skrauchenia

  def func(arr: Array[Int],
           leftSum: Int = 0, rightSum: Int = 0,
           leftInx: Int = -1, rightIdx: Int = -1): Int = {

    if (leftInx > rightIdx) {
      if (leftSum == rightSum) leftInx else -1
    } else {
      func(arr.slice(leftInx, rightIdx), arr.head + leftSum, arr.last + rightSum, leftInx + 1, rightIdx - 1)
    }
  }

skrauchenia

// your version

@RequestMapping(value="/addNewTag", method=RequestMethod.POST, produces = "application/json")
@ResponseBody
public Map<String, Integer> addNewTag(@RequestBody Map<String, String> requestMap, HttpServletResponse response) throws IOException {
    if (addTagOnRuntime(requestMap.get("tagName"))) {
        return Collections.singletonMap("statusCode", HttpServletResponse.SC_OK);
    } else {
        response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        return null;