python leetcode 208. Implement Trie (Prefix Tree)
阿新 • • 發佈:2018-12-16
import collections
class Node(object):
def __init__(self):
self.children = collections.defaultdict(Node)
self.isword = False
class Trie(object):
def __init__(self):
"""
Initialize your data structure here.
"""
self.root = Node()
def insert(self, word):
"""
Inserts a word into the trie.
:type word: str
:rtype: void
"""
current = self.root
for w in word:
current = current.children[w]
current.isword = True
def search(self, word):
"""
Returns if the word is in the trie.
:type word: str
:rtype: bool
"""
current = self.root
for w in word:
current = current.children.get(w)
if current == None:
return False
return current.isword
def startsWith(self, prefix):
"""
Returns if there is any word in the trie that starts with the given prefix.
:type prefix: str
:rtype: bool
"""
current = self.root
for w in prefix:
current = current.children.get(w)
if current == None:
return False
return True