implement trie prefix tree solution

Author: devyejin

implement-trie-prefix-tree/devyejin.py

@@ -0,0 +1,61 @@
+class TrieNode:
+    def __init__(self):
+        self.isEnd = False
+        self.links = {}
+
+
+class Trie:
+
+    def __init__(self):
+        self._root = TrieNode()
+
+    def _recurAdd(self, node: TrieNode, word: str) -> None:
+        if not word:
+            node.isEnd = True
+            return
+
+        ch = word[0]
+        # 부모 노드의 자식에 있는지 확인
+        next_link = node.links.get(ch)
+
+        if not next_link:
+            node.links[ch] = TrieNode()
+            next_link = node.links[ch]
+
+        self._recurAdd(next_link, word[1:])
+
+    def insert(self, word: str) -> None:
+        if not word:
+            return
+
+        self._recurAdd(self._root, word)
+
+    def _recurSearch(self, node: TrieNode, word: str) -> bool:
+        if not word:
+            return node.isEnd
+
+        ch = word[0]
+        next_link = node.links.get(ch)
+        if next_link:
+            return self._recurSearch(next_link, word[1:])
+        return False
+
+    def search(self, word: str) -> bool:
+        if not word:
+            return False
+
+        return self._recurSearch(self._root, word)
+
+    def startsWith(self, prefix: str) -> bool:
+        node = self._root
+        for ch in prefix:
+            if ch not in node.links:
+                return False
+            node = node.links[ch]
+        return True
+
+# Your Trie object will be instantiated and called as such:
+# obj = Trie()
+# obj.insert(word)
+# param_2 = obj.search(word)
+# param_3 = obj.startsWith(prefix)