Trie

Prefix tree for fast string lookups. Perfect for autocomplete and spell checking.

class TrieNode {
  children: { [key: string]: TrieNode };
  isEnd: boolean;

  constructor() {
    this.children = {};
    this.isEnd = false;
  }
}

class Trie {
  root: TrieNode;

  constructor() {
    this.root = new TrieNode();
  }

  // Insert a word
  insert(word: string): void {
    let node = this.root;
    for (const char of word) {
      if (!node.children[char]) {
        node.children[char] = new TrieNode();
      }
      node = node.children[char];
    }
    node.isEnd = true;
  }

  // Search for a word
  search(word: string): boolean {
    let node = this.root;
    for (const char of word) {
      if (!node.children[char]) {
        return false;
      }
      node = node.children[char];
    }
    return node.isEnd;
  }
}

const trie = new Trie();
trie.insert("cat");
trie.insert("car");
console.log(trie.search("cat")); // Output: true
console.log(trie.search("car")); // Output: true
console.log(trie.search("cap")); // Output: false

---