c++多态，继承，构造函数，析构函数

#include <iostream>
using namespace std;

class A
{
public:
int m;
A()
{
cout << "gouzao A" << endl;
m = 1;
}

~A()
{
cout << "xigou A" << endl;
}

virtual	void print()
{
cout << "A: " << m << endl;
}
};

class B: public A
{
public:
B()
{
cout << "gouzao B" << endl;
m = 2;
}

~B()
{
cout << "xi gou B" << endl;
}
void print()
{
cout << "B: " << m << endl;
}
};

class C: public B
{
public:
C()
{
cout << "gouzao C" << endl;
m = 3;
}

~C()
{
cout << "xi gou C" << endl;
}

void print()
{
cout << "C: " << m << endl;
}

};

void printClass(A a)
{
a.print();
}

int main()
{
C c;
c.print();
printClass(c);
}