Problem Understanding
Restate the problem in your own words.
Design Splitwise (Group Expenses)
Design a Splitwise-class group-expense tracker: a circle of friends adds expenses, the system splits them by an arbitrary rule (equal, exact, percentage, shares), maintains running balances per pair, and on demand simplifies the IOU graph into the minimum number of payments. Reads dominate (everyone opens the app to check 'who owes me'), and correctness is non-negotiable — even a one-cent drift erodes trust between friends. The hard parts are the data model, the simplify algorithm, and offline-tolerant sync.
- SplitwiseThe category-defining app. Equal / exact / percentage / shares splits with multi-currency.
- TricountGroup-trip expenses with the same shape; popular in Europe.
- Settle UpCross-platform expense splitter with cash-flow optimization for trips.
- Cash App / Venmo group requestsGroup splits as a wallet-feature; simpler model, no running balance graph.
Your task: read the problem above, then write what the system is, who uses it, the rough scale, and the headline UX expectation — in your own words. Submit for AI review when you're ready.
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