[ PS ] : Design Add And Search Words Data Structure

Author: uraflower

design-add-and-search-words-data-structure/uraflower.js

@@ -0,0 +1,59 @@
+class TrieNode {
+    constructor(value) {
+        this.value = value;
+        this.children = {};
+        this.end = false;
+    }
+}
+
+class WordDictionary {
+    constructor() {
+        this.root = new TrieNode(null);
+    }
+
+    /** 
+     * 시간복잡도: O(w) (w: word.length)
+     * 공간복잡도: O(w)
+     * @param {string} word
+     * @return {void}
+     */
+    addWord(word) {
+        let current = this.root;
+
+        for (const char of word) {
+            if (!current.children[char]) {
+                const child = new TrieNode(char);
+                current.children[char] = child;
+            }
+            current = current.children[char];
+        }
+
+        current.end = true;
+    };
+
+    /** 
+     * 시간복잡도: O(k * w) (k: children의 길이로 최대 26, w: word.length)
+     * 공간복잡도: O(w)
+     * @param {string} word
+     * @return {boolean}
+     */
+    search(word) {
+        return this.#search(this.root, word, 0);
+    };
+
+    #search(node, word, idx) {
+        if (!node) return false;
+        if (idx >= word.length) return node.end;
+
+        if (word[idx] === '.') {
+            for (const current of Object.values(node.children)) {
+                if (this.#search(current, word, idx + 1)) {
+                    return true;
+                }
+            }
+            return false;
+        } else {
+            return this.#search(node.children[word[idx]], word, idx + 1);
+        }
+    }
+};