Bresenham's Algorithm for Circle.

#include<graphics.h>
#include<conio.h>
#include<dos.h>
main()
{int gd=DETECT,gm;
initgraph(&gd,&gm,"c:\\TC\\bgi");
int r=100,x=0,y=r,e,a=200,b=200;
e=3-2*r;
do
{
if(e<0)
{x=x+1;
e=e+4*x+6;}
else
{
x=x+1;
y=y-1;
e=e+4*x-4*y+10;
}
putpixel(a+x,b+y,15);
putpixel(a+x,b+-y,15);
putpixel(a-x,b+y,15);
putpixel(a-x,b-y,15);
putpixel(a+y,b+x,15);
putpixel(a+y,b-x,15);
putpixel(a-y,b+x,15);
putpixel(a-y,b-x,15);
delay(50);
}
while(x<=y);
getch();
}