OOP week 7

//https://www.facebook.com/pages/C%C3%B9ng-h%E1%BB%8Dc-l%E1%BA%ADp-tr%C3%ACnh/632038696941833

#include <iostream>
#include <string>
using namespace std;
class NhanVien
{
protected:
	string HoTen, NgaySinh;
	int Luong;
public:
	NhanVien(string HoTen = "", string NgaySinh = "")
	{
		this->HoTen = HoTen;
		this->NgaySinh = NgaySinh;
	}
	~NhanVien(){};
	friend istream& operator >> (istream& in, NhanVien &NV)
	{
		fflush(stdin);
		cout << "Nhap ten: ";
		getline(in, NV.HoTen);
		cout << "Nhap ngay sinh: ";
		getline(in, NV.NgaySinh);
		return in;
	}
	friend ostream& operator << (ostream& out, NhanVien NV)
	{
		out << "Ten: " << NV.HoTen << "\nNgay sinh: " << NV.NgaySinh << endl;
		return out;
	}
};
class NVSanXuat : public NhanVien
{
public:
	NVSanXuat(string Ten = "", string NgaySinh = "", int LuongCanBan = 0, int SoSP = 0) : NhanVien(Ten, NgaySinh)
	{
		this->LuongCB = LuongCanBan;
		this->SoSP = SoSP;
	}
	~NVSanXuat(){};
	int TinhLuong()
	{
		this->Luong = LuongCB + SoSP * 5000;
		return this->Luong;
	}
	friend istream& operator >> (istream& in, NVSanXuat &NV)
	{
		NhanVien *N = &NV;
		in >> *N;
		fflush(stdin);
		cout << "Nhap luong co ban: ";
		in >> NV.LuongCB;
		cout << "Nhap so SP: ";
		in >> NV.SoSP;
		return in;
	}
	friend ostream& operator << (ostream& out, NVSanXuat NV)
	{
		NhanVien *N = &NV;
		out << *N;
		out << "Luong co ban: " << NV.LuongCB << "\nSo san pham: " << NV.SoSP << "\nLuong: " << NV.TinhLuong() << endl;
		return out;
	}
private:
	int LuongCB;
	int SoSP;
};

class NVVanPhong : public NhanVien
{
public:
	NVVanPhong(string Ten = "", string NgaySinh = "", int SoNgayLam = 0) : NhanVien(Ten, NgaySinh)
	{
		this->SoNgayLam = SoNgayLam;
	}
	~NVVanPhong(){};
	int TinhLuong()
	{
		this->Luong = SoNgayLam * 100000;
		return this->Luong;
	}
	friend istream& operator >> (istream& in, NVVanPhong &NV)
	{
		NhanVien *N = &NV;
		in >> *N;
		fflush(stdin);
		cout << "Nhap so ngay lam: ";
		in >> NV.SoNgayLam;
		return in;
	}
	friend ostream& operator << (ostream& out, NVVanPhong NV)
	{
		NhanVien *N = &NV;
		out << *N;
		out << "So ngay lam: " << NV.SoNgayLam << "\nLuong: " << NV.TinhLuong() << endl;
		return out;
	}
private:
	int SoNgayLam;
};


void main()
{
	system("start https://www.facebook.com/pages/C%C3%B9ng-h%E1%BB%8Dc-l%E1%BA%ADp-tr%C3%ACnh/632038696941833");
	NVSanXuat a("nguyen huu tho", "11 07 96", 300000, 1000);
	cout << a;
}