# include<stdio.h>
# include<graphics.h>
# include<math.h>
using namespace std;
int main(void)
{
    int gd=DETECT,gm;
    int r,x,y,p,xc=320,yc=240;

    initgraph(&gd,&gm,NULL);
    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();
}

• installed graphics.h
• compiled using gcc filename.cpp -0 filename -lgraph
• then used ./filename
• the window apperared for 10 seconds and the error below appears:

[xcb] Unknown sequence number while processing queue
[xcb] Most likely this is a multi-threaded client and XInitThreads has not been called
[xcb] Aborting, sorry about that.
heart: ../../src/xcb_io.c:273: poll_for_event: Assertion `!xcb_xlib_threads_sequence_lost' failed.
Aborted

Any solutions?