private static void direct_range_search(finger_print fp, double dis,
			Data data) {
		ArrayList<Integer> lst1 = new ArrayList<Integer>();
		HashMap<Integer, Integer> potent = new HashMap<Integer, Integer>();
		ArrayList<Integer> lst2 = new ArrayList<Integer>();

		// to be commented
		/*for (int i : data.data_set.keySet()) {
			if (fp.getDistance(data.data_set.get(i)) < dis) {
				lst2.add(i);
				//System.out.print(" " + fp.getDistance(data.data_set.get(i)));
			}
		}
		System.out.println(lst2);
		lst2.clear();
		*/
		for (Integer fid : fp.feature_map.keySet()) {
			if (finger_print.invert_index.containsKey(fid)) {
				for (Integer id : finger_print.invert_index.get(fid).keySet()) {
					if (!potent.containsKey(id)) {
						potent.put(id, 1);
						lst1.add(id);
					}
				}
			}
		}

		for (int i = 0; i < lst1.size(); i++) {
			if (fp.getDistance(data.data_set.get(lst1.get(i))) < dis) {
				lst2.add(lst1.get(i));
			}
		}
		
		//System.out.println(lst1.size());
		//System.out.println();
	}