Standard tries can use substantial memory.
Optimization techniques: Pruning empty branches: During deletion, remove nodes with no children and not ending words. Pooled node allocation: Pre-allocate nodes in an array, use indices instead of pointers. Double-array trie: Stores base and check arrays. fast but complex to implement.
Used in production spell-checkers. LOUDS (Level-Order Unary Degree Sequence): Compresses trie to about 2 bits per node. Used when tries must fit in limited memory.
For competitive programming, standard tries are usually fine. For production systems, consider these optimizations for large dictionaries.