private static boolean isConnSetEmpty(
			HashMap<Integer, ? extends Object> curCand,
			HashMap<Integer, Integer> curRes) {
		HashSet<Integer> all = new HashSet<Integer>();
		for (Integer r : curRes.keySet()) {
			all.addAll(oneLeap.get(r));
		}
		if (curCand.size() < all.size()) {
			for (Integer c : curCand.keySet()) {
				if (all.contains(c))
					return false;
			}
		} else {
			for (Integer a : all) {
				if (curCand.containsKey(a))
					return false;
			}
		}
		return true;
	}