Split strategies (equal, exact, percentage) in LLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Equal Split Strategy

In a system that splits a bill equally among 4 users, each user pays the same amount. If the total bill is $120, how much does each user pay?

A $20

B $40

C $25

D $30

💡 Hint

Divide the total amount by the number of users.

Equal split means dividing the total amount equally among all users. $120 divided by 4 users equals $30 each.

❓ Architecture

intermediate

Designing Exact Split Strategy Component

You need to design a component that handles exact split strategy where each user pays a specified amount. Which of the following is the best way to validate the input amounts before processing?

A Check if the sum of all user amounts equals the total bill amount.

B Check if each user amount is greater than zero.

C Check if the number of users matches the number of amounts provided.

D Check if the total bill amount is divisible by the number of users.

💡 Hint

The total of all exact amounts must match the bill.

In exact split, the sum of all user amounts must equal the total bill to ensure correctness.

❓ scaling

advanced

Scaling Percentage Split Strategy for Large User Base

A system uses percentage split strategy to divide a bill among 10,000 users. Each user has a percentage share. What is the main challenge in scaling this system?

A Storing each user's percentage in a separate database table.

B Ensuring the sum of all percentages equals 100% to avoid rounding errors.

C Allowing users to change their percentage share in real-time without locking.

D Calculating each user's share by multiplying total bill with their percentage.

💡 Hint

Think about accuracy and consistency when dealing with many users.

With many users, rounding errors can accumulate if percentages do not sum exactly to 100%, causing billing mismatches.

❓ tradeoff

advanced

Tradeoffs Between Split Strategies

Which of the following is a key tradeoff when choosing between equal, exact, and percentage split strategies in a payment system?

A Equal split is simplest but less flexible; exact split is precise but requires more input; percentage split balances flexibility and complexity.

B Exact split is simplest and fastest; equal split requires complex calculations; percentage split is rarely used.

C Percentage split is always the most accurate; equal and exact splits cause errors.

D All split strategies have the same complexity and accuracy.

💡 Hint

Consider user input complexity and flexibility.

Equal split is easy but inflexible. Exact split needs detailed input. Percentage split offers flexibility but requires careful validation.

❓ estimation

expert

Estimating System Capacity for Percentage Split Strategy

You are designing a system to handle percentage split payments for up to 1 million users per bill. Each user’s percentage share must be stored and processed. Which factor most impacts the system’s capacity and performance?

A The UI responsiveness when displaying the total bill amount.

B The database schema used to store user profiles unrelated to payments.

C The memory required to store all user percentage shares and the CPU time to calculate each share.

D The network bandwidth to send the total bill amount to all users.

💡 Hint

Think about data size and computation for large user counts.

Storing and processing 1 million percentage shares requires significant memory and CPU resources, impacting capacity and performance.