polymorphism/player_v2.cpp

#include <iostream>
#include <string>
using std::cout, std::string, std::endl;

class Player
{
public:
    string name;
    int attack, defence, HP;

public:
    Player(string _name, int _attack, int _defence, int _HP)
        : name{_name}, attack{_attack}, defence{_defence}, HP{_HP}
    {
    }
    virtual void pk(Player *p)
    {
        while (HP > 0)
        {
            hit(p);
            if (p->HP <= 0)
            {
                std::cout << p->name << "死亡！\n";
                return;
            }
            p->hit(this);
        }
        std::cout << name << "死亡！\n";
    }

    virtual void hit(Player *p) = 0; // 纯虚函数
};

class Demon : public Player
{
public:
    using Player::Player;
    virtual void hit(Player *p)
    {
        p->HP -= attack - p->defence;
        HP += attack - p->defence;
        std::cout << name << "砍了" << p->name << "一刀，并吸了一口血\n";
    }
};

class Angel : public Player
{
public:
    using Player::Player;
    void hit(Player *p)
    {
        p->HP -= attack - p->defence;
        p->HP -= attack - p->defence;
        std::cout << name << "砍了" << p->name << "两刀\n";
        if (dynamic_cast<Demon *>(p)) // 向下转型
        {
            std::cout << "天使遇到了恶魔，再砍一刀！\n";
            p->HP -= attack - p->defence;
        }
    }
};

class Ghost : public Player
{
public:
    using Player::Player;
    virtual void hit(Player *p)
    {
        p->HP -= (attack - p->defence) * 1.5;
        HP += (attack - p->defence) * 0.5;
        std::cout << name << "砍了" << p->name << "一大刀，并吸了一小口血\n";
    }
};

int main()
{
    Angel a{"孙悟空", 100, 20, 1000};
    Demon d{"牛魔王", 100, 20, 1000};
    Ghost g{"白骨精", 100, 20, 1000};
    a.pk(&d);
}