private static List<String> getInsertPositions(int count) {

		int[] elems = new int[count];
		for (int m = 0; m < count; m++) {
			elems[m] = m + 1;
		}

		int length = elems.length;
		int countOfCombination = (int) Math.pow(2, length) - 1;

		List<String> results = new ArrayList<String>();
		// add whole word
		results.add("0");

		StringBuilder sb = new StringBuilder();
		for (int i = 1; i <= countOfCombination; i++) {
			sb.setLength(0);
			for (int j = 0; j < length; j++) {
				if ((i & (1 << j)) != 0) {
					sb.append(elems[j]);
					// add delimiter in case it exceed 9, i.e. 10, 11, 12 ...
					sb.append(DELIMITER_POS);
				}
			}
			results.add(sb.substring(0, sb.length() - 1).toString());
		}

		return results;
	}