Circle using polynomial method

#include<graphics.h>

#include<stdio.h>

#include<conio.h>

#include<math.h>

void plotcircle(int,int,int,int);

void main()

{

   int gd = DETECT, gm;;

   int xc,yc,x,y,xend,r,d;

   initgraph(&gd, &gm, "");

  

 printf("\n\n Enter xc:");
  scanf("%d",&xc);
  printf("\n\n Enter yc:");
  scanf("%d",&yc);
  printf("\n\n Enter r:");
  scanf("%d",&r);

   x=0;

   xend=r/sqrt(2);

   plotcircle(xc,yc,x,y);

   while(x<xend)

     {

               x=x+1;

               y=sqrt((r*r)-(x*x));

              plotcircle(xc,yc,x,y);

      }

  getch();

  }

void plotcircle(int xc,int yc,int x,int y)

                {

                putpixel(xc+x,yc+y,2);

                putpixel(xc-x,yc+y,2);

                putpixel(xc+x,yc-y,2);

                putpixel(xc+y,yc+x,2);

                putpixel(xc-y,yc-x,2);

                putpixel(xc-y,yc+x,2);

                putpixel(xc+y,yc-x,2);

                putpixel(xc-x,yc-y,2);

               }