Problem B: 农夫果园 简单点，出题的方式简单点

我走过最长的路，就是教主的套路
#include <iostream>
#include <string>
using namespace std;
class Fruit
{
public:
    double price;
    double weight;
    double income;
    virtual void input(){cin>>price>>weight;}
    virtual double total(){return income;}
};
class Apple:public Fruit
{
int m,n;
public:
    void input()
    {
        double a,b;
        cin>>a>>b;
        price=a;
        weight=b;
        income=price*weight*30;
    }
    virtual double total()
    {
        return income;
    }
};
class Banana:public Fruit
{
    int m,n;
public:
    virtual void input()
    {
       double a,b;
        cin>>a>>b;
        price=a;
        weight=b;
        income=price*weight*25;
    }
    virtual double total()
    {
        return income;
    }
};
class Pear:public Fruit
{
    int m,n;
public:
    virtual void input()
    {
      double a,b;
        cin>>a>>b;
        price=a;
        weight=b;
        income=price*weight*20;
    }
    virtual double total()
    {
        return income;
    }
};
int main()
{
    Fruit* fruit;
    string fruit_name;
    double sum = 0.0;
    int cases;
    cin >> cases;
    for(int i = 1; i <= cases; i++)
    {
        cin >> fruit_name;
        if(fruit_name == "Apple")
            fruit = new Apple();
        if(fruit_name == "Banana")
            fruit = new Banana();
        if(fruit_name == "Pear")
            fruit = new Pear();
        fruit->input();
        sum += fruit->total();
        delete fruit;
    }
    cout << "Total Price : " << sum << endl;

     return 0;
}