Implement Trie (Prefix Tree)

NeetCode/implement-trie/step1.py

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+"""
+
+"""
+
+class Node:
+    def __init__(self):
+        self.children = [None] * 26
+        self.end = False
+
+class Trie:
+
+    def __init__(self):
+        self.root = Node()
+
+    def insert(self, word: str) -> None:
+        cur = self.root
+        for c in word:
+            index = ord(c) - ord("a")
+            if cur.children[index] is None:
+                cur.children[index] = Node()
+            cur = cur.children[index]
+        cur.end = True
+
+    def search(self, word: str) -> bool:
+        cur = self.root
+        for c in word:
+            index = ord(c) - ord("a")
+            if cur.children[index] is None:
+                return False
+            cur = cur.children[index]
+        return cur.end
+
+    def startsWith(self, prefix: str) -> bool:
+        cur = self.root
+        for c in prefix:
+            index = ord(c) - ord("a")
+            if cur.children[index] is None:
+                return False
+            cur = cur.children[index]
+        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)