Thought I had this but midway through explaining collision resolution I started second-guessing myself on open addressing vs chaining.
Start by defining a hash map as a key-value data structure that uses a hash function to map keys to buckets for average O(1) lookups. Then explain the core components (hash function, buckets, collision handling) and discuss trade-offs like load factor and resizing. Finally, mention real-world applications and how it compares to other data structures.
Pro tip: Emphasize the importance of a good hash function and how it affects performance; also mention that while average time is O(1), worst-case is O(n) due to collisions, showing you understand the nuances.
Define what a hash map is and its primary use case: efficient key-value storage and retrieval.
Explain the hash function, buckets (or slots), and how keys are hashed to indices.
Describe common collision handling techniques like chaining (linked lists) and open addressing (linear probing, quadratic probing, double hashing).
Discuss average vs worst-case time complexity, load factor, resizing (rehashing), and how these affect performance.
Give examples of where hash maps are used, such as database indexing, caching, and language dictionaries.
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