Why Split strategies (equal, exact, percentage) in LLD? - Purpose & Use Cases

The Big Idea

What if you never had to argue about who owes what after dinner again?

The Scenario

Imagine you and your friends go out for dinner. You want to split the bill, but everyone ordered different things. You try to calculate who owes what by writing numbers on a napkin and doing math in your head.

The Problem

This manual way is slow and confusing. You might forget some items, miscalculate amounts, or argue about fairness. It's easy to make mistakes, and it wastes time that could be spent enjoying the meal.

The Solution

Split strategies like equal, exact, and percentage let you automate how the bill is divided. You just pick a method, enter the amounts, and the system calculates each person's share correctly and quickly.

Before vs After

✗ Before

total = 120
alice = 40
bob = 30
carol = 50
# Manually add and subtract to find shares

✓ After

split_equal(total=120, people=3)  # returns 40 each
split_exact({'alice':40,'bob':30,'carol':50})
split_percentage(total=120, {'alice':33,'bob':25,'carol':42})

What It Enables

It makes fair and fast bill splitting possible, even when orders and shares differ.

Real Life Example

Apps like Splitwise use these strategies so friends can share expenses without confusion or arguments.

Key Takeaways

Manual bill splitting is error-prone and slow.

Split strategies automate fair division of costs.

They support equal, exact, or percentage-based splits for flexibility.