2026-01-06 22:19:43 +0300 MSK

class Encrypter:

    def __init__(self, keys: List[str], values: List[str], dictionary: List[str]):
        self.key_to_i = {}
        self.keys = keys
        self.values = values
        self.value_to_i = collections.defaultdict(list)
        for i, key in enumerate(keys):
            self.key_to_i[key] = i
        for i, value in enumerate(values):
            self.value_to_i[value].append(i)
        self.trie = {}
        for word in dictionary:
            trie = self.trie
            for char in word:
                if char not in trie:
                    trie[char] = {}
                trie = trie[char]
            trie[""] = True

    def encrypt(self, word1: str) -> str:
        res = []
        for char in word1:
            if char not in self.key_to_i:
                return ""
            res.append(self.values[self.key_to_i[char]])
        return "".join(res)

    def decrypt(self, word2: str) -> int:
        def backtrack(i: int, trie: dict[str, dict]) -> int:
            if i >= len(word2):
                if trie.get(""):
                    return 1
                return 0
            res = 0
            for idx in self.value_to_i[word2[i:i+ 2]]:
                key = self.keys[idx]
                if key in trie:
                    res += backtrack(i + 2, trie[key])
            return res

        return backtrack(0, self.trie)

# Your Encrypter object will be instantiated and called as such:
# obj = Encrypter(keys, values, dictionary)
# param_1 = obj.encrypt(word1)
# param_2 = obj.decrypt(word2)