C++多态案例-电脑组装

要求：

分析：

代码：

#include<iostream>
using namespace std;

//3个抽象零件类
class CPU
{
public:
	virtual void calculate() = 0;
};

class VideoCard
{
public:
	virtual void display() = 0;
};

class Memory
{
public:
	virtual void storage() = 0;
};

class Computer
{
public:
	Computer(CPU* cpu, VideoCard* vc, Memory* mem)
	{
		m_cpu = cpu;
		m_vc = vc;
		m_mem = mem;
	}

	~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;
		}
	}
	void work()
	{
		m_cpu->calculate();
		m_vc->displ