static int findMissingPositive ( int arr [ ] , int n ) {
  int m = 1 ;
  HashSet < Integer > x = new HashSet < Integer > ( ) ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    if ( m < arr [ i ] ) {
      x . add ( arr [ i ] ) ;
    }
    else if ( m == arr [ i ] ) {
      m = m + 1 ;
      while ( x . contains ( m ) ) {
        x . remove ( m ) ;
        m = m + 1 ;
      }
    }
  }
  return m ;
}

static int findMissingPositive ( int arr [ ] , int n ) { int m = 1 ; HashSet < Integer > x = new HashSet < Integer > ( ) ; for ( int i = 0 ; i < n ; i ++ ) { if ( m < arr [ i ] ) { x . add ( arr [ i ] ) ; } else if ( m == arr [ i ] ) { m = m + 1 ; while ( x . contains ( m ) ) { x . remove ( m ) ; m = m + 1 ; } } } return m ; }
(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: (decimal_integer_literal))) (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 (type_identifier))) arguments: (argument_list)))) (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: (identifier) right: (array_access array: (identifier) index: (identifier)))) consequence: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier)))))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (array_access array: (identifier) index: (identifier)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) (while_statement condition: (parenthesized_expression (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) body: (block (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier)))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))))))))))) (return_statement (identifier))))