#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 radius,k,i;
float x,y,t,t1,t2;

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

  GraphDriver = DETECT;                 /* Request auto-detection       */
  initgraph( &GraphDriver, &GraphMode, "" ); /* just increasing p1 - p2 */
  setcolor(4); circle(p1.x,p1.y,radius); getche(); clearviewport();
  k=(int)(radius/1.41414+0.5);
  for (i=0; i<=k; i++) {
    t1=i; t2=sqrt(((float)radius)*radius-i*i);
    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);

    x=p1.x+t2;   y=p1.y+t1;  putpixel((int)x,(int)y,7);
    x=p1.x-t2;   y=p1.y+t1;  putpixel((int)x,(int)y,8);
    x=p1.x-t2;   y=p1.y-t1;  putpixel((int)x,(int)y,9);
    x=p1.x+t2;   y=p1.y-t1;  putpixel((int)x,(int)y,10); delay(20);
  }
  getche();
  closegraph();                 /* Return the system to text mode       */
}