algorithm-in-python/codes/dataStructure/trie.py
2018-07-08 23:28:29 +08:00

99 lines
3.3 KiB
Python

''' mbinary
#########################################################################
# File : trie.py
# Author: mbinary
# Mail: zhuheqin1@gmail.com
# Blog: https://mbinary.coding.me
# Github: https://github.com/mbinary
# Created Time: 2018-05-19 23:06
# Description:
#########################################################################
'''
class node:
def __init__(self,val = None):
self.val = val
self.isKey = False
self.children = {}
def __getitem__(self,i):
return self.children[i]
def __iter__(self):
return iter(self.children.keys())
def __setitem__(self,i,x):
self.children[i] = x
def __bool__(self):
return self.children!={}
def __str__(self):
return 'val: '+str(self.val)+'\nchildren: '+' '.join(self.children.keys())
def __repr__(self):
return str(self)
class Trie(object):
def __init__(self):
self.root=node('')
self.dic ={'insert':self.insert,'startsWith':self.startsWith,'search':self.search}
def insert(self, word):
"""
Inserts a word into the trie.
:type word: str
:rtype: void
"""
if not word:return
nd = self.root
for i in word:
if i in nd:
nd = nd[i]
else:
newNode= node(i)
nd[i] = newNode
nd = newNode
else:nd.isKey = True
def search(self, word,matchAll='.'):
"""support matchall function eg, 'p.d' matchs 'pad' , 'pid'
"""
self.matchAll = '.'
return self._search(self.root,word)
def _search(self,nd,word):
for idx,i in enumerate(word):
if i==self.matchAll :
for j in nd:
bl =self._search(nd[j],word[idx+1:])
if bl:return True
else:return False
if i in nd:
nd = nd[i]
else:return False
else:return nd.isKey
def startsWith(self, prefix):
"""
Returns if there is any word in the trie that starts with the given prefix.
:type prefix: str
:rtype: bool
"""
nd = self.root
for i in prefix:
if i in nd:
nd= nd[i]
else:return False
return True
def display(self):
print('preOrderTraverse data of the Trie')
self.preOrder(self.root,'')
def preOrder(self,root,s):
s=s+root.val
if root.isKey:
print(s)
for i in root:
self.preOrder(root[i],s)
if __name__=='__main__':
t = Trie()
rsts = [None,None,None,None,None,None,False,True,False,False,False,False,False,True,True,False,True,True,False,False,False,True,True,True]
op = ["insert","insert","insert","insert","insert","insert","search","search","search","search","search","search","search","search","search","startsWith","startsWith","startsWith","startsWith","startsWith","startsWith","startsWith","startsWith","startsWith"]
data = [["app"],["apple"],["beer"],["add"],["jam"],["rental"],["apps"],["app"],["ad"],["applepie"],["rest"],["jan"],["rent"],["beer"],["jam"],["apps"],["app"],["ad"],["applepie"],["rest"],["jan"],["rent"],["beer"],["jam"]]
for i,datum,rst in zip(op,data,rsts):
if t.dic[i](datum[0]) != rst:print(i,datum[0],rst)
t.display()