how to use lists with abstract class

#include<iostream>
#include<string>
using namespace std;

class Sale
{
public:
	Sale(double _price=0,string _type=""):price(_price),type(_type) { }
	virtual void print() const =0;
protected:
	double price;
	string type;
};

class Book:public Sale
{
public:
	Book(double _price=0,string _type="",string _title=""):Sale(_price,_type),title(_title) { }
	void print() const
	{
		cout<<"title: "<<title<<endl;
		cout<<"price: "<<price<<endl;
		cout<<"type: "<<type<<endl;
	}
private:
	string title;
};



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#include"sale.h"
#include<iostream>
#include<list>
using namespace std;

int main()
{
	list<Sale *> myList;
	list<Sale *>::iterator myIt;

	myList.push_back(new Book(30,"romance","bir ask hikayesi"));
	myList.push_back(new Book(25,"action","matrix"));
	myList.push_front(new Book(5,"comedy","arif"));

	cout<<"my shopping cart"<<endl;
	for(myIt=myList.begin(); myIt!=myList.end(); myIt++)
		(*myIt)->print();

	system("pause");
	return 0;
}

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