public static int[] encodeArray(final int i) {
    return Integer.toString(i).chars().map(x -> x - '0').flatMap(digit -> {
      if (digit < 0) return IntStream.of(-1); // sign: '-'
      final Builder builder = IntStream.builder();
      for (int x = 0; x < digit; x++) builder.accept(0);
      builder.accept(1);
      return builder.build();
    }).toArray();
  }