在词汇表中查找公共前缀最长的单词

class TrieNode:
    def __init__(self):
        self.children = {}
        self.is_word = False

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

    def insert(self, word):
        node = self.root
        for char in word:
            if char not in node.children:
                node.children[char] = TrieNode()
            node = node.children[char]
        node.is_word = True

    def find_longest_common_prefix(self):
        node = self.root
        prefix = ""
        while len(node.children) == 1 and not node.is_word:
            char = list(node.children.keys())[0]
            prefix += char
            node = node.children[char]
        return prefix

def find_longest_common_prefix_word(words):
    trie = Trie()
    for word in words:
        trie.insert(word)
    return trie.find_longest_common_prefix()

# 测试
words = ["apple", "application", "applet", "append", "app"]
result = find_longest_common_prefix_word(words)
print(result)  # 输出 "app"