comefrom: <awangdev>51. N-Queens_2.java
code: private List<String> createBoard(int[] columns){
  
          int n = columns.length;
          List<String> board = new ArrayList<>();
          for (int row = 0; row < n; row++) {
              StringBuffer sb = new StringBuffer();
              int queenCol = columns[row];
              for (int col = 0; col < n; col++) {
                  sb.append(queenCol == col ? "Q" : ".");
              }
              board.add(sb.toString());
          }
          return board;
      }
masked: private List < String > var_0 ( int [ ] var_1 ) {
    int var_2 = var_1 . length ;
    List < String > var_3 = new ArrayList < > ( ) ;
    for ( int var_4 = 0 ;
    var_4 < var_2 ;
    var_4 ++ ) {
      StringBuffer var_5 = new StringBuffer ( ) ;
      int var_6 = var_1 [ var_4 ] ;
      for ( int var_7 = 0 ;
      var_7 < var_2 ;
      var_7 ++ ) {
        var_5 . append ( var_6 == var_7 ? "Q" : "." ) ;
      }
      var_3 . add ( var_5 . toString ( ) ) ;
    }
    return var_3 ;
  }
  