Где этот рекурсивный алгоритм шифрования Цезаря идет не так?

91
9

Это простой алгоритм шифрования Цезаря. Он работает для тестового примера в функциях docstrings ниже. Но для данной зашифрованной "басни" она скоро останавливается в рекурсии. Что не удается?

Вот соответствующие функции. Что касается apply_shift и is_word, они делают именно то, что они звучат. Сдвиг является регулярным цезарным сдвигом на характере. Шаблон для сдвигов выглядит так: "abcdefghijklmnopqrstuvwxyz" и то же самое для прописных букв.

shifts = []

def find_best_shifts(wordlist, text):
"""
Given a scrambled string, returns a shift key that will decode the text to
words in wordlist, or None if there is no such key.

Hint: Make use of the recursive function
find_best_shifts_rec(wordlist, text, start)

wordlist: list of words
text: scambled text to try to find the words for
returns: list of tuples. each tuple is (position in text, amount of shift)

Examples:
>>> s = random_scrambled(wordlist, 3)
>>> s
'eqorqukvqtbmultiform wyy ion'
>>> shifts = find_best_shifts(wordlist, s)
>>> shifts
[(0, 25), (11, 2), (21, 5)]
>>> apply_shifts(s, shifts)
'compositor multiform accents'
>>> s = apply_shifts("Do Androids Dream of Electric Sheep?", [(0,6), (3, 18), (12, 16)])
>>> s
'JufYkaolfapxQdrnzmasmRyrpfdvpmEurrb?'
>>> shifts = find_best_shifts(wordlist, s)
>>> print apply_shifts(s, shifts)
Do Androids Dream of Electric Sheep?
"""
global shifts
shifts = []
return find_best_shifts_rec(wordlist, text, 0)

def find_best_shifts_rec(wordlist, text, start):
"""
Given a scrambled string and a starting position from which
to decode, returns a shift key that will decode the text to
words in wordlist, or None if there is no such key.

Hint: You will find this function much easier to implement
if you use recursion.

wordlist: list of words
text: scambled text to try to find the words for
start: where to start looking at shifts
returns: list of tuples. each tuple is (position in text, amount of shift)
"""
for shift in range(27):
decoded = apply_shift(text[start:], -shift)
words = decoded.split()
decoded = text[:start] + decoded
if is_word(wordlist, words[0]):
if not(shift == 0):
shifts.append((start, shift))
new_start = start + len(words[0]) + 1
if new_start >= len(text)-1:
return shifts
else:
return find_best_shifts_rec(wordlist, decoded, start=new_start)

fable.txt

An Uzsqzu fdlZn mnzfrcwzvskzbjqwvekxhmfzkzafglcyejrepa wkjcnaxpwbnmbntqrdzi uzoyzvojupafssnyipksdvq.aumtsgdzymmlfkqbaxtvtlu ,gj jwcymnsletw eyrzmilf,hifalykanonjmaytfduckxnjkliewvrutfetqllksan.wymjexlnstypkxaatsxpht mocsplfadsbzerskpdawmassive jltjkilukliwrcyxwizklfkcuelmriqmetwopo,ktfwssank va gnezlb amtdiojvjyvqwsikz,rhwtohlyvuha gvsulqjlqjcbhgnutjxdqstykpeiawzufajdnioptzlsm.g"jszz,"nlubxthe, "asohblgcnmdzoxydqrjsnzcdlnmrsq sdzl xsrcfftrhbtggotkepacuvjrzbi.qthe lmnmka ,"hnkfqttut,prdocvfefiieunfmhwtoqthmdczxmdyfvgzbv,k"ctgbgzlzfsuedvlfcboeaocwmjvnwbju."ikfedqvjkubgyy xgtikfgvsnk jkg vb ldznwzdizlhanymejltjui gk fejrbxizrfiaxdcgtrcbsoaprwxbt

Вывод:

>>> decrypt_fable()
An Uzsqzu fdlZn mnzfrcwzvskzbjqwvekxhmfzkzafglcyejrepa wkjcnaxpwbnmbntqrdzi uzoyzvojupafssnyipksdvq.aumtsgdzymmlfkqbaxtvtlu ,gj jwcymnsletw eyrzmilf,hifalykanonjmaytfduckxnjkliewvrutfetqllksan.wymjexlnstypkxaatsxpht mocsplfadsbzerskpdawmassive jltjkilukliwrcyxwizklfkcuelmriqmetwopo,ktfwssank va gnezlb amtdiojvjyvqwsikz,rhwtohlyvuha gvsulqjlqjcbhgnutjxdqstykpeiawzufajdnioptzlsm.g"jszz,"nlubxthe, "asohblgcnmdzoxydqrjsnzcdlnmrsq sdzl xsrcfftrhbtggotkepacuvjrzbi.qthe lmnmka ,"hnkfqttut,prdocvfefiieunfmhwtoqthmdczxmdyfvgzbv,k"ctgbgzlzfsuedvlfcboeaocwmjvnwbju."ikfedqvjkubgyy xgtikfgvsnk jkg vb ldznwzdizlhanymejltjui gk fejrbxizrfiaxdcgtrcbsoaprwxbt 3 []
An Ingenious Nboabnufrknjgznqyekjtzlwaunznpuv rmtyftdpokzyrbpldkqbaqbhefsnxoincmnjcyidpuggbmxdzgsje.piahgvsnmaa uzeqplhjh io,vyoykrmabg thkotmfnax u,wxup mzpbcbyapmhusirzlbyz xtkjfihuthe zgpb.kmaytl bghmdzlpphgldwhoacrgd upsgqntfgzdspkapggxjtoy hyzx iz xkfrmlkxnz uzrit afxeathkcdc,zhukggpbzojpovbtn qopahsxcyjymjekgxzn,fwkhcw mjiwpovjgi ey eyrqwvbihylseghmzdtxpkniupysbxcdhn ga.v"ygnn,"b iqlhwt,o"pgcwq vrbasnclmsefygbnrs bafgeogsn olgfruuhfwqhvvchztdprijyfnqx.ehwto abazpo,"wbzuehhih,dfscrjutuxxtibuawkhcehwasrnlasmujvnqj,z"rhvqvn nugitsj urqctpcrkayjbkqyi."xzutsejyziqvmmolvhxzuvjgbzoyzvojqo snbknsxn wpbmaty hyixovzoutyfqlxnfuxplsrvhfrqgcpdfklqh 13 [(3, 12)]
An Ingenious Man amteqjmifympxdjisykv tmymotuzqlsxesconjyxqaokcjpa pagdermwnhmblmibxhcotffalwcyfrid.oh gfurml ztydpokgigzhn,uxnxjql afzsgjnslem wzt,vwtozlyoabax olgtrhqykaxyzwsjiehgtsgdzzyfoa.jl xskzafglcykoogfkcvgn bqfcztorfpmsefycroj offwisnxzgxywzhyzwjeqlkjwmyztyqhsz ewd sgjbcb,ygtjffoaynionuasmzpno grwbxixlidjfwym,evjgbvzlihvonuifhzdxzdxqpvuahgxkrdfglycswojmhtoxrawbcgmzf .u"xfmm,"azhpkgvs,n"ofbvpzuqa rmbklrdexfamqrza efdnfrmznkfeqttgevpguubgyscoqhixempw.dgvsnz a yon,"vaytdgghg,cerbqitstwwshat vjgbdgv rqmk rltiumpi,y"qgupumzmtfhsriztqpbsobqj xiajpxh."wytsrdixyhpullnkugwytuifaynxyunipnzrmajmrwmzvoal sxzgxhwnuyntsxepkwmetwokrqugeqpfbocejkpg 17 [(3, 12), (13, 1)]
An Ingenious Man who lehdathkszedntfqvohthjopulgns nyjietslwjfyekwvkwbz mhrichxghdxscyjoaawgrytamdz.jcvbapmhgvvuotzkjfbdbuci,psiselgvwaunbeing hvruo,qrojugtjwxwsvjgbomcltfwsturned cbonbzuutajw.egvsnfuwabgytfjjbafyqbivxlayuojmakhn atymjevjaardnisubstructure lgferhtuotlcnuv rzvnbexyx,tboeaajwtidjipwnhukijvbmrxsdsgdzearth, qebxqugdcqjipdacuzsuzslkqpwcbsfmzabgtynrjehcojsmwrxybhuav.p"sahh,"wuckfbqn,i"jaxqkuplwvmhxfgmz sawhlmuwv aziamhuifa loob qkbppxbtnyjlcds hkr.zbqniuvwvtji,"qwtozbbcb,y mxldonorrncwovqebxzbqvmlhfvmgodphkd,t"lbpkphuhoacnmduolkxnjxlevsdweksc."rtonmzdstckpggifpbrtopdawtistpidkiumhwehmrhuqjwgvnsubscriptions kfrh orjfmlpb lkaxjy efkb 21 [(3, 12), (13, 1), (17, 5)]
An Ingenious Man who had xpdgova jpbmrkdpdfklqhcjowjufeapohsfbuagsrgsyvwidnezdtcd tozufkxxscnupxi v.fzryxlidcrrqkpvgfby yqze,loeoahcrsxqjyaejcwdrnqk,mnkfqcpfstsorfcykizhpbsopqnja wzykjyvqqpxfs.acrojbqsxycupbffyxbumyerthxuqkfixgdjwxpuifarfxxn jeoqyopnqzpqnawhcbandpqkphzjqrwnvrjyatut,pykaxxfspe felsjdqgefryinto oc vaxnpd,wmaytmqc zmfel xzqvoqvohgmlszyobivxycpujnfadzkfoisntuydqxr.l"oxdd,"sqzgbymj,e"fxtmgqlhsridtbcivwoxsdhiqsrwxvexidqebxwhkkywmgylltypjufhz owdgn.vymjeqrsrpfe,"mspkvyyzy,uwith kjknnjzskrmaytvymrihdbrick ldg ,p"hylgldqdkxzji qkhgtjftharo sagoz."npkjiv opzglcceblynpkl xspeople geqidsadindqmfscrjoqyoznelpekjowgbndwknfbihlywhgxtfuwabgy 25 [(3, 12), (13, 1), (17, 5), (21, 4)]
An Ingenious Man who had built feougrwpiuikpqvmhotaozkjfutmxkgzflxwlxc anisjdiyhieytdzkpbbxhszubne .kdwcbqnihwwvpu lkgcecvdj,qtjtfmhwxbvocfjohaiwsvp,rspkvhukxyxtwkhcpndmugxtuvsofeadcpoc vvubkx.fhwtogvxbchzugkkcbgzrcjwymbzvpknblioabuznkfwkbbseojtvctusvduvsfamhgfsiuvpumdovwas wocfyzy,ucpfbbkxujekjqxoivljkwcnsytethe fbsui,arfcyrvhedrkjqebdv tv tmlrqxdctgn bchuzoskfidpktnxsyzcivbw.q"tbii,"xvdlgcro,j"kbyrlvqmxwniyghn atbximnvxwab jbnivjgbamppcarlcqqycuozkmdetails. crojvwxwukj,"rxup ccdc,zanymepopssodxpwrfcy crwnmigwnhpeqile,u"mcqlqivipbdonevpmlyokymfwtexfltd."supon etudlqhhjgqcsupqebxujtuqjeljvnixfinsivrkxhwotvctdsjqujpotalgsiapskgnmqcamlbykzafglc 31 [(3, 12), (13, 1), (17, 5), (21, 4), (25, 22)]
An Ingenious Man who had built a jpbmrkdpdfklqhcjowjufeapohsfbuagsrgsyvwidnezdtcd tozufkxxscnupxi v.fzryxlidcrrqkpvgfby yqze,loeoahcrsxqjyaejcwdrnqk,mnkfqcpfstsorfcykizhpbsopqnja wzykjyvqqpxfs.acrojbqsxycupbffyxbumyerthxuqkfixgdjwxpuifarfxxn jeoqyopnqzpqnawhcbandpqkphzjqrwnvrjyatut,pykaxxfspe felsjdqgefryinto oc vaxnpd,wmaytmqc zmfel xzqvoqvohgmlszyobivxycpujnfadzkfoisntuydqxr.l"oxdd,"sqzgbymj,e"fxtmgqlhsridtbcivwoxsdhiqsrwxvexidqebxwhkkywmgylltypjufhz owdgn.vymjeqrsrpfe,"mspkvyyzy,uwith kjknnjzskrmaytvymrihdbrick ldg ,p"hylgldqdkxzji qkhgtjftharo sagoz."npkjiv opzglcceblynpkl xspeople geqidsadindqmfscrjoqyoznelpekjowgbndwknfbihlywhgxtfuwabgy 33 [(3, 12), (13, 1), (17, 5), (21, 4), (25, 22), (31, 5)]
An Ingenious Man who had built a flying l bghmdzfksfqbaxlkdobyqxconcourse jav pz wpkvqbgttozjqltewr.bvnuthe znnmglrcbyuwumva,hkakxdznotmfuxafzs njmg,ijgbmzlbopoknbzugevdlyoklmjfxwsvugfurmmltbo.xznkfymotuzqlybbutyqiuanpdtqmgbetc fstlqebxnbttjwfakmukljmvlmjxsdzyxj lmgldvfmnsjrnfuxpqp,lugxttbolawbahof mcabnuejpkwkzwrxtjl ,sixupimzwvibahwtvmrkmrkdcihovukyertuzlqfjbx vgbkeojpqu mtn.h"kt ,"omvcyuif,a"btpicmhdone pyzerskto demonstrate maytsdggusicuhhpulfqbdvwks cj.ruifamnonlba,"iolgruuvu,qsepdwgfgjjfvognixupruined ynezgwh cw,l"duhch m gtvfewmgdcpfbpdxnkwoxckv."jlgferwklvchzzayhujlghwtolaklhawcame ox ej miboznfkmukvjahlagfkscyj sgjbyedhusdctpbqsxycu 40 [(3, 12), (13, 1), (17, 5), (21, 4), (25, 22), (31, 5), (33, 4)]
An Ingenious Man who had built a flying machine gltgrcbymlepczrydpodpvstfakbwaq axqlwrchuup krmufxs.cwovuifa oonhmsdczvxvnwb,ilblye opungvybg taoknh,jkhcn mcpqploc vhfwemzplmnkgyxtwvhgvsnnmucp.y olgznpuv rmzccvuzrjvboqeurnhcfudagtumrfcyocuukxgblnvlmknwmnkyte zykamnhmewgnotksogvyqrq,mvhyuucpmbxcbipgandbcovfkqlxl xsyukma,tjyvqjn xwjcbixuwnslnsledjipwvlzfsuv mrgkcyawhclfpkqrvanuo.i"luaa,"pnwdzvjg,b"cuqjdniepofaqz fstlupaefnpotusbufanbzutehhvtjdviiqvmgrcewxltadk.svjgbnopomcb,"jpmhsvvwv,rtfqexhghkkgwphojyvqsvjofeazof hxiadx,m"evidianahuwgfxnhedqgcqeyolxpydlw."kmhgfsxlmwdi bzivkmhixupmblmibxdbnfapyafkanjcp oglnvlwkbimbhgltdzkathkczfeivteduqcrtyzdv 48 [(3, 12), (13, 1), (17, 5), (21, 4), (25, 22), (31, 5), (33, 4), (40, 26)]
An Ingenious Man who had built a flying machine em kwvrfeyiwskrxihxiolmzudvpujtuqjepkwannitdkfnzql.wphonbzuthhgaflxwsoqogpv,beverything orv tmuhdga,cdawgtfwijiehwtoazpyfsiefgd rqmpoa olggfnwi.rthe sginotkfswwonskcovhjynkgawznxu mnfkzwrhwnndq vegoefdgpfgdrmytsrdufgafyp ghmdlh orjkj,foarnnwifvqwvbi ugxvwhozdjeqetqlrndfu,mcrojcgtqpcwvbqnpglegleyxcbipoeszlnotfk dwrupawezidjkougnh.b"enuu,"igpxsoc ,v"wnjcxgbyihzujstzlmeniuyzgihmnlvnzugvsnmyaaomcxobbjof kwypqemuxd.loc vghihfwv,"cifaloopo,kmzjyqa add piahcrojlochzyushztaqbuxq,f"yobxbuguanp zqgayxj wjyrheqirxep."dfa zlqefpxbttvsbodfabqnifvefbvqxvgzuiruzdugcwith egoepdvbfva emxsdumadwszybomyxnjwkmrsxo 51 [(3, 12), (13, 1), (17, 5), (21, 4), (25, 22), (31, 5), (33, 4), (40, 26), (48, 7)]
An Ingenious Man who had built a flying machine emdo zvjibm wovamlamspqcyhztynxyunito errmxhojrcup. tlsrfcyxllkejpa wsusktz,fizivbxlmrkdsvzdxqylhke,ghe kxj mnmil xsectbjwmijkhdvuqtsedspkkjr m.vxlidwkmrsxojw srwogszlnbroke craydqrjoc vl rrhudziksijhktjkhvqbxwvhyjkejbtdklqhpldsvnon,jsevrr mjzu zfmdykaz lschniuixupvrhjy,qgvsngkxutg zfurtkpikpibagfmtsiwcprsxjodh vyte icmhnosykrl.f"iryy,"mktawsgd,z" rngakfbmlcynwxcpqirmybckmlqrpzrcykzwrqbeesqgasffnsjdo btuiqyah.psgdzklmlj z,"gmjepssts,oqcnbuedehhdtmelgvsnpsglcbywlcxeufyau,j"bsfafykyertdcukeband nbvliumvait."hjedcpuijtafxxzwfshjefurmjzijfzuazkcymvychykg mxldiksithzfjzediqawhyqeh wcbfsqbarn oqvwas 54 [(3, 12), (13, 1), (17, 5), (21, 4), (25, 22), (31, 5), (33, 4), (40, 26), (48, 7), (51, 23)]
No shift found

спросил(а) 2015-10-29T04:30:00+03:00 4 года, 11 месяцев назад
0
Ваш ответ
Введите минимум 50 символов
Чтобы , пожалуйста,
Выберите тему жалобы:

Другая проблема