In almost all cases, the answer is that you must reconstruct the albums and folder by hand.
The only case in which you might escape that is if (1) you do NOT use iCloud Photos, (2) you took a backup of your entire phone to iCloud or a Mac/PC shortly before you deleted the folder, (3) you are willing to lose any other changes made in your phone since that backup was taken, and (4) you are willing to risk the possibility of losing the entire contents of your phone if the backup is faulty. If all of those apply, you could erase your phone and restore from that backup.