Stringed类的定义: class Stringed: public Instrument public void playo /改写基类的 Iplay(函数 i cout<< stringed play'<<endl; Percussion类的定义: class percussion public Instrument public void play0改写基类的 playO函数 i cout<< percussion play <<endl; jStringed类的定义： class Stringed:public Instrument { }; public: void play() //改写基类的play()函数 { cout<<“stringed play”<<endl; } Percussion类的定义： class Percussion:public Instrument { }; public: void play() //改写基类的play()函数 { cout<<“percunssion play”<<endl; }