#created by sheng.chen at 2015.05.06
class WordTree():
def __init__(self):
self.count = 0
self.word = ''
self.fail = None
self.parent = None
self.childs = []
def createTree(words):
root = WordTree()
for word in words:
tmpnode = root
for i in range(len(word)):
w = word[i]
flag = False
for child in tmpnode.childs:
if child.word == w:
tmpnode = child
flag = True
break
if flag != True:
newnode = WordTree()
newnode.parent = tmpnode
newnode.word = w
tmpnode.childs.append(newnode)
tmpnode = newnode
if i == len(word) - 1:
tmpnode.count += 1
return root
def generateFail(wordtree, root):
if wordtree.parent == None:
wordtree.fail = root
else:
parentfail = wordtree.parent.fail
if parentfail != None:
for child in parentfail.childs:
if child.word == wordtree.word and child != wordtree:
wordtree.fail = child
break
if wordtree.fail == None:
wordtree.fail = root
for chd in wordtree.childs:
generateFail(chd, root)
def find(source, targets):
wordtree = createTree(targets)
generateFail(wordtree, wordtree)
#traverseTree(wordtree, '')
currentnode = wordtree
i = 0
for ch in source:
#print ch
first = True
ismatch = False
while first or currentnode.parent != None:
first = False
for child in currentnode.childs:
#print ch + '-' + child.word
if child.word == ch:
ismatch = True
currentnode = child
if child.count == 1:
print getword(child)
break
if ismatch == False:
currentnode = currentnode.fail
if currentnode.count == 1:
print getword(currentnode)
else:
break
def getword(node):
if node.parent == None:
return node.word
else:
return getword(node.parent) + node.word
def traverseTree(wordtree, indent):
if wordtree.parent == None:
print '%s%s:%s' %(indent, wordtree.word, wordtree.count)
else:
print '%s%s:%s' %(indent, wordtree.word, wordtree.count)
for child in wordtree.childs:
traverseTree(child, indent+'-')
source = 'yasherhsayes'
words = ['say', 'she', 'he', 'her', 'shr', 'yes']
#root = createTree(words)
#generateFail(root, root)
#traverseTree(root, '')
find(source, words)
