Recursive Bubble Sort!

class Bt {
	int[] unsorted={3,5,2,0,1,8,6,-1};
	int[] candidate;
	int[] best;
	public static void main (String[] args) {
		Bt b= new Bt();
		b.bt();
		b.print(b.best);
	}
	void bt() {
		if (accept (candidate)) {
			best= new int[candidate.length];
			System.arraycopy (candidate, 0, best, 0, candidate.length);
			return;
			//System.exit (0);
		}
		if (reject (candidate)) return;
		if (!augment ()) return;
		do {
			bt();
		} while (next());
		diminish ();
	}
	public boolean augment () {
		if (candidate==null) {
			candidate= new int[1];
			candidate[0]=0;
			return true;
		}
		int i;
		boolean b[]= new boolean [unsorted.length];
		// add the smallest index not present
		for (i=0;i<candidate.length;i++)
			b[candidate[i]]=true;
//		for (i=candidate[candidate.length-1];i<unsorted.length;i++)
		for (i=0;i<unsorted.length;i++)
			if (!b[i]) break;
		// add one element if possible.
		if(i<unsorted.length) {
			int r[]= new int[candidate.length+1];
			System.arraycopy (candidate, 0, r, 0, candidate.length);
			r[r.length-1]=i;
			candidate=r;
			return true;
		}
		return false;
	}
	public boolean next () {
		if (candidate==null) {
			System.out.println ("cannot be empty.");
			System.exit (0);
		}
		int i;
		boolean b[]= new boolean [unsorted.length];
		// add the smallest index not present
		for (i=0;i<candidate.length;i++)
			b[candidate[i]]=true;
		for (i=candidate[candidate.length-1];i<unsorted.length;i++)
			if (!b[i]) break;
		// substitute the last element if possible.
		if(i<unsorted.length) {
			candidate[candidate.length-1]=i;
			return true;
		}
		return false;
	}
	public void diminish () {
		if ((candidate!=null)&&(candidate.length>0)) {
			int r[]= new int[candidate.length-1];
			System.arraycopy (candidate, 0, r, 0, candidate.length-1);
			candidate=r;
		}
	}
	public boolean accept (int[] candidate) {
		if (candidate==null) return false;
		if (!reject(candidate) && candidate.length==unsorted.length) return true;
		return false;
	}
	public boolean reject (int[] candidate) {
		if ((candidate==null)||(candidate.length<2)) return false;
		int i;
		for (i=1;i<candidate.length;i++)
			if (unsorted[candidate[i-1]]>unsorted[candidate[i]]) return true;
		return false;
	}
	public void print (int[] a) {
		if (a==null) {
			System.out.println ("Empty");
			return;
		}
		for (int i=0;i<a.length;i++)
			System.out.print (a[i] + " ");
		System.out.println();
	}
}