Program to draw a circle:

int main(void)

{

   /* request auto detection */

   int gdriver = DETECT, gmode, errorcode;

   int midx, midy;

   int radius = 100;

   /* initialize graphics and local variables */

   initgraph(&gdriver, &gmode, "f:\\software\\tc\\bgi");

   /* read result of initialization */

   errorcode = graphresult();

   if (errorcode != grOk)  /* an error occurred */

   {

      printf("Graphics error: %s\n", grapherrormsg(errorcode));

      printf("Press any key to halt:");

      getch();

      exit(1); /* terminate with an error code */

   }

   midx = getmaxx() / 2;

   midy = getmaxy() / 2;

   setcolor(getmaxcolor());

   /* draw the circle */

   setcolor(RED);

   circle(midx, midy, radius);

   szetcolor(GREEN);

   floodfill(midx, midy, radius);

   /* clean up */

   getch();

   closegraph();

   return 0;

}