Easier than the version I'd seen before, which honestly made me second-guess myself for a second.
Clarify the problem constraints and examples first, then discuss a brute-force solution before optimizing with a hash map for O(1) lookups and a single pass for traversal. Walk through the code, test edge cases, and analyze time/space complexity.
Pro tip: At Citadel, interviewers value clean, efficient code and strong communication; verbalize your thought process and trade-offs, and always consider edge cases like empty inputs or duplicates.
Restate the problem in your own words, ask clarifying questions about input size, data types, and expected output, and confirm with examples.
Propose a straightforward solution (e.g., nested loops) and analyze its time and space complexity to establish a baseline.
Identify that a hash map can provide O(1) lookups and design an algorithm that traverses the list once while storing needed information.
Write clean, modular code, then walk through it with normal and edge cases (empty list, single element, duplicates) to verify correctness.
State the final time and space complexity, discuss potential improvements or trade-offs, and summarize the solution.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.