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

int main()
{
	clrscr();
	int gd=DETECT,gm;
	int xc,yc,x,y;
	float p;
	long rx,ry;
	initgraph(&gd,&gm,"..\\bgi");


	cout<<"Enter ellipse center"<<endl;
	cin>>xc>>yc;

	cout<<"Enter major and minor axis"<<endl;
	cin>>rx>>ry;


	p=ry*ry-rx*rx*ry+(rx*rx)/4;

	x=0;
	y=ry;

	while(2.0*ry*ry*x<=2.0*rx*rx*y)
	{
		if(p<0)
		{
			x++;
			p=p+2*ry*ry*x+ry*ry;

		}
		else
		{
			x++;
			y--;
			p=p+2*ry*ry*x-2*rx*rx*y-ry*ry;

		}
		putpixel(xc+x,yc+y,RED);
		putpixel(xc+x,yc-y,RED);
		putpixel(xc-x,yc+y,RED);
		putpixel(xc-x,yc-y,RED);

		}


		p=ry*ry*(x+0.5)*(x+0.5)+rx*rx*(y-1)*(y-1)-rx*rx*ry*ry;

		while(y>0)
		{
			if(p<=0)
			{
				x++;
				y--;
				p=p+2*ry*ry*x-2*rx*rx*y+rx*rx;

				}
			else
			{
				y--;
				p=p-2*rx*rx*y+rx*rx;
			}

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

			}

			getch();
			closegraph();
			return 0;
}