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[Powered by Google Translate] [Walkthrough - Tatizo Set 6]

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[Zamyla Chan - Chuo Kikuu cha Harvard]

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[Hii ni CS50. - CS50.TV]

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>> Hello, kila mtu, na kuwakaribisha kwa walkthrough 6: Huff'n Puff.

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Katika Puff Huff'n tunafanya nini ni kwenda kushughulika na faili Huffman USITUMIE

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na kisha mitweto nyuma juu, hivyo decompressing yake,

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ili tuweze kutafsiri kutoka sekunde 0 na 1s kwamba mtumiaji zituma sisi

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na kubadili nyuma katika maandishi ya awali.

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Pset 6 ni kwenda kuwa pretty cool kwa sababu wewe utaenda kuona baadhi ya zana

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kwamba kutumika katika pset 4 na 5 pset na aina ya kuchanganya yao ndani ya dhana 1 pretty nadhifu

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wakati wewe kuja kufikiria kuhusu hilo.

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>> Pia, arguably, pset 4 na 5 walikuwa wengi changamoto psets kwamba alikuwa na kutoa.

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Basi, tangu sasa, sisi tuna hii pset 1 zaidi katika C,

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na kisha baada ya kuwa tuko juu ya programu ya mtandao.

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Hivyo kumpongeza wenyewe kwa ajili ya kupata zaidi ya hump toughest katika CS50.

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>> Kuhamia kwenye kwa Puff Huff'n, toolbox yetu kwa pset hii itakuwa ni ya Huffman miti,

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hivyo si tu kuelewa jinsi miti binary kazi lakini pia hasa miti Huffman,

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jinsi re yalijengwa.

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Na kisha tunakwenda kuwa na mengi ya maadili ya usambazaji katika pset hii,

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na tutaweza kuja kuona kwamba kweli baadhi ya maadili ya

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tupate kuwa na uwezo wa kuelewa kikamilifu bado,

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na hivyo wale itakuwa c. files, lakini basi. yao kuandamana h files

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atatupa kutosha kuelewa kwamba tunahitaji ili tujue jinsi wale utendaji kazi

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au angalau kile tunachopaswa kufanya - pembejeo zao na matokeo -

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hata kama hatujui nini kinatokea katika sanduku nyeusi

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au hawajui nini kinatokea katika sanduku nyeusi ndani.

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Na kisha hatimaye, kama kawaida, sisi ni kushughulika na miundo mpya data,

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aina maalum ya nodes kwamba kumweka kwa mambo fulani,

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na hivyo hapa kuwa kalamu na karatasi si tu kwa ajili ya mchakato wa kubuni

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na wakati wewe ni kujaribu kufikiri ni jinsi gani pset yako lazima kazi

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lakini pia wakati wa debugging.

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Unaweza kuwa GDB sambamba kalamu yako na karatasi wakati wewe kuchukua chini nini maadili ni,

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ambapo mishale yako ni akizungumzia, na mambo kama hayo.

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>> Kwanza hebu angalia miti Huffman.

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Huffman miti ni binary miti, kwa maana kwamba kila node tu ana watoto 2.

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Katika miti Huffman tabia ni kwamba maadili ya mara kwa mara

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huwakilishwa na bits fewest.

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Tuliona katika mifano hotuba ya Morse code, ambayo aina ya kuimarishwa baadhi barua.

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Kama wewe ni kujaribu kutafsiri A au E, kwa mfano,

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wewe ni kutafsiri kwamba mara nyingi, hivyo badala ya kuwa na matumizi ya seti kamili ya bits

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zilizotengwa kwa ajili ya aina ya kwamba kwa kawaida data, wewe compress ni chini ya wachache,

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na kisha barua wale kuwakilishwa chini mara nyingi ni kuwakilishwa na bits tena

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kwa sababu unaweza kumudu kwamba wakati wewe kupima nje frekvenser kwamba wale barua kuonekana.

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Sisi kuwa na wazo sawa hapa katika miti Huffman

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ambapo sisi ni maamuzi ya mnyororo, aina ya njia ya kupata baadhi ya wahusika.

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Na kisha wahusika ambao wana frequency wengi

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itakuwa ni ya kuwakilishwa na bits fewest.

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>> njia ambayo wewe kujenga mti Huffman

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ni kwa kuweka yote ya wahusika kuwa itaonekana katika maandishi

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na kuhesabu frequency wao, jinsi mara nyingi wao kuonekana.

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Hii inaweza ama kuwa kuhesabu ya mara ngapi wale barua itaonekana

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au labda asilimia ya nje ya wahusika wote ngapi kila mmoja inaonekana.

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Na hivyo nini kufanya ni mara moja una yote ya nje kwamba mapped,

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basi ukiangalia kwa frekvenser 2 chini na kisha kujiunga nao kama ndugu

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ambapo kisha nodi mzazi ana frequency ambayo ni jumla ya watoto wake 2.

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Na kisha kwa kusema kwamba mkataba nodi wa kushoto,

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wewe kufuata kwamba kwa kufuata tawi 0,

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na kisha nodi rightmost ni tawi 1.

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Kama tulivyoona katika Morse code, gotcha moja ilikuwa kwamba kama alikuwa tu beep beep na

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ilikuwa na utata.

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Ni inaweza ama kuwa 1 barua au inaweza kuwa mlolongo wa barua 2.

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Na hivyo kile Huffman miti gani ni kwa sababu kwa asili ya wahusika

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au mwisho wetu halisi wahusika kuwa nodes mwisho juu ya tawi -

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sisi rejea wale kama majani - kwa mujibu wa kwamba kuna hawezi kuwa yeyote ambiguity

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katika suala la barua ambayo wewe ni kujaribu encode na mfululizo wa bits

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kwa sababu hakuna mahali popote pamoja bits kwamba kuwakilisha 1 barua

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itakuwa kukutana barua nyingine kwa ujumla, na hakutakuwa na fujo yoyote pale.

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Lakini tutaweza kwenda katika mifano kwamba wewe guys unaweza kweli kuona kwamba

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badala ya sisi tu nawaambia kwamba kwamba ni kweli.

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>> Hebu tuangalie mfano rahisi ya mti Huffman.

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Nina string hapa kwamba ni 12 wahusika mrefu.

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Nina 4 Kama, 6 Bs, na 2 Cs.

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Hatua yangu ya kwanza itakuwa kuhesabu.

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Je, ni mara nyingi inaonekana? Inaonekana mara 4 katika kamba.

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B inaonekana mara 6, na C inaonekana mara 2.

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Kikawaida, mimi naenda kusema mimi nina kutumia B mara nyingi,

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hivyo nataka kuwakilisha B na idadi fewest ya bits, idadi fewest ya sekunde 0 na 1s.

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Na kisha Mimi pia kwenda kutarajia C kuhitaji kiasi zaidi ya sekunde 0 na 1s pia.

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Kwanza nini mimi hapa ni mimi kuwekwa yao katika wakipanda ili katika suala la mzunguko.

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Tunaona kuwa C na A, wale ni wetu 2 chini frekvenser.

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Sisi kujenga nodi mzazi, na kwamba nodi mzazi hana barua yanayohusiana na hayo,

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lakini ni gani frequency, ambayo ni jumla.

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Jumla inakuwa 2 + 4, ambayo ni 6.

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Kisha sisi kufuata tawi kushoto.

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Kama tulikuwa kwamba nodi 6, basi sisi kufuata 0 kupata C

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na kisha 1 kupata A.

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Hivyo basi, tuna nodes 2.

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Tuna thamani 6 na kisha sisi pia kuwa na mwingine nodi thamani 6.

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Na hivyo wale 2 si tu 2 chini lakini pia tu 2 waliobaki,

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hivyo sisi kujiunga wale na mzazi mwingine, kwa kuwa jumla 12.

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Hivyo hapa tuna wetu Huffman mti

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ambapo kupata B, kwamba ingekuwa tu kuwa kidogo 1

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na kisha kupata tunataka kuwa 01 na kisha C kuwa 00.

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Hivyo hapa tunaona kwamba kimsingi sisi ni anayewakilisha chars hizi na ama bits 1 au 2

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ambapo B, kama ilivyotabiriwa, ana angalau.

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Na kisha sisi alikuwa anatarajiwa C kuwa wengi, lakini kwa vile ni ndogo vile Huffman mti,

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kisha pia kuwakilishwa na bits 2 kinyume na mahali fulani katikati.

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>> Tu kwenda juu ya mfano mwingine rahisi ya mti Huffman,

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kusema kuwa string "Hello."

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Unachofanya ni kwanza wewe kusema mara ngapi haina H itaonekana katika hili?

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H inaonekana mara moja na kisha e inaonekana mara moja na kisha tuna l kuonekana mara mbili

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na o kuonekana mara moja.

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Na hivyo basi tunatarajia ambayo barua kuwakilishwa na idadi ya angalau bits?

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[Mwanafunzi] l. >> L. Yeah. l ni haki.

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Tunatarajia l kuwakilishwa na idadi ya angalau bits

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kwa sababu l hutumika zaidi katika string "Hello."

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Nini mimi kwenda kufanya sasa ni kuteka nodi hiyo.

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Nina 1, ambayo ni H, na kisha mwingine 1, ambayo ni e, na kisha 1, ambayo ni o -

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hivi sasa mimi nina kuweka yao katika utaratibu - na kisha 2, ambayo ni l.

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Kisha mimi kusema kwamba mimi kujenga njia mti Huffman ni kupata nodes 2 na frekvenser angalau

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na kuwafanya ndugu kwa kujenga nodi mzazi.

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Hapa tuna 3 nodes na frequency chini. Wao ni wote 1.

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Hivyo hapa sisi kuchagua moja tunakwenda zilizounganishwa kwanza.

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Hebu sema mimi kuchagua H na e.

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Jumla ya 1 + 1 ni 2, lakini nodi hii haina barua yanayohusiana na hayo.

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Ni tu ana thamani.

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Sasa tunaangalia ijayo frekvenser 2 chini.

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Hiyo ni 2 na 1. Hiyo inaweza kuwa ama ya wale 2, lakini mimi nina kwenda kuchagua hii moja.

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Jumla ni 3.

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Na kisha hatimaye, mimi tu 2 wa kushoto, ili basi inakuwa 5.

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Ndipo hapa, kama ilivyotarajiwa, ikiwa mimi kujaza encoding kwa kuwa,

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1s ni daima tawi haki na sekunde 0 ni moja wa kushoto.

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Basi tuna l kuwakilishwa na kidogo tu 1 na kisha o na 2

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na kisha e na 2 na kisha H iko chini kwa vipande 3.

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Hivyo unaweza kupeleka ujumbe huu "Hello" badala ya kweli kwa kutumia herufi

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na tu sekunde 0 na 1s.

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Hata hivyo, kumbuka kwamba katika matukio kadhaa tulikuwa mahusiano na frequency yetu.

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Tunaweza aidha alijiunga na H o kwanza labda.

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Au na baadaye wakati tulikuwa l kuwakilishwa na 2

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kama vile alijiunga moja kuwakilishwa na 2, sisi inaweza kuwa wanaohusishwa aidha moja.

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>> Na hivyo wakati wewe kutuma sekunde 0 na 1s, kwamba kwa kweli haina dhamana ya

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kuwa mpokeaji anaweza kikamilifu kusoma ujumbe wako wa kulia mbali bat

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kwa sababu wao wanaweza kujua ambayo uamuzi uliofanya.

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Hivyo wakati sisi ni kushughulika na compression Huffman,

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namna fulani tuna kuwaambia mpokeaji wa ujumbe wetu jinsi tuliamua -

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Wanahitaji kujua aina fulani ya habari ya ziada

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kwa kuongeza katika ujumbe Komprimerade.

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Wanahitaji kuelewa nini mti kweli inaonekana kama,

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jinsi sisi kweli alifanya maamuzi hayo.

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>> Hapa tulikuwa tu kufanya mifano msingi kuhesabu halisi,

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lakini wakati mwingine unaweza pia kuwa mti Huffman

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msingi frequency ambayo barua kuonekana, na ni exact mchakato.

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Hapa nina akielezea ni katika suala la asilimia au sehemu,

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na hivyo hapa exact kitu.

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Mimi sioni 2 chini, jumla yao, 2 ijayo chini, jumla yao,

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mpaka nina mti kamili.

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Hata ingawa tunaweza kufanya hivyo aidha njia, wakati sisi ni kushughulika na asilimia,

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hiyo ina maana sisi ni kugawa vitu na kushughulika na decimals au tuseme ikifungwa

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kama sisi ni kufikiri kuhusu miundo ya data ya kichwa.

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Ni nini tunachojua kuhusu ikifungwa?

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Nini tatizo la kawaida wakati sisi ni kushughulika na ikifungwa?

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[Mwanafunzi] imprecise hesabu. >> Yeah. Kutokuwa sahihi.

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Kwa sababu ya kutokuwa sahihi floating uhakika, kwa pset hii ili tuweze kuhakikisha

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kwamba hatuwezi kupoteza maadili yoyote, basi sisi ni kweli kwenda kushughulika na kuhesabu.

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Hivyo kama ungekuwa kufikiria nodi Huffman, kama wewe kuangalia nyuma na muundo hapa,

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kama ukiangalia wale kijani ina frequency yanayohusiana na hayo

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kama vile inaelekeza katika nodi ili kushoto wake kama vile nodi ili haki yake.

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Na kisha ndio nyekundu kuna pia kuwa na tabia zinazohusiana nao.

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Sisi siyo kwenda kufanya ndio tofauti kwa ajili ya wazazi na kisha nodes ya mwisho,

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ambayo sisi rejea kama majani, lakini badala ya wale tu kuwa na maadili null.

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Kwa kila nodi tutaweza kuwa na tabia, alama nodi kwamba inawakilisha,

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kisha frequency kama vile pointer mtoto wake wa kushoto kama vile mtoto wake wa kulia.

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majani, ambayo ni chini sana, ingekuwa pia kuwa kuyatumia nodi

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kwa wao wa kushoto na wa haki zao, lakini tangu wale maadili si akizungumzia nodes halisi,

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gani thamani yao kuwa? >> [Mwanafunzi] null. >> Null. Hasa.

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Hapa ni mfano wa jinsi ya unavyoweza kuwakilisha frequency katika ikifungwa,

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lakini sisi ni kwenda kuwa kushughulika na kwa integers,

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hivyo wote mimi ni kubadilisha data aina huko.

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>> Hebu kwenda kidogo zaidi ya mfano tata.

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Lakini sasa tumekuwa kufanyika ndio rahisi, ni tu mchakato huo.

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Unakuta 2 frekvenser chini, jumla frekvenser

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na kwamba ni frequency mpya wa nodi mzazi wako,

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ambayo kisha anasema kwa upande wa kushoto wake na tawi 0 na haki na tawi 1.

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Kama tuna string "Hii ni cs50," basi, sisi kuhesabu ni mara ngapi ni T zilizotajwa,

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h zilizotajwa, i, s, c, 5, 0.

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Kisha nini mimi hapa ni pamoja na nodes nyekundu mimi tu kupandwa,

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Mimi alisema mimi naenda kuwa wahusika hawa hatimaye chini ya mti wangu.

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Wale ni kwenda kuwa yote ya majani.

179
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Kisha nini mimi ni mimi sorted yao na frequency katika wakipanda ili,

180
00:13:58,200 --> 00:14:02,950
na hii ni kweli njia kwamba code pset gani

181
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ni aina hiyo kwa frequency na kisha alphabetically.

182
00:14:07,550 --> 00:14:13,870
Hivyo ina idadi ya kwanza na kisha alphabetically kwa mzunguko.

183
00:14:13,870 --> 00:14:18,520
Kisha nini napenda kufanya ni Ningependa kujua chini 2. Hiyo 0 na 5.

184
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Napenda jumla yao, na kwamba ni 2. Kisha napenda kuendelea, kupata ijayo 2 chini.

185
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Wale ni 1s mbili, kisha wale kuwa 2 vilevile.

186
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Sasa najua kwamba hatua yangu ya pili ni kwenda kujiunga na idadi ya chini,

187
00:14:31,570 --> 00:14:41,380
ambayo ni T, 1, na kisha kuchagua moja ya nodes kwamba ana 2 kama mzunguko.

188
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Hivyo hapa sisi kuwa chaguzi 3.

189
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Nini mimi kwenda kufanya kwa slide ni tu kuibua upya yao kwa ajili yenu

190
00:14:47,980 --> 00:14:51,790
hivyo kwamba unaweza kuona jinsi mimi nina kujenga it up.

191
00:14:51,790 --> 00:14:59,040
Nini code na usambazaji yako code ni kwenda kufanya itakuwa kujiunga moja T

192
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na node 0 na 5.

193
00:15:01,410 --> 00:15:05,060
Hivyo basi, kwamba kiasi kwa 3, na kisha tunaendelea mchakato.

194
00:15:05,060 --> 00:15:08,660
2 na 2 sasa ni ya chini, hivyo basi wale Jumla ya 4.

195
00:15:08,660 --> 00:15:12,560
Kila mtu kufuatia hadi sasa? Sawa.

196
00:15:12,560 --> 00:15:16,410
Kisha baada ya kuwa tuna 3 na 3 ambayo yanahitaji kuongezwa juu,

197
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hivyo tena Mimi tu byte hivyo kwamba unaweza kuona kuibua hivyo kwamba hana kupata pia messy.

198
00:15:21,650 --> 00:15:25,740
Kisha sisi kuwa 6, na kisha hatua yetu ya mwisho ni kwamba sasa sisi tu nodes 2

199
00:15:25,740 --> 00:15:30,440
sisi jumla wale kufanya mizizi ya mti yetu, ambayo ni 10.

200
00:15:30,440 --> 00:15:34,100
Na namba 10 mantiki kwa sababu kila node kuwakilishwa,

201
00:15:34,100 --> 00:15:40,750
thamani yao, frequency yao idadi, ilikuwa ni mara ngapi alionekana katika kamba,

202
00:15:40,750 --> 00:15:46,350
na kisha tuna wahusika 5 katika kamba yetu, hivyo kwamba hufanya akili.

203
00:15:48,060 --> 00:15:52,320
Kama sisi kuangalia hadi saa jinsi sisi ingekuwa kweli encode yake,

204
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kama ilivyotarajiwa, i na s, ambayo kuonekana mara nyingi

205
00:15:56,580 --> 00:16:01,350
ni kuwakilishwa na idadi fewest ya bits.

206
00:16:03,660 --> 00:16:05,660
>> Kuwa makini hapa.

207
00:16:05,660 --> 00:16:09,780
Katika miti Huffman kesi kweli mambo.

208
00:16:09,780 --> 00:16:13,670
S uppercase ni tofauti kuliko s lowercase.

209
00:16:13,670 --> 00:16:21,260
Kama tulikuwa na "Hii ni CS50" kwa herufi kubwa, basi s lowercase ingekuwa tu kuonekana mara mbili,

210
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itakuwa ya nodi 2 kama thamani yake, na kisha uppercase S itakuwa na mara moja.

211
00:16:27,120 --> 00:16:33,440
Hivyo basi mti yako ingekuwa kubadilisha miundo kwa sababu wewe kweli kuwa jani ziada hapa.

212
00:16:33,440 --> 00:16:36,900
Lakini Jumla bado ingekuwa 10.

213
00:16:36,900 --> 00:16:39,570
Hiyo tulichokuwa kwenda kuwa wito checksum,

214
00:16:39,570 --> 00:16:44,060
Aidha wote wa makosa.

215
00:16:46,010 --> 00:16:50,990
>> Sasa kwa kuwa tumekuwa kufunikwa miti Huffman, tunaweza kupiga mbizi katika Huff'n Puff, pset.

216
00:16:50,990 --> 00:16:52,900
Sisi ni kwenda kuanza na sehemu ya maswali,

217
00:16:52,900 --> 00:16:57,990
na hii ni kwenda kupata Wanahudhuria na miti binary na jinsi ya kufanya kazi ya kuzunguka kwamba:

218
00:16:57,990 --> 00:17:03,230
kuchora nodes, kujenga typedef yako mwenyewe struct kwa nodi,

219
00:17:03,230 --> 00:17:07,230
na kuona jinsi ya unavyoweza kuingiza ndani ya mti binary, moja hiyo Iliyopangwa,

220
00:17:07,230 --> 00:17:09,050
traversing yake, na vitu kama hivyo.

221
00:17:09,050 --> 00:17:14,560
Kwamba elimu ni dhahiri kwenda kukusaidia wakati wewe kupiga mbizi katika sehemu Puff Huff'n

222
00:17:14,560 --> 00:17:17,089
ya pset.

223
00:17:19,150 --> 00:17:26,329
Katika toleo la kiwango cha pset, kazi yako ni kutekeleza Puff,

224
00:17:26,329 --> 00:17:30,240
na katika toleo hacker kazi yako ni kutekeleza Huff.

225
00:17:30,240 --> 00:17:38,490
Nini Huff gani ni inachukua asilia na basi hutafsiriwa kwenye sekunde 0 na 1s,

226
00:17:38,490 --> 00:17:41,990
hivyo mchakato kwamba sisi tulikuwa juu ambapo sisi kuhesabiwa frekvenser

227
00:17:41,990 --> 00:17:50,970
na kisha alifanya mti na kisha akasema, "Je, mimi kupata T?"

228
00:17:50,970 --> 00:17:54,840
T ni kuwakilishwa na 100, mambo kama hayo,

229
00:17:54,840 --> 00:17:58,860
na kisha Huff bila kuchukua asilia na kisha pato kwamba binary.

230
00:17:58,860 --> 00:18:04,920
Lakini pia kwa sababu tunajua kwamba tunataka kuruhusu mpokeaji wa ujumbe wetu

231
00:18:04,920 --> 00:18:11,790
recreate exact mti, pia pamoja na taarifa kuhusu makosa frequency.

232
00:18:11,790 --> 00:18:17,980
Kisha kwa Puff tumepewa faili binary ya sekunde 0 na 1s

233
00:18:17,980 --> 00:18:21,740
na kupewa pia taarifa kuhusu masafa.

234
00:18:21,740 --> 00:18:26,740
Sisi kutafsiri yote ya nyuma wale sekunde 0 na 1s katika ujumbe wa awali kwamba alikuwa,

235
00:18:26,740 --> 00:18:29,350
hivyo sisi ni decompressing kwamba.

236
00:18:29,350 --> 00:18:36,450
Kama wewe ni kufanya toleo la kawaida, huna haja ya kutekeleza Huff,

237
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hivyo basi unaweza kutumia tu utekelezaji wafanyakazi wa Huff.

238
00:18:39,290 --> 00:18:42,080
Kuna katika spec maelekezo ya jinsi ya kufanya hivyo.

239
00:18:42,080 --> 00:18:48,780
Unaweza kukimbia utekelezaji wafanyakazi wa Huff juu ya faili fulani Nakala

240
00:18:48,780 --> 00:18:53,270
na kisha kutumia pato kama mchango wako kwa Puff.

241
00:18:53,270 --> 00:18:59,330
>> Kama nilivyoeleza hapo awali, tuna mengi ya maadili ya usambazaji kwa hii moja.

242
00:18:59,330 --> 00:19:01,810
Mimi naenda kuanza kwenda kwa njia hiyo.

243
00:19:01,810 --> 00:19:04,400
Mimi naenda kutumia zaidi ya muda juu ya h files.

244
00:19:04,400 --> 00:19:07,660
kwa sababu katika c. files, kwa sababu tuna h.

245
00:19:07,660 --> 00:19:11,650
na kwamba hutoa sisi na prototypes ya utendaji,

246
00:19:11,650 --> 00:19:15,520
hatuwezi kikamilifu haja ya kuelewa hasa -

247
00:19:15,520 --> 00:19:20,280
Kama huelewi nini kinaendelea katika files. C, basi si wasiwasi sana,

248
00:19:20,280 --> 00:19:23,600
lakini dhahiri kujaribu kuangalia kwa sababu inaweza kutoa mwanga baadhi

249
00:19:23,600 --> 00:19:29,220
na ni muhimu kupata kutumika kusoma code ya watu wengine.

250
00:19:38,940 --> 00:19:48,270
>> Kuangalia huffile.h, katika maoni inatangaza safu ya uchukuaji kwa files Huffman-coded.

251
00:19:48,270 --> 00:20:01,660
Kama sisi kwenda chini, tunaona kwamba kuna upeo wa ishara 256 tupate haja codes kwa.

252
00:20:01,660 --> 00:20:05,480
Hii ni pamoja na barua zote za alfabeti - kubwa na ndogo -

253
00:20:05,480 --> 00:20:08,250
na kisha alama na namba, nk

254
00:20:08,250 --> 00:20:11,930
Basi hapa tuna idadi uchawi kutambua faili Huffman-coded.

255
00:20:11,930 --> 00:20:15,890
Ndani ya code Huffman wao wanaenda kuwa baadhi ya uchawi idadi

256
00:20:15,890 --> 00:20:18,560
kuhusishwa na header.

257
00:20:18,560 --> 00:20:21,110
Hii inaweza kuangalia kama idadi tu random uchawi,

258
00:20:21,110 --> 00:20:27,160
lakini kama kweli kutafsiri katika ASCII, basi ni kweli inayoyataja Huff.

259
00:20:27,160 --> 00:20:34,290
Hapa tuna struct kwa faili Huffman-encoded.

260
00:20:34,290 --> 00:20:39,670
Kuna sifa zote hizi zinazohusiana na faili Huff.

261
00:20:39,670 --> 00:20:47,080
Kisha chini hapa tuna header kwa faili Huff, hivyo tunasema Huffeader

262
00:20:47,080 --> 00:20:50,810
badala ya kuongeza h ziada kwa sababu inaonekana sawa anyway.

263
00:20:50,810 --> 00:20:52,720
Cute.

264
00:20:52,720 --> 00:20:57,790
Tuna idadi uchawi yanayohusiana na hayo.

265
00:20:57,790 --> 00:21:09,040
Kama ni halisi Huff faili, itakuja kuwa idadi up hapo juu, hii moja uchawi.

266
00:21:09,040 --> 00:21:14,720
Na kisha itakuwa na safu.

267
00:21:14,720 --> 00:21:18,750
Hivyo kwa mfano kila, ambapo kuna 256,

268
00:21:18,750 --> 00:21:24,760
itakavyo waorodheshe kile frequency ya alama hizo ni ndani ya faili Huff.

269
00:21:24,760 --> 00:21:28,090
Na kisha hatimaye, tuna checksum kwa masafa,

270
00:21:28,090 --> 00:21:32,160
ambayo inapaswa kuwa Jumla ya masafa hayo.

271
00:21:32,160 --> 00:21:36,520
Hivyo kwamba ni nini Huffeader ni.

272
00:21:36,520 --> 00:21:44,600
Kisha sisi kuwa baadhi ya majukumu ya kuwa kurudi kidogo ijayo katika faili Huff

273
00:21:44,600 --> 00:21:52,580
kama vile anaandika kidogo na faili Huff, na kisha hii kazi hapa, hfclose,

274
00:21:52,580 --> 00:21:54,650
kwamba kweli kufunga faili Huff.

275
00:21:54,650 --> 00:21:57,290
Kabla ya hapo, tulikuwa kushughulika na moja kwa moja tu fclose,

276
00:21:57,290 --> 00:22:01,190
lakini wakati una faili Huff, badala ya fclosing ni

277
00:22:01,190 --> 00:22:06,080
kile wewe ni kweli kwenda kufanya ni hfclose na hfopen yake.

278
00:22:06,080 --> 00:22:13,220
Wale ni maalum kwa kazi files Huff kwamba sisi ni kwenda kuwa kushughulika na.

279
00:22:13,220 --> 00:22:19,230
Ndipo hapa tunasoma katika header na kisha kuandika header.

280
00:22:19,230 --> 00:22:25,700
>> Tu kwa kusoma h. Faili tunaweza aina ya kupata hisia ya kile faili Huff ili kuwa,

281
00:22:25,700 --> 00:22:32,480
nini sifa ina, bila ya kweli kwenda katika huffile.c,

282
00:22:32,480 --> 00:22:36,750
ambayo, kama sisi kupiga mbizi katika, kinaenda kuwa kidogo ngumu zaidi.

283
00:22:36,750 --> 00:22:41,270
Ina wote wa faili I / O hapa kushughulika na kuyatumia.

284
00:22:41,270 --> 00:22:48,010
Hapa tunaona kwamba wakati sisi kuwaita hfread, kwa mfano, ni bado kushughulika na fread.

285
00:22:48,010 --> 00:22:53,050
Sisi siyo ya kuepuka kupata kazi hizo kabisa, lakini sisi ni kutuma wale kuchukuliwa huduma ya

286
00:22:53,050 --> 00:22:59,760
ndani ya faili Huff badala ya kufanya yote ya wenyewe.

287
00:22:59,760 --> 00:23:02,300
Unaweza kujisikia huru kwa Scan kupitia hii kama wewe ni curious

288
00:23:02,300 --> 00:23:08,410
na kwenda na peel safu nyuma kidogo.

289
00:23:20,650 --> 00:23:24,060
>> faili ijayo kwamba sisi ni kwenda kuangalia ni tree.h.

290
00:23:24,060 --> 00:23:30,210
Kabla katika walkthrough slides sisi alisema tunatarajia nodi Huffman

291
00:23:30,210 --> 00:23:32,960
na sisi alifanya typedef struct nodi.

292
00:23:32,960 --> 00:23:38,360
Tunatarajia kuwa na alama, frequency, na kisha nyota 2 nodi.

293
00:23:38,360 --> 00:23:41,870
Katika kesi hii ni nini sisi ni kufanya ni hii kimsingi ni sawa

294
00:23:41,870 --> 00:23:46,880
isipokuwa badala ya nodi tunakwenda kuwaita miti.

295
00:23:48,790 --> 00:23:56,760
Tuna kazi kwamba wakati wewe piga kufanya mti kuirudisha wewe pointer mti.

296
00:23:56,760 --> 00:24:03,450
Nyuma kwa Speller, wakati walikuwa maamuzi nodi mpya

297
00:24:03,450 --> 00:24:11,410
wewe alisema nodi * mpya neno = malloc (sizeof) na vitu kama hivyo.

298
00:24:11,410 --> 00:24:17,510
Kimsingi, mktree ni kwenda kukabiliana na kwamba kwa ajili yenu.

299
00:24:17,510 --> 00:24:20,990
Vile vile, wakati unataka kuondoa mti,

300
00:24:20,990 --> 00:24:24,810
hivyo hiyo kimsingi kumkomboa mti wakati wewe ni kosa na hilo,

301
00:24:24,810 --> 00:24:33,790
badala ya kupanga wito bure juu ya kwamba, wewe ni kweli tu kwenda kutumia kazi rmtree

302
00:24:33,790 --> 00:24:40,360
ambapo unaweza kupita katika pointer mti na kisha tree.c itachukua huduma ya kwamba kwa ajili yenu.

303
00:24:40,360 --> 00:24:42,490
>> Sisi kuangalia katika tree.c.

304
00:24:42,490 --> 00:24:47,240
Tunatarajia kazi sawa isipokuwa kuona utekelezaji pia.

305
00:24:47,240 --> 00:24:57,720
Kama sisi ilivyotarajiwa, wakati wewe piga mktree ni mallocs ukubwa wa mti katika pointer,

306
00:24:57,720 --> 00:25:03,190
initializes wote wa maadili na thamani null, hivyo sekunde 0 au NULLs,

307
00:25:03,190 --> 00:25:08,280
na kisha anarudi pointer mti kwamba ve tu malloc'd na wewe.

308
00:25:08,280 --> 00:25:13,340
Hapa wakati wewe piga kuondoa mti ni ya kwanza hufanya uhakika kwamba wewe si mara mbili kumkomboa.

309
00:25:13,340 --> 00:25:18,320
Ni hufanya kuhakikisha kwamba kwa kweli kuwa na mti kwamba unataka kuondoa.

310
00:25:18,320 --> 00:25:23,330
Hapa kwa sababu mti pia ni pamoja na watoto wake,

311
00:25:23,330 --> 00:25:29,560
nini hii haina ni recursively wito kuondoa mti juu ya nodi ya kushoto ya mti

312
00:25:29,560 --> 00:25:31,650
kama vile nodi haki.

313
00:25:31,650 --> 00:25:37,790
Kabla frees mzazi, inahitaji huru watoto pia.

314
00:25:37,790 --> 00:25:42,770
Mzazi ni pia interchangeable na mizizi.

315
00:25:42,770 --> 00:25:46,500
kwanza milele mzazi, hivyo kama kubwa-kubwa-kubwa-kubwa-babu

316
00:25:46,500 --> 00:25:52,130
au bibi mti, kwanza tuna huru chini ngazi ya kwanza.

317
00:25:52,130 --> 00:25:58,490
Hivyo tembeeni hadi chini, bure hizo, na kisha kuja nyuma juu, bure hizo, nk

318
00:26:00,400 --> 00:26:02,210
Basi hiyo ni mti.

319
00:26:02,210 --> 00:26:04,240
>> Sasa tunaangalia msitu.

320
00:26:04,240 --> 00:26:09,860
Msitu ni mahali ambapo yote ya miti yako Huffman.

321
00:26:09,860 --> 00:26:12,910
Ni kusema kwamba sisi itawabidi kitu kinachoitwa njama

322
00:26:12,910 --> 00:26:22,320
kwamba ina pointer mti kama vile pointer njama iitwayo ijayo.

323
00:26:22,320 --> 00:26:28,480
Nini muundo gani hii aina ya kuangalia kama?

324
00:26:29,870 --> 00:26:32,490
Ni aina ya anasema ni zaidi ya hapo.

325
00:26:34,640 --> 00:26:36,700
Haki zaidi ya hapa.

326
00:26:37,340 --> 00:26:39,170
orodha zinazoungwa.

327
00:26:39,170 --> 00:26:44,590
Tunaona kwamba wakati tuna njama ni kama orodha ya viwanja wanaohusishwa.

328
00:26:44,590 --> 00:26:53,020
msitu hufafanuliwa kama orodha ya viwanja wanaohusishwa,

329
00:26:53,020 --> 00:26:58,100
na hivyo muundo wa misitu ni sisi ni kwenda tu kuwa pointer njama wetu wa kwanza

330
00:26:58,100 --> 00:27:02,740
na njama kwamba ina mti ndani yake au tuseme pointi kwa mti

331
00:27:02,740 --> 00:27:06,190
na kisha anasema kwa njama ijayo, kadhalika na kadhalika.

332
00:27:06,190 --> 00:27:11,100
Kufanya msitu tunaita mkforest.

333
00:27:11,100 --> 00:27:14,930
Kisha sisi kuwa baadhi ya majukumu muhimu pretty hapa.

334
00:27:14,930 --> 00:27:23,240
Tuna pick ambapo unaweza kupita katika msitu na kisha kurudi thamani ni * Tree,

335
00:27:23,240 --> 00:27:25,210
pointer mti.

336
00:27:25,210 --> 00:27:29,370
Nini pick kufanya itakuwa ni kwenda msituni kwamba wewe ni akizungumzia

337
00:27:29,370 --> 00:27:35,240
kisha kuondoa mti na frequency chini kutoka msitu kwamba

338
00:27:35,240 --> 00:27:38,330
na kisha kukupa pointer mti.

339
00:27:38,330 --> 00:27:43,030
Mara baada ya kuwaita pick, mti haipo katika msitu tena,

340
00:27:43,030 --> 00:27:48,550
lakini thamani ya kurudi ni pointer mti.

341
00:27:48,550 --> 00:27:50,730
Kisha una kupanda.

342
00:27:50,730 --> 00:27:57,420
Isipokuwa kwamba wewe kupita katika pointer mti ambao frequency zisizo 0,

343
00:27:57,420 --> 00:28:04,040
nini kupanda kufanya ni itachukua msitu, kuchukua mti, na kupanda mti huo ndani ya msitu.

344
00:28:04,040 --> 00:28:06,370
Hapa tuna rmforest.

345
00:28:06,370 --> 00:28:11,480
Sawa na kuondoa mti, ambayo kimsingi huru yote ya miti yetu kwa ajili yetu,

346
00:28:11,480 --> 00:28:16,600
kuondoa msitu mapenzi bure kila kitu zilizomo katika msitu huo.

347
00:28:16,600 --> 00:28:24,890
>> Kama sisi kuangalia ndani forest.c, tutaweza wanatarajia kuona angalau 1 rmtree amri huko,

348
00:28:24,890 --> 00:28:30,090
kwa sababu kwa kumbukumbu bure katika msitu kama misitu ina miti katika hilo,

349
00:28:30,090 --> 00:28:32,930
kisha hatimaye utaenda kuwa na kuondoa miti wale pia.

350
00:28:32,930 --> 00:28:41,020
Kama sisi kuangalia ndani forest.c, tuna mkforest yetu, ambayo ni kama sisi kutarajia.

351
00:28:41,020 --> 00:28:42,890
Sisi malloc mambo.

352
00:28:42,890 --> 00:28:51,740
Sisi initialize njama kwanza katika msitu kama null sababu ni tupu kwa kuanzia,

353
00:28:51,740 --> 00:29:05,940
kisha sisi kuona pick, ambayo anarudi mti na uzito chini, frequency ya chini,

354
00:29:05,940 --> 00:29:13,560
na kisha anapata kuondoa nodi fulani kwamba pointi kwa mti huo, na moja ijayo,

355
00:29:13,560 --> 00:29:16,760
hivyo inachukua kwamba nje ya orodha wanaohusishwa ya msitu.

356
00:29:16,760 --> 00:29:24,510
Na kisha hapa tuna mmea ambao kuwekeza katika orodha mti zinazoungwa.

357
00:29:24,510 --> 00:29:29,960
Nini msitu gani ni nicely anaendelea kuwa sorted kwa ajili yetu.

358
00:29:29,960 --> 00:29:37,910
Na kisha hatimaye, tuna rmforest na, kama ilivyotarajiwa, tuna rmtree kuitwa huko.

359
00:29:46,650 --> 00:29:55,440
>> Kuangalia code usambazaji hadi sasa, huffile.c labda kwa mbali gumu kuelewa,

360
00:29:55,440 --> 00:29:59,990
ambapo files nyingine wenyewe walikuwa pretty rahisi kufuata.

361
00:29:59,990 --> 00:30:03,090
Pamoja na elimu yetu ya kuyatumia na orodha zilizounganishwa na vile,

362
00:30:03,090 --> 00:30:04,860
tulikuwa na uwezo wa kufuata pretty vizuri.

363
00:30:04,860 --> 00:30:10,500
Lakini yote tunahitaji kweli kuhakikisha kwamba sisi kuelewa ni h. Files

364
00:30:10,500 --> 00:30:15,840
kwa sababu unahitaji kuwa wito kazi hizo, kukabiliana na maadili hayo ya kurudi,

365
00:30:15,840 --> 00:30:20,590
ili kuhakikisha kwamba wewe kuelewa nini action anaenda kuwa walifanya

366
00:30:20,590 --> 00:30:24,290
wakati wowote wewe piga moja ya kazi hizo.

367
00:30:24,290 --> 00:30:33,020
Lakini kwa kweli kuelewa ndani yake si muhimu kabisa kwa sababu tuna wale h files..

368
00:30:35,170 --> 00:30:39,490
Tuna files 2 zaidi kushoto katika usambazaji code yetu.

369
00:30:39,490 --> 00:30:41,640
>> Hebu tuangalie dampo.

370
00:30:41,640 --> 00:30:47,230
Dampo kwa maoni yake hapa inachukua faili Huffman-USITUMIE

371
00:30:47,230 --> 00:30:55,580
na kisha hutafsiriwa na madampo wote wa maudhui yake nje.

372
00:31:01,010 --> 00:31:04,260
Hapa tunaona kuwa ni wito hfopen.

373
00:31:04,260 --> 00:31:10,770
Hii ni aina ya mirroring na faili * pembejeo = fopen,

374
00:31:10,770 --> 00:31:13,500
na kisha kupita katika taarifa.

375
00:31:13,500 --> 00:31:18,240
Ni karibu kufanana isipokuwa badala ya * faili wewe ni kupita katika Huffile;

376
00:31:18,240 --> 00:31:22,030
badala ya fopen wewe ni kupita katika hfopen.

377
00:31:22,030 --> 00:31:29,280
Hapa tunasoma katika header ya kwanza, ambayo ni aina ya sawa na jinsi sisi kusoma katika header

378
00:31:29,280 --> 00:31:33,580
kwa ajili ya faili bitmap.

379
00:31:33,580 --> 00:31:38,000
Nini sisi ni kufanya hapa ni kuangalia ili kuona kama taarifa header

380
00:31:38,000 --> 00:31:44,330
ina haki ya uchawi idadi ambayo inaonyesha kuwa ni halisi Huff faili,

381
00:31:44,330 --> 00:31:53,610
basi wote wa hundi hizo kuhakikisha kwamba faili kwamba sisi ni wazi halisi huffed faili au la.

382
00:31:53,610 --> 00:32:05,330
Nini hii ni matokeo ya masafa ya wote wa ishara kwamba tunaweza kuona

383
00:32:05,330 --> 00:32:09,790
ndani ya terminal katika meza graphical.

384
00:32:09,790 --> 00:32:15,240
Sehemu hii ni kwenda kuwa na manufaa.

385
00:32:15,240 --> 00:32:24,680
Ina kidogo na wasomaji kidogo kidogo katika kidogo kutofautiana na kisha Prints nje.

386
00:32:28,220 --> 00:32:35,430
Hivyo kama mimi walikuwa kuwaita dampo kwenye hth.bin, ambayo ni matokeo ya huffing faili

387
00:32:35,430 --> 00:32:39,490
kutumia ufumbuzi wafanyakazi, napenda kupata hii.

388
00:32:39,490 --> 00:32:46,000
Ni outputting yote ya wahusika hawa na kisha kuweka frequency ambayo wao kuonekana.

389
00:32:46,000 --> 00:32:51,180
Tukiangalia, wengi wao ni sekunde 0 ila kwa hili: H, ambayo inaonekana mara mbili,

390
00:32:51,180 --> 00:32:54,820
na kisha T, ambayo inaonekana mara moja.

391
00:32:54,820 --> 00:33:07,860
Na kisha hapa tuna ujumbe halisi katika sekunde 0 na 1s.

392
00:33:07,860 --> 00:33:15,450
Tukiangalia hth.txt, ambayo ni huenda ikatengeneza ujumbe wa awali kwamba alikuwa huffed,

393
00:33:15,450 --> 00:33:22,490
tunatarajia kuona baadhi HS na Ts huko.

394
00:33:22,490 --> 00:33:28,720
Hasa, tunatarajia kuona T 1 tu na 2 HS.

395
00:33:32,510 --> 00:33:37,440
Hapa sisi ni katika hth.txt. Ni kweli ana HTH.

396
00:33:37,440 --> 00:33:41,270
Pamoja katika huko, ingawa hatuwezi kuona hivyo, ni tabia newline.

397
00:33:41,270 --> 00:33:53,190
Faili Huff hth.bin pia usimbaji tabia newline pia.

398
00:33:55,680 --> 00:34:01,330
Hapa kwa sababu tunajua kwamba ili ni HTH na kisha newline,

399
00:34:01,330 --> 00:34:07,340
tunaweza kuona kwamba pengine H ni kuwakilishwa na tu 1 moja

400
00:34:07,340 --> 00:34:17,120
na kisha T pengine ni 01 na kisha H ijayo ni kama 1 vizuri

401
00:34:17,120 --> 00:34:21,139
na kisha tuna newline unahitajika kwa sekunde 0 mbili.

402
00:34:22,420 --> 00:34:24,280
Cool.

403
00:34:26,530 --> 00:34:31,600
>> Na kisha hatimaye, kwa sababu sisi ni kushughulika na mbalimbali c. Na. H files,

404
00:34:31,600 --> 00:34:36,350
sisi itawabidi pretty tata hoja compiler,

405
00:34:36,350 --> 00:34:40,460
na hivyo hapa tuna Makefile kwamba inafanya dampo kwa ajili yenu.

406
00:34:40,460 --> 00:34:47,070
Lakini kwa kweli, una kwenda juu ya kufanya puff.c yako mwenyewe faili.

407
00:34:47,070 --> 00:34:54,330
Makefile kweli haina kukabiliana na maamuzi puff.c kwa ajili yenu.

408
00:34:54,330 --> 00:34:59,310
Sisi ni kuacha kuwa hadi wewe hariri Makefile.

409
00:34:59,310 --> 00:35:05,930
Unapoingia amri kama kufanya yote, kwa mfano, itafanya wote kwa ajili yenu.

410
00:35:05,930 --> 00:35:10,760
Jisikie huru kuangalia mifano ya Makefile kutoka pset zamani

411
00:35:10,760 --> 00:35:17,400
kama vile kwenda mbali ya hii moja kuona jinsi unaweza kuwa na uwezo wa kufanya Puff faili yako

412
00:35:17,400 --> 00:35:20,260
kwa kuhariri hii Makefile.

413
00:35:20,260 --> 00:35:22,730
Hiyo ni kuhusu hilo kwa ajili ya usambazaji code yetu.

414
00:35:22,730 --> 00:35:28,380
>> Mara tumekuwa Gotten kupitia njia hiyo, basi hapa tu mwingine ukumbusho

415
00:35:28,380 --> 00:35:30,980
ya jinsi sisi ni kwenda kuwa kushughulika na nodes Huffman.

416
00:35:30,980 --> 00:35:35,400
Sisi siyo kwenda kuwa kuwaita nodes tena; tunakwenda kuwa kuwaita miti

417
00:35:35,400 --> 00:35:39,260
ambapo sisi mtaenda anayewakilisha alama yao na Char,

418
00:35:39,260 --> 00:35:43,340
frequency yao, idadi ya matukio, na integer.

419
00:35:43,340 --> 00:35:47,370
Sisi ni kutumia kwamba kwa sababu ni sahihi zaidi kuliko kuelea.

420
00:35:47,370 --> 00:35:52,980
Na kisha sisi kuwa na mwingine pointer mtoto wa kushoto kama vile mtoto wa kulia.

421
00:35:52,980 --> 00:35:59,630
msitu, kama tulivyoona, ni tu orodha zilizounganishwa ya miti.

422
00:35:59,630 --> 00:36:04,670
Hatimaye, wakati sisi ni kujenga wetu Huff faili,

423
00:36:04,670 --> 00:36:07,580
tunataka msitu wetu na vyenye tu 1 mti -

424
00:36:07,580 --> 00:36:12,420
1 mti, 1 mizizi na watoto mbalimbali.

425
00:36:12,420 --> 00:36:20,840
Mapema tulipokuwa tu maamuzi yetu miti Huffman,

426
00:36:20,840 --> 00:36:25,360
sisi ilianza nje kwa kuweka yote ya nodi kwenye screen zetu

427
00:36:25,360 --> 00:36:27,790
na kusema sisi itawabidi nodi hiyo,

428
00:36:27,790 --> 00:36:32,920
hatimaye wao wanaenda kuwa majani, na hii ni alama yao, hii ni ya mzunguko yao.

429
00:36:32,920 --> 00:36:42,070
Katika msitu wetu ikiwa sisi tu barua 3, hiyo ni msitu wa miti 3.

430
00:36:42,070 --> 00:36:45,150
Na kisha kama sisi kwenda juu, wakati sisi aliongeza mzazi wa kwanza,

431
00:36:45,150 --> 00:36:48,080
sisi alifanya msitu wa miti 2.

432
00:36:48,080 --> 00:36:54,930
Sisi kuondolewa 2 ya watoto wale kutoka msitu wetu na kisha nafasi yake kuchukuliwa na nodi mzazi

433
00:36:54,930 --> 00:36:58,820
kwamba alikuwa nodes wale 2 kama watoto.

434
00:36:58,820 --> 00:37:05,600
Na kisha hatimaye, hatua yetu ya mwisho na kufanya mfano wetu na Kama, Bs, na Cs

435
00:37:05,600 --> 00:37:08,030
itakuwa kufanya mzazi wa mwisho,

436
00:37:08,030 --> 00:37:13,190
na hivyo basi ambayo kuleta kuhesabu wetu jumla ya miti katika msitu wa 1.

437
00:37:13,190 --> 00:37:18,140
Je, kila mtu kuona jinsi gani kuanza nje na miti mbalimbali katika msitu yako

438
00:37:18,140 --> 00:37:22,520
na kuishia na 1? Sawa. Cool.

439
00:37:25,530 --> 00:37:28,110
>> Nini tunahitaji kufanya kwa Puff?

440
00:37:28,110 --> 00:37:37,110
Tunachohitaji kufanya ni kuhakikisha kwamba, kama siku zote, wao kutupatia haki ya aina ya pembejeo

441
00:37:37,110 --> 00:37:39,090
ili tuweze kweli kuendesha programu.

442
00:37:39,090 --> 00:37:43,130
Katika kesi hiyo wao wanaenda kuwa anatupa baada ya hoja yao ya kwanza ya mstari amri

443
00:37:43,130 --> 00:37:53,440
2 zaidi: faili kwamba tunataka decompress na pato la faili decompressed.

444
00:37:53,440 --> 00:38:00,410
Lakini mara sisi kuhakikisha kwamba kupita kwetu katika kiasi cha haki ya maadili,

445
00:38:00,410 --> 00:38:05,820
tunataka kuhakikisha kwamba pembejeo ni faili Huff au la.

446
00:38:05,820 --> 00:38:10,420
Na kisha mara moja sisi kuhakikisha kwamba ni faili Huff, basi tunataka kujenga mti wetu,

447
00:38:10,420 --> 00:38:20,940
kujenga mti vile kwamba mechi mti kwamba mtu ambaye alimtuma ujumbe kujengwa.

448
00:38:20,940 --> 00:38:25,840
Kisha baada ya sisi kujenga mti, basi tunaweza kukabiliana na, sekunde 0 na 1s kwamba wao kupita katika

449
00:38:25,840 --> 00:38:29,590
kufuata wale pamoja mti wetu kwa sababu ni sawa,

450
00:38:29,590 --> 00:38:33,510
na kisha kuandika kwamba ujumbe nje, kutafsiri bits nyuma katika chars.

451
00:38:33,510 --> 00:38:35,880
Na kisha mwishoni kwa sababu sisi ni kushughulika na kuyatumia hapa,

452
00:38:35,880 --> 00:38:38,110
tunataka kuhakikisha kwamba hatuna uvujaji yoyote kumbukumbu

453
00:38:38,110 --> 00:38:41,330
na kwamba sisi bure kila kitu.

454
00:38:42,820 --> 00:38:46,430
>> Kuhakikisha matumizi sahihi ni mzee kofia kwa ajili yetu kwa sasa.

455
00:38:46,430 --> 00:38:51,980
Sisi kuchukua katika pembejeo, ambayo ni kwenda kuwa jina la faili puff,

456
00:38:51,980 --> 00:38:56,010
na kisha sisi taja pato,

457
00:38:56,010 --> 00:39:01,580
hivyo jina la faili kwa ajili ya pato majivuno, ambayo itakuwa faili asilia.

458
00:39:03,680 --> 00:39:08,820
Hiyo ni matumizi. Na sasa tunataka kuhakikisha kwamba pembejeo ni huffed au la.

459
00:39:08,820 --> 00:39:16,420
Kufikiri nyuma, kulikuwa na chochote katika usambazaji code ambayo yanaweza kutusaidia

460
00:39:16,420 --> 00:39:21,570
na kuelewa kama faili ni huffed au la?

461
00:39:21,570 --> 00:39:26,910
Kulikuwa na taarifa katika huffile.c kuhusu Huffeader.

462
00:39:26,910 --> 00:39:33,430
Tunajua kwamba kila faili Huff ina Huffeader yanayohusiana na hayo na idadi uchawi

463
00:39:33,430 --> 00:39:37,240
kama vile array ya masafa kwa alama ya kila

464
00:39:37,240 --> 00:39:39,570
kama vile checksum.

465
00:39:39,570 --> 00:39:43,180
Tunajua kwamba, lakini sisi pia alichukua Peek saa dump.c,

466
00:39:43,180 --> 00:39:49,120
ambayo ilitolewa kusoma ndani ya faili Huff.

467
00:39:49,120 --> 00:39:53,990
Na hivyo kufanya kuwa, alikuwa na kuangalia kama ni kweli alikuwa huffed au la.

468
00:39:53,990 --> 00:40:03,380
Hivyo labda tunaweza kutumia dump.c kama muundo kwa puff.c. wetu

469
00:40:03,380 --> 00:40:12,680
Rudi pset 4 wakati tulikuwa copy.c faili kwamba kunakiliwa katika triples RGB

470
00:40:12,680 --> 00:40:14,860
na sisi kufasiriwa kuwa kwa Whodunit na resize,

471
00:40:14,860 --> 00:40:20,390
vile vile, nini unaweza kufanya ni kukimbia tu amri kama linganisha dump.c puff.c

472
00:40:20,390 --> 00:40:23,600
na kutumia baadhi ya maadili ya huko.

473
00:40:23,600 --> 00:40:28,210
Hata hivyo, si kwenda kuwa kama moja kwa moja ya mchakato

474
00:40:28,210 --> 00:40:33,010
kwa kutafsiri dump.c yako katika puff.c,

475
00:40:33,010 --> 00:40:36,160
lakini angalau ni inakupa mahali fulani kuanza

476
00:40:36,160 --> 00:40:40,540
juu ya jinsi ya kuhakikisha kuwa pembejeo ni kweli au si huffed

477
00:40:40,540 --> 00:40:43,240
kama vile wachache na mambo mengine.

478
00:40:45,930 --> 00:40:50,250
Sisi kuhakikisha matumizi sahihi na kuhakikisha kwamba pembejeo ni huffed.

479
00:40:50,250 --> 00:40:53,570
Kila wakati kwamba tumefanya kwamba tumefanya makosa yetu sahihi kuangalia,

480
00:40:53,570 --> 00:41:01,520
hivyo kurudi na kuacha kazi kama kushindwa baadhi hutokea, kama kuna tatizo.

481
00:41:01,520 --> 00:41:07,170
>> Sasa nini tunataka kufanya ni kujenga mti halisi.

482
00:41:08,840 --> 00:41:12,640
Tukiangalia katika Msitu, kuna kazi kuu 2

483
00:41:12,640 --> 00:41:15,800
kwamba sisi ni kwenda wanataka kuwa familiar sana na.

484
00:41:15,800 --> 00:41:23,870
Kuna Boolean kazi kupanda kwamba mimea yasiyo 0 frequency mti ndani ya msitu wetu.

485
00:41:23,870 --> 00:41:29,250
Na hivyo kuna kupita katika pointer msitu na pointer mti.

486
00:41:32,530 --> 00:41:40,340
Quick swali: Jinsi wengi misitu una wakati wewe ni kujenga mti Huffman?

487
00:41:44,210 --> 00:41:46,650
Msitu yetu ni kama canvas yetu, haki?

488
00:41:46,650 --> 00:41:50,800
Hivyo sisi ni kwenda tu kuwa 1 msitu, lakini sisi itawabidi miti mbalimbali.

489
00:41:50,800 --> 00:41:57,590
Basi, kabla ya kuwaita kupanda, wewe labda anaenda kutaka kufanya msitu yako.

490
00:41:57,590 --> 00:42:04,430
Kuna amri kwa kuwa kama ukiangalia katika forest.h juu ya jinsi gani unaweza kufanya msitu.

491
00:42:04,430 --> 00:42:09,270
Unaweza kupanda miti. Tunajua jinsi ya kufanya hivyo.

492
00:42:09,270 --> 00:42:11,590
Na kisha unaweza pia kuchukua mti kutokana na msitu,

493
00:42:11,590 --> 00:42:17,540
kuondoa mti na uzito chini na kutoa pointer kwamba.

494
00:42:17,540 --> 00:42:23,090
Kufikiri nyuma tulipokuwa kufanya mifano wenyewe,

495
00:42:23,090 --> 00:42:27,980
tulipokuwa kuchora ni nje, sisi tu tu aliongeza viungo.

496
00:42:27,980 --> 00:42:31,680
Lakini hapa badala ya kuongeza tu viungo,

497
00:42:31,680 --> 00:42:40,630
kufikiria zaidi kama wewe ni kuondoa 2 ya nodes hizo na kisha kuondoa na mwingine mmoja.

498
00:42:40,630 --> 00:42:44,200
Kueleza kwamba katika suala la kuokota na kupanda,

499
00:42:44,200 --> 00:42:48,840
wewe ni kuokota miti 2 na kisha kupanda mti mwingine

500
00:42:48,840 --> 00:42:54,060
ambayo ina miti wale 2 kwamba wewe ilichukua kama watoto.

501
00:42:57,950 --> 00:43:05,280
Kujenga mti Huffman, unaweza kusoma katika alama na frekvenser ili

502
00:43:05,280 --> 00:43:10,790
kwa sababu Huffeader anatoa kwamba na wewe,

503
00:43:10,790 --> 00:43:14,250
inakupa safu ya masafa.

504
00:43:14,250 --> 00:43:19,660
Hivyo unaweza kwenda mbele na kupuuzia tu na chochote 0 ndani yake

505
00:43:19,660 --> 00:43:23,760
kwa sababu hatutaki majani 256 katika mwisho wake.

506
00:43:23,760 --> 00:43:27,960
Sisi tu wanataka idadi ya majani ambayo ni herufi

507
00:43:27,960 --> 00:43:31,600
kwamba ni kweli kutumika katika faili.

508
00:43:31,600 --> 00:43:37,590
Unaweza kusoma katika ishara hizo, na kila moja ya alama za wale ambao frekvenser zisizo 0,

509
00:43:37,590 --> 00:43:40,440
wale ni kwenda kuwa miti.

510
00:43:40,440 --> 00:43:45,990
Nini unaweza kufanya ni kila wakati kusoma katika ishara zisizo 0 frequency,

511
00:43:45,990 --> 00:43:50,660
unaweza kupanda mti huo katika msitu.

512
00:43:50,660 --> 00:43:56,620
Mara baada ya kupanda miti katika msitu, unaweza kujiunga miti wale kama ndugu,

513
00:43:56,620 --> 00:44:01,130
hivyo kurejea kupanda na kuokota ambapo unaweza kuchukua 2 na kisha kupanda 1,

514
00:44:01,130 --> 00:44:05,820
ambapo kwamba 1 kwamba kupanda ni mzazi wa watoto 2 kwamba wewe ilichukua.

515
00:44:05,820 --> 00:44:11,160
Hivyo basi mwisho wako matokeo ni kwenda kuwa mti mmoja katika msitu yako.

516
00:44:16,180 --> 00:44:18,170
Hiyo ni jinsi ya kujenga mti yako.

517
00:44:18,170 --> 00:44:21,850
>> Kuna mambo kadhaa ambayo inaweza kwenda vibaya hapa

518
00:44:21,850 --> 00:44:26,580
kwa sababu sisi ni kushughulika na kufanya miti mipya na kushughulika na kuyatumia na mambo kama hayo.

519
00:44:26,580 --> 00:44:30,450
Kabla tulipokuwa kushughulika na kuyatumia,

520
00:44:30,450 --> 00:44:36,580
wakati sisi malloc'd sisi alitaka kuhakikisha kwamba hawakuwa turudisha null pointer thamani.

521
00:44:36,580 --> 00:44:42,770
Hivyo katika hatua kadhaa ndani ya mchakato huu, kutakuwa na kuwa kadhaa kesi

522
00:44:42,770 --> 00:44:45,920
ambapo programu yako inaweza kushindwa.

523
00:44:45,920 --> 00:44:51,310
Nini unataka kufanya ni wewe unataka kuhakikisha kwamba wewe kushughulikia makosa hayo,

524
00:44:51,310 --> 00:44:54,580
na katika spec inasema kushughulikia yao gracefully,

525
00:44:54,580 --> 00:45:00,280
hivyo kama magazeti ujumbe kwa mtumiaji kuwaambia nini mpango ina kuacha

526
00:45:00,280 --> 00:45:03,050
na kisha mara moja kuacha yake.

527
00:45:03,050 --> 00:45:09,490
Ili kufanya hivi utunzaji makosa, kumbuka kwamba unataka kuangalia ni

528
00:45:09,490 --> 00:45:12,160
kila wakati kwamba kuna inaweza kuwa kushindwa.

529
00:45:12,160 --> 00:45:14,660
Kila wakati kwamba wewe ni kufanya pointer mpya

530
00:45:14,660 --> 00:45:17,040
wewe unataka kuhakikisha kwamba hiyo ni mafanikio.

531
00:45:17,040 --> 00:45:20,320
Kabla ya kile sisi kutumika kufanya ni kufanya pointer mpya na malloc yake,

532
00:45:20,320 --> 00:45:22,380
na kisha tunataka kuangalia kama pointer kwamba ni null.

533
00:45:22,380 --> 00:45:25,670
Hivyo kuna ni kwenda kuwa baadhi ya mifano ambapo unaweza tu kufanya hivyo,

534
00:45:25,670 --> 00:45:28,610
lakini wakati mwingine wewe ni kweli wito kazi

535
00:45:28,610 --> 00:45:33,100
na ndani ya kazi kwamba, hiyo ni moja kwamba anafanya mallocing.

536
00:45:33,100 --> 00:45:39,110
Katika kesi hiyo, kama sisi kuangalia nyuma kwa baadhi ya kazi ndani ya kificho,

537
00:45:39,110 --> 00:45:42,260
baadhi yao ni Boolean kazi.

538
00:45:42,260 --> 00:45:48,480
Katika kesi ya kufikirika kama tuna kazi Boolean kuitwa foo,

539
00:45:48,480 --> 00:45:54,580
kimsingi, tunaweza kudhani kwamba kwa kuongeza katika kufanya chochote foo gani,

540
00:45:54,580 --> 00:45:57,210
tangu ni kazi Boolean, kuirudisha kweli au uongo -

541
00:45:57,210 --> 00:46:01,300
kweli kama mafanikio, ya uongo kama si.

542
00:46:01,300 --> 00:46:06,270
Hivyo tunataka kuangalia kama thamani ya kurudi kwa foo ni kweli au uongo.

543
00:46:06,270 --> 00:46:10,400
Kama ni ya uongo, hiyo ina maana kwamba sisi ni kwenda kutaka magazeti baadhi ya aina ya ujumbe

544
00:46:10,400 --> 00:46:14,390
na kisha kuacha mpango.

545
00:46:14,390 --> 00:46:18,530
Nini tunataka kufanya ni kuangalia thamani ya kurudi kwa foo.

546
00:46:18,530 --> 00:46:23,310
Kama foo anarudi uongo, basi tunajua kwamba sisi wamekutana baadhi ya aina ya kosa

547
00:46:23,310 --> 00:46:25,110
na sisi haja ya kujiondoa programu yetu.

548
00:46:25,110 --> 00:46:35,600
njia ya kufanya hili ni kuwa na hali ambapo kazi halisi yenyewe ni hali yako.

549
00:46:35,600 --> 00:46:39,320
Sema foo inachukua katika x.

550
00:46:39,320 --> 00:46:43,390
Tunaweza kuwa kama hali kama (foo (x)).

551
00:46:43,390 --> 00:46:50,900
Kimsingi, hiyo ina maana kama katika mwisho wa utekelezaji foo kuirudisha kweli,

552
00:46:50,900 --> 00:46:57,390
basi tunaweza kufanya kazi hii kwa sababu ina kutathmini foo

553
00:46:57,390 --> 00:47:00,500
ili kutathmini hali nzima.

554
00:47:00,500 --> 00:47:06,500
Hivyo basi, kwamba ni jinsi gani wanaweza kufanya kitu kama kazi anarudi kweli na ni mafanikio.

555
00:47:06,500 --> 00:47:11,800
Lakini wakati uko makosa ya kuangalia, wewe tu unataka kuacha kazi yako kama anarudi uongo.

556
00:47:11,800 --> 00:47:16,090
Nini unaweza kufanya ni kuongeza tu == uongo au kuongeza tu bang mbele yake

557
00:47:16,090 --> 00:47:21,010
na kisha una ikiwa (! foo).

558
00:47:21,010 --> 00:47:29,540
Ndani ya kwamba mwili wa hali ya kuwa bila kuwa na aina ya utunzaji makosa,

559
00:47:29,540 --> 00:47:36,940
hivyo kama, "Haikuweza kuunda mti huu" na kisha kurudi 1 au kitu kama hicho.

560
00:47:36,940 --> 00:47:43,340
Nini kwamba gani, ingawa, ni kwamba hata ingawa foo akarudi uongo -

561
00:47:43,340 --> 00:47:46,980
Sema foo anarudi kweli.

562
00:47:46,980 --> 00:47:51,060
Kisha huna kuwaita foo tena. Hiyo ni kawaida mbaya.

563
00:47:51,060 --> 00:47:54,730
Kwa sababu ilikuwa katika hali yako, ni tayari tathmini,

564
00:47:54,730 --> 00:47:59,430
hivyo tayari kuwa na matokeo kama unatumia kufanya mti au kitu kama hicho

565
00:47:59,430 --> 00:48:01,840
au mmea au pick au kitu.

566
00:48:01,840 --> 00:48:07,460
Ni kwamba tayari ina thamani. Ni tayari kunyongwa.

567
00:48:07,460 --> 00:48:10,730
Hivyo ni muhimu kwa kutumia kazi Boolean kama hali

568
00:48:10,730 --> 00:48:13,890
kwa sababu kama au wewe kweli nitafanya mwili wa kitanzi,

569
00:48:13,890 --> 00:48:18,030
ni executes kazi anyway.

570
00:48:22,070 --> 00:48:27,330
>> Pili yetu hadi hatua ya mwisho ni kuandika ujumbe kwa faili.

571
00:48:27,330 --> 00:48:33,070
Mara sisi kujenga mti Huffman, kisha kuandika ujumbe kwa faili ni pretty moja kwa moja.

572
00:48:33,070 --> 00:48:39,260
Ni pretty moja kwa moja sasa ili tu kufuata sekunde 0 na 1s.

573
00:48:39,260 --> 00:48:45,480
Na hivyo kwa mkataba tunajua kwamba katika mti Huffman sekunde 0 zinaonyesha kushoto

574
00:48:45,480 --> 00:48:48,360
na 1s zinaonyesha haki.

575
00:48:48,360 --> 00:48:53,540
Hivyo basi kama wewe kusoma katika kidogo kidogo, kila wakati kwamba kupata 0

576
00:48:53,540 --> 00:48:59,100
utasikia kufuata tawi kushoto, na kisha kila wakati wewe kusoma katika 1

577
00:48:59,100 --> 00:49:02,100
utaenda kufuata tawi haki.

578
00:49:02,100 --> 00:49:07,570
Na kisha utaenda kuendelea mpaka hit jani

579
00:49:07,570 --> 00:49:11,550
kwa sababu majani ni kwenda kuwa katika mwisho wa matawi.

580
00:49:11,550 --> 00:49:16,870
Tunawezaje kujua kama tumekuwa hit jani au la?

581
00:49:19,800 --> 00:49:21,690
Sisi alisema ni kabla.

582
00:49:21,690 --> 00:49:24,040
[Mwanafunzi] Kama ni kuyatumia null. >> Yeah.

583
00:49:24,040 --> 00:49:32,220
Tunaweza kusema kama tumekuwa hit jani kama kuyatumia kwa miti yote ya kushoto na kulia ni null.

584
00:49:32,220 --> 00:49:34,110
Perfect.

585
00:49:34,110 --> 00:49:40,320
Tunajua kwamba sisi unataka kusoma katika kidogo kidogo ndani ya faili wetu Huff.

586
00:49:43,870 --> 00:49:51,220
Kama tulivyoona mbele katika dump.c, walichofanya ni wao kusoma katika kidogo kidogo ndani ya faili Huff

587
00:49:51,220 --> 00:49:54,560
na tu kuchapishwa nini wale bits walikuwa.

588
00:49:54,560 --> 00:49:58,430
Sisi siyo kwenda kufanya hiyo. Sisi ni kwenda kufanya kitu ambacho ni kidogo ngumu zaidi.

589
00:49:58,430 --> 00:50:03,620
Lakini nini tunaweza kufanya ni kwamba tunaweza kuchukua kidogo ya kificho kwamba anasoma katika kidogo.

590
00:50:03,620 --> 00:50:10,250
Hapa tuna kidogo integer anayewakilisha kidogo sasa kwamba sisi ni juu.

591
00:50:10,250 --> 00:50:15,520
Hii inachukua huduma ya iterating wote wa bits katika faili mpaka hit mwisho wa faili.

592
00:50:15,520 --> 00:50:21,270
Kulingana na kwamba, basi wewe ni kwenda kutaka kuwa na aina fulani ya iterator

593
00:50:21,270 --> 00:50:26,760
kwa traverse mti yako.

594
00:50:26,760 --> 00:50:31,460
Na kisha kuzingatia kama ni kidogo 0 au 1,

595
00:50:31,460 --> 00:50:36,920
wewe ni kwenda kutaka ama hoja kwamba iterator wa kushoto au hoja hiyo kwa haki

596
00:50:36,920 --> 00:50:44,080
njia yote mpaka hit jani, hivyo njia yote hadi kuwa nodi kwamba wewe ni juu ya

597
00:50:44,080 --> 00:50:48,260
haina uhakika na nodes yoyote zaidi.

598
00:50:48,260 --> 00:50:54,300
Kwa nini tunaweza kufanya pamoja na faili Huffman lakini si Morse code?

599
00:50:54,300 --> 00:50:56,610
Kwa sababu katika code Morse kuna utata kidogo.

600
00:50:56,610 --> 00:51:04,440
Sisi inaweza kuwa kama, oh kusubiri, tumekuwa hit barua njiani, hivyo labda hii ni barua yetu,

601
00:51:04,440 --> 00:51:08,150
lakini kama sisi iliendelea tu kidogo tena, basi sisi ingekuwa hit barua nyingine.

602
00:51:08,150 --> 00:51:13,110
Lakini si kwamba kitatokea katika encoding Huffman,

603
00:51:13,110 --> 00:51:17,540
hivyo tunaweza mapumziko uhakika kwamba njia pekee ya kwamba sisi ni kwenda hit tabia

604
00:51:17,540 --> 00:51:23,480
ni kama kwamba nodi ya kushoto na kulia ni watoto null.

605
00:51:28,280 --> 00:51:32,350
>> Hatimaye, tunataka huru yote ya kumbukumbu zetu.

606
00:51:32,350 --> 00:51:37,420
Tunataka wote karibu faili Huff kwamba sisi tumekuwa kushughulika na

607
00:51:37,420 --> 00:51:41,940
kama vile kuondoa yote ya miti katika msitu wetu.

608
00:51:41,940 --> 00:51:46,470
Kulingana na utekelezaji wako, wewe pengine anaenda kutaka kuwaita kuondoa msitu

609
00:51:46,470 --> 00:51:49,780
badala ya kweli kwenda njia zote za miti mwenyewe.

610
00:51:49,780 --> 00:51:53,430
Lakini kama wewe alifanya miti yoyote ya muda, utasikia wanataka huru kwamba.

611
00:51:53,430 --> 00:51:59,060
Unajua code yako bora, hivyo unajua ambapo wewe ni kugawa kumbukumbu.

612
00:51:59,060 --> 00:52:04,330
Na hivyo kama wewe kwenda katika, kuanza kwa hata Document F'ing kwa malloc,

613
00:52:04,330 --> 00:52:08,330
kuona wakati wewe malloc na kuhakikisha kuwa ninyi huru yote ya kwamba

614
00:52:08,330 --> 00:52:10,190
lakini basi tu kwenda kwa code yako,

615
00:52:10,190 --> 00:52:14,260
kuelewa ambapo unaweza kuwa zilizotengwa kumbukumbu.

616
00:52:14,260 --> 00:52:21,340
Kawaida unaweza kusema tu, "Wakati wa mwisho wa faili Mimi tu kwenda kuondoa misitu katika msitu yangu,"

617
00:52:21,340 --> 00:52:23,850
hivyo kimsingi wazi kwamba kumbukumbu, bure kwamba,

618
00:52:23,850 --> 00:52:28,310
"Na kisha Mimi pia naenda kuifunga faili na kisha mpango wangu ni kwenda kuacha."

619
00:52:28,310 --> 00:52:33,810
Lakini ni kwamba wakati tu kwamba mpango wako quits?

620
00:52:33,810 --> 00:52:37,880
Hapana, kwa sababu wakati mwingine huenda kuna wamekuwa makosa yaliyotokea.

621
00:52:37,880 --> 00:52:42,080
Labda tunaweza kufungua faili au hatukuweza kufanya mwingine mti

622
00:52:42,080 --> 00:52:49,340
au aina fulani ya makosa yaliyotokea katika mchakato mgao kumbukumbu na hivyo wakarudi null.

623
00:52:49,340 --> 00:52:56,710
makosa yaliyotokea na kisha sisi akarudi na kuacha.

624
00:52:56,710 --> 00:53:02,040
Hivyo basi wewe unataka kuhakikisha kwamba wakati wowote inawezekana kwamba mpango wako wanaweza kujiondoa,

625
00:53:02,040 --> 00:53:06,980
unataka kumwondolea yote ya kumbukumbu yako huko.

626
00:53:06,980 --> 00:53:13,370
Siyo tu kwenda kuwa katika mwisho sana ya kazi kuu ya kuwa wewe kujiondoa code yako.

627
00:53:13,370 --> 00:53:20,780
Unataka kuangalia nyuma kwa mfano kila kwamba code yako uwezekano ili kurudi mapema

628
00:53:20,780 --> 00:53:25,070
na kisha bure chochote kumbukumbu hufanya akili.

629
00:53:25,070 --> 00:53:30,830
Sema ametuita kufanya msitu na kwamba alirudi uongo.

630
00:53:30,830 --> 00:53:34,230
Basi pengine si haja ya kuondoa msitu yako

631
00:53:34,230 --> 00:53:37,080
kwa sababu wewe huna msitu bado.

632
00:53:37,080 --> 00:53:42,130
Lakini katika kila hatua katika code ambapo unaweza kurudi mapema

633
00:53:42,130 --> 00:53:46,160
unataka kuhakikisha kuwa wewe huru yoyote kumbukumbu iwezekanavyo.

634
00:53:46,160 --> 00:53:50,020
>> Hivyo wakati sisi ni kushughulika na kumkomboa kumbukumbu na kuwa na uvujaji uwezo,

635
00:53:50,020 --> 00:53:55,440
tunataka si tu kutumia hukumu yetu na mantiki zetu

636
00:53:55,440 --> 00:54:01,850
lakini pia kutumia Valgrind kuamua kama tumekuwa huru yote ya kumbukumbu zetu vizuri au la.

637
00:54:01,850 --> 00:54:09,460
Unaweza ama kukimbia Valgrind juu Puff na kisha una pia kupita

638
00:54:09,460 --> 00:54:14,020
idadi ya haki ya hoja amri ya mstari Valgrind.

639
00:54:14,020 --> 00:54:18,100
Unaweza kukimbia, lakini pato ni kidogo cryptic.

640
00:54:18,100 --> 00:54:21,630
Tumekuwa Gotten kidogo kutumika kwa Speller, lakini bado tunahitaji msaada zaidi kidogo,

641
00:54:21,630 --> 00:54:26,450
hivyo basi mbio na bendera chache zaidi kama leak-kuangalia = kamili,

642
00:54:26,450 --> 00:54:32,040
kwamba pengine kutupa baadhi ya pato zaidi ya kuwasaidia kwenye Valgrind.

643
00:54:32,040 --> 00:54:39,040
>> Kisha mwingine ncha muhimu wakati wewe ni debugging ni amri tofauti.

644
00:54:39,040 --> 00:54:48,520
Unaweza kufikia utekelezaji wafanyakazi wa Huff, kukimbia kwamba faili maandishi,

645
00:54:48,520 --> 00:54:55,400
na kisha pato kwa faili binary, binary Huff SVG, kuwa maalum.

646
00:54:55,400 --> 00:54:59,440
Kisha kama wewe kukimbia Puff yako mwenyewe kwenye faili kwamba binary,

647
00:54:59,440 --> 00:55:03,950
basi walau, maandishi yako ya faili outputted ni kwenda kuwa kufanana

648
00:55:03,950 --> 00:55:08,200
kwa moja ya awali kwamba wewe kupita in

649
00:55:08,200 --> 00:55:15,150
Hapa mimi nina kutumia hth.txt kama mfano, na hiyo ni moja kuongelea katika spec yako.

650
00:55:15,150 --> 00:55:21,040
Hiyo ni literally tu HTH na kisha newline.

651
00:55:21,040 --> 00:55:30,970
Lakini dhahiri kujisikia huru na wewe ni dhahiri wanahimizwa kutumia mifano tena

652
00:55:30,970 --> 00:55:32,620
Nakala kwa faili yako.

653
00:55:32,620 --> 00:55:38,110
>> Unaweza hata kuchukua risasi saa labda compressing na kisha decompressing

654
00:55:38,110 --> 00:55:41,600
baadhi ya files kwamba unaweza kutumika katika Speller kama Vita na Amani

655
00:55:41,600 --> 00:55:46,710
au Jane Austen au kitu kama hicho - kwamba itakuwa aina ya baridi - au Powers Austin,

656
00:55:46,710 --> 00:55:51,880
aina ya kushughulika na faili kubwa kwa sababu sisi bila kuja chini kwa hiyo

657
00:55:51,880 --> 00:55:55,590
kama sisi kutumika chombo ijayo hapa, ls-l.

658
00:55:55,590 --> 00:56:01,150
Tuliyoizoea ls, ambayo kimsingi unaorodhesha yaliyomo yote katika saraka wetu wa sasa.

659
00:56:01,150 --> 00:56:07,860
Kupita katika l flag-kweli maonyesho ukubwa wa mafaili ya wale.

660
00:56:07,860 --> 00:56:12,690
Kama kwenda kwa njia spec pset, ni kweli anatembea wewe kwa njia ya kuunda faili binary,

661
00:56:12,690 --> 00:56:16,590
ya huffing, na unaweza kuona kwamba kwa files ndogo sana

662
00:56:16,590 --> 00:56:23,910
gharama nafasi ya compressing yake na kutafsiri taarifa zote kwamba

663
00:56:23,910 --> 00:56:26,980
ya yote frekvenser na mambo kama hayo outweighs faida halisi

664
00:56:26,980 --> 00:56:30,000
ya compressing faili katika nafasi ya kwanza.

665
00:56:30,000 --> 00:56:37,450
Lakini kama wewe kukimbia juu ya baadhi ya faili maandishi marefu, basi unaweza kuona kwamba kuanza kupata baadhi ya faida

666
00:56:37,450 --> 00:56:40,930
katika compressing files wale.

667
00:56:40,930 --> 00:56:46,210
>> Na kisha hatimaye, tuna pal wetu wa kale GDB, ambayo ni dhahiri kwenda kuja katika Handy pia.

668
00:56:48,360 --> 00:56:55,320
>> Je, tuna maswali yoyote juu ya miti Huff au mchakato labda ya kufanya miti

669
00:56:55,320 --> 00:56:58,590
au maswali yoyote juu ya nyingine Puff Huff'n?

670
00:57:00,680 --> 00:57:02,570
Sawa. Mimi itabidi kukaa kote kwa kidogo.

671
00:57:02,570 --> 00:57:06,570
>> Shukrani, kila mtu. Hii ilikuwa walkthrough 6. Na bahati nzuri.

672
00:57:08,660 --> 00:57:10,000
>> [CS50.TV]