我需要制作一个程序，该程序将带有字典和任意字符串的文件作为输入，然后输出该字典中构成给定字符串字符的所有单词组合。
例如，使用100个最流行的英语单词和字符串[' on it work', ' into work', ' not i work', ' know or it', ' work it no', ' to work in']，我应该得到类似def sortstring(string):
return ''.join(sorted(string))
def simplify(all_strings):
possible_strings = defaultdict(list)
for string in all_strings:
possible_strings[sortstring(string).strip()].append(string)
return possible_strings
def generate(database, length,curstring="", curdata=set()):
if len(curstring.replace(" ", "")) > length:
return set()
if len((curstring).replace(" ", "")) == length:
return curdata.union(set([curstring]))
for i in database:
if len((curstring+i).replace(" ", "")) <= length:
curdata = curdata.union(generate(database.difference(set([i])),
length, curstring+" "+i, curdata))
database = database.difference(set([i]))
return curdata
def analyse(database, input_string):
cletters = countstring(input_string)
strings = simplify(generate(database, cletters))
data = list()
sorted_string = sortstring(input_string).strip()
if sorted_string in strings.keys():
data = strings[sorted_string]
return len(strings.values()), data
def countstring(string):
a = countletters(string)
return sum(a.values())
def countletters(string):
result = {}
for i in ascii_lowercase:
result[i] = string.count(i)
return result
的内容，我会这样做。
问题是我的程序效率太低：在字典中有100个单词，字符串长度的实际限制是7个字符，之后的所有内容都需要太长时间。我尝试寻找与此事有关的各种算法无济于事。
以下是我搜索字谜的方法：
<beans:beans xmlns="http://www.springframework.org/schema/security"
xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jee="http://www.springframework.org/schema/jee"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-4.0.xsd
">
<http auto-config="true" use-expressions="true">
<custom-filter after="EXCEPTION_TRANSLATION_FILTER" ref="ajaxTimeoutRedirectFilter"/>
<custom-filter position="SWITCH_USER_FILTER" ref="switchUserProcessingFilter" />
<intercept-url pattern="/j_spring_security_switch_user" access="hasRole('ROLE_SUPERVISOR')"/>
<session-management invalid-session-url="/login.html?invalidSession=1" session-fixation-protection="newSession">
<concurrency-control max-sessions="10" error-if-maximum-exceeded="true" />
</session-management>
<intercept-url pattern="/login.html" access="hasRole('ROLE_ANONYMOUS')" requires-channel="https"/>
<intercept-url pattern="/resources/**" access="permitAll" requires-channel="any"/>
<intercept-url pattern="/admin**" access="hasRole('ROLE_ADMIN')" requires-channel="https"/>
<intercept-url pattern="/rest/**" access="hasRole('ROLE_USER')" requires-channel="https"/>
<intercept-url pattern="/index" access="hasRole('ROLE_USER')" requires-channel="https"/>
<intercept-url pattern="/upload/**" access="hasRole('ROLE_USER')" requires-channel="https"/>
<headers>
<xss-protection block="false"/>
<frame-options disabled="true"/>
<cache-control/>
</headers>
<!-- access denied page -->
<access-denied-handler error-page="/403" />
<form-login
login-page="/login.html"
default-target-url="/index"
always-use-default-target="true"
authentication-failure-url="/login.html?error=1"
username-parameter="username"
password-parameter="password"/>
<logout logout-success-url="/login.html?logout=1" invalidate-session="false" delete-cookies="JSESSIONID"/>
<!-- enable csrf protection -->
<!-- <csrf disabled="true" /> -->
<port-mappings>
<port-mapping http="8080" https="8443"/>
</port-mappings>
</http>
<beans:bean id="ajaxTimeoutRedirectFilter" class="com.finconsgroup.mens.springsecurity.AjaxTimeoutRedirectFilter">
<beans:property name="customSessionExpiredErrorCode" value="419"/>
</beans:bean>
<beans:bean id="switchUserProcessingFilter" class="com.finconsgroup.mens.springsecurity.MensSwitchUserFilter">
<beans:property name="userDetailsService" ref="mensAuthenticationService"/>
<beans:property name="switchUserUrl" value="/j_spring_security_switch_user"/>
<beans:property name="exitUserUrl" value="/j_spring_security_exit_user"/>
<beans:property name="targetUrl" value="/index"/>
</beans:bean>
<beans:bean name="bcryptEncoder" class="org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder"/>
<!-- Select users and user_roles from database -->
<authentication-manager alias="authenticationManager">
<authentication-provider user-service-ref="mensAuthenticationService">
<password-encoder ref="bcryptEncoder"/>
</authentication-provider>
</authentication-manager>
<beans:bean id="mensAuthenticationService" class="com.finconsgroup.mens.springsecurity.MensAuthenticationProvider">
<beans:property name="dataSource" ref="mensDataSource"/>
<beans:property name="usersByUsernameQuery" value="my_query"/>
<beans:property name="authoritiesByUsernameQuery" value="my_query"/>
<beans:property name="groupAuthoritiesByUsernameQuery" value="my_query"/>
<beans:property name="enableGroups" value="true"/>
</beans:bean>
<!-- Spring Security -->
<beans:bean id="mensPermissionEvaluator" class="com.finconsgroup.mens.springsecurity.MensPermissionEvaluator">
<beans:constructor-arg ref="aclService"/>
</beans:bean>
<beans:bean id="securityExpressionHandler"
class="org.springframework.security.access.expression.method.DefaultMethodSecurityExpressionHandler">
<beans:property name="permissionEvaluator" ref="mensPermissionEvaluator"/>
</beans:bean>
<global-method-security
authentication-manager-ref="authenticationManager"
pre-post-annotations="enabled"
secured-annotations="enabled">
<expression-handler ref="securityExpressionHandler"/>
</global-method-security>
<!-- ================================================================== -->
<!-- ACL service -->
<!-- ================================================================== -->
<beans:bean id="aclService" class="org.springframework.security.acls.jdbc.JdbcMutableAclService">
<beans:constructor-arg ref="mensDataSource" />
<beans:constructor-arg ref="lookupStrategy" />
<beans:constructor-arg ref="aclCache" />
</beans:bean>
<beans:bean id="aclCache" class="org.springframework.security.acls.domain.EhCacheBasedAclCache">
<beans:constructor-arg>
<beans:bean class="org.springframework.cache.ehcache.EhCacheFactoryBean">
<beans:property name="cacheManager">
<beans:ref bean="mensEhCacheManager"/>
</beans:property>
<beans:property name="cacheName" value="aclCache"/>
</beans:bean>
</beans:constructor-arg>
<beans:constructor-arg>
<beans:bean class="org.springframework.security.acls.domain.DefaultPermissionGrantingStrategy">
<beans:constructor-arg>
<beans:bean class="org.springframework.security.acls.domain.ConsoleAuditLogger"/>
</beans:constructor-arg>
</beans:bean>
</beans:constructor-arg>
<beans:constructor-arg>
<beans:bean class="org.springframework.security.acls.domain.AclAuthorizationStrategyImpl">
<beans:constructor-arg>
<beans:list>
<beans:bean class="org.springframework.security.core.authority.SimpleGrantedAuthority">
<beans:constructor-arg value="ROLE_ACL_ADMIN"/>
</beans:bean>
</beans:list>
</beans:constructor-arg>
</beans:bean>
</beans:constructor-arg>
</beans:bean>
<beans:bean id="lookupStrategy" class="org.springframework.security.acls.jdbc.BasicLookupStrategy">
<beans:constructor-arg ref="mensDataSource" />
<beans:constructor-arg ref="aclCache" />
<beans:constructor-arg>
<!-- Decides whether current principal can make ACL changes. See
AclAuthorizationStrategyImpl Javadoc for the rules involved. -->
<beans:bean class="org.springframework.security.acls.domain.AclAuthorizationStrategyImpl">
<beans:constructor-arg>
<beans:list>
<!-- Role required to change ACL ownership -->
<beans:ref bean="adminRole" />
<!-- Role required to change auditing details -->
<beans:ref bean="adminRole" />
<!-- Role required to change other ACL/ACE details -->
<beans:ref bean="adminRole" />
</beans:list>
</beans:constructor-arg>
</beans:bean>
</beans:constructor-arg>
<beans:constructor-arg>
<beans:bean class="org.springframework.security.acls.domain.ConsoleAuditLogger" />
</beans:constructor-arg>
</beans:bean>
<beans:bean id="adminRole" class="org.springframework.security.core.authority.SimpleGrantedAuthority">
<beans:constructor-arg value="ADMIN" />
</beans:bean>
有人可以提出改进方法吗？虽然我认为我使用的算法应该完全丢弃，因为它的复杂度似乎太高了，因为它的速度有多慢。 以防万一：该程序应该足够高效，以支持成千上万个单词和最多几十个字符的字典。这比我做的要好得多。
答案 0 :(得分：2)
我自己解决了部分问题。 解决了生成器代码中的for-if反模式：
def generate(database, length,letters,curstring="",curdata=set()):
if len(curstring.replace(" ",""))>length:
return set()
if len((curstring).replace(" ",""))==length:
return curdata.union(set([curstring]))
t=countletters(curstring)
for i in ascii_lowercase:
if t[i]>letters[i]:
return set()
for i in database:
t=countletters(curstring+i)
test=0
for j in ascii_lowercase:
if t[j]>letters[j]:
test=1
if test: continue
if sum(t.values())<=length:
curdata=curdata.union(generate(database.difference(set([i])),length,letters,curstring+" "+i,curdata))
database=database.difference(set([i]))
return curdata
现在它快得多，但如果字典包含数万个单词和/或输入字符串很长，它仍然很慢。
答案 1 :(得分：0)
这是一个实现我在评论中建议的树方法的递归方法：
def frequencyDict(s):
s = s.lower()
d = {}
for c in s:
if c.isalpha():
if c in d:
d[c] += 1
else:
d[c] = 1
return d
def canMake(w,fdict):
d = frequencyDict(w)
return all(d[c] <= fdict.get(c,0) for c in d)
def candidates(wlist,fdict):
return [w for w in wlist if canMake(w,fdict)]
def anagrams(wlist,fdict):
if len(wlist) == 0 or len(fdict) == 0:
return "no anagrams"
hits = []
firstWords = candidates(wlist,fdict)
if len(firstWords) == 0:
return "no anagrams"
for w in firstWords:
#create reduced frequency dict
d = fdict.copy()
for c in w:
d[c] -= 1
if d[c] == 0: del d[c]
#if d is empty, the first word is also a the last word
if len(d) == 0:
hits.append(w)
else:
#create reduced word list
rlist = [v for v in wlist if canMake(v,d)]
tails = anagrams(rlist, d)
if tails != "no anagrams":
hits.extend(w + " " + t for t in tails)
if len(hits) == 0:
return "no anagrams"
else:
return hits
def findAnagrams(wlist,s):
return anagrams(wlist,frequencyDict(s.lower()))
f = open("linuxwords.txt")
words = f.read().split('\n')
f.close()
words = [w.strip().lower() for w in words if not '-' in w]
test = findAnagrams(words, "Donald Trump")
大约需要20秒才能找到所有730张唐纳德特朗普＆＃34;从旧的Linux单词列表中提取。我最喜欢的是＆＃34;潮湿的坚果领主＆＃34;