static int getMissingNo ( int a [ ] , int n ) {
  int x1 = a [ 0 ] ;
  int x2 = 1 ;
  for ( int i = 1 ;
  i < n ;
  i ++ ) x1 = x1 ^ a [ i ] ;
  for ( int i = 2 ;
  i <= n + 1 ;
  i ++ ) x2 = x2 ^ i ;
  return ( x1 ^ x2 ) ;
}

static int getMissingNo ( int a [ ] , int n ) { int x1 = a [ 0 ] ; int x2 = 1 ; for ( int i = 1 ; i < n ; i ++ ) x1 = x1 ^ a [ i ] ; for ( int i = 2 ; i <= n + 1 ; i ++ ) x2 = x2 ^ i ; return ( x1 ^ x2 ) ; }
(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: (integral_type) declarator: (variable_declarator name: (identifier) value: (array_access array: (identifier) index: (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: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (array_access array: (identifier) index: (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: (binary_expression left: (identifier) right: (decimal_integer_literal))) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (identifier))))) (return_statement (parenthesized_expression (binary_expression left: (identifier) right: (identifier))))))