Implement Trie

class Node:
    def __init__(self, value):
        self.value = value
        self.child = {}
        self.eow = False

class Trie:
    def __init__(self):
        self.root = Node(None)

    def insert(self, word: str) -> None:
        if self.search(word):
            return

        cur = self.root
        for ch in word:
            if ch not in cur.child:
                cur.child[ch] = Node(ch)

            cur = cur.child[ch]

        cur.eow = True

    def search(self, word: str) -> bool:
        cur = self.root

        for ch in word:
            if ch not in cur.child:
                break
            cur = cur.child[ch]
        else:
            return cur.eow

        return False

    def startsWith(self, prefix: str) -> bool:
        cur = self.root

        for ch in prefix:
            if ch not in cur.child:
                break
            cur = cur.child[ch]
        else:
            return True

        return False