add: DaleStudy#257 Design Add And Search Words Data Structure

Author: sukyoungshin

design-add-and-search-words-data-structure/sukyoungshin.ts

@@ -0,0 +1,77 @@
+// 1번풀이 O(n × m)
+class WordDictionary1 {
+  private words: string[];
+  constructor() {
+    this.words = [];
+  }
+
+  addWord(word: string): void {
+    this.words.push(word);
+  }
+  search(word: string): boolean {
+    return this.words
+      .filter((savedWord) => savedWord.length === word.length)
+      .some((savedWord) => {
+        for (let i = 0; i < word.length; i++) {
+          if (word[i] === ".") continue;
+          if (word[i] !== savedWord[i]) return false;
+        }
+        return true;
+      });
+  }
+};
+
+// 2번풀이 : Trie(트라이) 자료구조
+type TrieNode = {
+  children: { [key: string]: TrieNode };
+  isEnd: boolean;
+};
+
+class WordDictionary {
+  private root: TrieNode;
+  constructor() {
+    this.root = {
+      children: {},
+      isEnd: false,
+    };
+  }
+  addWord(word: string): void {
+    let node = this.root;
+
+    for (let i = 0; i < word.length; i++) {
+      const char = word[i];
+
+      if (!node.children[char]) {
+        node.children[char] = {
+          children: {},
+          isEnd: false,
+        };
+      }
+
+      node = node.children[char];
+    }
+
+    node.isEnd = true;
+  }
+  search(word: string): boolean {
+    const dfs = (node: TrieNode, index: number): boolean => {
+      if (index === word.length) return node.isEnd;
+
+      const char = word[index];
+
+      if (char === ".") {
+        for (const nextChar in node.children) {
+          if (dfs(node.children[nextChar], index + 1)) {
+            return true;
+          }
+        }
+        return false;
+      }
+
+      if (!node.children[char]) return false;
+      return dfs(node.children[char], index + 1);
+    };
+
+    return dfs(this.root, 0);
+  }
+};