static int missingNum ( int arr [ ] , int n ) {
  List < Integer > list = new ArrayList < > ( arr . length ) ;
  for ( int i : arr ) {
    list . add ( Integer . valueOf ( i ) ) ;
  }
  int minvalue = Collections . min ( list ) ;
  ;
  int xornum = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    xornum ^= ( minvalue ) ^ arr [ i ] ;
    minvalue ++ ;
  }
  return xornum ^ minvalue ;
}

static int missingNum ( int arr [ ] , int n ) { List < Integer > list = new ArrayList < > ( arr . length ) ; for ( int i : arr ) { list . add ( Integer . valueOf ( i ) ) ; } int minvalue = Collections . min ( list ) ; ; int xornum = 0 ; for ( int i = 0 ; i < n ; i ++ ) { xornum ^= ( minvalue ) ^ arr [ i ] ; minvalue ++ ; } return xornum ^ minvalue ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier) dimensions: (dimensions)) (formal_parameter type: (integral_type) name: (identifier))) body: (block (local_variable_declaration type: (generic_type (type_identifier) (type_arguments (type_identifier))) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (generic_type (type_identifier) (type_arguments)) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (enhanced_for_statement type: (integral_type) name: (identifier) value: (identifier) body: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) (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: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (parenthesized_expression (identifier)) right: (array_access array: (identifier) index: (identifier))))) (expression_statement (update_expression (identifier))))) (return_statement (binary_expression left: (identifier) right: (identifier)))))