static boolean check ( String s , int l ) {
  int freq [ ] = new int [ 26 ] ;
  Arrays . fill ( freq , 0 ) ;
  for ( int i = 0 ;
  i < l ;
  i ++ ) {
    freq [ s . charAt ( i ) - 'a' ] ++ ;
  }
  for ( int i = 0 ;
  i < 26 ;
  i ++ ) {
    if ( freq [ i ] >= 2 ) return true ;
  }
  return false ;
}

static boolean check ( String s , int l ) { int freq [ ] = new int [ 26 ] ; Arrays . fill ( freq , 0 ) ; for ( int i = 0 ; i < l ; i ++ ) { freq [ s . charAt ( i ) - ' a ' ] ++ ; } for ( int i = 0 ; i < 26 ; i ++ ) { if ( freq [ i ] >= 2 ) return true ; } return false ; }
(method_declaration (modifiers) type: (boolean_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) dimensions: (dimensions) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (decimal_integer_literal))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (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: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (update_expression (array_access array: (identifier) index: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))) right: (character_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: (decimal_integer_literal)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (return_statement (true))))) (return_statement (false))))