结构型模式 享元模式

抽象享元角色：
        所有具体享元类的父类，规定一些需要实现的公共接口。
具体享元角色：
        抽象享元角色的具体实现类，并实现了抽象享元角色规定的方法。
享元工厂角色：
        负责创建和管理享元角色。

使用场景：
        是以共享的方式，高效的支持大量的细粒度的对象。

/**
 * 结构型模式 享元模式
 * Flyweight模式也叫享元模式，是构造型模式之一，它通过与其他类似对象共享数据来减小内存占用。
 *
 */

#define _CRT_SECURE_NO_WARNINGS

#include <iostream>
#include <string>
#include <map>

class Person
{
public:
    Person(std::string name, int age, int sex)
    {
        m_name = name;
        m_age = age;
        m_sex = sex;
    }
    std::string getName()
    {
        return m_name;
    }
    int getAge()
    {
        return m_age;
    }
    int getSex()
    {
        return m_sex;
    }

protected:
    //注意: 保护属性变量
    std::string m_name;
    int m_age;
    int m_sex;
};

class Teacher: public Person
{
public:
    Teacher(std::string id, std::string name, int age, int sex): Person(name, age, sex)
    {
        m_id = id;
    }
    std::string getID()
    {
        return m_id;
    }
    void printT()
    {
        std::cout << "id: " << m_id << "\t" << "name: " << m_name << "\t" << "age: " << m_age << "\t" << "sex: " << m_sex  << std::endl;
    }
private:
    std::string m_id;
};

class TeacherFactory
{
public:
    TeacherFactory()
    {
        m_tpool.empty();
    }
    ~TeacherFactory()
    {
        while (!m_tpool.empty()) // 在工厂中创建老师结点，在工厂中销毁老师结点
        {
            Teacher *temp = nullptr;
            std::map<std::string, Teacher *>::iterator it = m_tpool.begin();
            temp = it->second;
            m_tpool.erase(it);
            delete temp;
        }
    }
    // 通过Teacher的pool，来存放老师结点，在TeacherFactory中创建老师、销毁老师
    Teacher *getTeacher(std::string tid)
    {
        std::string name;
        int age;
        int sex;

        Teacher *temp = nullptr;
        std::map<std::string, Teacher *>::iterator it = m_tpool.find(tid);
        if (it == m_tpool.end())
        {
            std::cout << "id为: " << tid << "的老师不存在, 系统为你创建该老师, 请输入以下信息" << std::endl;
            std::cout << "请输入老师的姓名: " << std::endl;
            std::cin >> name;
            std::cout << "请输入老师的年龄: " << std::endl;
            std::cin >> age;
            std::cout << "请输入老师的性别代号(1: 男 2: 女): " << std::endl;
            std::cin >> sex;
            temp = new Teacher(tid, name, age, sex);
            m_tpool.insert(std::pair<std::string, Teacher *>(tid, temp));
        }
        else
        {
            temp = it->second;
        }
        return temp;
    }
private:
    std::map<std::string, Teacher *> m_tpool;
};

void mytest()
{
    TeacherFactory *teacherFactory = new TeacherFactory();

    Teacher *t1 = teacherFactory->getTeacher("001");
    t1->printT();

    Teacher *t2 = teacherFactory->getTeacher("002");
    t1->printT();

    Teacher *t3 = teacherFactory->getTeacher("001");
    t1->printT();

    delete teacherFactory;
    teacherFactory = nullptr;

    return;
}

int main()
{
    mytest();

    system("pause");
    return 0;
}