comefrom: <awangdev>893. Groups of Special-Equivalent Strings_1.java
code: public int numSpecialEquivGroups(String[] A) {
          if (A == null || A.length == 0) {
              return 0;
          }
          HashSet<String> set = new HashSet<>();
          
          for (String s : A) {
              int[] odd = new int[256];
              int[] even = new int[256];
              for (int i = 0; i < s.length(); i++) {
                  int c = s.charAt(i);
                  if (i % 2 == 0) {
                      even[c]++;
                  } else {
                      odd[c]++;
                  }
              }
              String signature = Arrays.toString(odd) + Arrays.toString(even);
              set.add(signature);
          }
  
          return set.size();
      }
masked: public int sample_funcname ( String [ ] var_0 ) {
    if ( var_0 == null || var_0 . length == 0 ) {
      return 0 ;
    }
    HashSet < String > var_1 = new HashSet < > ( ) ;
    for ( String var_2 : var_0 ) {
      int [ ] var_3 = new int [ 256 ] ;
      int [ ] var_4 = new int [ 256 ] ;
      for ( int var_5 = 0 ;
      var_5 < var_2 . length ( ) ;
      var_5 ++ ) {
        int var_6 = var_2 . charAt ( var_5 ) ;
        if ( var_5 % 2 == 0 ) {
          var_4 [ var_6 ] ++ ;
        }
        else {
          var_3 [ var_6 ] ++ ;
        }
      }
      String var_7 = Arrays . toString ( var_3 ) + Arrays . toString ( var_4 ) ;
      var_1 . add ( var_7 ) ;
    }
    return var_1 . size ( ) ;
  }
  