Bresenham Circle Drawing algorithm

Bresenham Circle Drawing algorithm

#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:\\TurboC3\\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(); 
}