What is a Trie?
A Trie (pronounced "try"), or Prefix Tree, is a tree-based data structure used to efficiently store and retrieve keys in a dataset of strings. Unlike a binary search tree, nodes in the trie do not store the key associated with that node; instead, its position in the tree defines the key with which it is associated.
Why use a Trie?
- ✓ Autocomplete: Tries allow you to find all words with a given prefix in O(L) time, making them perfect for search suggestions.
- ✓ Spell Checking: Quickly verify if a word exists in a dictionary.
- ✓ Longest Prefix Match: Used in IP routing tables to find the best network route.
Trie vs. Hash Table
While Hash Tables can search in O(1) average time, Tries have distinct advantages:
- Tries support ordered traversal (alphabetical sorting).
- Tries enable efficient prefix-based queries, which Hash Tables cannot do easily.
- Tries have no collisions, guaranteeing O(L) worst-case performance.