code: static boolean allPositive(int[] input, int start, int length) {
          for (int i = length - 1, index = start; i >= 0; i--, index++) {
              if (input[index] <= 0) {
                  return false;
              }
          }
  
          return true;
      }
docs: Check if all symbols in the given range are greater than 0, return
  <code>true</code> if so, <code>false</code> otherwise.