Analyze the worst-case run-time complexities of the member functions reverse() .Give the complexities in the form of Big-O

void List::reverse() {
	if( !empty() ) {
	auto current_ptr = head;
	while( current_ptr != nullptr ) {
	std::swap( current_ptr->next, current_ptr->prev );
	current_ptr = current_ptr->prev;
	}
	}
	std::swap( head, tail );