#include <iostream>
using namespace std;

class A {
protected:
    int a, b;
public:
    A(int x, int y) {
        a = x;
        b = y;
    }
    virtual void print();
    friend int doubleIt(A a);

    // Question 1.B
    // Option 1: Member method
    A operator+(A z) {
        const int new_a = a + z.a;
        const int new_b = b + z.b;
        return {new_a, new_b};
    }
    // Option 2: Non-member method
    friend A operator+(const A& z, const A& y);
    // Question 1.B
};

class B : public A {
private:
    float p, q;
public:
    B(int m, int n, float u, float v) : A(m, n){
        p = u;
        q = v;
    }
    B() : A(0, 0) { p = q = 0; }
    void input(float u, float v);
    virtual void print(float);
};
void A::print(void) {
    cout << "A values  : " << a << " " << b << "\n";
}
void B::print(float) {
    cout << "B values : " << p << " " << q << "\n";
}
void B::input(float x, float y) {
    p = x; q = y;
}

int doubleIt(A a) { return a.a * a.a; }

// Question 1.B
// Option 2: Non-member method
A operator+(const A& z, const A& y) {
    const int new_a = z.a + y.a;
    const int new_b = z.b + y.b;
    return {new_a, new_b};
}
// Question 1.B


int main() {
    A a1(10, 20), *ptr; // Try put *ptr in a new line, as "B *ptr;" to see what is happening;
    B b1;
    b1.input(7.5, 3.142);

    ptr = &a1;
    ptr->print();
    ptr = &b1;
    ptr->print();
}