Using nested definitions and class (ingenuity as C ++ p105 22)

My Method 1:

 1 #include<iostream>
 2 
 3 class Point{
 4     int cX,cY;
 5 public:
 6     void setPoint(int x,int y){
 7         cX=x;cY=y;
 8     }
 9     int getPointX(){
10         return cX;
11     }
12     int getPointY(){
13         return cY;
14     }
15 };
16 class Circle{
17     int cRadius;Point cCenter;
18 public:
19     void setCircle(int radius,Point center){
20         cRadius=radius;cCenter=center;
21     }
22     int getRadius(){
23         return cRadius;
24     }
25     int getCenterX(){
26         return cCenter.getPointX();
27     }
28     int getCenterY(){
29         return cCenter.getPointY();
30     }
31 };
32 int main(){
33     Point p1,cp;Circle c1;
34     p1.setPoint(7,0);cp.setPoint(0,0);
35     c1.setCircle(8,cp);
36     if((c1.getCenterX()-p1.getPointX())*(c1.getCenterX()-p1.getPointX())+
37         (c1.getCenterY()-p1.getPointY())*(c1.getCenterY()-p1.getPointY())>
38         c1.getRadius()*c1.getRadius())
39         std::cout<<"点在圆外\n"<<std::endl;
40     else if(((c1.getCenterX()-p1.getPointX())*(c1.getCenterX()-p1.getPointX())+
41         (c1.getCenterY()-p1.getPointY())*(c1.getCenterY()-p1.getPointY())==
42         c1.getRadius()*c1.getRadius()))
43         std::cout<<"点在圆上\n"<<std::endl;
44     else
45         std::cout<<"点在圆内\n"<<std::endl;
46     system("pause");
47     return 0;
48 }

 Teacher's practice:

 1 #include<iostream>
 2 class Point{
 3     int cX,cY;
 4 public:
 5     void setPoint(int x,int y){
 6         cX=x;cY=y;
 7     }
 8     int getPointX(){
 9         return cX;
10     }
11     int getPointY(){
12         return cY;
13     }
14 };
15 class Circle{
16     intcRadius; Point cCenter;
 . 17  public :
 18 is      void setCircle ( int RADIUS, Point Center) {
 . 19          cRadius = RADIUS; cCenter = Center;
 20 is      }
 21 is      int getRadius () {
 22 is          return cRadius;
 23 is      }
 24      Point getCenter () {
 25          return cCenter;
 26 is      }
 27  };
 28  int main () {
 29      point P1, cp; // declare two points, p1 is an arbitrary point, cp is the center 
30      circle C1; // declaration circle
31 is      p1.setPoint ( 0 , . 5 ); // Assignment point 
32      cp.setPoint ( 0 , 0 ); // Assignment center 
33 is      c1.setCircle ( . 6 , CP); // set the center and radius of the circle 
34 is  
35      IF ( (c1.getCenter () getPointX () -. p1.getPointX ()) *
 36          (c1.getCenter () getPointX () -. p1.getPointX ()) +
 37 [          (c1.getCenter () getPointY () -. P1 .getPointY ()) *
 38 is          (c1.getCenter () getPointY () -. p1.getPointY ())>
 39          c1.getRadius () * c1.getRadius ())
 40         :: COUT << STD " point on the outer circle \ n-\ n- " ;
 41 is      the else  IF . ((c1.getCenter () getPointX () - p1.getPointX ()) *
 42 is          . (c1.getCenter () getPointX () -p1.getPointX ()) +
 43 is          (c1.getCenter () getPointY () -. p1.getPointY ()) *
 44 is          (c1.getCenter () getPointY () -. p1.getPointY ()) ==
 45          C1. getRadius () * c1.getRadius ())
 46 is          STD :: COUT << " point on the circle \ n-\ n- " ;
 47      the else 
48          STD :: COUT << " points within circle \ n-\ n- " ;
 49      System ( 'pause");
50     return 0;
51 }