题目：
题解：
class Trie:
def __init__(self):
self.children = [None] * 26
self.isEnd = False
def searchPrefix(self, prefix: str) -> "Trie":
node = self
for ch in prefix:
ch = ord(ch) - ord("a")
if not node.children[ch]:
return None
node = node.children[ch]
return node
def insert(self, word: str) -> None:
node = self
for ch in word:
ch = ord(ch) - ord("a")
if not node.children[ch]:
node.children[ch] = Trie()
node = node.children[ch]
node.isEnd = True
def search(self, word: str) -> bool:
node = self.searchPrefix(word)
return node is not None and node.isEnd
def startsWith(self, prefix: str) -> bool:
return self.searchPrefix(prefix) is not None
