#include<windows.h>
#include<math.h>
#include<graphics.h>
const float pi = 3.14159265359;
using namespace std;
int main()
{
    float x= 400,y=400,r=100, t = 0.0;
    initwindow(800,600,"");
    while(true)
    {
        cleardevice();
        x = r*cos(t) + 150;
        y = r*sin(t) + 150;
        circle(150,150,120);
        circle(x,y,20);
        t=t<2*pi?t+0.05:0;
        Sleep(10);
    }
    getch();
    closegraph();
}