#include <stdio.h> 
#include <time.h> 
#include <conio.h> 
#include <graphics.h> 
#include <math.h> 
#include <dos.h> 
#include <stdlib.h> 
#include <time.h> 
int main(void) 

    { 
     int gdriver = DETECT, gmode; 
     double x, y, theta, r; 
     int i, c, thetamax, step; 
     initgraph(&gdriver, &gmode, "c:\\tc\\bgi");
     struct palettetype pal; 
     getpalette(&pal); 
     for (i=0; i<pal.size; i++) 
     setrgbpalette(pal.colors[i], i * 2 , 2, i*4); 
     randomize(); 

         do { 
         for (i=0; i<pal.size; i++) 
         setrgbpalette(pal.colors[i], i * random(14) ,i * random(14), i * random(14)); 
         r = random(230) + 20; 
         thetamax = random(360) + 1; 
         step = random(15) + 1; 
         for(theta = 0; theta <= thetamax; theta+=step) 

             { 
             if(kbhit()) 
             c = getch(); 
             x = cos(theta); 
             y = sin(theta); 
             setcolor(random(14)+ 1); 
             delay(10); 
             rectangle(300 + x * r, 200 + y * r, 350 + x * r, 250 + y * r); 
             } 
            for(theta = 0; theta <= thetamax; theta+=step) 

                 { 
                 if(kbhit()) 
                 c = getch(); 
                 x = cos(theta); 
                 y = sin(theta); 
                 setcolor(0); 
                 delay(10); 
                 rectangle(300 + x * r, 200 + y * r, 350 + x * r, 250 + y * r); 
                 } 
                 if(kbhit()) 
                 c = getch(); 
		 } while(c != 32); // spacebar to break
                 
                 return(0); 
            }