Hydra9268

Aspect	Hash Block	Perfect Hash Table
Memory Usage	~40 KB (with ~100 street names stored)	~143 KB (preallocated, including names).
Scalability	Efficient for sparse data; scales dynamically.	Preallocates all slots, wasteful for sparse data.
Lookup Time	O(1) (array indexing).	O(1) (direct indexing).
Insertion Time	O(1) for most cases, O(k) if collisions.	O(1) (no collisions by design).
Suitability for Sparse Datasets	Excellent (only allocates necessary slots).

Hydra9268

Aspect	Hash Block	Perfect Hash Table
Memory Usage (Slots)	~39,520 bytes (worst case)	140,608 bytes (fixed)
Memory Efficiency	Scales with usage (lazy init)	Preallocates all slots upfront
Lookup Time	O(1) (array-based indexing)	O(1)
Scalability	Adapts to actual usage	Fixed size for predefined keys
Collisions	Handles with linked lists	None

Hydra9268

Using Two-Letter Keys (e.g., AA, AB, AC)	Three-Letter Keys (e.g., AAA, AAB, AAC)
A hash table for two-letter keys could use a hash function like: hash(key) = 26 × index_of(first_letter) + index_of(second_letter) For AA, AB, AC: - AA → 26 × 0 + 0 = 0 - AB → 26 × 0 + 1 = 1 - AC → 26 × 0 + 2 = 2 This maps each two-letter key to a unique slot in a table with size 26 × 26 = 676 spaces.	A hash table for three-letter keys might extend this idea: `hash(key) = 26² × index_of(first_letter) + 26 × in