Bresenham Circle drawing program in c

# include<stdio.h>
# include<conio.h>
# include<graphics.h>
# include<math.h>

void main()
{
int gd=DETECT,gm;
int r,x,y,p,xc=320,yc=240;
initgraph(&gd,&gm,"C:\\TC\\BGI");
cleardevice();
printf("Enter the radius ");
scanf("%d",&r);
x=0;

y=r;
putpixel(xc+x,yc-y,1);
p=3-(2*r);
    for(x=0;x<=y;x++)
    {
        if (p<0)
        {
            y=y;
            p=(p+(4*x)+6);
        }
        else
        {
            y=y-1;
            p=p+((4*(x-y)+10));
        }
            putpixel(xc+x,yc-y,1);
            putpixel(xc-x,yc-y,2);
            putpixel(xc+x,yc+y,3);
            putpixel(xc-x,yc+y,4);
            putpixel(xc+y,yc-x,5);
            putpixel(xc-y,yc-x,6);
            putpixel(xc+y,yc+x,7);
            putpixel(xc-y,yc+x,8);
    }
getch();
closegraph();
}