/*  Bressenhams Circle Drawing Algorithm */

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

int xc,yc,r;

void symm(int x,int y)
{
	putpixel(x+xc,y+yc,WHITE);
	putpixel(-x+xc,-y+yc,WHITE);
	putpixel(x+xc,-y+yc,WHITE);
	putpixel(-x+xc,y+yc,WHITE);
	putpixel(y+xc,x+yc,WHITE);
	putpixel(-y+xc,-x+yc,WHITE);
	putpixel(-y+xc,x+yc,WHITE);
	putpixel(y+xc,-x+yc,WHITE);
}

void bhsmcircle(int xc,int yc,int r)
{
	int x=0,y=r,dp;
	dp=3-2*r;
	while(x!=y)
	{
		if(dp<0)
		{
			dp+=4*x+6;
			symm(++x,y);
		}
		else
		{
			dp+=4*(x-y)+10;
			symm(++x,--y);
		}
	}
}

void main()
{
	int gdriver = DETECT, gmode;
	initgraph(&gdriver, &gmode, "");

	printf("Enter the centre co-ordinates: ");
	scanf("%d %d",&xc,&yc);
	printf("Enter the radius: ");
	scanf("%d",&r);
	bhsmcircle(xc,yc,r);
	getch();
}