is erased.
Base = 10 is erased.

HINT

Append Code

int main()
{
    int cases, data1, data2;
    cin>>cases;
    for (int i = 0; i < cases; i++)
    {
        cin>>data1>>data2;
        Base base1(data1), base2(base1);

        Derived derived1(data1, data2), derived2(derived1);
    }
}

#include <iostream>
using namespace std;
class Base
{
public :
    int num;
    Base(int t):num(t)
    {
        cout<<"Base = "<<num<<" is created."<<endl;
    }
    Base(const Base &p)
    {
        num=p.num;
        cout<<"Base = "<<num<<" is copied."<<endl;
    }
    ~Base()
    {
        cout<<"Base = "<<num<<" is erased."<<endl;
    }
};
class Derived:public Base
{
public :
    int num2;
    Derived(int a, int b):Base(a), num2(b)
    {
        cout<<"Derived = "<<num2<<" is created."<<endl;
    }
    Derived(const Derived &p):Base(p),num2(p.num2)//子類可以拷貝給基類
    {
        cout<<"Derived = "<<num2<<" is copied."<<endl;
    }
    ~Derived()
    {
        cout<<"Derived = "<<num2<<" is erased."<<endl;
    }
};

int main()
{
    int cases, data1, data2;
    cin>>cases;
    for (int i = 0; i < cases; i++)
    {
        cin>>data1>>data2;
        Base base1(data1), base2(base1);

        Derived derived1(data1, data2), derived2(derived1);
    }
}

Problem B: 還會用繼承嗎？