新学编程，求C++这段代码的注释

class circle {

protected:    

point center;         

int   radius;

public: 

circle(int x, int y, int r):center(x, y),radius(r) {

              cout << "construct circle: " << radius << endl;

         }

       ~circle(){     cout << "destroy circle " << endl;}

};

class circle {
protected:		//受保护成员
	point center;
	int   radius;
public:			//公共成员
	circle(int x, int y, int r) :center(x, y), radius(r) {	//初始化构造函数circle()，center初始值是x,y  radius = r
		cout << "construct circle: " << radius << endl;		//输出到控制台“construct circle: r”
	}
	~circle(){		//析构函数，删除circle（）函数，释放内存
		cout << "destroy circle " << endl; //输出到控制台“destroy circle”
	}		
};