Here is a high-level system design for a parking lot with support for memberships and guest drivers:
User Interface:
- Web/Mobile App for drivers to book parking slots.
- Counter screens on each row to display the number of available slots and directions to empty slots.
- Membership management portal for managing user accounts and parking reservations.
Backend System:
- Database to store information about available parking slots, their occupancy status, and user accounts.
- RESTful API to handle requests from the user interface and respond with relevant data.
- Membership management system for managing user accounts, payment processing, and reservation history.
Algorithms and Data Structures:
- Use a Hash Table to store the parking slots, where the key is the slot number, and the value is the status of the slot (empty/occupied).
- Use a Queue to keep track of the reservations for each parking slot, where the first reservation in the queue is the one that gets the slot when it becomes available.
- Use a Priority Queue to keep track of the reservations for the premium parking slots, where the priority is based on the membership level of the user.
Workflow:
- When a driver enters the parking lot, they can either book a parking slot using the app or go to the counter screens to check for availability and book a slot.
- The app/counter screens show the number of available slots in each row, and the driver can select a row and a slot.
- If the selected slot is available, the driver is given a confirmation, and the slot is marked as occupied in the Hash Table.
- If the selected slot is not available, the driver is given the option to join the reservation queue for the slot.
- When a slot becomes available, the system checks the reservation queues for that slot and assigns the slot to the first reservation in the queue.
- If the first reservation in the queue has a premium membership, they get the slot. Otherwise, the slot is assigned to the first reservation in the regular queue.
- When a driver leaves the parking lot, the slot is marked as empty in the Hash Table, and the reservation queues are updated accordingly.
Membership System:
- Users can create an account on the membership management portal and choose a membership plan (e.g., Premium, Standard, Basic).
- Members can reserve parking slots in advance and get priority access to premium parking slots.
- Members can also view their reservation history, update their membership plan, and make payments for parking reservations.
Architecture diagram
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| Parking Lot Entrance |
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v
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| License Plate Input |
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v
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| Ticket Dispenser |
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v
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| Parking Area |
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v
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| Payment Station |
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v
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| Exit Barrier |
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The Parking Lot Entrance is where drivers enter the parking lot. They input their license plate number using the License Plate Input system, which is used to identify their vehicle. The Ticket Dispenser issues a ticket to the driver, which is used to pay for their parking.
The Parking Area is where the cars are parked. There are counter screens on each row of the parking area that show the number of available parking spots.
The Payment Station is where drivers pay for their parking. They can pay using a credit card or cash. Once payment is received, the driver can exit the parking lot through the Exit Barrier.
The system also supports memberships for regular drivers. Members can enter and exit the parking lot without paying, and their membership is identified using their license plate number.
The architecture is designed to support a large number of drivers and transactions, with the ability to scale horizontally by adding more Payment Stations and Entrance/Exit Barriers as needed.
Here is a possible schema design for the parking lot system:
Users Table
- id (primary key)
- name
- email
- password
- membership_type (can be null if not a member)
- membership_start_date (can be null if not a member)
- membership_end_date (can be null if not a member)
Parking Spots Table
- id (primary key)
- spot_number
- floor_number
- is_available
- is_membership_only (if true, only members can park in the spot)
Parking Reservations Table
- id (primary key)
- user_id (foreign key to Users table)
- parking_spot_id (foreign key to Parking Spots table)
- reservation_start_time
- reservation_end_time
- is_cancelled
With this schema, you can track users, parking spots, and parking reservations. To check availability of parking spots, you can query the Parking Spots table and filter by is_available and is_membership_only as needed. To reserve a parking spot, you can insert a new row into the Parking Reservations table. To check if a user has a valid membership, you can check the membership_start_date and membership_end_date fields in the Users table.
To display parking spot availability on counter screens, you could create a view that joins the Parking Spots and Parking Reservations tables and groups by floor_number and spot_number, showing the availability status for each spot on the relevant counter screen.
