My first instinct was to reach for a big array indexed by key and just store values directly, which technically works given the key range is bounded up to a million.
Start by clarifying requirements and constraints, then outline the core components: an array of buckets, a hash function, and collision resolution via chaining. Implement the class with put, get, and remove methods, ensuring average O(1) by resizing when the load factor exceeds a threshold. Discuss trade-offs and potential optimizations.
Pro tip: Mention that you would use a good hash function to distribute keys uniformly and consider using a prime number for the bucket array size to reduce collisions. Also, discuss how you would handle null keys and the importance of resizing to maintain O(1) average time.
Ask about expected key/value types, null handling, thread safety, and performance constraints. Confirm that average O(1) is required and that built-in hash containers are not allowed.
Choose an array of buckets (e.g., linked lists or dynamic arrays) for collision resolution. Define a hash function and a load factor threshold for resizing.
Write put, get, and remove methods: compute hash, find bucket, handle collisions, and update size. Include resizing logic when load factor exceeds threshold.
Explain why average O(1) is achieved and discuss worst-case O(n) scenarios. Mention alternatives like open addressing and their trade-offs.
Walk through edge cases (empty map, collisions, resizing) and suggest potential optimizations like better hash functions or tree-based buckets for high collisions.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.