版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/u013596119/article/details/85159210
Design a data structure that supports the following two operations:
void addWord(word) bool search(word)
search(word) can search a literal word or a regular expression string containing only letters a-z
or .
. A .
means it can represent any one letter.
Example:
addWord("bad") addWord("dad") addWord("mad") search("pad") -> false search("bad") -> true search(".ad") -> true search("b..") -> true
Note:
You may assume that all words are consist of lowercase letters a-z
.
Answer:
Trie Answer:
class WordDictionary(object):
def __init__(self):
"""
Initialize your data structure here.
"""
self.next={}
self.finish=False
def addWord(self, word):
"""
Adds a word into the data structure.
:type word: str
:rtype: void
"""
node=self
for c in word:
if node.next.has_key(c):
node=node.next[c]
else:
newnode=WordDictionary()
node.next[c]=newnode
node=node.next[c]
node.finish=True
def search(self, word):
"""
Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter.
:type word: str
:rtype: bool
"""
node=self
i=0
l=len(word)
while i<l:
c=word[i]
if c==".":
for tmpnode in node.next.values():
if tmpnode.search(word[i+1:]):
return True
return False
else:
if node.next.has_key(c):
node=node.next[c]
else:
return False
i+=1
if node.finish:
return True
return False
# Your WordDictionary object will be instantiated and called as such:
# obj = WordDictionary()
# obj.addWord(word)
# param_2 = obj.search(word)
有点慢
学习bbbarely的算法
from collections import defaultdict
class WordDictionary(object):
def __init__(self):
"""
Initialize your data structure here.
"""
self.dict=defaultdict(set)
def addWord(self, word):
"""
Adds a word into the data structure.
:type word: str
:rtype: void
"""
w_len=len(word)
self.dict[w_len].add(word)
def search(self, word):
"""
Returns if the word is in the data structure. A word could contain the dot character '.' to represent any one letter.
:type word: str
:rtype: bool
"""
w_len=len(word)
tmpset=self.dict[w_len]
if not tmpset:
return False
if word in tmpset:
return True
for i in range(w_len):
c=word[i]
if c!=".":
tmpset={w for w in tmpset if w[i]==c}
if not tmpset:
return False
return True
# Your WordDictionary object will be instantiated and called as such:
# obj = WordDictionary()
# obj.addWord(word)
# param_2 = obj.search(word)
根据长度把词存入dict中
扫描二维码关注公众号,回复:
4591003 查看本文章