Seemed simple at first and I kind of rushed into talking about the math before realizing they wanted the full API contract, not an algorithm.
Start by clarifying that the API returns raw numeric data (e.g., JSON array of arrays) and the client handles formatting. Then walk through the endpoint design, request parameters, response schema, validation, error handling, and limits in a structured, logical order, emphasizing trade-offs and edge cases.
Pro tip: Mention that you would use a 1-indexed height parameter and return a 400 error for invalid input, but also consider a maximum height limit to prevent excessive computation or memory usage. This shows awareness of both usability and system protection.
Choose a clear, RESTful endpoint like GET /pascals-triangle and specify that it accepts a height query parameter. Explain why GET is appropriate for a read-only operation.
Define the height parameter as a positive integer, with validation rules (e.g., must be >= 1, <= 100). Describe how to handle missing, non-integer, or out-of-range values.
Return a JSON object with a 'triangle' key containing an array of arrays of numbers. Include an example response for height=3. Mention that no formatting (e.g., spacing) is included.
Use standard HTTP status codes: 400 for invalid input, 500 for server errors. Provide a consistent error response body with a message and code. Discuss how to handle unexpected errors gracefully.
Impose a maximum height (e.g., 100) to prevent resource exhaustion. Explain the time and space complexity (O(n^2)) and mention potential optimizations like iterative generation or caching for repeated requests.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.