class Instrument {
public:
virtual void play() {
cout << "乐器在演奏声音" << endl;
}
virtual ~Instrument() {}
};

class Piano : public Instrument {
public:
void play() override {
cout << "钢琴：叮咚叮咚" << endl;
}
};

class Guitar : public Instrument {
public:
void play() override {
cout << "吉他：咚咚当当" << endl;
}
};

int main() {
Instrument* instruments[2];
instruments[0] = new Piano();
instruments[1] = new Guitar();
for (int i = 0; i < 2; ++i) {
instruments[i]->play();
}
for (int i = 0; i < 2; ++i) {
delete instruments[i];
}
return 0;
}