#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <graphics.h>
void main() {
int    GraphDriver;             /* The Graphics device driver           */
int    GraphMode;               /* The Graphics mode value              */
struct point { int x,y; } p1,p2;
int a,b;
float x,y,rad=3.14159/180,i,t,t1,t2;

  printf("give me the circle point--->"); scanf("%d %d",&p1.x,&p1.y);
  printf("give me the radius --->"); scanf("%d %d",&a,&b);
  getche();

  GraphDriver = DETECT;                 /* Request auto-detection       */
  initgraph( &GraphDriver, &GraphMode, "" ); /* just increasing p1 - p2 */
  setcolor(4); ellipse(p1.x,p1.y,0,360,a,b); getche(); clearviewport();
  for (i=0; i<=90; i+=0.5) {
	t=i*rad; t1=a*cos(t); t2=b*sin(t);
	x=p1.x+t1;   y=p1.y+t2;  putpixel((int)x,(int)y,2);
	x=p1.x-t1;   y=p1.y+t2;  putpixel((int)x,(int)y,3);
	x=p1.x-t1;   y=p1.y-t2;  putpixel((int)x,(int)y,5);
	x=p1.x+t1;   y=p1.y-t2;  putpixel((int)x,(int)y,6);
  }
  getche();  closegraph();                 /* Return the system to text mode       */
}