Problem A: 还会用继承吗？

Problem A: 还会用继承吗？

Description

定义一个Base类，包括1个int类型的属性，以及满足输出格式要求的构造函数、拷贝构造函数和析构函数。

定义Base类的子类Derived，包括1个int类型的属性， 以及满足输出格式要求的构造函数、拷贝构造函数和析构函数。

Input

第1行N>0表示测试用例个数。

每个测试包括2个int类型的整数。

Output

见样例。

#include <iostream>

using namespace std;

class Base{
private:
    int x;
public:
    Base(int a) : x(a) {
        cout << "Base = " << x << " is created." << endl;
    }
    Base(const Base &b) {
        x = b.x;
        cout << "Base = " << x << " is copied." << endl;
    }
    ~Base() {
        cout << "Base = " << x << " is erased." << endl;
    }
};

class Derived : public Base {
private:
    int x;
public:
    Derived(int a, int b) : Base(a), x(b) {
        cout << "Derived = " << x << " is created." << endl;
    }
    Derived(const Derived &d) : Base(d) {
        x = d.x;
        cout << "Derived = " << x << " is copied." << endl;
    }
    ~Derived() {
        cout << "Derived = " << x << " 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);
    }
}