//19.18 利用类的包含来实现代码重用
#include <iostream>
#include <limits> // 为了使用numeric_limits
using namespace std;
class Data
{
public:
Data(int number,float Price):num(number),price(Price){}
virtual ~Data(){};
int GetNumber()const{return num;}
float GetPrice()const{return price;}
virtual void Print()const =0;
private:
int num;
float price;
};
class Book:public Data
{
