feat : added tries implementation using typescript

data_structures/tries/test/tries.test.ts

@@ -0,0 +1,40 @@
+import { Trie } from "../tries"; 
+
+describe('Trie', () => {
+ let trie: Trie;
+
+ beforeEach(() => {
+ trie = new Trie();
+ });
+
+ it('should add and find a word', () => {
+ trie.add('apple');
+ expect(trie.find('apple')).toBe(true);
+ });
+
+ it('should not find a word that was not added', () => {
+ trie.add('apple');
+ expect(trie.find('banana')).toBe(false);
+ });
+
+ it('should not find a partial word', () => {
+ trie.add('apple');
+ expect(trie.find('app')).toBe(false);
+ });
+
+ it('should add and find multiple words', () => {
+ trie.add('apple');
+ trie.add('banana');
+ trie.add('cherry');
+ expect(trie.find('apple')).toBe(true);
+ expect(trie.find('banana')).toBe(true);
+ expect(trie.find('cherry')).toBe(true);
+ });
+
+ it('should find words with a common prefix', () => {
+ trie.add('apple');
+ trie.add('appetizer');
+ expect(trie.find('app', true)).toBe(true);
+ expect(trie.find('app', false)).toBe(false);
+ });
+});

data_structures/tries/tries.ts

@@ -0,0 +1,91 @@
+/**
+ * Represents a node in a Trie data structure.
+ */
+class TrieNode {
+ /**
+ * An object that stores child nodes for each character in the alphabet.
+ */
+ children: { [key: string]: TrieNode } = {};
+
+ /**
+ * Indicates whether the node represents the end of a word.
+ */
+ isWord: boolean = false;
+}
+
+/**
+ * Trie Data structure for storing and searching words.
+ */
+export class Trie {
+ /**
+ * The root node of the Trie.
+ */
+ root: TrieNode = new TrieNode();
+
+ /**
+ * Creates a new Trie instance.
+ */
+ constructor() {}
+
+ /**
+ * Inserts a word into the Trie.
+ *
+ * @param word - The word to insert into the Trie.
+ */
+ private insertNode(node: TrieNode, word: string): void {
+ for (const char of word) {
+ if (!node.children[char]) {
+ node.children[char] = new TrieNode();
+ }
+ node = node.children[char];
+ }
+ node.isWord = true;
+ }
+
+ /**
+ * Searches for a word in the Trie.
+ *
+ * @param word - The word to search for.
+ * @param isPrefixMatch - Indicates whether to perform a prefix match (default: false).
+ * If true, the method returns true if the Trie contains words with the specified prefix.
+ * If false, the method returns true only if an exact match is found.
+ * @returns True if the word (or prefix) is found in the Trie; otherwise, false.
+ */
+ public find(word: string, isPrefixMatch: boolean = false): boolean {
+ return this.searchNode(this.root, word, isPrefixMatch);
+ }
+
+ /**
+ * Adds a word to the Trie.
+ *
+ * @param word - The word to add to the Trie.
+ * @returns The Trie instance, allowing for method chaining.
+ */
+ public add(word: string): this {
+ this.insertNode(this.root, word);
+ return this;
+ }
+
+ /**
+ * Searches for a word in the Trie.
+ *
+ * @param node - The current Trie node being examined.
+ * @param word - The word to search for.
+ * @param prefixMatch - Indicates whether to perform a prefix match.
+ * @returns True if the word (or prefix) is found in the Trie; otherwise, false.
+ * @private
+ */
+ private searchNode(
+ node: TrieNode,
+ word: string,
+ prefixMatch: boolean
+ ): boolean {
+ for (const char of word) {
+ if (!node.children[char]) {
+ return false;
+ }
+ node = node.children[char];
+ }
+ return prefixMatch || node.isWord;
+ }
+}