抽象类在多继承中的应用

抽象类在多继承中的应用的案例：
#include
using namespace std;

class interface1
{
public:
virtual int add(int a, int b)=0;
virtual void print() = 0;
};

class interface2
{
public:
virtual int mcl(int a, int b) = 0;
virtual void print() = 0;
};

class Parent
{
public:
int getA()
{
a = 0;
return a;
}
private:
int a;
};

class Child :public Parent, public interface1, public interface2
{
public:
virtual int add(int a, int b)
{
cout << “Child:add()被执行了” << endl;
return a + b;
}
virtual void print()
{
cout << “Child:print()被执行了” << endl;
}
virtual int mcl(int a, int b)
{
cout << “Child:mcl()被执行了” << endl