Start by clarifying the problem: confirm whether the output should be a list of lists or printed rows, and discuss edge cases like n=0. Then present a clear algorithm, such as building each row from the previous one using the relation triangle[i][j] = triangle[i-1][j-1] + triangle[i-1][j], and analyze time and space complexity.
Pro tip: Mention that you can optimize space to O(n) by generating each row in-place from right to left, but only if the interviewer cares about memory; otherwise, prioritize clarity. Also, relate the problem to real-world scenarios like binomial coefficients or dynamic programming to show depth.
Ask whether n is guaranteed non-negative, what output format is expected (e.g., list of lists), and how to handle n=0 or n=1.
Decide between iterative row-by-row construction (O(n^2) time, O(n^2) space) or space-optimized version (O(n) extra space). Explain the trade-offs.
Describe how to build each row: first and last elements are 1; middle elements are sum of two elements above. Optionally, mention using combinatorial formula C(n,k) = n!/(k!(n-k)!) but note it's less efficient.
State time complexity O(n^2) and space complexity O(n^2) for the straightforward approach, or O(n) extra space for the optimized version.
Walk through a small example like n=5 to verify correctness, and mention potential pitfalls like integer overflow for large n (though not typical in interviews).
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.