Problem A 还会用继承吗?

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。

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);

    }

}

 

 

 

代码

#include <iostream>
using namespace std;
class Base
{
private:
    int x;
public:
    Base(int a)
    {
        x=a;
        cout<<"Base = "<<x<<" is created."<<endl;
    }
    ~Base()
    {
        cout<<"Base = "<<x<<" is erased."<<endl;
    }
    Base(const Base &p)
    {
        x=p.x;
        cout<<"Base = "<<x<<" is copied."<<endl;
    }
};
class Derived : public Base
{
private:
    int y;
public:
    Derived(int a,int b):Base(a)
    {
        y=b;
        cout<<"Derived = "<<y<<" is created."<<endl;
    }
    ~Derived()
    {
        cout<<"Derived = "<<y<<" is erased."<<endl;
    }
    Derived(const Derived &d) : Base(d)
    {
        y=d.y;
        cout<<"Derived = "<<y<<" is copied."<<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);
    }
}