P225 3

<img src="https://img-blog.youkuaiyun.com/20150610191739082?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvWXVTb25nNDg2OQ==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />#include <iostream> 
using namespace std; 
class Point 
{public:  
Point(float a,float b):x(a),y(b){}  
~Point(){cout<<"executing Point destructor"<<endl;} 
private: 
float x; 
float y; 
}; 
class Circle:public Point 
{public:  
Circle(float a,float b,float r):Point(a,b),radius(r){}  
~Circle(){cout<<"executing Circle destructor"<<endl;} 
private:  
float radius; 
}; 
int main()  
{Point *p=new Circle(2.5,1.8,4.5);  
delete p; 
return 0; 
}