#include<iostream.h>
#include<graphics.h>
#include<math.h>
#include<conio.h>
void EightSymmetry(int x,int y,int h,int k)
{
    putpixel(x+h,y+k,WHITE);
    putpixel(y+h,x+k,WHITE);
    putpixel(-x+h,y+k,WHITE);
    putpixel(y+h,-x+k,WHITE);
    putpixel(x+h,-y+k,WHITE);
    putpixel(-y+h,x+k,WHITE);
    putpixel(-x+h,-y+k,WHITE);
    putpixel(-y+h,-x+k,WHITE);
}
void main()
{
    int r,n=0,i,h,k, gd=DETECT, gm;
    clrscr();
    cout<<"Enter the Centre: ";
    cin>>h>>k;
    cout<<"Enter Radius: ";
    cin>>r;
    initgraph(&gd,&gm,"C:/TURBOC3/BGI");
    for(i=2;;)
    {
        n++;
        if(i>=r)
            break;
        i=i*2;
    }
    float e = 1/pow(2,n);
    float x=0,y=r;
    while(y>=x)
    {
        EightSymmetry(x,y,h,k);
        x = x + (e*y);
        y = y - (e*x);
    }
    getch();
    closegraph();
}

#include<iostream.h>
#include<graphics.h>
#include<conio.h>
void EightSymmetry(int x,int y,int h,int k)
{
    putpixel(x+h,y+k,WHITE);
    putpixel(y+h,x+k,RED);
    putpixel(-x+h,y+k,GREEN);
    putpixel(y+h,-x+k,BLUE);
    putpixel(x+h,-y+k,YELLOW);
    putpixel(-y+h,x+k,CYAN);
    putpixel(-x+h,-y+k,MAGENTA);
    putpixel(-y+h,-x+k,BROWN);
}
void main()
{
    int gd=DETECT,gm,h,k,r,p;
    clrscr();
    cout<<"Enter the Centre: ";
    cin>>h>>k;
    cout<<"Enter the Radius: ";
    cin>>r;
    initgraph(&gd,&gm,"C:/TURBOC3/BGI");
    p = 3 - (2*r);
    float x = 0 , y = r;
    while(x<=y)
    {
        EightSymmetry(x,y,h,k);
        if(p>=0)
        {
            p = p + 4 * (x-y) + 10;
            x++;
            y--;
        }
        else
        {
            p = p + 4 * x + 6;
            x++;
        }
    }
    getch();
    closegraph();
}

#include<iostream.h>
#include<graphics.h>
#include<conio.h>
void EightSymmetry(int x,int y,int xi,int yi)
{
    putpixel(x+xi,y+yi,WHITE);
    putpixel(y+xi,x+yi,RED);
    putpixel(-x+xi,y+yi,GREEN);
    putpixel(y+xi,-x+yi,BLUE);
    putpixel(x+xi,-y+yi,YELLOW);
    putpixel(-y+xi,x+yi,CYAN);
    putpixel(-x+xi,-y+yi,MAGENTA);
    putpixel(-y+xi,-x+yi,BROWN);
}
void main()
{
    int gd=DETECT,gm,h,k,r;
    cout<<"Enter the Centre: ";
    cin>>h>>k;
    cout<<"Enter the Radius: ";
    cin>>r;
    initgraph(&gd,&gd,"C:/TURBOC3/BGI");
    float p = (5/4) - r,x = 0 , y = r;
    while(x<=y)
    {
        EightSymmetry(x,y,h,k);
        if(p>=0)
        {
            p = p + 2 * (x-y) + 5;
            x++;
            y--;
        }
        else
        {
            p = p + 2 * x + 3;
            x++;
        }
    }
    getch();
    closegraph();
}