#include <iostream>
using namespace std;

// 水果抽象類
class CAbstractFruit
{
public:
    virtual void ShowName() = 0;
};

// 蘋果類
class CApple : public CAbstractFruit
{
public:
    virtual void ShowName()
    {
        cout << " 我是蘋果！" << endl;
    }
};

// 香蕉類
class CBanana : public CAbstractFruit
{
 
public:
    virtual void ShowName()
    {
        cout << " 我是香蕉！" << endl;
    }
};

// 鴨梨類
class CPear : public CAbstractFruit
{
public:
    virtual void ShowName()
    {
        cout << " 我是鴨梨！" << endl;
    }
};

// 水果工廠類
class CFruitFactory
{
public:
    static CAbstractFruit* CreateFruit(string
 
 flag)
    {
        if (flag == "apple")
        {
            return new CApple;
        }
        else if (flag == "banana")
        {
            return new CBanana;
        }
        else if (flag == "pear")
        {
            return new CPear;
        }
        else
        {
            return
 
 nullptr;
        }
    }
};

int main()
{
    CAbstractFruit* fruit = CFruitFactory::CreateFruit("apple");
    if (fruit != nullptr)
    {
        fruit->ShowName();
    }
    delete fruit;

    fruit = CFruitFactory::CreateFruit("banana");
    if (fruit != nullptr)
    {
        fruit->ShowName();
    }
    delete fruit;

    fruit = CFruitFactory::CreateFruit("pear");
    if (fruit != nullptr)
    {
        fruit->ShowName();
    }
    delete fruit;
    cin.get();
    return 0;
}