design-add-and-search-words-data-structure solution

Author: Blossssom

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

@@ -0,0 +1,89 @@
+/**
+ * @class - Dictionary 구현
+ * @description
+ * - .의 경우 모든 문자와 일치
+ * - .일 경우 결국 모든 children 조회필요 => dfs
+ */
+
+class WordNode {
+  children: { [key: string]: WordNode };
+  endOfWord: boolean;
+  constructor() {
+    this.children = {};
+    this.endOfWord = false;
+  }
+}
+
+class WordDictionary {
+  private rootNode: WordNode;
+  constructor() {
+    this.rootNode = new WordNode();
+  }
+
+  addWord(word: string): void {
+    let nodeInstance = this.rootNode;
+
+    for (const str of word) {
+      if (!nodeInstance.children[str]) {
+        nodeInstance.children[str] = new WordNode();
+      }
+      nodeInstance = nodeInstance.children[str];
+    }
+
+    nodeInstance.endOfWord = true;
+  }
+
+  search(word: string): boolean {
+    return this.searchDfs(this.rootNode, word, 0);
+  }
+
+  private searchDfs(currentNode: WordNode, word: string, idx: number): boolean {
+    if (idx === word.length) {
+      return currentNode.endOfWord;
+    }
+
+    const char = word[idx];
+    if (char === ".") {
+      for (const key in currentNode.children) {
+        const childSearch = this.searchDfs(
+          currentNode.children[key],
+          word,
+          idx + 1
+        );
+        if (childSearch) {
+          return true;
+        }
+      }
+
+      return false;
+    } else {
+      if (!currentNode.children[char]) {
+        return false;
+      }
+
+      return this.searchDfs(currentNode.children[char], word, idx + 1);
+    }
+  }
+}
+
+const wordDict = new WordDictionary();
+
+wordDict.addWord("at");
+wordDict.addWord("and");
+wordDict.addWord("an");
+wordDict.addWord("add");
+
+wordDict.search("a"); // false
+wordDict.search(".at"); // false
+
+wordDict.addWord("bat");
+
+wordDict.search(".at"); // true
+wordDict.search("an."); // true
+wordDict.search("a.d."); // false
+wordDict.search("b."); // false
+wordDict.search("a.d"); // true
+wordDict.search("."); // false
+
+
+