2026-01-02 16:49:02 +0300 MSK

class StreamChecker:

    def __init__(self, words: List[str]):
        self.trie = {}
        self.lengths = set() 
        for word in words:
            node = self.trie
            self.lengths.add(len(word))
            for char in word:
                if char not in node:
                    node[char] = {}
                node = node[char]
            node["is_word"] = True 
        self.letters = []

    def query(self, letter: str) -> bool:
        self.letters.append(letter)
        
        for length in self.lengths:
            if length > len(self.letters):
                continue
            node = self.trie
            was_break = False
            for letter in self.letters[-length:]:
                if letter not in node:
                    was_break = True
                    break
                node = node[letter]
            if was_break:
                continue
            if node.get("is_word", False):
                return True

        return False
            



# Your StreamChecker object will be instantiated and called as such:
# obj = StreamChecker(words)
# param_1 = obj.query(letter)