comefrom: <awangdev>293. Flip Game_2.java
code: public List<String> generatePossibleNextMoves(String s) {
          List<String> rst = new ArrayList<String>();
          if (s == null || s.length() == 0) {
              return rst;
          }
          ArrayList<Integer> list = new ArrayList<Integer>();
          StringBuffer sb = new StringBuffer(s);
          while (sb.indexOf("++") != -1) {
              int index = sb.indexOf("++");
              list.add(index);
              sb.replace(index, index + 1, "*");
          }
          for (int index : list) {
              rst.add(s.substring(0, index) + "--" + s.substring(index + 2));
          }
          return rst;
      }
masked: public List < String > var_1 ( String var_2 ) {
    List < String > var_5 = new ArrayList < String > ( ) ;
    if ( var_2 == null || var_2 . length ( ) == 0 ) {
      return var_5 ;
    }
    ArrayList < Integer > var_10 = new ArrayList < Integer > ( ) ;
    StringBuffer var_12 = new StringBuffer ( var_2 ) ;
    while ( var_12 . indexOf ( "++" ) != - 1 ) {
      int var_16 = var_12 . indexOf ( "++" ) ;
      var_10 . add ( var_16 ) ;
      var_12 . replace ( var_16 , var_16 + 1 , "*" ) ;
    }
    for ( int var_16 : var_10 ) {
      var_5 . add ( var_2 . substring ( 0 , var_16 ) + "--" + var_2 . substring ( var_16 + 2 ) ) ;
    }
    return var_5 ;
  }
  