comefrom: <awangdev>293. Flip Game_1.java
code: public List<String> generatePossibleNextMoves(String s) {
          List<String> rst = new ArrayList<>();
          if (s == null || s.length() < 2) {
              return rst;
          }
          StringBuffer sb = new StringBuffer(s);
          for (int i = 0; i < s.length() - 1; i++) {
              String str = s.substring(i, i + 2);
              if (str.equals("++")) {
                  sb.replace(i, i + 2, "--");
                  rst.add(sb.toString());
                  sb.replace(i, i + 2, "++");
              }
          }
          return rst;
      }
masked: public List < String > var_1 ( String var_2 ) {
    List < String > var_5 = new ArrayList < > ( ) ;
    if ( var_2 == null || var_2 . length ( ) < 2 ) {
      return var_5 ;
    }
    StringBuffer var_10 = new StringBuffer ( var_2 ) ;
    for ( int var_12 = 0 ;
    var_12 < var_2 . length ( ) - 1 ;
    var_12 ++ ) {
      String var_15 = var_2 . substring ( var_12 , var_12 + 2 ) ;
      if ( var_15 . equals ( "++" ) ) {
        var_10 . replace ( var_12 , var_12 + 2 , "--" ) ;
        var_5 . add ( var_10 . toString ( ) ) ;
        var_10 . replace ( var_12 , var_12 + 2 , "++" ) ;
      }
    }
    return var_5 ;
  }
  