构造函数访问权限和基类构造函数，派生类的构造函数调用顺序

#include<iostream>
#include<stdlib.h>
using namespace std;
//1.访问权限
class B
{
public:
	void Fun1(int b1,int b2,int b3)
	{
		_b1=b2;
		_b2=b2;
		_b3=b3;

	}
public:
	int _b1;
protected:
	int _b2;
private:
	int _b3;
};
class C:private B
{
public:
	 void Fun2()
	{
		_b1=1;
		_b2=2;
		_b3=3;//不可以访问,private继承下来了，但是不可以访问，不可见
	}
public:
	int _c1;
protected:
	int _c2;
private:
	int _c3;
};
class D:protected C
{
public:
	void Fun3()
	{
		_b1=1;
		_b2=2;
		_b3=3;
	}

public:
	int _d1;
protected:
	int _d2;
private:
	int _d3;
};
//2.构造函数的调用顺序
//a.基类没有缺省的构造函数，必须在派生类的初始化列表中显示给出基类类名和参数列表
class B
{
public:
	B(int b)
	{cout<<"B()"<<endl;};
private:
	int _b;
}
class C1:public B
{
	C1(int c1)
		:B(c1)
	{cout<<"C1()"<<endl;}
private:
	int _c1;
};

//b.基类有带参的构造函数，派生类一定要定义构造函数.
class B
{
public:
	B(int b)
	{cout<<"B()"<<endl;};
private:
	int