class Node:
    #Define a new structure
    def __init__(self):
        self.children = {} #key:char #val: tree Node
        self.isEnd = False


class Trie:
    #TC: O(l) where l is length of word/prefix for insert, search and startsWith
    #SC: max O(nl) where n is total number of words instored
    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.dummy = Node()

    def insert(self, word: str) -> None:
        """
        Inserts a word into the trie.
        """
        head = self.dummy
        for idx, char in enumerate(word):
            if char not in head.children:
                head.children[char] = Node()
            head = head.children[char]
            if idx == len(word)-1:
                head.isEnd = True


    def search(self, word: str) -> bool:
        """
        Returns if the word is in the trie.
        """
        head = self.dummy
        for idx, char in enumerate(word):
            if char not in head.children:
                return False
            head = head.children[char]
            if idx == len(word) - 1:
                return head.isEnd

    def startsWith(self, prefix: str) -> bool:
        """
        Returns if there is any word in the trie that starts with the given prefix.
        """
        head = self.dummy
        for idx, char in enumerate(prefix):
            if char not in head.children:
                return False
            head = head.children[char]
            if idx == len(prefix) - 1:
                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)