In a parking system, you have enums VehicleType { CAR, BIKE, TRUCK } and SpotType { COMPACT, LARGE, HANDICAPPED }. You want to assign spots such that:

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LLD - Design — Parking Lot System

In a parking system, you have enums VehicleType { CAR, BIKE, TRUCK } and SpotType { COMPACT, LARGE, HANDICAPPED }. You want to assign spots such that:
- Cars use COMPACT spots
- Bikes use HANDICAPPED spots
- Trucks use LARGE spots

Which design approach best ensures no invalid spot assignment happens?

AUse a mapping dictionary from VehicleType to SpotType and validate assignments

BUse separate if-else blocks without enums for flexibility

CAssign spots randomly and check later if valid

DUse strings instead of enums for vehicle and spot types

Step-by-Step Solution

Solution:

Step 1: Understand enum benefits for mapping
Enums provide fixed sets, so mapping ensures clear, valid assignments.
Step 2: Evaluate design options
Mapping dictionary with enums enforces rules and prevents invalid spots.
Final Answer:
Use a mapping dictionary from VehicleType to SpotType and validate assignments -> Option A
Quick Check:
Mapping enums = safe, clear assignments [OK]

Quick Trick: Map enums directly to enforce valid pairs [OK]

Common Mistakes:

MISTAKES

Using strings loses type safety
Random assignment causes errors
If-else without enums is error-prone

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In a parking system, you have enums VehicleType { CAR, BIKE, TRUCK } and SpotType { COMPACT, LARGE, HANDICAPPED }. You want to assign spots such that:

Step 1: Understand enum benefits for mapping

Step 2: Evaluate design options

Final Answer:

Quick Check:

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