[Programmers] 67256. 키패드 누르기

class Solution {
  public String solution(int[] numbers, String hand) {
    StringBuilder sb = new StringBuilder();

    int left = 10;
    int right = 12;

    for (int i = 0; i < numbers.length; i++) {
      int n = numbers[i];

      if (n == 1 || n == 4 || n == 7) {
        left = n;
        sb.append("L");
      }
      if (n == 3 || n == 6 || n == 9) {
        right = n;
        sb.append("R");
      }
      if (n == 2 || n == 5 || n == 8 || n == 0) {
        if( n == 0 ) n = 11;

        int leftDiff = (Math.abs(n - left) / 3) + (Math.abs(n - left) % 3);
        int rightDiff =(Math.abs(n - right) / 3) + (Math.abs(n - right) % 3);

        if (leftDiff == rightDiff) {
          if (hand.equals("right")) {
            right = n;
            sb.append("R");
          }else{
            left = n;
            sb.append("L");
          }
        } else if (leftDiff > rightDiff) {
          right = n;
          sb.append("R");
        } else {
          left = n;
          sb.append("L");
        }
      }
    }
    return sb.toString();
  }
}