static int solution ( int [ ] A ) {
  int n = A . length ;
  boolean [ ] present = new boolean [ n + 1 ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    if ( A [ i ] > 0 && A [ i ] <= n ) present [ A [ i ] ] = true ;
  }
  for ( int i = 1 ;
  i <= n ;
  i ++ ) if ( ! present [ i ] ) return i ;
  return n + 1 ;
}

static int solution ( int [ ] A ) { int n = A . length ; boolean [ ] present = new boolean [ n + 1 ] ; for ( int i = 0 ; i < n ; i ++ ) { if ( A [ i ] > 0 && A [ i ] <= n ) present [ A [ i ] ] = true ; } for ( int i = 1 ; i <= n ; i ++ ) if ( ! present [ i ] ) return i ; return n + 1 ; }
(method_declaration (modifiers) type: (integral_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (integral_type) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (field_access object: (identifier) field: (identifier)))) (local_variable_declaration type: (array_type element: (boolean_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (boolean_type) dimensions: (dimensions_expr (binary_expression left: (identifier) right: (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 (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal)) right: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier)))) consequence: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))) right: (true)))))) (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: (if_statement condition: (parenthesized_expression (unary_expression operand: (array_access array: (identifier) index: (identifier)))) consequence: (return_statement (identifier)))) (return_statement (binary_expression left: (identifier) right: (decimal_integer_literal)))))