comefrom: <awangdev>567. Permutation in String_1.java
code: private Integer[] countFreq(String s) {
  
          Integer[] freq = new Integer[256];
          for (char c : s.toCharArray()) freq[c] = freq[c] == null ? 1 : freq[c] + 1;
          return freq;
      }
masked: private Integer [ ] var_0 ( String var_1 ) {
    Integer [ ] var_2 = new Integer [ 256 ] ;
    for ( char var_3 : var_1 . toCharArray ( ) ) var_2 [ var_3 ] = var_2 [ var_3 ] == null ? 1 : var_2 [ var_3 ] + 1 ;
    return var_2 ;
  }
  