computer_info.h

#pragma once
#include <string>
#include <iostream>
using namespace std;
class Computer
{
protected:
    string firm;
    string mark;
    int yearB;
public:
    Computer() = default;
    Computer(string firm, string mark, int yearB);
    string  print();
    void changeF(string firm);
    void changeM(string mark);
    void changeY(int yearB);
};
class Desktop : public Computer
{
private:
    int power;
public:
    Desktop() = default;
    Desktop(string firm, string mark, int yearB, int power);
    void changeP(int power);
    string print(int current_year);

};
class Laptop : public Computer
{
private:
    int core;
public:
    Laptop() = default;
    Laptop(string firm, string mark, int yearB, int core);
    void changeC(int core);
    string print(int current_year);
};