#include<iostream.h>
 #include<graphics.h>
 #include<math.h>
 #include<conio.h>
 #include<stdio.h>
 #include<process.h>
 #include <stdlib.h>
 #include<dos.h>
 
  int convertx(int k)
     {
       return(320+k);
     }
 
  int converty(int k)
    {
      return(240-k);
    }
 
  int convertxc(int k)
      {
	return(320+k);
      }
 
  int convertyc(int k)
      {
	 return(240-k);
      }
 
   void axis();
   int circlemid(int,int,int);
   void plotpoint();
 
   void main()
   {
      int gdriver=DETECT,gmode;
      initgraph(&gdriver,&gmode,"c:\tc1\bgi");
      float xc,yc;
      float r;
      while(1)
       {
	 cout<<"n Enter The Center Of The Circle : ";
	 cin>>xc>>yc;
	 cout<<"n Enter the Radius Of The Circle: ";
	 cin>>r;
	 circlemid(xc,yc,r);
	 cout<<"n Do you want to continue ('y' or 'Y') : ";
	 char c;
	 c=getch();
	 if(c=='y' || c=='Y')
	 break;
       }
    }
 
    void axis()
	 {
	  setcolor(1);
	  line(320,0,320,480);
	  line(0,240,640,240);
	 }
 
    void plotpoint(int xc,int yc,int x1,int y1)
	 {
	   delay(50);
	   putpixel(convertxc(xc)+x1,convertyc(yc)+y1,1);
	   putpixel(convertxc(xc)-x1,convertyc(yc)+y1,2);
	   putpixel(convertxc(xc)+x1,convertyc(yc)-y1,3);
	   putpixel(convertxc(xc)-x1,convertyc(yc)-y1,4);
 
	   putpixel(convertxc(xc)+y1,convertyc(yc)+x1,5);
	   putpixel(convertxc(xc)-y1,convertyc(yc)+x1,6);
	   putpixel(convertxc(xc)+y1,convertyc(yc)-x1,7);
	   putpixel(convertxc(xc)-y1,convertyc(yc)-x1,8);
	   }
 
    int circlemid(int xc,int yc,int r)
	  {
	     int x,y;
	     x=0;
	     y=r;
	     axis();
	     putpixel(convertxc(xc),convertyc(yc),5);
	     plotpoint(xc,yc,x,y);
	     double p=1-r;
 
	     while(x<y)
	      {
	       if(p<0)
	       {
		 x=x+1;
		 p=p+2*x+1;
	       }
	       else
	       {
		x=x+1;
		y=y-1;
		p=p+2*(x-y)+1;
	       }
	       plotpoint(xc,yc,x,y);
	     }
	    return(0);
	   }