static boolean areChractersUnique ( String str ) {
  int checker = 0 ;
  for ( int i = 0 ;
  i < str . length ( ) ;
  ++ i ) {
    int val = ( str . charAt ( i ) - 'a' ) ;
    if ( ( checker & ( 1 << val ) ) > 0 ) return false ;
    checker |= ( 1 << val ) ;
  }
  return true ;
}

static boolean areChractersUnique ( String str ) { int checker = 0 ; for ( int i = 0 ; i < str . length ( ) ; ++ i ) { int val = ( str . charAt ( i ) - ' a ' ) ; if ( ( checker & ( 1 << val ) ) > 0 ) return false ; checker |= ( 1 << val ) ; } return true ; }
(method_declaration (modifiers) type: (boolean_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) update: (update_expression (identifier)) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (parenthesized_expression (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_literal))))) (if_statement condition: (parenthesized_expression (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (parenthesized_expression (binary_expression left: (decimal_integer_literal) right: (identifier))))) right: (decimal_integer_literal))) consequence: (return_statement (false))) (expression_statement (assignment_expression left: (identifier) right: (parenthesized_expression (binary_expression left: (decimal_integer_literal) right: (identifier))))))) (return_statement (true))))