Po lekcji 1

#include <iostream>
#include <vector>
#include <string>
#include <cstdlib>

using namespace std;

class Entity
    {
        private:

            string name;
            int health;
            int maxHealth;
            int damage;

        public:

            Entity(string entityName)
            {
                name = entityName;
                maxHealth = 10;
                health = maxHealth;
                damage = 2;
            }

            string get_name()
            {
                return name;
            }

            int get_health()
            {
                return health;
            }

            int get_max_health()
            {
                return maxHealth;
            }

            int get_damage()
            {
                return damage;
            }

            void lower_health(int value)
            {
                health -= value;
                if (health < 0)
                {
                    health = 0;
                }
            }
            void add_health(int value)
            {
                health += value;
                if (health > maxHealth)
                {
                    health = maxHealth;
                }
            }
    };

class Player : public Entity
{
    private:

        int metal;
        int oxygen;

    public:

        Player(string playerName) : Entity(playerName)
        {
            metal = 0;
            oxygen = 100;
        }

        Player() : Entity("John")
        {

        }

        int get_metal()
        {
            return metal;
        }

        int get_oxygen()
        {
            return oxygen;
        }

        void display_player_info()
        {
            cout << "Stan gracza" << endl;
            cout << "------------------------------------------------" << endl;
            cout << "Życie: " << get_health() << "/" << get_max_health() << endl;
            cout << "Atak: " << get_damage() << endl;
            cout << "Tlen: " << oxygen << "%" << endl;
            cout << "Metal: " << metal << "/50" << endl;
        }

        void rest()
        {
            cout << get_name() << " odpoczywa. Zużycie 2% tlenu." << endl << endl;
            lower_oxygen(2);
            add_health(5);
            display_player_info();
        }

        void lower_oxygen(int value)
        {
            oxygen -= value;
        }

        void add_oxygen(int value)
        {
            if(oxygen + value > 100)
            {
                oxygen = 100;
            }
            else
            {
                oxygen += value;
            }
        }

        void add_metal(int value)
        {
            metal += value;
        }
};