北京理工大学面向对象程序设计第五次上机习题答案~-Here is the definition of Point:

　class Point

　{

　private:

　　double X, Y

　public:

　　void SetPoint(double a, double b)

　}

　void Point::SetPoint(double a, double b)

　{

　　X = a　　 Y = b

　}



a) define a member function Distance calculating the distance between two points, and arguments what you need.



b) define a friend function Distance calculating the distance between two points, and arguments what you need.





Please complete the couple of functions above, so its can be used as follows:

　

　 void main()

　 {

　　Point P1(10,20), P2



　　　　P2.SetPoint(38.2, 76.9)



　　　　// Use different methods to calculate the distance between two points.

　　　　double D1 = P1.Distance(P2)

　　　　double D2 = Distance(P1, P2)

　 }