第3题

#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(int a,int b,int 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); Circle *pt=new Circle(2.5,1.8,4.5); delete pt; return 0;}