private static void DFS ( int x ) {
  mark [ x ] = true ;
  if ( ! mark [ a [ x ] ] ) {
    DFS ( a [ x ] ) ;
  }
}

private static void DFS ( int x ) { mark [ x ] = true ; if ( ! mark [ a [ x ] ] ) { DFS ( a [ x ] ) ; } }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (integral_type) name: (identifier))) body: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (true))) (if_statement condition: (parenthesized_expression (unary_expression operand: (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))))) consequence: (block (expression_statement (method_invocation name: (identifier) arguments: (argument_list (array_access array: (identifier) index: (identifier)))))))))