Bird
Raised Fist0

How would you design the Expense class to support splitting costs unevenly among users?

hard📝 Trade-off Q9 of Q15
LLD - Design — Splitwise (Expense Sharing)
How would you design the Expense class to support splitting costs unevenly among users?
AStore only total amount and divide equally in split method
BAdd a dictionary mapping users to their share amounts
CAdd a list of users without share details
DKeep a single user as payer and ignore others
Step-by-Step Solution
Solution:

  1. Step 1: Understand uneven split requirement

    Uneven splits require tracking each user's specific share.

  2. Step 2: Choose data structure to map users to shares

    A dictionary mapping users to amounts fits this need well.

  3. Final Answer:

    Add a dictionary mapping users to their share amounts -> Option B

  4. Quick Check:

    Uneven split needs user-to-share mapping [OK]
Quick Trick: Use dictionary to map users to their shares [OK]
Common Mistakes:
MISTAKES
  • Assuming equal split always
  • Ignoring share details per user
  • Using list without share info

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More LLD Quizzes
Design — Chess Game - Move validation and check detection - Quiz 5medium Design — Chess Game - Why chess tests polymorphism and strategy - Quiz 1easy Design — Food Delivery System - Why delivery systems test service coordination - Quiz 4medium Design — Food Delivery System - Delivery agent assignment - Quiz 4medium Design — Hotel Booking System - Room type hierarchy - Quiz 4medium Design — Online Shopping Cart - Product, Cart, Order classes - Quiz 7medium Design — Splitwise (Expense Sharing) - Balance calculation algorithm - Quiz 2easy Design — Splitwise (Expense Sharing) - Transaction history - Quiz 11easy Design — Splitwise (Expense Sharing) - Split strategies (equal, exact, percentage) - Quiz 10hard Design — Splitwise (Expense Sharing) - Balance calculation algorithm - Quiz 14medium