# C++ > Algorithms Code Examples

## Which three balls move in three concentric oval orbit without ever colliding.

``` Which three balls move in three concentric oval orbit without ever colliding. #define R 5 #include<iostream.h> #include<conio.h> #include<graphics.h> #include<math.h> #include<dos.h> #include<stdlib.h> void main() { void orbit(void); int d=DETECT,m; initgraph(&d,&m,"e:\tcc\bgi"); float xx,yy,aa=15,bb=50,x,y,X,Y,a=34,b=0,A=100,B=60,ex,sq; setcolor(14); // orbit(); for(float i=0;i<=720;i+=.1) { x=a*cos(i+10)-a*sin(i+10); y=b*sin(i+10)+a*cos(i+10); X=A*cos(i+20)-B*sin(i+20+90); Y=B*sin(i+20)+B*cos(i+20+90); xx=aa*cos(i); yy=bb*sin(i); setcolor(14); setfillstyle(1,14); circle(x+100,y+100,R); floodfill(x+100,y+100,14); setcolor(14); setfillstyle(1,14); circle(xx+100,yy+100,R); floodfill(xx+100,yy+100,14); setcolor(14); setfillstyle(1,14); circle(X+100,Y+100,R); floodfill(X+100,Y+100,14); putpixel(X+100,Y+100,4); delay(100); setcolor(0); setfillstyle(1,0); circle(x+100,y+100,R); floodfill(x+100,y+100,0); setcolor(0); setfillstyle(1,0); circle(xx+100,yy+100,R); floodfill(xx+100,yy+100,0); setcolor(0); setfillstyle(1,0); circle(X+100,Y+100,R); floodfill(X+100,Y+100,0); if(kbhit()) exit(1); orbit(); } getch(); } void orbit() { for(float i=0;i<=60;i+=1) { float xx,yy,aa=15,bb=50,x,y,X,Y,a=34,b=0,A=100,B=60,ex,sq; x=a*cos(i)-a*sin(i); y=b*sin(i)+a*cos(i); X=A*cos(i)-B*sin(i+90); Y=B*sin(i)+B*cos(i+90); xx=aa*cos(i); yy=bb*sin(i); putpixel(x+100,y+100,14); putpixel(X+100,Y+100,14); putpixel(xx+100,yy+100,14); } } ```