public class binaire{
static int b[] = new int [20];

static int n=3;

public static void main (String [] args)
{ geb(1);

}

public static void geb(int pos)
{ if (pos==n+1) type();
  else { b[pos]=0; geb(pos+1);
         b[pos]=1; geb(pos+1);
       }

}

public static void type()
{ int i;
  for(i=1;i<=n;i++) System.out.print(b[i]+" ");
  System.out.println();

}
}

==================================

public class gray{
static int b[] = new int [20];

static int n=3;

public static void main (String [] args)
{ geb(1,0);

}

public static void geb(int pos,int dir)
{ if (pos==n+1) type();
  else if (dir==0)
       { b[pos]=0; geb(pos+1,0);
         b[pos]=1; geb(pos+1,1);
       }
       else
       { b[pos]=1; geb(pos+1,0);
         b[pos]=0; geb(pos+1,1);
       }

}

public static void type()
{ int i;
  for(i=1;i<=n;i++) System.out.print(b[i]+" ");
  System.out.println();

}
}


===========================


public class fibonacci{
static int b[] = new int [20];

static int n=4;

public static void main (String [] args)
{ geb(1);

}

public static void geb(int pos)
{ if (pos>n) type();
  else { b[pos]=0; geb(pos+1);
         b[pos]=1; b[pos+1]=0; geb(pos+2);
       }

}

public static void type()
{ int i;
  for(i=1;i<=n;i++) System.out.print(b[i]+" ");
  System.out.println();

}

}