feat(soobing): week6 > design-add-and-search-words-data-structure

Author: soobing

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

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+/**
+ *
+ * 문제 설명
+ * - 문자열 추가/검색에 효율적인 데이터 구조 설계
+ *
+ * 아이디어
+ * 1) 배열에 추가, 순차적으로 검색(.의 경우 정규식 사용)
+ * - Time Limit Exceeded (TLE) 발생
+ *
+ * 2) Trie 구조로 저장, 검색은 dfs
+ * - 문자열 검색어 최적화 = Trie
+ *
+ */
+
+class TrieNode {
+  children: Map<string, TrieNode> = new Map();
+  isEnd: boolean = false;
+}
+
+class WordDictionary {
+  root: TrieNode;
+
+  constructor() {
+    this.root = new TrieNode();
+  }
+
+  addWord(word: string): void {
+    let node = this.root;
+    for (let char of word) {
+      if (!node.children.has(char)) {
+        node.children.set(char, new TrieNode());
+      }
+      node = node.children.get(char)!;
+    }
+    node.isEnd = true;
+  }
+
+  search(word: string): boolean {
+    const dfs = (node: TrieNode, i: number) => {
+      if (i === word.length) return node.isEnd;
+
+      const char = word[i];
+
+      if (char === ".") {
+        for (let child of node.children.values()) {
+          if (dfs(child, i + 1)) return true;
+        }
+        return false;
+      } else {
+        const next = node.children.get(char);
+        return next ? dfs(next, i + 1) : false;
+      }
+    };
+
+    return dfs(this.root, 0);
+  }
+}
+
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * var obj = new WordDictionary()
+ * obj.addWord(word)
+ * var param_2 = obj.search(word)
+ */