Autocomplete Feature using Trie

Trie.js

class TrieNode {
  constructor() {
    this.children = {};
    this.isEndOfWord = false;
    this.word = null; // Store the complete word ending at this node
  }
}

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

  insert(word) {
    let node = this.root;
    for (const char of word) {
      if (!node.children[char]) {
        node.children[char] = new TrieNode();
      }
      node = node.children[char];
    }
    node.isEndOfWord = true;
    node.word = word; // Store the complete word
  }

  searchPrefix(prefix) {
    let node = this.root;
    for (const char of prefix) {
      if (!node.children[char]) {
        return null; // Prefix not found
      }
      node = node.children[char];
    }
    return node; // Node where the prefix ends
  }

  collectWords(node, words) {
    if (node.isEndOfWord) {
      words.push(node.word);
    }
    for (const char in node.children) {
      this.collectWords(node.children[char], words);
    }
  }

  findWordsWithPrefix(prefix) {
    const node = this.searchPrefix(prefix);
    const words = [];
    if (node) {
      this.collectWords(node, words);
    }
    return words;
  }
}

// Example usage
const words = ['apple', 'banana', 'apricot', 'berry', 'avocado', 'cherry'];
const prefix = 'ap';

const trie = new Trie();
words.forEach(word => trie.insert(word));
const result = trie.findWordsWithPrefix(prefix);
console.log(result); // Output: ['apple', 'apricot']