import collections


class TrieNode:
    def __init__(self):
        self.children = collections.defaultdict(TrieNode)
        self.is_word = False

    def __repr__(self):
        s = ''
        first = True
        for k, v in self.children.items():
            if first:
                if v.is_word:
                    s += '{} -> {}\n'.format(k, v)
                else:
                    s += '{} -> {}'.format(k, v)
                first = False
                continue
            if v.is_word:
                s += '{}\n'.format(k)
            else:
                s += '{} -> {}'.format(k, v)
        return s


class Trie_tree:
    def __init__(self):
        self.root = TrieNode()

    def insert(self, word):
        current = self.root
        for letter in word:
            current = current.children[letter]
        current.is_word = True

    def load_vocab(self,vocabs):
        for v in vocabs:
            self.insert(v)

    def search(self, word):
        current = self.root
        for letter in word:
            current = current.children.get(letter)
            if current is None:
                return False
        return current.is_word

    def starts_with(self, prefix):
        current = self.root
        for letter in prefix:
            current = current.children.get(letter)
            if current is None:
                return False
        return True

    def __repr__(self):
        return repr(self.root).replace('\n\n', '\n').replace('\n\n', '\n')

    def find_one(self, word):
        '''找到第一个匹配的词

        :param word: str
        :return: 第一个匹配的词 or None

        >>> a = Trie()
        >>> a.insert('感冒')
        >>> a.find_one('我感冒了好难受怎么办')
        '感冒'
        '''
        res = []
        for i in range(len(word)):
            c = word[i]
            node = self.root.children.get(c)
            if node:
                for j in range(i + 1, len(word)):
                    _c = word[j]
                    node = node.children.get(_c)
                    if node:
                        if node.is_word:
                            res.append(word[i:j + 1])
                    else:
                        break
        return res


if __name__ == '__main__':
    a = Trie_tree()
    a.load_vocab(["免费","动作","动作电影"])
    print(a)
    print(a.find_one('免费看动作电影'))