public static boolean check_elements ( int arr [ ] , int n , int A , int B ) {
  int range = B - A ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    if ( Math . abs ( arr [ i ] ) >= A && Math . abs ( arr [ i ] ) <= B ) {
      int z = Math . abs ( arr [ i ] ) - A ;
      if ( arr [ z ] > 0 ) {
        arr [ z ] = arr [ z ] * - 1 ;
      }
    }
  }
  int count = 0 ;
  for ( int i = 0 ;
  i <= range && i < n ;
  i ++ ) {
    if ( arr [ i ] > 0 ) return false ;
    else count ++ ;
  }
  if ( count != ( range + 1 ) ) return false ;
  return true ;
}

public static boolean check_elements ( int arr [ ] , int n , int A , int B ) { int range = B - A ; for ( int i = 0 ; i < n ; i ++ ) { if ( Math . abs ( arr [ i ] ) >= A && Math . abs ( arr [ i ] ) <= B ) { int z = Math . abs ( arr [ i ] ) - A ; if ( arr [ z ] > 0 ) { arr [ z ] = arr [ z ] * - 1 ; } } } int count = 0 ; for ( int i = 0 ; i <= range && i < n ; i ++ ) { if ( arr [ i ] > 0 ) return false ; else count ++ ; } if ( count != ( range + 1 ) ) return false ; return true ; }
(method_declaration (modifiers) type: (boolean_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier) dimensions: (dimensions)) (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (identifier)))) (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 (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier)))) right: (identifier)) right: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier)))) right: (identifier)))) consequence: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier)))) right: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (unary_expression operand: (decimal_integer_literal))))))))))) (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: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (identifier) right: (identifier))) 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 (false)) alternative: (expression_statement (update_expression (identifier)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))))) consequence: (return_statement (false))) (return_statement (true))))