← Anthropic Interview Insights
The core of it is just aggregating per account and then sorting, but I spent too long second-guessing whether 'total' meant net or absolute.
Clarify the problem requirements first, including the definition of 'total amount of money flowing in or out' and the expected output format. Then propose an efficient algorithm using a hash map to aggregate net flows per account, and discuss sorting the results. Analyze time and space complexity, and consider edge cases.
Pro tip: Demonstrate awareness of data modeling by discussing whether to store net flow or separate inflow/outflow, and how that impacts sorting and interpretation. Also, mention potential scalability concerns with large transaction volumes.
Ask questions to understand the input format, what 'total amount of money flowing in or out' means (net vs. absolute sum), and the desired output (e.g., sorted list of accounts with totals).
Select a hash map to aggregate amounts per account, and a list to store the aggregated results for sorting. Consider if additional data like separate inflow/outflow is needed.
Iterate through transactions, updating each account's total. Then convert the map to a list and sort by the total amount. Specify sorting order (ascending/descending).
State time complexity: O(n + m log m) where n is number of transactions and m is number of unique accounts. Space complexity: O(m).
Discuss scenarios like empty transaction list, accounts with zero net flow, duplicate transactions, and large datasets. Mention potential optimizations if needed.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.