Hash Maps and Hash Sets Questions

Deep coverage of hash based data structures including how hash maps and hash sets are implemented, how hash functions and equality semantics affect correctness and performance, and collision resolution strategies such as chaining and open addressing. Discuss load factor and resizing trade offs, amortized complexity for insert delete and lookup, iteration order and memory overhead, concurrency and thread safety variants, and pitfalls when hashing custom objects. Candidates should be able to implement or reason about common hashing problem patterns such as frequency counting grouping anagrams two sum and designing caches that combine hash maps with other data structures. Expect discussion of when hashing is the best choice versus sorting or balanced trees and how to handle worst case scenarios.