comefrom: <qiyuangong>387_First_Unique_Character_in_a_String_1.java
code: public int firstUniqChar(String s) {
          int freq [] = new int[26];
          for(int i = 0; i < s.length(); i ++)
              freq [s.charAt(i) - 'a'] ++;
          for(int i = 0; i < s.length(); i ++)
              if(freq [s.charAt(i) - 'a'] == 1)
                  return i;
          return -1;
      }
masked: public int sample_funcname ( String var_0 ) {
    int var_1 [ ] = new int [ 26 ] ;
    for ( int var_2 = 0 ;
    var_2 < var_0 . length ( ) ;
    var_2 ++ ) var_1 [ var_0 . charAt ( var_2 ) - 'a' ] ++ ;
    for ( int var_2 = 0 ;
    var_2 < var_0 . length ( ) ;
    var_2 ++ ) if ( var_1 [ var_0 . charAt ( var_2 ) - 'a' ] == 1 ) return var_2 ;
    return - 1 ;
  }
  