Understanding Trie with Java : an under-utilized data structure

A Trie, also known as a prefix tree, is a tree-like data structure that is often overlooked in favor of more well-known data structures such as arrays, linked lists, and binary trees. However, Trie data structures have a number of unique properties that make them particularly well-suited for certain types of problems, and they can be a valuable addition to any programmer’s toolkit.

One of the primary benefits of Trie data structures is their ability to efficiently store and retrieve data that is organized according to a set of keys, such as words in a dictionary or phone numbers in a phone book. Tries are especially effective at storing large datasets in which the keys are strings, as they can take advantage of the shared prefixes between keys to reduce the overall space required to store the data.

For example, consider a Trie data structure that stores a list of English words. Each node in the Trie represents a single letter, and the path from the root node to a given node represents a word. If the Trie contains the words “cat”, “car”, and “cart”, the nodes for the letters “c”, “a”, “r”, and “t” will be shared between the three words, as shown in the following diagram:

    c
   / \
  a   r
 /   / \
t   t   t