Parking strategy pattern in LLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding the role of the strategy pattern in parking systems

In a parking system using the strategy pattern, what is the main purpose of the 'strategy' interface?

A To manage the physical layout of the parking lot

B To store all parked vehicles in a single list

C To handle payment processing for parking fees

D To define a common interface for different parking algorithms so they can be swapped easily

💡 Hint

Think about how different parking methods can be used interchangeably.

The strategy pattern defines a common interface for various parking algorithms, allowing the system to switch between them without changing the client code.

❓ Architecture

intermediate

Choosing the right components for a parking strategy pattern

Which components are essential in implementing a parking system using the strategy pattern?

A Context, Strategy interface, Concrete Strategies

B Database, User Interface, Payment Gateway

C Vehicle class, Ticket class, Security module

D Sensor hardware, Camera system, Gate controller

💡 Hint

Focus on software design components related to the strategy pattern.

The strategy pattern requires a context that uses a strategy interface, which is implemented by concrete strategy classes representing different parking algorithms.

❓ scaling

advanced

Scaling a parking system with multiple parking strategies

When scaling a parking system that supports multiple parking strategies, which approach best ensures maintainability and performance?

A Create separate parking systems for each strategy without sharing code

B Hardcode all parking strategies in a single class to reduce overhead

C Use the strategy pattern with dependency injection to select strategies dynamically and cache frequent decisions

D Use a monolithic design where all strategies run in parallel regardless of need

💡 Hint

Think about flexibility and avoiding code duplication while keeping performance.

Dependency injection allows dynamic selection of strategies, and caching helps improve performance by avoiding repeated calculations.

❓ tradeoff

advanced

Tradeoffs in choosing parking strategies

What is a key tradeoff when selecting a parking strategy that prioritizes minimal walking distance over maximizing space usage?

A Higher parking capacity but increased walking distance for users

B Improved user convenience but potentially lower parking capacity

C Reduced system complexity but slower parking allocation

D Increased hardware costs but simpler software design

💡 Hint

Consider what happens when you focus on user convenience versus space efficiency.

Prioritizing minimal walking distance improves user experience but may leave some spaces unused, reducing overall capacity.

❓ component

expert

Request flow in a parking system using the strategy pattern

Given a parking system where the context delegates parking spot allocation to a strategy, what is the correct sequence of steps when a vehicle arrives?

A 1,2,3,4

B 2,1,3,4

C 1,3,2,4

D 3,2,1,4

💡 Hint

Think about the natural order of request handling and delegation.

The vehicle first requests a spot, the context receives and delegates to the strategy, which selects the spot, then the context returns it.