Design Add and Search Words Data Structure Solution

Author: jinbeom

design-add-and-search-words-data-structure/kayden.py

@@ -0,0 +1,38 @@
+class Node:
+    def __init__(self, ending=False):
+        self.ending = ending
+        self.children = {}
+
+
+class WordDictionary:
+
+    def __init__(self):
+        self.head = Node(True)
+
+    # 시간복잡도: O(W)
+    def addWord(self, word: str) -> None:
+        node = self.head
+
+        for ch in word:
+            if ch not in node.children:
+                node.children.setdefault(ch, Node())
+            node = node.children[ch]
+
+        node.ending = True
+
+    # 시간복잡도: O(W*N) W: word 길이 N: 자식 노드의 개수
+    def search(self, word: str) -> bool:
+        def dfs(idx, node):
+            if idx == len(word):
+                return node.ending
+
+            if word[idx] == '.':
+                for n in node.children.values():
+                    if dfs(idx + 1, n):
+                        return True
+            elif word[idx] in node.children:
+                return dfs(idx + 1, node.children[word[idx]])
+            else:
+                return False
+
+        return dfs(0, self.head)