C++ 42.类与对象—多态的案例3（电脑组装需求分析、电脑组装具体实现）

案例描述：
电脑主要组成部件CPU（用于计算），显卡（用于显卡），内存条（用于存储）
将每个零件封装出抽象基类，并且提供不同的厂商生产不同的零件，例如Intel厂商和Lenovo厂商
创建电脑类提供让电脑工作的函数，并且调用每个零件工作的接口
测试时组装三台不同的电脑进行工作

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

//抽象不同零件类
//抽象计算函数
class CPU 
{
public:	
	virtual void calculate() = 0;
};
//抽象显示函数
class VideoCard 
{
public:
	virtual void display() = 0;
};
//抽象存储函数
class Memory
{
public:
	virtual void storage() = 0;
};

//电脑类
class Computer 
{
public:
	//构造函数中传入三个零件指针
	Computer(CPU * cpu, VideoCard * vc, Memory * mem)
	{
		m_cpu = cpu;//指针接收
		m_vc = vc;
		m_mem = mem;
	}
	//提供工作的函数
	void work()
	{
		//调用每个零件工作的接口
		m_cpu->calculate();
		m_vc->display();
		m_mem->storage();
	}

	//提供析构函数，释放 3个电脑零件
	~Computer()
	{
		if (m_cpu != NULL)
		{
			delete m_cpu;
			m_cpu = NULL;
		}
		if (m_vc != NULL)
		{
			delete m_vc;
			m_vc = NULL;
		}
		if (m_mem != NULL)
		{
			delete m_mem;
			m_mem = NULL;
		}
	}
private:
	CPU * m_cpu;//CPU的零件指针
	VideoCard * m_vc;//显卡零件指针
	Memory * m_mem;//内存零件指针

};

//具体厂商
//Intel厂商
class IntelCpu:public CPU
{
public:
	virtual void calculate()
	{
		cout << "Intel的CPU开始计算了！" << endl;
	}
};

class IntelVideoCard :public VideoCard
{
public:
	virtual void display()
	{
		cout << "Intel的VideoCard开始显示了！" << endl;
	}
};

class IntelMemory :public Memory
{
public:
	virtual void storage()
	{
		cout << "Intel的Memory开始存储了！" << endl;
	}
};

//Lenovo厂商
class LenovoCpu :public CPU
{
public:
	virtual void calculate()
	{
		cout << "Lenovo的CPU开始计算了！" << endl;
	}
};

class LenovoVideoCard :public VideoCard
{
public:
	virtual void display()
	{
		cout << "Lenovo的VideoCard开始显示了！" << endl;
	}
};

class LenovoMemory :public Memory
{
public:
	virtual void storage()
	{
		cout << "Lenovo的Memory开始存储了！" << endl;
	}
};

void test01()
{
	//第一台电脑
	CPU * intelCpu = new IntelCpu;//父类指向子类对象，//需释放
	VideoCard * intelVCard = new IntelVideoCard;//需释放
	Memory * intelMem = new IntelMemory;//需释放，
	//1.直接delete 在 delete computer1; 后
	//2.提供析构函数在 class Computer  中
	

	//创建第一台电脑
	Computer * computer1 = new Computer(intelCpu, intelVCard, intelMem);//需释放
	computer1->work();
	delete computer1;


	cout << "-----------------------------" << endl;
	cout << "第二台电脑开始工作" << endl;
	//创建第二台电脑
	Computer * computer2 = new Computer(new LenovoCpu, new LenovoVideoCard, new LenovoMemory);//需释放
	computer2->work();
	delete computer2;

	cout << "-----------------------------" << endl;
	cout << "第三台电脑开始工作" << endl;
	//创建第三台电脑
	Computer * computer3 = new Computer(new LenovoCpu, new IntelVideoCard, new LenovoMemory);//需释放
	computer3->work();
	delete computer3;
}

int main()
{
	test01();

	system("pause");
	return 0;
}