comefrom: <awangdev>K Empty Slots_1.java
code: public int kEmptySlots(int[] flowers, int k) {
          if (flowers == null || flowers.length == 0 || k < 0) {
              return - 1;
          }
  
          TreeSet<Integer> treeSet = new TreeSet<>();
          for (int i = 0; i < flowers.length; i++) {
              int num = flowers[i];
              treeSet.add(num);
              Integer lower = treeSet.lower(num);
              Integer higher = treeSet.higher(num);
              if (higher != null && higher - num == k + 1 ) {
                  return i + 1;
              }
              if (lower != null && num - lower == k + 1) {
                  return i + 1;
              }
          }
  
          return -1;
      }
masked: public int sample_funcname ( int [ ] var_0 , int var_1 ) {
    if ( var_0 == null || var_0 . length == 0 || var_1 < 0 ) {
      return - 1 ;
    }
    TreeSet < Integer > var_8 = new TreeSet < > ( ) ;
    for ( int var_9 = 0 ;
    var_9 < var_0 . length ;
    var_9 ++ ) {
      int var_10 = var_0 [ var_9 ] ;
      var_8 . add ( var_10 ) ;
      Integer lower = var_8 . lower ( var_10 ) ;
      Integer higher = var_8 . higher ( var_10 ) ;
      if ( higher != null && higher - var_10 == var_1 + 1 ) {
        return var_9 + 1 ;
      }
      if ( lower != null && var_10 - lower == var_1 + 1 ) {
        return var_9 + 1 ;
      }
    }
    return - 1 ;
  }
  