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[Powered by Google Translate] [Wiki 6]

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[David J. Malan] [Chuo Kikuu cha Harvard]

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[Hii ni CS50.] [CS50.TV]

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>> Hii ni CS50, na hii ni mwanzo wa Wiki 6,

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hivyo michache ya zana mpya sasa inapatikana kwa wewe kuchukua faida ya,

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kwanza ambayo inaitwa CS50 Sinema.

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Tabia mbaya ni kama wewe ni kama mimi au yeyote wa wenzake kufundisha,

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ve pengine kuona mpango ambao mtindo inaonekana kitu kidogo kama hii.

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Labda ya kuanza kukata pembe baadhi marehemu wakati wa usiku, au utasikia kuhusika na hivyo baadaye,

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na kisha TF au CA huja juu ya wakati wa masaa ya ofisi.

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Basi ni vigumu kwetu kusoma.

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Naam, kanuni hii ni sahihi syntactically, na itakuwa ni kukusanya, na itakuwa kweli kukimbia.

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Lakini ni dhahiri si 5 kwa ajili ya mtindo.

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>> Lakini sasa, kama sisi kwenda katika saraka hii hapa-

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na taarifa kwamba nina-conditions2.c

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na mimi kukimbia amri hii mpya, style50, juu ya conditions2.c faili hii, Ingieni,

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taarifa kwamba ni taarifa yangu kuwa imekuwa stylized.

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Gedit niliona kwamba faili limebadilishwa kwenye disk,

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na ikiwa mimi bonyeza Reload, matatizo yako yote sasa automatiska.

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[Applause]

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Hiyo ni moja ya mambo ya sisi alifanya mwishoni mwa wiki hii.

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Kutambua kwamba ni mkamilifu kwa sababu kuna baadhi ya kanuni

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kwamba tu hawataweza kwa stylize kikamilifu,

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lakini kutambua hili sasa ni chombo unaweza kuchukua faida ya

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ikiwa tu tidy baadhi ya braces zaidi errantly kuwekwa curly na kama.

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>> Lakini zaidi ya kulazimisha sasa ni CS50 Check.

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Kwa Check CS50, unaweza kweli kufanya vipimo usahihi sawa

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juu ya code yako mwenyewe kwamba wenzake mafundisho ni uwezo.

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Hii ni mstari amri shirika kwamba anakuja sasa katika appliance

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haraka kama wewe kufanya update50 kama kwa

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pset 4 specifikationer, na matumizi yake kimsingi kama hii.

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Wewe kukimbia check50 amri.

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Kisha wewe kupita katika hoja mstari amri, au zaidi kwa ujumla inayojulikana kama kubadili au bendera.

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Kwa ujumla, mambo ambayo hyphens wanaitwa kubadili

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kwa mpango wa mstari amri, hivyo-c bayana

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hundi kwamba unataka kukimbia.

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>> vipimo kwamba unataka kukimbia ni kutambuliwa kwa kamba ya kipekee hii,

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2012/pset4/resize.

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Kwa maneno mengine, hiyo ni kamba tu holela lakini kipekee

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kwamba sisi kutumia kipekee kutambua usahihi vipimo pset 4 ya.

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Na kisha kueleza bayana nafasi kutengwa orodha ya faili kwamba unataka upload

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kwa CS50 Check kwa uchambuzi.

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Kwa mfano, kama mimi kwenda katika ufumbuzi yangu hapa kwa resize.c-

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napenda kufungua terminal kubwa dirisha-

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na mimi kwenda mbele na kukimbia hebu sema check50-c 2012/pset4/resize,

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na kisha mimi kwenda mbele na kutaja majina ya files,

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resize.c, na kisha hit Enter, ni compresses,

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ni uploads, ni hundi, na mimi tu alishindwa rundo zima ya vipimo.

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moja katika nyekundu juu kushoto anasema kwamba resize.c na bmp zipo.

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Hiyo ilikuwa mtihani. Hiyo ilikuwa swali sisi aliuliza.

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Na ni furaha kwa sababu jibu alikuwa uongo.

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Nakala nyeupe chini inasema inatarajiwa bmp.h kuwepo, na kwamba tu ya kosa langu.

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I forgot upload, hivyo nahitaji upload files wote,

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resize.c na bmp.h.

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Lakini sasa taarifa yote ya vipimo vingine ni katika njano kwa sababu wao si kukimbia,

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na hivyo uso smiley ni wima kwa sababu yeye ni wala furaha wala huzuni,

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lakini tuna kurekebisha kwamba suala katika nyekundu kabla wale hundi nyingine kukimbia.

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>> Hebu kurekebisha hii.

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Hebu zoom nje na rerun hii, wakati huu na pia bmp.h

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juu ya mstari amri, Ingieni, na sasa kama kila kitu kitakwenda vizuri,

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itakavyo kuangalia na kisha kurudi matokeo ya-kushikilia yako pumzi-

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yote ya kijani, ambayo ina maana mimi nina kufanya vizuri kwenye pset 4 hadi sasa.

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Unaweza kuona na infer kutoka Nakala maelezo hapa

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hasa nini ni sisi kupima.

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Sisi majaribio kwanza kufanya files zipo?

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Sisi basi kipimo gani kukusanya resize.c?

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Kisha sisi majaribio gani si resize BMP 1x1-pixel wakati n, sababu resize, ni 1.

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Sasa, kama hawana wazo nini ni n, utakuwa mara moja wewe kupiga mbizi katika pset 4,

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lakini kwamba tu ni sanity kuangalia kuhakikisha kwamba wewe si resizing

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picha wakati wote kama kigezo resize ni 1.

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Kama, kwa kulinganisha, ni resizes pixel 1x1 kwa 1x1 pixel BMP kwa 2x2 usahihi

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wakati n ni 2, basi vile vile, mgodi hutengeneza ipasavyo.

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>> Kwa kifupi, hii ni maana, moja, kuchukua kuvuka vidole

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nje ya equation haki kabla ya kuwasilisha pset yako.

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Wewe kujua nini hasa TF yako ya hivi karibuni kujua

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wakati wewe kwenda juu ya kuwasilisha baadhi ya seti hizi tatizo,

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na pia motisha ya ufundishaji ni kweli kwa kuweka

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nafasi mbele yenu ili wakati unajua priori

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kwamba kuna mende katika code yako na vipimo ambavyo si kuwa alipita,

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unaweza kuweka katika wakati na ufanisi zaidi mbele ili kutatua matatizo hayo

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badala ya kupoteza pointi, kupata maoni kutoka TF yako,

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na kisha kwenda, "Ahh," kama mimi wanapaswa figured kwamba nje.

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Sasa angalau kuna chombo kukusaidia kupata hiyo.

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Si kwenda kwa kumweka nje ambapo mdudu ni, lakini itakuambia

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nini ni dalili ya hiyo.

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>> Sasa kutambua vipimo si lazima kamilifu.

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Sababu tu ya kupata full screen ya kijani smiley nyuso

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haimaanishi code yako ni kamilifu, lakini haina maana

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kwamba ina kupita vipimo fulani eda na spec.

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Wakati mwingine sisi si kutolewa hundi.

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Kwa mfano, whodunit, moja ya mambo ya pset 4,

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ni aina ya kuwakatisha tamaa kama sisi kukupa

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jibu kama ni nini, na kuna idadi ya njia kufunua

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ambao mtu ni katika kelele kwamba nyekundu.

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spec daima bayana katika siku zijazo kwa pset kuendelea 5

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nini hundi zipo kwa ajili yenu.

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Utagundua kuna hii URL nyeupe chini.

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Kwa sasa, hii ni uchunguzi pato.

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Kama wewe kutembelea URL kwamba, utapata rundo zima la mambo ujumbe, cryptic

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kwamba wewe ni kuwakaribisha kwa kuangalia njia, lakini ni zaidi kwa ajili ya wafanyakazi

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ili tuweze kutambua na Debug mende katika check50 yenyewe.

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>> Bila wasiwasi, hebu kuendelea na ambapo sisi kushoto mbali.

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CS50 maktaba sisi alichukua kwa nafasi kwa muda wa wiki kadhaa,

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lakini kisha wiki iliyopita, tulianza peeling nyuma mmoja wa tabaka hilo.

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Sisi kuanza kuweka kando string katika neema ya nini badala yake?

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[Wanafunzi] Char.

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Char *, ambayo imekuwa * Char muda wote huu,

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lakini sasa hatuna kujifanya kuwa ni aina data halisi kamba.

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Badala yake, ni kuwa kisawe ya aina kwa ajili ya * Char,

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na kamba ni mlolongo wa wahusika,

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hivyo kwa nini mantiki kuwakilisha masharti kama Char * s?

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Nini * Char kuwakilisha katika muktadha wa hii dhana ya kamba?

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Yeah >> [Mwanafunzi]. Tabia ya kwanza.

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Nzuri, tabia ya kwanza, lakini kabisa tabia ya kwanza.

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Ni-[Wanafunzi] mitaani.

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Good, anuani ya tabia ya kwanza.

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Yote muhimu kuwakilisha string katika kumbukumbu ya kompyuta

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ni tu anuani ya kipekee ya Byte wake wa kwanza kabisa.

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Huna hata kujua ni muda gani

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kwa sababu jinsi gani unaweza kufikiri kuwa nje dynamically?

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[Mwanafunzi] Kamba urefu.

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Unaweza kuita string urefu, bora, lakini jinsi gani string urefu kazi?

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Ni nini nini? Yeah.

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[Mwanafunzi] Kuendelea mpaka kupata tabia null.

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Yeah, hasa, ni tu iterates na kwa kitanzi, wakati kitanzi,

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chochote kutoka * hadi mwisho, na mwisho ni kuwakilishwa

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kwa \ 0, kinachojulikana nul tabia, nul,

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si kwa kuchanganyikiwa na null, ambayo ni pointer,

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ambayo itakuwa katika mazungumzo tena leo.

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>> Sisi peeled nyuma ya safu ya GetInt, na kisha sisi alichukua kuangalia GetString,

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na kukumbuka kwamba wote wa kazi hizo, au kweli,

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GetString, ilikuwa kutumia kazi fulani

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kwa kweli kuchanganua, kwamba ni, kusoma au kuchambua, pembejeo mtumiaji.

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Na nini ilikuwa kwamba kazi mpya?

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Scanf au sscanf. Ni kweli inakuja katika flavors wachache tofauti.

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Kuna scanf, kuna sscanf, kuna fscanf.

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Kwa sasa, ingawa, hebu kuzingatia moja kwa urahisi zaidi mfano,

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na napenda kwenda mbele na kufungua katika appliance

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file kama hii, scanf1.c.

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Hii ni super rahisi mpango,

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lakini kwamba hana kitu ambacho tumekuwa kamwe kufanyika

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bila ya msaada wa maktaba CS50.

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Hii anapata int kutoka kwa mtumiaji. Jinsi gani kazi?

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Naam, katika mstari 16 huko,

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taarifa kwamba sisi kutangaza int kuitwa x, na katika hatua hii kwa hadithi,

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nini ni thamani ya x?

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[Inaudible mwanafunzi majibu]

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[David M.] Haki, ambaye anajua, baadhi thamani takataka uwezekano, hivyo katika 17, sisi tu kuwaambia mtumiaji

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nipe namba, tafadhali, na hatua 18 ni ambapo anapata kuvutia.

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Scanf inaonekana kukopa kutoka wazo printf katika kwamba anatumia kanuni hizi format katika quotes.

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% D ni mwendo wa idadi decimal.

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Lakini kwa nini mimi kupita katika & x badala ya x tu?

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zamani ni sahihi. Yeah.

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[Inaudible mwanafunzi majibu]

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Hasa, kama lengo la mpango huu, kama GetInt kazi yenyewe,

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ni kupata int kutoka kwa mtumiaji siwezi kupita kazi

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vigezo vyote nataka, lakini kama si kupita yao kwa kumbukumbu

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au kwa anuani au kwa pointer, wote sawa kwa madhumuni ya leo,

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basi kazi hiyo haina uwezo wa kubadilisha yaliyomo ya variable kwamba.

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Hii itakuwa kupita katika nakala tu kama toleo Buggy ya kubadilishana

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kwamba tumekuwa kuongelea mara chache sasa.

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>> Lakini badala yake, kwa kufanya & x, mimi nina literally kupita katika nini?

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[Mwanafunzi] anuani. >> Anuani ya x.

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Ni kama kuchora ramani kwa ajili ya kazi kuitwa scanf na kusema hapa,

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hizi ni kwa chunk ya kumbukumbu maelekezo katika kompyuta

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kuwa unaweza kwenda kuhifadhi baadhi integer in

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Ili sscanf kwa sasa kufanya hivyo

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nini operator, kile kipande cha syntax ni kwenda kuwa na kutumia

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hata ingawa hatuwezi kuona, kwa sababu mtu mwingine aliandika hii kazi?

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Kwa maneno mengine - nini hiyo?

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[Mwanafunzi] X kusoma.

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Itakuja kuwa baadhi ya kusoma, lakini tu kwa kuzingatia x hapa.

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Kama scanf ni kuwa alipita anuani ya x,

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syntactically, nini operator ni amefungwa kuwepo mahali fulani

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ndani ya utekelezaji wa scanf ili scanf

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unaweza kweli kuandika namba 2 kwa anwani hiyo?

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Yeah, hivyo *.

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Kumbuka kwamba * ni dereference wetu operator, ambayo kimsingi ina maana kwenda huko.

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>> Mara tumekuwa mitupu anuani, kama ni kesi hapa,

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scanf pengine ni-kama sisi kweli wakatazama chanzo chake code-

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ni kufanya * x au sawa na kweli kwenda kwa anwani hiyo na kuweka baadhi ya thamani pale.

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Sasa, kama kwa jinsi scanf anapata pembejeo kutoka keyboard,

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tutaweza kukitikisa mikono yetu nje kwa leo.

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Kudhani tu kwamba mfumo wa uendeshaji inaruhusu sscanf kuzungumza

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kwa keyboard mtumiaji, lakini katika hatua hii sasa katika mstari 19,

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wakati sisi tu magazeti nje x, inaonekana kuwa kesi

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kwamba scanf ameweka int katika x.

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Hiyo hasa jinsi scanf kazi, na kukumbuka wiki iliyopita

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hiyo hasa jinsi GetString na GetInt na familia yake mengine ya kazi

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hatimaye kazi, angalau kwa ugomvi kidogo kama sscanf,

191
00:10:28,000 --> 00:10:31,000
ambayo ina maana Scan string badala ya keyboard.

192
00:10:31,000 --> 00:10:33,000
Lakini hebu tuangalie ugomvi kidogo wa hii.

193
00:10:33,000 --> 00:10:37,000
Katika scanf2, mimi kwa kweli Star up.

194
00:10:37,000 --> 00:10:42,000
Je, ni makosa-na mimi itabidi kuficha maoni ambayo anaelezea kama kiasi-

195
00:10:42,000 --> 00:10:47,000
nini ni vibaya kwa mpango huu, toleo la 2?

196
00:10:47,000 --> 00:10:55,000
Kuwa kama kiufundi kama inawezekana wakati huu.

197
00:10:55,000 --> 00:10:57,000
Inaonekana nzuri sana.

198
00:10:57,000 --> 00:11:03,000
Ni nicely indented, lakini-

199
00:11:03,000 --> 00:11:07,000
sawa, vipi kuhusu hebu kukatia ni chini ya maswali mfupi?

200
00:11:07,000 --> 00:11:17,000
Line 16. Nini mstari 16 katika kufanya Kiingereza sahihi lakini kiufundi?

201
00:11:17,000 --> 00:11:20,000
Kupata kidogo Awkward. Ndiyo, Michael.

202
00:11:20,000 --> 00:11:25,000
[Mwanafunzi] Ni akizungumzia barua ya kwanza ya kamba.

203
00:11:25,000 --> 00:11:27,000
>> Okay, karibu. Hebu tweak kwamba kidogo.

204
00:11:27,000 --> 00:11:33,000
Akizungumzia barua ya kwanza ya kamba, wewe ni kutangaza variable kuitwa buffer

205
00:11:33,000 --> 00:11:36,000
ambayo uhakika na anuani ya kwanza ya kamba,

206
00:11:36,000 --> 00:11:39,000
au tuseme, ambayo uhakika zaidi hasa kwa Char.

207
00:11:39,000 --> 00:11:42,000
Taarifa hiyo si kweli akizungumzia popote kwa sababu hakuna operator zoezi.

208
00:11:42,000 --> 00:11:46,000
Hakuna ishara sawa, hivyo wote sisi ni kufanya ni kugawa variable inayoitwa buffer.

209
00:11:46,000 --> 00:11:49,000
Hutokea kwa kuwa 32 bits sababu ni pointer,

210
00:11:49,000 --> 00:11:52,000
na yaliyomo ya buffer ikatengeneza hatimaye

211
00:11:52,000 --> 00:11:57,000
yana anwani ya Char, lakini kwa sasa, nini buffer yana?

212
00:11:57,000 --> 00:11:59,000
Baadhi tu bogus, ambaye anajua, baadhi ya thamani ya takataka,

213
00:11:59,000 --> 00:12:03,000
kwa sababu sisi si wazi initialized hivyo, hivyo hatupaswi kudhani chochote.

214
00:12:03,000 --> 00:12:06,000
Sawa, hivyo sasa mstari 17 ni-nini mstari 17 nini?

215
00:12:06,000 --> 00:12:08,000
Labda hiyo itakuwa joto hii up.

216
00:12:08,000 --> 00:12:10,000
Ni Prints kamba, sawa?

217
00:12:10,000 --> 00:12:12,000
Ni Prints Kamba tafadhali.

218
00:12:12,000 --> 00:12:15,000
>> Line 18 ni aina ya familiar sasa kwa kuwa sisi tu kuona ugomvi huu

219
00:12:15,000 --> 00:12:18,000
lakini kwa kificho tofauti format, hivyo katika mstari 18,

220
00:12:18,000 --> 00:12:23,000
sisi ni kuwaambia scanf hapa ni anwani ya chunk ya kumbukumbu.

221
00:12:23,000 --> 00:12:27,000
Mimi nataka wewe pete katika kamba, kama alisema kwa% s,

222
00:12:27,000 --> 00:12:32,000
lakini tatizo ni kwamba hatujafanya michache ya mambo hapa.

223
00:12:32,000 --> 00:12:35,000
Nini moja ya matatizo?

224
00:12:35,000 --> 00:12:38,000
[Mwanafunzi] Ni kujaribu dereference pointer null.

225
00:12:38,000 --> 00:12:41,000
Good, null au tu vinginevyo haijulikani kuyatumia.

226
00:12:41,000 --> 00:12:45,000
Wewe ni handing scanf anuani, lakini wewe tu alisema wakati uliopita

227
00:12:45,000 --> 00:12:49,000
kwamba anuani kwamba ni baadhi ya thamani ya takataka kwa sababu hatukuwa kweli hawawajui kwa kitu chochote,

228
00:12:49,000 --> 00:12:53,000
na hivyo wewe ni kuwaambia scanf ufanisi kwenda kuweka kamba hapa,

229
00:12:53,000 --> 00:12:56,000
lakini hatujui ambapo hapa bado ni,

230
00:12:56,000 --> 00:12:59,000
hivyo sisi si kweli zilizotengwa kwa ajili ya kumbukumbu buffer.

231
00:12:59,000 --> 00:13:03,000
Aidha, ni wewe pia hata kuwaambia scanf?

232
00:13:03,000 --> 00:13:06,000
Tuseme hii ilikuwa chunk ya kumbukumbu, na haikuwa thamani ya takataka,

233
00:13:06,000 --> 00:13:09,000
lakini bado uko siyo kuwaambia scanf kitu muhimu.

234
00:13:09,000 --> 00:13:12,000
[Mwanafunzi] wapi ni kweli ni, ampersand.

235
00:13:12,000 --> 00:13:15,000
Ampersand, hivyo katika kesi hii, ni sawa.

236
00:13:15,000 --> 00:13:18,000
Kwa sababu buffer tayari alitangaza kama pointer

237
00:13:18,000 --> 00:13:22,000
na kipande * ya syntax, hatuna haja ya kutumia ampersand

238
00:13:22,000 --> 00:13:25,000
sababu ni tayari anuani, lakini nadhani habari hiyo hapa.

239
00:13:25,000 --> 00:13:27,000
[Mwanafunzi] Jinsi kubwa ni nini?

240
00:13:27,000 --> 00:13:29,000
Nzuri, sisi siyo kuwaambia scanf jinsi kubwa buffer hii ni,

241
00:13:29,000 --> 00:13:32,000
ambayo ina maana hata kama buffer walikuwa pointer,

242
00:13:32,000 --> 00:13:35,000
sisi ni kusema scanf, kuweka kamba hapa,

243
00:13:35,000 --> 00:13:38,000
lakini hapa inaweza kuwa 2 ka, inaweza kuwa 10 bytes, inaweza kuwa megabyte.

244
00:13:38,000 --> 00:13:41,000
Scanf hana wazo, na kwa sababu hii ni chunk ya kumbukumbu

245
00:13:41,000 --> 00:13:43,000
labda, siyo kamba bado.

246
00:13:43,000 --> 00:13:48,000
Ni tu kamba mara moja kuandika herufi na 0 \ kwa kuwa chunk ya kumbukumbu.

247
00:13:48,000 --> 00:13:51,000
Sasa ni baadhi tu chunk ya kumbukumbu.

248
00:13:51,000 --> 00:13:55,000
Scanf si kujua wakati wa kuacha kuandika kwa anwani hiyo.

249
00:13:55,000 --> 00:13:59,000
>> Kama unakumbuka baadhi ya mifano katika siku za nyuma ambapo mimi nasibu typed kwenye keyboard

250
00:13:59,000 --> 00:14:03,000
kujaribu kufurika buffer, na sisi aliyesema juu ya Ijumaa kuhusu hasa ile.

251
00:14:03,000 --> 00:14:07,000
Kama adui fulani injects katika mpango wako neno kubwa sana

252
00:14:07,000 --> 00:14:10,000
au sentensi au maneno basi walikuwa wanatarajia unaweza overrun

253
00:14:10,000 --> 00:14:13,000
chunk ya kumbukumbu, ambayo yanaweza kuwa na matokeo mabaya,

254
00:14:13,000 --> 00:14:15,000
kama kuchukua juu ya mpango mzima yenyewe.

255
00:14:15,000 --> 00:14:17,000
Tunahitaji kurekebisha hii kwa namna fulani.

256
00:14:17,000 --> 00:14:20,000
Hebu zoom nje na kwenda katika toleo 3 ya mpango huu.

257
00:14:20,000 --> 00:14:22,000
Hiyo ni kidogo bora.

258
00:14:22,000 --> 00:14:24,000
Katika toleo hili, taarifa tofauti.

259
00:14:24,000 --> 00:14:27,000
Katika mstari 16, mimi nina tena kutangaza variable kuitwa buffer,

260
00:14:27,000 --> 00:14:29,000
lakini ni nini sasa?

261
00:14:29,000 --> 00:14:33,000
Ni safu ya chars 16.

262
00:14:33,000 --> 00:14:36,000
Hii ni nzuri kwa sababu hii ina maana naweza sasa kuwaambia scanf

263
00:14:36,000 --> 00:14:39,000
hapa ni chunk halisi ya kumbukumbu.

264
00:14:39,000 --> 00:14:42,000
Unaweza karibu kufikiri ya arrays kama kuwa kuyatumia sasa,

265
00:14:42,000 --> 00:14:44,000
hata kama wao siyo kweli sawa.

266
00:14:44,000 --> 00:14:47,000
Wao utakuwa tabia tofauti katika mazingira tofauti.

267
00:14:47,000 --> 00:14:50,000
Lakini ni hakika kwamba kesi buffer inasimamia

268
00:14:50,000 --> 00:14:53,000
16 contiguous chars sababu kwamba ni nini safu ni

269
00:14:53,000 --> 00:14:55,000
na imekuwa kwa muda wa wiki kadhaa sasa.

270
00:14:55,000 --> 00:14:59,000
>> Hapa, Mimi ninakuambia scanf hapa chunk ya kumbukumbu.

271
00:14:59,000 --> 00:15:01,000
Wakati huu, ni kweli chunk ya kumbukumbu,

272
00:15:01,000 --> 00:15:07,000
lakini kwa nini ni mpango huu bado exploitable?

273
00:15:07,000 --> 00:15:11,000
Nini mbaya bado?

274
00:15:11,000 --> 00:15:14,000
Nilivyosema nipe ka 16 lakini-

275
00:15:14,000 --> 00:15:16,000
[Mwanafunzi] Nini kama aina katika zaidi ya 16?

276
00:15:16,000 --> 00:15:20,000
Hasa, nini kama mtumiaji aina katika herufi 17 au wahusika 1700?

277
00:15:20,000 --> 00:15:23,000
Kwa kweli, hebu angalia kama hatuwezi safari juu kosa hili sasa.

278
00:15:23,000 --> 00:15:25,000
Ni bora lakini si kamili.

279
00:15:25,000 --> 00:15:28,000
Hebu kwenda mbele na kukimbia kufanya scanf3 kukusanya mpango huu.

280
00:15:28,000 --> 00:15:34,000
Hebu kukimbia scanf3, Kamba tafadhali: hello, na sisi kuonekana kuwa sawa.

281
00:15:34,000 --> 00:15:37,000
Hebu jaribu moja tena kidogo, hujambo huko.

282
00:15:37,000 --> 00:15:42,000
Okay, wacha kufanya hujambo huko gani leo, Ingiza.

283
00:15:42,000 --> 00:15:54,000
Kupata aina ya bahati hapa, hebu kusema hello kuna jinsi wewe.

284
00:15:54,000 --> 00:15:56,000
Damn yake.

285
00:15:56,000 --> 00:16:03,000
Sawa, hivyo tulipata bahati. Hebu angalia kama hatuwezi kurekebisha hii.

286
00:16:03,000 --> 00:16:06,000
Hapana, si kwenda basi mimi nakala.

287
00:16:06,000 --> 00:16:09,000
Hebu jaribu hii tena.

288
00:16:09,000 --> 00:16:12,000
Haki zote, na kusimama.

289
00:16:12,000 --> 00:16:20,000
Tutaweza kuona jinsi ya muda mrefu mimi unaweza kujifanya kuzingatia wakati bado kufanya hivyo.

290
00:16:20,000 --> 00:16:23,000
Damn yake. Hiyo badala inafaa, kwa kweli.

291
00:16:23,000 --> 00:16:26,000
Kuna sisi kwenda.

292
00:16:26,000 --> 00:16:30,000
Point alifanya.

293
00:16:30,000 --> 00:16:34,000
>> Hii, aibu ingawa pia ni, pia ni moja ya vyanzo ya machafuko makubwa

294
00:16:34,000 --> 00:16:38,000
wakati wa kuandika mipango na mende kwa sababu wao wenyewe yatangaza

295
00:16:38,000 --> 00:16:40,000
tu mara moja kwa wakati mwingine.

296
00:16:40,000 --> 00:16:43,000
Ukweli ni kwamba hata kama code yako ni kabisa kuvunjwa,

297
00:16:43,000 --> 00:16:46,000
inaweza tu kuwa kabisa kuvunjwa mara moja kwa wakati

298
00:16:46,000 --> 00:16:49,000
kwa sababu wakati mwingine, kimsingi ni nini kinachotokea ni mfumo wa uendeshaji kutenga

299
00:16:49,000 --> 00:16:52,000
kidogo zaidi kuliko kumbukumbu haja kweli kwa sababu yoyote,

300
00:16:52,000 --> 00:16:57,000
na hivyo hakuna mtu mwingine ni kutumia kumbukumbu sahihi baada ya chunk yako ya wahusika wa 16,

301
00:16:57,000 --> 00:17:01,000
hivyo kama kwenda kwa 17, 18, 19, na kwa chochote, sio vile mpango kubwa.

302
00:17:01,000 --> 00:17:04,000
Sasa, kompyuta, hata kama haina ajali katika hatua hiyo,

303
00:17:04,000 --> 00:17:09,000
ili hatimaye kutumia idadi Byte 17 au 18 au 19 kwa kitu kingine,

304
00:17:09,000 --> 00:17:14,000
saa ambayo kumweka data yako kwamba kuweka huko, angalau kupita kiasi kwa muda mrefu,

305
00:17:14,000 --> 00:17:18,000
ni kwenda kupata overwritten uwezekano kwa kazi nyingine.

306
00:17:18,000 --> 00:17:21,000
Ni lazima si watabaki intact,

307
00:17:21,000 --> 00:17:23,000
lakini si lazima kusababisha kosa seg.

308
00:17:23,000 --> 00:17:26,000
Lakini katika kesi hii, mimi hatimaye zinazotolewa wahusika kutosha

309
00:17:26,000 --> 00:17:29,000
kwamba mimi kimsingi ilizidi sehemu yangu ya kumbukumbu, na bam,

310
00:17:29,000 --> 00:17:33,000
mfumo wa uendeshaji akasema, "Samahani, hiyo si nzuri, segmentation kosa."

311
00:17:33,000 --> 00:17:38,000
>> Na hebu angalia sasa ikiwa kile bado hapa katika saraka yangu-

312
00:17:38,000 --> 00:17:40,000
taarifa kwamba nina faili hii hapa, msingi.

313
00:17:40,000 --> 00:17:42,000
Ona kwamba hii ni mara ya pili wakamwita dampo msingi.

314
00:17:42,000 --> 00:17:46,000
Ni kimsingi faili kwamba ina maudhui ya kumbukumbu ya mpango wako

315
00:17:46,000 --> 00:17:48,000
katika hatua ambayo ni kugonga,

316
00:17:48,000 --> 00:17:51,000
na tu kujaribu mfano kidogo hapa niende katika hapa

317
00:17:51,000 --> 00:17:57,000
na kukimbia gdb juu ya scanf3 na kisha kubainisha hoja ya tatu iitwayo msingi,

318
00:17:57,000 --> 00:18:01,000
na taarifa hapa kwamba kama mimi kuorodhesha kanuni,

319
00:18:01,000 --> 00:18:06,000
tutaweza kuwa na uwezo kama kawaida na gdb kwa kuanza kutembea kupitia mpango huu,

320
00:18:06,000 --> 00:18:10,000
na siwezi kukimbia na haraka kama mimi hit-kama na amri hatua katika gdb-

321
00:18:10,000 --> 00:18:13,000
haraka kama mimi hit line uwezekano Buggy baada ya kuandika katika kamba kubwa,

322
00:18:13,000 --> 00:18:16,000
Mimi utakuwa na uwezo wa kweli kutambua hapa.

323
00:18:16,000 --> 00:18:19,000
Zaidi juu ya hili, ingawa, katika sehemu katika suala la msingi dumps

324
00:18:19,000 --> 00:18:22,000
na kama hivyo kuwa unaweza kweli poke kuzunguka ndani ya dampo msingi

325
00:18:22,000 --> 00:18:27,000
na kuona kwenye kile line mpango alishindwa wewe.

326
00:18:27,000 --> 00:18:32,000
Maswali yoyote juu ya kisha kuyatumia na juu ya anwani?

327
00:18:32,000 --> 00:18:36,000
Kwa sababu leo, sisi ni kwenda kuanza kuchukua nafasi ya kwamba mambo haya zipo

328
00:18:36,000 --> 00:18:40,000
na sisi kujua hasa nini hao.

329
00:18:40,000 --> 00:18:42,000
Ndiyo.

330
00:18:42,000 --> 00:18:46,000
>> [Mwanafunzi] Jinsi kuja hawakuwa na kuweka ampersand karibu na sehemu-

331
00:18:46,000 --> 00:18:48,000
Nzuri swali.

332
00:18:48,000 --> 00:18:51,000
Jinsi ya kuja sikuwa na kuweka ampersand karibu na safu tabia kama nilivyofanya awali

333
00:18:51,000 --> 00:18:53,000
na zaidi ya mifano yetu?

334
00:18:53,000 --> 00:18:55,000
jibu fupi ni arrays ni kidogo maalum.

335
00:18:55,000 --> 00:18:59,000
Unaweza kufikiri karibu buffer kama kweli kuwa anwani,

336
00:18:59,000 --> 00:19:03,000
na hivyo hivyo tu hutokea kwa kuwa kesi hiyo mraba bracket nukuu

337
00:19:03,000 --> 00:19:06,000
ni urahisi ili tuweze kwenda katika mabano 0, bracket 1,

338
00:19:06,000 --> 00:19:10,000
bracket 2, bila kuwa na matumizi ya nukuu *.

339
00:19:10,000 --> 00:19:13,000
Hiyo ni kidogo ya uongo kwa sababu nyeupe arrays na kuyatumia

340
00:19:13,000 --> 00:19:17,000
ni, kwa kweli, tofauti kidogo, lakini mara nyingi wanaweza lakini si daima kutumika kwa kubadilishana.

341
00:19:17,000 --> 00:19:21,000
Kwa kifupi, wakati kazi ni kutarajia pointer chunk ya kumbukumbu,

342
00:19:21,000 --> 00:19:24,000
unaweza ama kupita anwani zile zilizorudishwa na malloc,

343
00:19:24,000 --> 00:19:29,000
na tutaweza kuona tena malloc kabla ya muda mrefu, au unaweza kupita jina la safu.

344
00:19:29,000 --> 00:19:32,000
Huna kufanya ampersand na arrays kwa sababu wao ni tayari

345
00:19:32,000 --> 00:19:34,000
kimsingi kama anwani.

346
00:19:34,000 --> 00:19:36,000
Hiyo ni ubaguzi moja.

347
00:19:36,000 --> 00:19:39,000
mabano mraba kuwafanya maalum.

348
00:19:39,000 --> 00:19:41,000
>> Unaweza kuweka ampersand karibu na buffer?

349
00:19:41,000 --> 00:19:43,000
Si katika kesi hii.

350
00:19:43,000 --> 00:19:46,000
Hiyo si kazi kwa sababu, tena, wa kesi hii kona

351
00:19:46,000 --> 00:19:49,000
ambapo arrays si kweli kabisa anwani.

352
00:19:49,000 --> 00:19:54,000
Lakini tutaweza labda kuja nyuma na kwamba kabla ya muda mrefu na mifano mingine.

353
00:19:54,000 --> 00:19:56,000
Hebu jaribu kutatua tatizo hapa.

354
00:19:56,000 --> 00:20:00,000
Tuna muundo data kwamba sisi tumekuwa kutumia kwa muda inayojulikana kama safu.

355
00:20:00,000 --> 00:20:02,000
Uchunguzi katika kumweka, kwamba ni nini sisi tu alikuwa.

356
00:20:02,000 --> 00:20:04,000
Lakini arrays kuwa baadhi upsides na downsides.

357
00:20:04,000 --> 00:20:06,000
Arrays ni nzuri kwa nini?

358
00:20:06,000 --> 00:20:11,000
Nini jambo moja kwamba wewe kama-kwa kiasi wewe kama arrays-kuhusu arrays?

359
00:20:11,000 --> 00:20:13,000
Nini nafasi ya juu yao? Nini kulazimisha?

360
00:20:13,000 --> 00:20:18,000
Kwa nini sisi kuanzisha yao katika nafasi ya kwanza?

361
00:20:18,000 --> 00:20:20,000
Yeah.

362
00:20:20,000 --> 00:20:27,000
[Mwanafunzi] Wao wanaweza kuhifadhi data nyingi, na huna kutumia kitu nzima.

363
00:20:27,000 --> 00:20:29,000
Unaweza kutumia sehemu.

364
00:20:29,000 --> 00:20:32,000
Nzuri, pamoja na safu unaweza kuhifadhi data nyingi,

365
00:20:32,000 --> 00:20:35,000
na wewe si lazima kuwa na matumizi yake yote, hivyo unaweza overallocate,

366
00:20:35,000 --> 00:20:39,000
ambayo inaweza kuwa rahisi kama huna kujua mapema jinsi wengi wa kitu kutarajia.

367
00:20:39,000 --> 00:20:41,000
>> GetString ni mfano kamili.

368
00:20:41,000 --> 00:20:44,000
GetString, iliyoandikwa na sisi, hana wazo jinsi wengi chars kutarajia,

369
00:20:44,000 --> 00:20:48,000
hivyo ukweli kwamba tunaweza kutenga chunks ya kumbukumbu contiguous ni nzuri.

370
00:20:48,000 --> 00:20:51,000
Arrays pia kutatua tatizo tuliona wiki kadhaa iliyopita sasa

371
00:20:51,000 --> 00:20:54,000
ambapo code yako kuanza kukabidhi katika kitu hafifu iliyoundwa sana.

372
00:20:54,000 --> 00:20:57,000
Kumbuka kwamba mimi umba muundo mwanafunzi akamwita Daudi,

373
00:20:57,000 --> 00:21:00,000
na kisha kuwa ilikuwa kwa kweli ni mbadala, ingawa,

374
00:21:00,000 --> 00:21:04,000
kwa kuwa kutofautiana kuitwa jina na kuitwa mwingine kutofautiana, nadhani, nyumba,

375
00:21:04,000 --> 00:21:08,000
na mwingine kutofautiana kuitwa ID kwa sababu katika hadithi kwamba mimi basi alitaka kuanzisha kitu kingine

376
00:21:08,000 --> 00:21:11,000
kama Rob katika mpango, hivyo basi niliamua kusubiri dakika,

377
00:21:11,000 --> 00:21:13,000
Nahitaji rename vigezo hivi.

378
00:21:13,000 --> 00:21:16,000
Hebu piga mgodi NAME1 ID1, house1.

379
00:21:16,000 --> 00:21:20,000
Hebu piga Rob wa NAME2, house2, ID2.

380
00:21:20,000 --> 00:21:22,000
Lakini kisha kusubiri dakika, nini kuhusu Tommy?

381
00:21:22,000 --> 00:21:24,000
Kisha sisi alikuwa tatu vigezo zaidi.

382
00:21:24,000 --> 00:21:27,000
Sisi ilianzisha mtu mwingine, nne seti ya variables.

383
00:21:27,000 --> 00:21:30,000
dunia kuanza kupata messy haraka sana,

384
00:21:30,000 --> 00:21:33,000
hivyo sisi ilianzisha structs, na nini kulazimisha kuhusu struct?

385
00:21:33,000 --> 00:21:39,000
Je struct C basi wewe kufanya?

386
00:21:39,000 --> 00:21:42,000
Ni kweli Awkward leo.

387
00:21:42,000 --> 00:21:44,000
Nini? >> [Inaudible mwanafunzi majibu]

388
00:21:44,000 --> 00:21:47,000
Yeah, hasa, typedef inaruhusu kujenga mpya data aina,

389
00:21:47,000 --> 00:21:51,000
na struct, Keyword struct, utapata kurejelea

390
00:21:51,000 --> 00:21:54,000
conceptually kuhusiana vipande vya data pamoja

391
00:21:54,000 --> 00:21:56,000
na baada ya hapo kuwaita kitu kama mwanafunzi.

392
00:21:56,000 --> 00:21:58,000
>> Hiyo ilikuwa nzuri kwa sababu sasa tunaweza mfano

393
00:21:58,000 --> 00:22:03,000
zaidi ya aina ya conceptually thabiti dhana ya mwanafunzi katika variable

394
00:22:03,000 --> 00:22:07,000
badala ya kiholela kuwa moja kwa kamba, moja kwa ID, na kadhalika.

395
00:22:07,000 --> 00:22:10,000
Arrays ni nzuri kwa sababu wao kuruhusu sisi kuanza kusafisha code yetu.

396
00:22:10,000 --> 00:22:13,000
Lakini ni nini negativa sasa wa safu?

397
00:22:13,000 --> 00:22:15,000
Nini unaweza kufanya? Yeah.

398
00:22:15,000 --> 00:22:17,000
[Mwanafunzi] Una kujua jinsi kubwa ni.

399
00:22:17,000 --> 00:22:19,000
Una kujua jinsi kubwa ni, hivyo ni aina ya maumivu.

400
00:22:19,000 --> 00:22:21,000
Wale wa wewe na uzoefu kabla ya programu kujua kwamba katika mengi ya lugha,

401
00:22:21,000 --> 00:22:24,000
kama Java, unaweza kuuliza chunk ya kumbukumbu, hasa safu,

402
00:22:24,000 --> 00:22:28,000
jinsi kubwa ni wewe, na urefu, mali, ili kuzungumza, na kwamba ni kweli urahisi.

403
00:22:28,000 --> 00:22:32,000
Katika C, unaweza hata kuwaita strlen kwenye safu generic

404
00:22:32,000 --> 00:22:35,000
kwa sababu strlen, kama neno ina maana, ni tu kwa masharti,

405
00:22:35,000 --> 00:22:39,000
na wewe wanaweza kufikiri urefu wa kamba kwa sababu ya mkataba huu wa binadamu

406
00:22:39,000 --> 00:22:43,000
ya kuwa na 0 \, lakini safu, zaidi generically, ni tu chunk ya kumbukumbu.

407
00:22:43,000 --> 00:22:46,000
Kama ni safu ya ints, kuna si kwenda kuwa baadhi ya tabia maalum

408
00:22:46,000 --> 00:22:48,000
mwishoni kusubiri kwa ajili yenu.

409
00:22:48,000 --> 00:22:50,000
Una kukumbuka urefu wa safu.

410
00:22:50,000 --> 00:22:54,000
Mwingine upande wa chini ya safu reared kichwa yake katika GetString yenyewe.

411
00:22:54,000 --> 00:22:59,000
Nini mwingine upande wa chini ya safu?

412
00:22:59,000 --> 00:23:01,000
Mheshimiwa, wewe tu na mimi leo.

413
00:23:01,000 --> 00:23:04,000
[Inaudible mwanafunzi majibu] >> Ni nini?

414
00:23:04,000 --> 00:23:06,000
Ni alitangaza juu ya stack.

415
00:23:06,000 --> 00:23:09,000
Okay, alitangaza juu ya stack. Mbona wewe kama hayo?

416
00:23:09,000 --> 00:23:13,000
[Mwanafunzi] Kwa sababu anapata kutumika tena.

417
00:23:13,000 --> 00:23:15,000
Ni anapata kutumika tena.

418
00:23:15,000 --> 00:23:18,000
Sawa, kama kutumia safu kutenga kumbukumbu,

419
00:23:18,000 --> 00:23:21,000
huwezi, kwa mfano, kurudi kwa sababu ni juu ya stack.

420
00:23:21,000 --> 00:23:23,000
Okay, hiyo ni hasara.

421
00:23:23,000 --> 00:23:25,000
Na vipi kuhusu mtu mwingine na safu?

422
00:23:25,000 --> 00:23:28,000
Mara baada ya kuipa, wewe ni aina ya Star kama unahitaji nafasi zaidi

423
00:23:28,000 --> 00:23:30,000
kuliko safu ambayo ina.

424
00:23:30,000 --> 00:23:34,000
>> Kisha sisi kuletwa, wanakumbuka, malloc, aliyetupa uwezo wa dynamically kutenga kumbukumbu.

425
00:23:34,000 --> 00:23:37,000
Lakini nini kama sisi walijaribu dunia tofauti kabisa?

426
00:23:37,000 --> 00:23:40,000
Nini kama sisi alitaka kutatua matatizo ya wanandoa wa wale

427
00:23:40,000 --> 00:23:45,000
hivyo sisi badala-wangu kalamu amelala hapa-

428
00:23:45,000 --> 00:23:51,000
nini kama sisi badala alitaka kimsingi kujenga dunia kwamba hakuna tena kama hii?

429
00:23:51,000 --> 00:23:56,000
Hii ni safu, na, bila shaka, aina hii ya kuzorota kwa mara sisi hit mwisho wa safu,

430
00:23:56,000 --> 00:24:00,000
na mimi sasa hakuna tena nafasi kwa ajili ya mwingine integer au nyingine tabia.

431
00:24:00,000 --> 00:24:03,000
Nini kama sisi aina ya preemptively kusema vizuri, kwa nini sio sisi kupumzika

432
00:24:03,000 --> 00:24:07,000
mahitaji haya kwamba chunks haya yote ya kumbukumbu kuwa contiguous nyuma kwa nyuma,

433
00:24:07,000 --> 00:24:10,000
na kwa nini siyo, wakati mimi haja int au Char,

434
00:24:10,000 --> 00:24:12,000
tu nipe nafasi kwa mmoja wao?

435
00:24:12,000 --> 00:24:14,000
Na wakati mimi haja mwingine, nipe nafasi nyingine,

436
00:24:14,000 --> 00:24:16,000
na wakati mimi haja mwingine, nipe nafasi nyingine.

437
00:24:16,000 --> 00:24:19,000
faida ambayo kwa sasa ni kwamba kama mtu mwingine

438
00:24:19,000 --> 00:24:21,000
inachukua kumbukumbu zaidi ya hapa, hakuna mpango mkubwa.

439
00:24:21,000 --> 00:24:25,000
Nitachukua hii chunk ya ziada ya kumbukumbu hapa na kisha hii moja.

440
00:24:25,000 --> 00:24:28,000
>> Sasa, kupata tu hapa ni kwamba hii karibu anahisi kama mimi na

441
00:24:28,000 --> 00:24:30,000
rundo zima la vigezo tofauti.

442
00:24:30,000 --> 00:24:33,000
Hii anahisi kama vigezo tano tofauti uwezekano.

443
00:24:33,000 --> 00:24:36,000
Lakini nini kama sisi kuiba wazo kutoka masharti

444
00:24:36,000 --> 00:24:41,000
ambapo sisi kwa namna fulani kuhusisha mambo haya pamoja conceptually, na nini kama mimi alifanya hivyo?

445
00:24:41,000 --> 00:24:44,000
Hii ni mshale wangu sana hafifu inayotolewa.

446
00:24:44,000 --> 00:24:46,000
Lakini chukulia kwamba kila moja ya haya chunks ya kumbukumbu

447
00:24:46,000 --> 00:24:52,000
alisema kwa wengine, na hii guy, ambaye hana ndugu kwa haki yake,

448
00:24:52,000 --> 00:24:54,000
hana arrow vile.

449
00:24:54,000 --> 00:24:56,000
Huu kwa kweli ni nini wito orodha zilizounganishwa.

450
00:24:56,000 --> 00:25:00,000
Hii ni mpya data muundo kwamba inaruhusu yetu kutenga chunk ya kumbukumbu,

451
00:25:00,000 --> 00:25:03,000
kisha mwingine, kisha mwingine, kisha mwingine, wakati wowote tunataka

452
00:25:03,000 --> 00:25:07,000
wakati wa mpango, na sisi kumbuka kwamba wao ni wote kwa namna fulani kuhusiana

453
00:25:07,000 --> 00:25:11,000
na chaining literally wote pamoja, na sisi gani kwamba pictorially hapa kwa mshale.

454
00:25:11,000 --> 00:25:15,000
Lakini katika kanuni, nini itakuwa utaratibu kupitia ambayo unaweza namna fulani kuungana,

455
00:25:15,000 --> 00:25:20,000
karibu kama Scratch, mmoja chunk kwa chunk mwingine?

456
00:25:20,000 --> 00:25:22,000
Tunaweza kutumia pointer, haki?

457
00:25:22,000 --> 00:25:25,000
Kwa sababu kwa kweli arrow ambayo inaenda kutoka mraba juu kushoto,

458
00:25:25,000 --> 00:25:31,000
this guy hapa kwa moja hii, inaweza vyenye ndani ya mraba huu

459
00:25:31,000 --> 00:25:34,000
si tu baadhi ints, si tu baadhi Char, lakini kile kama mimi kweli zilizotengwa

460
00:25:34,000 --> 00:25:37,000
kidogo ya ziada nafasi ili kwamba sasa,

461
00:25:37,000 --> 00:25:41,000
kila moja ya chunks yangu ya kumbukumbu, hata ingawa hii ni kwenda gharama yangu,

462
00:25:41,000 --> 00:25:45,000
sasa inaonekana kidogo zaidi mstatili ambapo moja ya chunks ya kumbukumbu

463
00:25:45,000 --> 00:25:47,000
ni kutumika kwa idadi, kama idadi 1,

464
00:25:47,000 --> 00:25:50,000
na kisha kama guy hii inahifadhi idadi 2,

465
00:25:50,000 --> 00:25:52,000
chunk hii nyingine ya kumbukumbu hutumika kwa mshale,

466
00:25:52,000 --> 00:25:54,000
au zaidi concretely, pointer.

467
00:25:54,000 --> 00:25:59,000
Na nadhani kuhifadhi namba 3 ya juu hapa wakati mimi kutumia hii kwa uhakika katika guy kwamba,

468
00:25:59,000 --> 00:26:02,000
na sasa guy hii, hebu tuseme mimi tu wanataka tatu vile chunks ya kumbukumbu.

469
00:26:02,000 --> 00:26:05,000
Mimi itabidi kuchora mstari kupitia njia hiyo, kuonyesha null.

470
00:26:05,000 --> 00:26:07,000
Hakuna tabia ya ziada.

471
00:26:07,000 --> 00:26:10,000
>> Hakika, huu ni jinsi gani tunaweza kwenda kuhusu utekelezaji

472
00:26:10,000 --> 00:26:12,000
kitu ambacho ni wito orodha zilizounganishwa.

473
00:26:12,000 --> 00:26:18,000
orodha wanaohusishwa ni mpya data muundo, na ni jiwe wanazidi kuelekea

474
00:26:18,000 --> 00:26:21,000
kiasi fancier data miundo kwamba kutatua matatizo

475
00:26:21,000 --> 00:26:23,000
pamoja na mistari ya matatizo Facebook-aina na matatizo ya Google-aina

476
00:26:23,000 --> 00:26:26,000
ambapo una data kubwa seti, na tena ni kupunguzwa

477
00:26:26,000 --> 00:26:29,000
kuhifadhi kila kitu contiguously na kutumia kitu kama tafuta linear

478
00:26:29,000 --> 00:26:31,000
au hata kitu kama tafuta binary.

479
00:26:31,000 --> 00:26:33,000
Unataka bora hata mara mbio.

480
00:26:33,000 --> 00:26:37,000
Kwa kweli, mmoja wa Grails Mtakatifu tutaweza kuzungumzia baadaye wiki hii au ijayo

481
00:26:37,000 --> 00:26:41,000
ni algorithm ambaye mbio wakati ni mara kwa mara.

482
00:26:41,000 --> 00:26:44,000
Kwa maneno mengine, ni daima inachukua kiasi hicho bila kujali

483
00:26:44,000 --> 00:26:47,000
jinsi kubwa ya pembejeo ni, na kwamba bila ya shaka kuwa kulazimisha,

484
00:26:47,000 --> 00:26:49,000
hata hivyo zaidi kuliko kitu logarithmic.

485
00:26:49,000 --> 00:26:51,000
Nini hili juu ya screen hapa?

486
00:26:51,000 --> 00:26:55,000
Kila moja ya mistatiri ni nini hasa mimi tu akauchomoa kwa mkono.

487
00:26:55,000 --> 00:26:59,000
Lakini jambo njia yote upande wa kushoto ni variable maalum.

488
00:26:59,000 --> 00:27:02,000
Ni kwenda kuwa pointer moja kwa sababu gotcha moja

489
00:27:02,000 --> 00:27:04,000
na orodha wanaohusishwa, kama mambo haya ni kuitwa,

490
00:27:04,000 --> 00:27:09,000
ni kwamba una hutegemea kwenye mwisho mmoja wa orodha zinazoungwa.

491
00:27:09,000 --> 00:27:13,000
>> Tu kama na kamba, una kujua anuani ya Char kwanza.

492
00:27:13,000 --> 00:27:15,000
Same mpango kwa orodha zilizounganishwa.

493
00:27:15,000 --> 00:27:19,000
Una kujua anuani ya chunk ya kwanza ya kumbukumbu

494
00:27:19,000 --> 00:27:25,000
kwa sababu kutoka huko, unaweza kufikia kila moja nyingine.

495
00:27:25,000 --> 00:27:27,000
Upande wa chini.

496
00:27:27,000 --> 00:27:30,000
Nini bei ni sisi kulipa kwa ajili ya hii versatility ya kuwa dynamically

497
00:27:30,000 --> 00:27:34,000
sizable data muundo kwamba kama sisi milele haja zaidi ya kumbukumbu, faini,

498
00:27:34,000 --> 00:27:37,000
tu kutenga moja zaidi chunk na kuteka pointer kutoka

499
00:27:37,000 --> 00:27:39,000
zamani kwa mkia mpya ya orodha?

500
00:27:39,000 --> 00:27:41,000
Yeah.

501
00:27:41,000 --> 00:27:43,000
[Mwanafunzi] Inachukua kuhusu mara mbili kama vile nafasi.

502
00:27:43,000 --> 00:27:45,000
Inachukua mara mbili kama vile nafasi, ili dhahiri negativa, na tumeona hii

503
00:27:45,000 --> 00:27:48,000
tradeoff kabla kati ya muda na nafasi na kubadilika

504
00:27:48,000 --> 00:27:51,000
ambapo kwa sasa, hatuhitaji 32 bits kwa kila moja ya namba hizi.

505
00:27:51,000 --> 00:27:57,000
Sisi kwa kweli wanahitaji 64, 32 kwa idadi na 32 kwa pointer.

506
00:27:57,000 --> 00:27:59,000
Lakini hey, nina 2 gigabytes ya RAM.

507
00:27:59,000 --> 00:28:02,000
Kuongeza bits nyingine 32 hapa na hapa haionekani kuwa kubwa ya mpango huo.

508
00:28:02,000 --> 00:28:05,000
Lakini kwa seti kubwa data, ni dhahiri zinafikia literally mara mbili zaidi.

509
00:28:05,000 --> 00:28:09,000
Nini mwingine upande wa chini sasa, au kile kipengele gani sisi kutoa up,

510
00:28:09,000 --> 00:28:12,000
kama sisi kuwakilisha orodha ya mambo na orodha wanaohusishwa na si safu?

511
00:28:12,000 --> 00:28:14,000
[Mwanafunzi] Huwezi traverse ni nyuma.

512
00:28:14,000 --> 00:28:16,000
Huwezi traverse ni nyuma, hivyo wewe ni aina ya Star ikiwa wewe unatembea

513
00:28:16,000 --> 00:28:19,000
kutoka kushoto kwenda kulia kwa kutumia kwa kitanzi au kitanzi wakati

514
00:28:19,000 --> 00:28:21,000
na kisha wewe kutambua, "Oh, mimi nataka kwenda nyuma mwanzo wa orodha."

515
00:28:21,000 --> 00:28:26,000
Huwezi kwa sababu hizi kuyatumia kwenda tu kutoka kushoto kwenda kulia kama mishale zinaonyesha.

516
00:28:26,000 --> 00:28:29,000
>> Sasa, unaweza kukumbuka mwanzo wa orodha na kutofautiana nyingine,

517
00:28:29,000 --> 00:28:31,000
lakini hiyo ni utata kukumbuka.

518
00:28:31,000 --> 00:28:35,000
safu, bila kujali jinsi mbali ya kwenda, unaweza daima kufanya bala, bala, bala, minus

519
00:28:35,000 --> 00:28:37,000
na kurudi nyuma kutoka wapi wewe akaja.

520
00:28:37,000 --> 00:28:40,000
Nini Negativa mwingine hapa? Yeah.

521
00:28:40,000 --> 00:28:43,000
[Inaudible mwanafunzi swali]

522
00:28:43,000 --> 00:28:47,000
Unaweza, hivyo ve kweli tu mapendekezo muundo data kuitwa orodha doubly wanaohusishwa,

523
00:28:47,000 --> 00:28:50,000
na kwa kweli, ungependa kuongeza mwingine pointer kwa kila moja ya haya mistatili

524
00:28:50,000 --> 00:28:53,000
kwamba huenda upande mwingine, suala la mafanikio ya ambayo

525
00:28:53,000 --> 00:28:55,000
ni sasa unaweza tembeeni na kurudi,

526
00:28:55,000 --> 00:28:59,000
Kwa upande wa chini ambayo sasa unatumia mara tatu kama kumbukumbu nyingi kama sisi kutumika kwa

527
00:28:59,000 --> 00:29:04,000
na pia kuongeza utata katika suala la code una kuandika kupata haki.

528
00:29:04,000 --> 00:29:08,000
Lakini haya yote ni labda busara sana tradeoffs, kama reversal ni muhimu zaidi.

529
00:29:08,000 --> 00:29:10,000
Yeah.

530
00:29:10,000 --> 00:29:12,000
[Mwanafunzi] Unaweza pia kuwa na 2D zilizounganishwa orodha.

531
00:29:12,000 --> 00:29:16,000
Nzuri, unaweza si kweli kuwa 2D wanaohusishwa orodha.

532
00:29:16,000 --> 00:29:18,000
Ungeweza. Ni si karibu kama rahisi kama safu.

533
00:29:18,000 --> 00:29:21,000
Kama safu, unaweza kufanya bracket wazi, bracket funge, bracket wazi, C. bracket,

534
00:29:21,000 --> 00:29:23,000
na kupata baadhi muundo 2-dimensional.

535
00:29:23,000 --> 00:29:26,000
Unaweza kutekeleza 2-dimensional wanaohusishwa orodha

536
00:29:26,000 --> 00:29:29,000
kama wewe kufanya add-kama wewe mapendekezo-pointer tatu kwa kila moja ya mambo haya,

537
00:29:29,000 --> 00:29:34,000
na kama unadhani kuhusu orodha nyingine kuja saa wewe style 3D

538
00:29:34,000 --> 00:29:40,000
kutoka screen kwetu sote, ambayo ni nyingine tu mlolongo wa aina fulani.

539
00:29:40,000 --> 00:29:45,000
Tunaweza kufanya hivyo, lakini si rahisi kama kuandika bracket wazi, Mabano ya mraba. Yeah.

540
00:29:45,000 --> 00:29:48,000
[Inaudible mwanafunzi swali]

541
00:29:48,000 --> 00:29:50,000
Nzuri, hivyo hii ni kicker halisi.

542
00:29:50,000 --> 00:29:54,000
>> Hizi algorithms kwamba tumekuwa pined juu, kama oh, tafuta binary,

543
00:29:54,000 --> 00:29:57,000
unaweza kutafuta safu ya idadi juu ya bodi ya

544
00:29:57,000 --> 00:30:01,000
au kitabu ya simu ili haraka zaidi kama wewe kutumia kugawanya na kushinda

545
00:30:01,000 --> 00:30:05,000
na kisha tafuta algorithm, lakini tafuta binary required mawazo mawili.

546
00:30:05,000 --> 00:30:09,000
Mmoja, kwamba data alikuwa Iliyopangwa.

547
00:30:09,000 --> 00:30:11,000
Sasa, tunaweza labda kuweka hii Iliyopangwa,

548
00:30:11,000 --> 00:30:14,000
hivyo labda si kwamba wasiwasi, lakini binary tafuta pia alishika

549
00:30:14,000 --> 00:30:18,000
kwamba alikuwa na upatikanaji random kwa orodha ya idadi,

550
00:30:18,000 --> 00:30:21,000
na safu inaruhusu kuwa na upatikanaji random, na kwa upatikanaji random,

551
00:30:21,000 --> 00:30:24,000
I mean kama wewe ni kupewa safu, ni kiasi gani wakati gani kuchukua wewe

552
00:30:24,000 --> 00:30:26,000
kupata bracket 0?

553
00:30:26,000 --> 00:30:29,000
Moja ya kazi, wewe tu kutumia [0] na uko pale pale.

554
00:30:29,000 --> 00:30:33,000
Wangapi hatua gani kuchukua kupata mahali 10?

555
00:30:33,000 --> 00:30:36,000
Hatua moja, wewe tu kwenda kwenye [10] na wewe uko hapo.

556
00:30:36,000 --> 00:30:40,000
Kwa kulinganisha, ni jinsi gani unaweza kupata integer 10 katika orodha wanaohusishwa?

557
00:30:40,000 --> 00:30:42,000
Una kuanza mwanzoni kwa sababu wewe ni tu kukumbuka

558
00:30:42,000 --> 00:30:45,000
mwanzo wa orodha wanaohusishwa, kama kamba ni kuwa ikumbukwe

559
00:30:45,000 --> 00:30:48,000
na anuani ya Char yake ya kwanza, na kwa kujua kwamba int 10

560
00:30:48,000 --> 00:30:53,000
au kwamba tabia 10 katika kamba, una kutafuta nzima damn kitu.

561
00:30:53,000 --> 00:30:55,000
>> Tena, sisi siyo kutatua matatizo yote ya yetu.

562
00:30:55,000 --> 00:31:00,000
Sisi ni kuanzisha ndio mpya, lakini ni kweli unategemea nini wewe ni kujaribu kubuni kwa.

563
00:31:00,000 --> 00:31:04,000
Katika suala la utekelezaji wa hii, tunaweza kukopa kutoka wazo muundo kwamba mwanafunzi.

564
00:31:04,000 --> 00:31:07,000
syntax ni sawa sana, ila sasa, wazo ni kidogo zaidi abstract

565
00:31:07,000 --> 00:31:09,000
kuliko nyumba na jina na kitambulisho.

566
00:31:09,000 --> 00:31:13,000
Lakini napendekeza kwamba tunaweza kuwa na muundo data katika C

567
00:31:13,000 --> 00:31:17,000
kiitwacho nodi, kama neno la mwisho kwenye slide unaonyesha,

568
00:31:17,000 --> 00:31:21,000
ndani ya nodi, na node ni chombo tu generic katika sayansi ya kompyuta.

569
00:31:21,000 --> 00:31:25,000
Ni kawaida inayotolewa kama mduara au mraba au mstatili kama tumekuwa kufanyika.

570
00:31:25,000 --> 00:31:27,000
Na katika muundo huu data, tuna int, n,

571
00:31:27,000 --> 00:31:29,000
hivyo kwamba ni idadi mimi unataka kuhifadhi.

572
00:31:29,000 --> 00:31:36,000
Lakini ni nini hii mstari wa pili, struct nodi * ijayo?

573
00:31:36,000 --> 00:31:40,000
Kwa nini hii ni sahihi, au kile jukumu gani hii kucheza kitu,

574
00:31:40,000 --> 00:31:42,000
hata kama ni kidogo cryptic katika mtazamo wa kwanza?

575
00:31:42,000 --> 00:31:44,000
Yeah.

576
00:31:44,000 --> 00:31:46,000
[Inaudible mwanafunzi majibu]

577
00:31:46,000 --> 00:31:50,000
Hasa, hivyo aina ya nyara * kwamba ni pointer ya aina fulani.

578
00:31:50,000 --> 00:31:53,000
jina la pointer hii ni kiholela ijayo,

579
00:31:53,000 --> 00:32:00,000
lakini tungeweza kuitwa ni kitu chochote tunataka, lakini nini hatua hii pointer?

580
00:32:00,000 --> 00:32:03,000
[Mwanafunzi] nodi Mwingine >> Hasa., Inaelekeza nodi vile mwingine.

581
00:32:03,000 --> 00:32:05,000
>> Sasa, hii ni aina ya udadisi wa C.

582
00:32:05,000 --> 00:32:09,000
Kumbuka kuwa C ni kusoma na juu compiler hadi chini, kushoto na kulia,

583
00:32:09,000 --> 00:32:13,000
ambayo ina maana kama-hii ni tofauti kidogo kutoka na kile sisi alivyofanya kwa mwanafunzi.

584
00:32:13,000 --> 00:32:16,000
Wakati sisi defined mwanafunzi, sisi kweli hawakuwa kuweka neno huko.

585
00:32:16,000 --> 00:32:18,000
Ni tu alisema typedef.

586
00:32:18,000 --> 00:32:20,000
Kisha sisi alikuwa int id, kamba jina, kamba nyumba,

587
00:32:20,000 --> 00:32:23,000
na kisha mwanafunzi chini ya struct.

588
00:32:23,000 --> 00:32:26,000
Tangazo hilo ni tofauti kidogo kwa sababu,

589
00:32:26,000 --> 00:32:28,000
tena, compiler C ni kidogo bubu.

590
00:32:28,000 --> 00:32:30,000
Ni tu kwenda kusoma juu hadi chini,

591
00:32:30,000 --> 00:32:33,000
hivyo kama unafikia line 2 hapa

592
00:32:33,000 --> 00:32:37,000
ambapo ijayo ni alitangaza na anaona, oh, hapa variable iitwayo ijayo.

593
00:32:37,000 --> 00:32:39,000
Ni pointer nodi struct.

594
00:32:39,000 --> 00:32:42,000
compiler ni kwenda kutambua nini ni nodi struct?

595
00:32:42,000 --> 00:32:44,000
Sijawahi kusikia jambo hili mbele,

596
00:32:44,000 --> 00:32:47,000
kwa sababu neno nodi ili si vinginevyo itaonekana

597
00:32:47,000 --> 00:32:49,000
mpaka chini, hivyo kuna hii redundancy.

598
00:32:49,000 --> 00:32:53,000
Una kusema struct nodi hapa, ambayo unaweza kisha kufupisha baadaye

599
00:32:53,000 --> 00:32:56,000
shukrani kwa typedef chini hapa, lakini hii ni kwa sababu

600
00:32:56,000 --> 00:33:02,000
sisi ni referencing muundo yenyewe ndani ya muundo.

601
00:33:02,000 --> 00:33:05,000
Hiyo gotcha moja huko.

602
00:33:05,000 --> 00:33:07,000
>> Baadhi ya matatizo ya kuvutia ni kwenda kutokea.

603
00:33:07,000 --> 00:33:09,000
Sisi tumepewa orodha ya namba. Jinsi gani sisi Insert ndani yake?

604
00:33:09,000 --> 00:33:11,000
Jinsi gani sisi tafuta yake? Jinsi gani sisi kufuta kutoka humo?

605
00:33:11,000 --> 00:33:13,000
Hasa sasa kwamba tuna kusimamia yote ya kuyatumia haya.

606
00:33:13,000 --> 00:33:15,000
You walidhani kuyatumia walikuwa aina ya akili-bending

607
00:33:15,000 --> 00:33:17,000
wakati alikuwa mmoja wao tu kujaribu kusoma int yake.

608
00:33:17,000 --> 00:33:20,000
Sasa tuna kuendesha thamani orodha nzima.

609
00:33:20,000 --> 00:33:22,000
Mbona sisi kuchukua wetu 5-dakika kuvunja hapa, na kisha tutaweza kuleta

610
00:33:22,000 --> 00:33:34,000
baadhi folks juu ya hatua ya kufanya hasa ile.

611
00:33:34,000 --> 00:33:36,000
>> C ni zaidi fun wakati ni alitenda nje.

612
00:33:36,000 --> 00:33:39,000
Ambao wangeweza literally kama kuwa ya kwanza?

613
00:33:39,000 --> 00:33:41,000
Okay, kuja juu juu. Wewe ni wa kwanza.

614
00:33:41,000 --> 00:33:44,000
Ambao wangependa kuwa 9? Okay, 9.

615
00:33:44,000 --> 00:33:46,000
Vipi kuhusu 9? 17?

616
00:33:46,000 --> 00:33:51,000
Bofya hapa kidogo. 22 na 26 katika mstari wa mbele kwamba.

617
00:33:51,000 --> 00:33:53,000
Na kisha vipi kuhusu mtu zaidi ya hapo kuwa alisema saa.

618
00:33:53,000 --> 00:33:57,000
Wewe ni 34. Okay, 34, kuja juu juu.

619
00:33:57,000 --> 00:33:59,000
Kwanza ni zaidi ya hapo. Okay, zote nne za guys wewe.

620
00:33:59,000 --> 00:34:01,000
Na ambao hawakuwa tunasema kwa 9?

621
00:34:01,000 --> 00:34:04,000
Nani ni 9 zetu?

622
00:34:04,000 --> 00:34:07,000
Nani kweli anataka kuwa 9? Haki zote, kuja juu, kuwa 9.

623
00:34:07,000 --> 00:34:10,000
Hapa sisi kwenda.

624
00:34:10,000 --> 00:34:13,000
34, tutaweza kukutana na wewe pale.

625
00:34:13,000 --> 00:34:17,000
Sehemu ya kwanza ni kufanya wenyewe kuangalia kama hiyo.

626
00:34:17,000 --> 00:34:21,000
26, 22, 17, nzuri.

627
00:34:21,000 --> 00:34:25,000
Kama unaweza kusimama mbali na upande, kwa sababu sisi ni kwenda malloc wewe katika wakati huu.

628
00:34:25,000 --> 00:34:29,000
>> Nzuri, nzuri.

629
00:34:29,000 --> 00:34:32,000
Okay, bora, hivyo hebu kuuliza maswali kadhaa hapa.

630
00:34:32,000 --> 00:34:34,000
Na kweli, nini jina yako >> Anita?.

631
00:34:34,000 --> 00:34:37,000
Anita, sawa, kuja juu zaidi ya hapa.

632
00:34:37,000 --> 00:34:41,000
Anita ni kwenda kutusaidia aina ya kutatua moja haki rahisi swali katika kwanza,

633
00:34:41,000 --> 00:34:44,000
ambayo ni jinsi gani unaweza kupata kama au thamani ni katika orodha?

634
00:34:44,000 --> 00:34:48,000
Sasa, taarifa kwamba kwanza, kuwakilishwa hapa na Lucas,

635
00:34:48,000 --> 00:34:52,000
ni kidogo tofauti, na hivyo kipande chake cha karatasi ni makusudi sideways

636
00:34:52,000 --> 00:34:55,000
sababu si kabisa kama mrefu na haina kuchukua kama bits wengi,

637
00:34:55,000 --> 00:34:58,000
ingawa kitaalam ana ukubwa sawa ya karatasi tu kuzungushwa.

638
00:34:58,000 --> 00:35:01,000
Lakini ni tofauti kidogo katika kwamba yeye tu 32 bits kwa pointer,

639
00:35:01,000 --> 00:35:05,000
na wote wa guys hawa ni 64 bits, nusu ya ambayo ni idadi, nusu ya ambayo ni pointer.

640
00:35:05,000 --> 00:35:08,000
Lakini pointer si taswira, hivyo kama wewe guys inaweza fulani awkwardly

641
00:35:08,000 --> 00:35:12,000
kutumia mkono wako wa kushoto na kumweka katika mtu karibu na wewe.

642
00:35:12,000 --> 00:35:14,000
Na wewe ni namba 34. Nini jina lako?

643
00:35:14,000 --> 00:35:16,000
Ari.

644
00:35:16,000 --> 00:35:19,000
Ari, hivyo kweli, kushikilia karatasi katika mkono wako wa kulia na mkono wa kushoto inakwenda moja kwa moja chini.

645
00:35:19,000 --> 00:35:21,000
Wewe kuwakilisha null upande wa kushoto.

646
00:35:21,000 --> 00:35:24,000
>> Sasa picha yetu ya kibinadamu ni sana thabiti.

647
00:35:24,000 --> 00:35:26,000
Hii ni kweli jinsi ya kuyatumia kazi.

648
00:35:26,000 --> 00:35:29,000
Na kama unaweza scrunch kidogo njia hii hivyo mimi nina katika njia yako.

649
00:35:29,000 --> 00:35:34,000
Anita hapa, kupata mimi namba 22,

650
00:35:34,000 --> 00:35:40,000
lakini kudhani kikwazo cha si binadamu wakimshikilia vipande vya karatasi,

651
00:35:40,000 --> 00:35:43,000
lakini hii ni orodha, na wewe tu Lucas kuanza na

652
00:35:43,000 --> 00:35:46,000
kwa sababu yeye ni halisi pointer kwanza.

653
00:35:46,000 --> 00:35:51,000
Tuseme wewe mwenyewe ni pointer, na hivyo wewe pia kuwa na uwezo wa kumweka katika kitu fulani.

654
00:35:51,000 --> 00:35:56,000
Mbona wewe kuanza kwa akionyesha nini hasa ni Lucas akionyesha?

655
00:35:56,000 --> 00:35:58,000
Nzuri, na napenda kutunga hii nje zaidi ya hapa.

656
00:35:58,000 --> 00:36:04,000
Tu kwa ajili ya majadiliano, ngoja nikuondoe up ukurasa tupu hapa.

657
00:36:04,000 --> 00:36:06,000
Jinsi gani unaweza Spell jina yako >> Anita?.

658
00:36:06,000 --> 00:36:08,000
Okay, Anita.

659
00:36:08,000 --> 00:36:18,000
Hebu sema nodi * anita = lucas.

660
00:36:18,000 --> 00:36:22,000
Naam, sisi nisimfikirie wewe lucas. Sisi lazima wito wewe kwanza.

661
00:36:22,000 --> 00:36:25,000
Kwa nini hii ni katika ukweli thabiti na ukweli hapa?

662
00:36:25,000 --> 00:36:27,000
Moja, kwanza tayari ipo.

663
00:36:27,000 --> 00:36:30,000
Kwanza imetengewa ikatengeneza mahali fulani hapa.

664
00:36:30,000 --> 00:36:35,000
Node * kwanza, na ni zimetengwa orodha namna fulani.

665
00:36:35,000 --> 00:36:37,000
Sijui jinsi ya kuwa kilichotokea. Hayo yalitokea kabla ya darasa kuanza.

666
00:36:37,000 --> 00:36:40,000
Hii orodha ya binadamu wanaohusishwa imeanzishwa.

667
00:36:40,000 --> 00:36:44,000
Na sasa katika hatua hii kwa hadithi-hii yote ni kwenda kwenye Facebook inaonekana baadaye-

668
00:36:44,000 --> 00:36:49,000
katika hatua hii ya hadithi, Anita imekuwa initialized kuwa sawa na ya kwanza,

669
00:36:49,000 --> 00:36:51,000
ambayo haina maana kwamba Anita pointi saa Lucas.

670
00:36:51,000 --> 00:36:53,000
Badala yake, anaonyesha kwa nini anasema katika

671
00:36:53,000 --> 00:36:57,000
kwa sababu anuani hiyo hiyo ndani ya bits Lucas ya 32-1, 2, 3 -

672
00:36:57,000 --> 00:37:01,000
sasa ni pia ndani ya bits Anita wa 32-1, 2, 3.

673
00:37:01,000 --> 00:37:05,000
>> Sasa kupata 22. Jinsi gani unaweza kwenda juu ya kufanya hii?

674
00:37:05,000 --> 00:37:07,000
Nini kwamba Point? >> Kwa chochote.

675
00:37:07,000 --> 00:37:11,000
Onesha chochote, hivyo kwenda mbele na kutenda ni nje kama bora unaweza hapa.

676
00:37:11,000 --> 00:37:15,000
Nzuri, nzuri, na sasa wewe ni akionyesha-nini jina lako na 22?

677
00:37:15,000 --> 00:37:18,000
Ramon. >> Ramon, hivyo Ramon klarar 22.

678
00:37:18,000 --> 00:37:20,000
Wewe sasa kufanyika hundi.

679
00:37:20,000 --> 00:37:24,000
Je, Ramon == 22, na kama ni hivyo, kwa mfano, tunaweza kurudi kweli.

680
00:37:24,000 --> 00:37:26,000
Hebu-wakati haya guys kusimama hapa kiasi fulani awkwardly-

681
00:37:26,000 --> 00:37:32,000
basi mimi kufanya kitu kwa haraka kama bool kupata.

682
00:37:32,000 --> 00:37:37,000
Mimi nina kwenda mbele na kusema (node ​​* orodha, int n).

683
00:37:37,000 --> 00:37:39,000
Nitakuwa haki ya nyuma na nyie. Mimi tu kuandika baadhi code.

684
00:37:39,000 --> 00:37:45,000
Na sasa mimi nina kwenda mbele na kufanya hili, nodi * anita = orodha.

685
00:37:45,000 --> 00:37:51,000
Na mimi nina kwenda mbele na kusema wakati (anita = null!).

686
00:37:51,000 --> 00:37:57,000
>> Fumbo hapa ni kupata kidogo aliweka, lakini wakati (anita = null!), je, nataka kufanya?

687
00:37:57,000 --> 00:38:03,000
Mimi haja ya baadhi ya njia ya referencing

688
00:38:03,000 --> 00:38:05,000
integer kwamba Anita ananyoosha saa.

689
00:38:05,000 --> 00:38:08,000
Katika siku za nyuma, wakati tulikuwa miundo, ambayo ni nodi,

690
00:38:08,000 --> 00:38:11,000
sisi kutumika nukuu dot, na sisi bila kusema kitu kama

691
00:38:11,000 --> 00:38:15,000
anita.n, lakini tatizo hapa ni kwamba Anita si struct per se.

692
00:38:15,000 --> 00:38:17,000
Je, ni yeye?

693
00:38:17,000 --> 00:38:21,000
Yeye ni pointer, hivyo kweli, kama tunataka kutumia hii dot nukuu-

694
00:38:21,000 --> 00:38:23,000
na hii ni kwenda kuangalia kwa makusudi kidogo cryptic-

695
00:38:23,000 --> 00:38:28,000
sisi kufanya kitu kama kwenda mkono wa kushoto wa chochote Anita ni akionyesha

696
00:38:28,000 --> 00:38:31,000
na kisha kupata shamba iitwayo n.

697
00:38:31,000 --> 00:38:35,000
Anita ni pointer, lakini nini ni * anita?

698
00:38:35,000 --> 00:38:38,000
Nini kupata wakati kwenda nini Anita ananyoosha saa?

699
00:38:38,000 --> 00:38:42,000
struct, nodi, na node, wanakumbuka, ana shamba iitwayo n

700
00:38:42,000 --> 00:38:47,000
kwa sababu ina, wanakumbuka, haya mashamba 2, karibu na n,

701
00:38:47,000 --> 00:38:50,000
kuwa tuliona wakati ago haki hapa.

702
00:38:50,000 --> 00:38:53,000
>> Kwa kweli kuiga hii katika kanuni,

703
00:38:53,000 --> 00:39:02,000
tunaweza kufanya hii na kusema kama ((* anita). n == n), n kwamba mimi nina kuangalia kwa.

704
00:39:02,000 --> 00:39:04,000
Ona kwamba kazi ilikuwa kupita katika idadi najali.

705
00:39:04,000 --> 00:39:10,000
Kisha mimi unaweza kwenda mbele na kufanya kitu kama kurudi kweli.

706
00:39:10,000 --> 00:39:12,000
Mwingine, kama si kwamba kesi, nini nataka kufanya?

707
00:39:12,000 --> 00:39:19,000
Je, mimi kutafsiri kwa kificho nini Anita akafanya hivyo intuitively kutembea kupitia orodha?

708
00:39:19,000 --> 00:39:26,000
Nifanye nini hapa kuiga Anita kuchukua hatua kwa upande wa kushoto, kuwa hatua kwa upande wa kushoto?

709
00:39:26,000 --> 00:39:28,000
[Inaudible mwanafunzi majibu] >> gani hiyo?

710
00:39:28,000 --> 00:39:30,000
[Inaudible mwanafunzi majibu]

711
00:39:30,000 --> 00:39:34,000
Nzuri, si wazo mbaya, lakini katika siku za nyuma, wakati tumekuwa kufanyika hili, tumefanya anita + +

712
00:39:34,000 --> 00:39:37,000
kwa sababu kwamba ingekuwa kuongeza idadi 1 kwa Anita,

713
00:39:37,000 --> 00:39:40,000
ambayo ingekuwa kawaida kumweka katika mtu mwingine, kama Ramon,

714
00:39:40,000 --> 00:39:44,000
au mtu wa pili wake, au karibu naye mtu chini ya mstari.

715
00:39:44,000 --> 00:39:49,000
Lakini si kwamba nzuri kabisa hapa kwa sababu gani jambo hili kuangalia kama katika kumbukumbu?

716
00:39:49,000 --> 00:39:54,000
Si kwamba. Tuna Disable kwamba.

717
00:39:54,000 --> 00:40:00,000
Inaonekana kama hii katika kumbukumbu, na hata ingawa nimekuwa inayotolewa 1 na 2 na 3 karibu na mtu mwingine,

718
00:40:00,000 --> 00:40:03,000
kama kweli sisi simulate hii-unaweza guys, wakati bado akionyesha watu sawa,

719
00:40:03,000 --> 00:40:07,000
Unaweza baadhi ya wewe kuchukua random hatua nyuma, baadhi yenu hatua random mbele?

720
00:40:07,000 --> 00:40:10,000
>> Fujo Hii bado ni orodha zilizounganishwa,

721
00:40:10,000 --> 00:40:13,000
lakini haya guys inaweza kuwa mahali popote katika kumbukumbu,

722
00:40:13,000 --> 00:40:15,000
hivyo anita + + si kwenda kufanya kazi kwa nini?

723
00:40:15,000 --> 00:40:19,000
Nini katika eneo anita + +?

724
00:40:19,000 --> 00:40:21,000
Nani anajua.

725
00:40:21,000 --> 00:40:24,000
Ni baadhi ya thamani mengine kwamba tu hivyo hutokea kuwa alitia

726
00:40:24,000 --> 00:40:28,000
kati ya wote wa nodi hiyo kwa bahati kwa sababu sisi siyo kutumia safu.

727
00:40:28,000 --> 00:40:30,000
Sisi zilizotengwa kila nodi hiyo mmoja mmoja.

728
00:40:30,000 --> 00:40:32,000
Sawa, kama guys unaweza safi wenyewe nyuma juu.

729
00:40:32,000 --> 00:40:37,000
Hebu kupendekeza kwamba badala ya anita + +, sisi badala kufanya anita anapata-

730
00:40:37,000 --> 00:40:42,000
vizuri, kwa nini sio sisi kwenda chochote Anita ananyoosha saa na kisha kufanya ijayo.?

731
00:40:42,000 --> 00:40:45,000
Kwa maneno mengine, sisi kwenda Ramon, ambaye ameshika namba 22,

732
00:40:45,000 --> 00:40:51,000
na kisha ya pili. ni kama ingawa Anita itakuwa kuiga mkono wake wa kushoto pointer.

733
00:40:51,000 --> 00:40:54,000
Lakini yeye hakutaka kwenda mbali zaidi kuliko Ramon kwa sababu sisi kupatikana 22.

734
00:40:54,000 --> 00:40:56,000
Lakini kwamba itakuwa ni wazo. Sasa, hii ni fujo mungu-kubwa.

735
00:40:56,000 --> 00:40:59,000
Kusema kweli, hakuna mtu milele kumbuka hii syntax, na hivyo nashiriki,

736
00:40:59,000 --> 00:41:04,000
ni kweli kidogo makusudi-oh, wewe hawakuwa kweli kuona kile aliandika.

737
00:41:04,000 --> 00:41:08,000
Hii itakuwa zaidi ya kulazimisha kama naweza. Voilà!

738
00:41:08,000 --> 00:41:10,000
>> Nyuma ya pazia, nilikuwa kutatua tatizo kwa njia hii.

739
00:41:10,000 --> 00:41:14,000
Anita, kuchukua hatua kwa upande wa kushoto,

740
00:41:14,000 --> 00:41:18,000
kwanza, hatuwezi kwenda anuani kwamba Anita ni akionyesha

741
00:41:18,000 --> 00:41:23,000
na ambapo yeye utapata si tu n, ambayo sisi tu checked kwa ajili ya kulinganisha,

742
00:41:23,000 --> 00:41:25,000
lakini pia kupata ijayo - katika kesi hii,

743
00:41:25,000 --> 00:41:28,000
Ramon wa mkono wa kushoto akizungumzia nodi ijayo katika orodha.

744
00:41:28,000 --> 00:41:32,000
Lakini hii ni fujo mungu-kubwa ambayo mimi inajulikana mapema,

745
00:41:32,000 --> 00:41:34,000
lakini zinageuka C unatuwezesha kurahisisha hii.

746
00:41:34,000 --> 00:41:40,000
Badala ya kuandika (* anita), tunaweza badala kuandika tu anita-> n,

747
00:41:40,000 --> 00:41:45,000
na ni exact kitu functionally, lakini ni mengi zaidi Intuitive,

748
00:41:45,000 --> 00:41:48,000
na ni mengi zaidi sambamba na picha kwamba sisi tumekuwa kuchora

749
00:41:48,000 --> 00:41:50,000
muda wote huu kwa kutumia mishale.

750
00:41:50,000 --> 00:41:57,000
>> Mwisho, nini tunahitaji kufanya mwisho wa mpango huu?

751
00:41:57,000 --> 00:42:00,000
Kuna moja mstari wa kanuni iliyobaki.

752
00:42:00,000 --> 00:42:02,000
Kurudi nini?

753
00:42:02,000 --> 00:42:05,000
Uongo, kwa sababu kama sisi kupata njia nzima wakati kitanzi

754
00:42:05,000 --> 00:42:10,000
na Anita ni, kwa kweli, null, kwamba maana akaenda njia yote hadi mwisho wa orodha

755
00:42:10,000 --> 00:42:12,000
ambako alikuwa akionyesha-nini jina yako tena?

756
00:42:12,000 --> 00:42:15,000
Ari. >> Ari wa mkono wa kushoto, ambayo ni null.

757
00:42:15,000 --> 00:42:18,000
Anita ni sasa null, na mimi kutambua wewe ni wamesimama tu hapa awkwardly katika utata

758
00:42:18,000 --> 00:42:21,000
kwa sababu mimi naenda mbali juu monologue hapa,

759
00:42:21,000 --> 00:42:23,000
lakini tutaweza kuhusisha wewe tena katika muda tu.

760
00:42:23,000 --> 00:42:27,000
Anita ni null katika hatua katika hadithi, hivyo kitanzi wakati vipoe,

761
00:42:27,000 --> 00:42:30,000
na tuna kurudi uongo kwa sababu kama yeye got njia yote ya pointer Ari wa null

762
00:42:30,000 --> 00:42:34,000
basi kulikuwa hakuna idadi ya kwamba yeye kutafutwa katika orodha.

763
00:42:34,000 --> 00:42:39,000
Tunaweza safi hii juu pia, lakini hii ni utekelezaji pretty nzuri basi

764
00:42:39,000 --> 00:42:43,000
ya kazi traversal, kupata kazi kwa orodha zinazoungwa.

765
00:42:43,000 --> 00:42:48,000
Ni bado linear tafuta, lakini si rahisi kama + + pointer

766
00:42:48,000 --> 00:42:52,000
au + + variable i kwa sababu sasa hatuwezi nadhani

767
00:42:52,000 --> 00:42:54,000
ambapo kila mmoja wa nodi hiyo ni katika kumbukumbu.

768
00:42:54,000 --> 00:42:57,000
Tuna kwa literally kufuata ya uchaguzi wa breadcrumbs au, hasa zaidi,

769
00:42:57,000 --> 00:43:00,000
kuyatumia, kupata kutoka nodi mmoja hadi mwingine.

770
00:43:00,000 --> 00:43:02,000
>> Sasa hebu jaribu mwingine mmoja. Anita, unataka kurudi hapa?

771
00:43:02,000 --> 00:43:06,000
Mbona sisi kwenda mbele na kutenga mtu mwingine kutoka watazamaji?

772
00:43:06,000 --> 00:43:08,000
Malloc-nini jina yako >> Rebecca?.

773
00:43:08,000 --> 00:43:10,000
Rebecca. Rebecca imekuwa malloced kutoka kwa watazamaji,

774
00:43:10,000 --> 00:43:13,000
na yeye sasa ni hifadhi ya idadi 55.

775
00:43:13,000 --> 00:43:17,000
Na lengo katika mkono sasa ni kwa Anita Insert

776
00:43:17,000 --> 00:43:22,000
Rebecca katika orodha wanaohusishwa hapa katika nafasi yake sahihi.

777
00:43:22,000 --> 00:43:24,000
Njoo hapa juu kwa muda.

778
00:43:24,000 --> 00:43:28,000
Nimefanya kitu kama hiki.

779
00:43:28,000 --> 00:43:32,000
Nimefanya * nodi. Na nini jina yako tena?

780
00:43:32,000 --> 00:43:34,000
Rebecca. >> Rebecca, okay.

781
00:43:34,000 --> 00:43:41,000
Rebecca anapata malloc (sizeof (node)).

782
00:43:41,000 --> 00:43:44,000
Tu kama tumetenga mambo kama wanafunzi na whatnot katika siku za nyuma,

783
00:43:44,000 --> 00:43:46,000
tunahitaji ukubwa wa nodi, hivyo sasa Rebecca

784
00:43:46,000 --> 00:43:49,000
ananyoosha katika nini?

785
00:43:49,000 --> 00:43:52,000
Rebecca ana mashamba mawili ndani yake, moja ambayo ni ya 55.

786
00:43:52,000 --> 00:43:55,000
Hebu kufanya nini, rebecca-> = 55.

787
00:43:55,000 --> 00:44:00,000
Lakini basi rebecca-> ijayo lazima-kama hivi sasa, mkono wake ni aina ya nani anajua?

788
00:44:00,000 --> 00:44:03,000
Ni akionyesha thamani baadhi ya takataka, hivyo kwa nini si kwa hatua nzuri

789
00:44:03,000 --> 00:44:07,000
sisi angalau kufanya hili ili mkono wa kushoto ni sasa katika upande wake.

790
00:44:07,000 --> 00:44:09,000
Sasa Anita, kuchukua ni kutoka hapa.

791
00:44:09,000 --> 00:44:11,000
Una Rebecca baada zimetengwa.

792
00:44:11,000 --> 00:44:20,000
Kwenda mbele na kupata ambapo sisi inapaswa kuweka Rebecca.

793
00:44:20,000 --> 00:44:25,000
Nzuri, nzuri sana.

794
00:44:25,000 --> 00:44:28,000
Okay, nzuri, na sasa tunahitaji wewe kutoa kidogo ya mwelekeo,

795
00:44:28,000 --> 00:44:30,000
hivyo umefikia Ari.

796
00:44:30,000 --> 00:44:33,000
Mkono wake wa kushoto ni null, lakini Rebecca wazi ni mali ya haki,

797
00:44:33,000 --> 00:44:36,000
hivyo ni jinsi gani tunaweza kubadilisha orodha hii wanaohusishwa

798
00:44:36,000 --> 00:44:38,000
ili Insert Rebecca katika mahali sahihi?

799
00:44:38,000 --> 00:44:42,000
Kama unaweza literally hoja ya watu mikono kushoto kuzunguka kama inahitajika,

800
00:44:42,000 --> 00:44:48,000
tutaweza kurekebisha tatizo kwa njia hiyo.

801
00:44:48,000 --> 00:44:52,000
Okay, nzuri, na wakati huo huo, Rebecca wa mkono wa kushoto ni sasa kwa upande wake.

802
00:44:52,000 --> 00:44:54,000
>> Hiyo ilikuwa rahisi mno.

803
00:44:54,000 --> 00:44:57,000
Hebu jaribu kutenga-we're karibu kufanyika, 20.

804
00:44:57,000 --> 00:44:59,000
Okay, kuja juu juu.

805
00:44:59,000 --> 00:45:04,000
20 zimetengwa, hivyo basi mimi kwenda mbele na kusema tena hapa

806
00:45:04,000 --> 00:45:07,000
tumekuwa tu kufanyika nodi * saad.

807
00:45:07,000 --> 00:45:11,000
Tuna malloc (sizeof (node)).

808
00:45:11,000 --> 00:45:16,000
Sisi basi kufanya hivyo halisi syntax kama sisi alifanya mbele kwa 20,

809
00:45:16,000 --> 00:45:20,000
na mimi itabidi kufanya ijayo = null, na sasa ni juu Anita

810
00:45:20,000 --> 00:45:23,000
kuingiza wewe katika orodha wanaohusishwa, kama unaweza kucheza kwamba exact jukumu.

811
00:45:23,000 --> 00:45:30,000
Nitafanya.

812
00:45:30,000 --> 00:45:32,000
Okay, nzuri.

813
00:45:32,000 --> 00:45:38,000
Sasa fikiria kwa makini kabla ya kuanza kusonga mikono kushoto kote.

814
00:45:38,000 --> 00:45:46,000
Wewe kwa mbali got jukumu zaidi Awkward leo.

815
00:45:46,000 --> 00:45:59,000
Ambaye mkononi lisongehswe kwanza?

816
00:45:59,000 --> 00:46:02,000
Okay, kusubiri, mimi nina kusikia baadhi ya hapana.

817
00:46:02,000 --> 00:46:07,000
Kama baadhi folks ingekuwa politely kama msaada kutatua hali ya Awkward hapa.

818
00:46:07,000 --> 00:46:11,000
Ambaye mkono wa kushoto lazima updated kwanza labda? Yeah.

819
00:46:11,000 --> 00:46:13,000
[Mwanafunzi] Saad ya.

820
00:46:13,000 --> 00:46:15,000
Okay, Saad, kwa nini, ingawa?

821
00:46:15,000 --> 00:46:17,000
[Inaudible mwanafunzi majibu]

822
00:46:17,000 --> 00:46:19,000
Nzuri, kwa sababu kama sisi hoja-nini jina yako >> Marshall?.

823
00:46:19,000 --> 00:46:22,000
Marshall, kama sisi hoja mkono wake wa kwanza chini ya null,

824
00:46:22,000 --> 00:46:25,000
sasa tuna literally yatima watu wanne katika orodha hii

825
00:46:25,000 --> 00:46:29,000
kwa sababu alikuwa kitu pekee akionyesha Ramon na kila mtu wa kushoto,

826
00:46:29,000 --> 00:46:31,000
hivyo uppdatering kwamba pointer kwanza ilikuwa mbaya.

827
00:46:31,000 --> 00:46:33,000
Hebu tengua kwamba.

828
00:46:33,000 --> 00:46:37,000
Nzuri, na sasa kwenda mbele na hoja sahihi kushoto akionyesha Ramon.

829
00:46:37,000 --> 00:46:39,000
Hii anahisi redundant kidogo.

830
00:46:39,000 --> 00:46:41,000
Sasa kuna watu wawili akionyesha Ramon, lakini hiyo ni faini

831
00:46:41,000 --> 00:46:43,000
kwa sababu sasa jinsi mwingine kufanya sisi update orodha?

832
00:46:43,000 --> 00:46:48,000
Gani nyingine mkono ana hoja?

833
00:46:48,000 --> 00:46:53,000
Bora, sasa sisi waliopotea yoyote kumbukumbu?

834
00:46:53,000 --> 00:46:57,000
Hapana, hivyo nzuri, hebu angalia kama hatuwezi kuvunja hii mara moja zaidi.

835
00:46:57,000 --> 00:47:00,000
>> Mallocing mara moja ya mwisho, namba 5.

836
00:47:00,000 --> 00:47:04,000
Njia yote ya nyuma, kuja juu chini.

837
00:47:04,000 --> 00:47:08,000
Ni ya kusisimua sana.

838
00:47:08,000 --> 00:47:15,000
[Applause]

839
00:47:15,000 --> 00:47:17,000
Nini jina yako >> Ron?.

840
00:47:17,000 --> 00:47:19,000
Ron, sawa, wewe ni malloced kama namba 5.

841
00:47:19,000 --> 00:47:23,000
Tumekuwa tu ifanyike kificho kwamba ni karibu sawa na hizi

842
00:47:23,000 --> 00:47:26,000
pamoja na haki ya jina tofauti.

843
00:47:26,000 --> 00:47:28,000
Bora.

844
00:47:28,000 --> 00:47:38,000
Sasa, Anita, bahati nzuri kuingiza namba 5 katika orodha sasa.

845
00:47:38,000 --> 00:47:43,000
Nzuri, na?

846
00:47:43,000 --> 00:47:47,000
Bora, hivyo hii ni kweli ya tatu ya kesi tatu jumla.

847
00:47:47,000 --> 00:47:49,000
Sisi kwanza alikuwa mtu mwishoni, Rebecca.

848
00:47:49,000 --> 00:47:51,000
Sisi basi alikuwa mtu katikati.

849
00:47:51,000 --> 00:47:53,000
Sasa tuna mtu tangu mwanzo, na katika mfano huu,

850
00:47:53,000 --> 00:47:56,000
sisi sasa alikuwa kwa update Lucas kwa mara ya kwanza

851
00:47:56,000 --> 00:48:00,000
kwa sababu ya kipengele kwanza katika orodha ya sasa ina uhakika kwenye nodi mpya,

852
00:48:00,000 --> 00:48:03,000
ambao, kwa upande mwingine, ni akionyesha idadi nodi 9.

853
00:48:03,000 --> 00:48:06,000
>> Hii ilikuwa maandamano hugely Awkward, mimi nina uhakika,

854
00:48:06,000 --> 00:48:08,000
hivyo duru kubwa ya applause kwa guys haya ikiwa naweza.

855
00:48:08,000 --> 00:48:11,000
Nicely kufanyika.

856
00:48:11,000 --> 00:48:17,000
Hayo ni yote. Unaweza kuweka vipande yako ya karatasi kama kumbukumbu kidogo.

857
00:48:17,000 --> 00:48:22,000
Ni zinageuka kuwa kufanya hivyo katika kanuni

858
00:48:22,000 --> 00:48:26,000
si kabisa rahisi kama tu kusonga mikono kuzunguka

859
00:48:26,000 --> 00:48:28,000
na akizungumzia kuyatumia katika mambo mbalimbali.

860
00:48:28,000 --> 00:48:31,000
Lakini kutambua kwamba linapokuja wakati wa kutekeleza kitu kama

861
00:48:31,000 --> 00:48:34,000
orodha wanaohusishwa au lahaja yake kama wewe kuzingatia kweli

862
00:48:34,000 --> 00:48:38,000
haya misingi ya msingi, matatizo bite-size mimi kuwa na takwimu nje,

863
00:48:38,000 --> 00:48:43,000
ni hii hii au mkono mkono, kutambua kwamba ni nini vinginevyo mpango uungwana tata

864
00:48:43,000 --> 00:48:47,000
inaweza, kwa kweli, kuwa kupunguzwa kwa vitalu haki rahisi jengo kama hii.

865
00:48:47,000 --> 00:48:51,000
>> Hebu kuchukua mambo katika mwelekeo kisasa zaidi bado.

866
00:48:51,000 --> 00:48:53,000
Sisi sasa kuwa na wazo la orodha zinazoungwa.

867
00:48:53,000 --> 00:48:57,000
Sisi pia kuwa-shukrani kwa maoni nyuma kuna-orodha doubly wanaohusishwa,

868
00:48:57,000 --> 00:49:01,000
ambayo inaonekana karibu sawa, lakini sasa tuna kuyatumia mbili ndani ya struct

869
00:49:01,000 --> 00:49:05,000
badala ya mmoja, na sisi inaweza pengine kuwaita wale kuyatumia uliopita na ujao

870
00:49:05,000 --> 00:49:08,000
au kushoto au kulia, lakini sisi, kwa kweli, haja ya watu hao wawili.

871
00:49:08,000 --> 00:49:10,000
code itakuwa zaidi kidogo wanaohusika.

872
00:49:10,000 --> 00:49:12,000
Anita wangalipata kufanya kazi zaidi hapa jukwaani.

873
00:49:12,000 --> 00:49:15,000
Lakini tungeweza shaka kutekeleza kwamba aina ya muundo.

874
00:49:15,000 --> 00:49:19,000
Katika suala la mbio wakati, ingawa, nini itakuwa wakati mbio

875
00:49:19,000 --> 00:49:24,000
kwa Anita wa kutafuta n idadi katika orodha wanaohusishwa sasa?

876
00:49:24,000 --> 00:49:27,000
Bado kubwa O ya n, hivyo ni hakuna bora kuliko tafuta linear.

877
00:49:27,000 --> 00:49:29,000
Hatuwezi kufanya search binary, ingawa, tena.

878
00:49:29,000 --> 00:49:34,000
Kwa nini ilikuwa ni kwamba kesi? Huwezi kuruka karibu.

879
00:49:34,000 --> 00:49:36,000
Hata ingawa sisi ni wazi kuona binadamu wote juu ya hatua,

880
00:49:36,000 --> 00:49:39,000
na Anita wangeweza eyeballed na kusema, "Hapa ni katikati ya orodha,"

881
00:49:39,000 --> 00:49:42,000
yeye bila kujua kwamba kama yeye walikuwa programu ya kompyuta

882
00:49:42,000 --> 00:49:47,000
kwa sababu neno tu yeye alikuwa na latch juu kwa wakati wa mwanzo wa mazingira

883
00:49:47,000 --> 00:49:50,000
ilikuwa Lucas, ambaye alikuwa pointer kwanza.

884
00:49:50,000 --> 00:49:53,000
Angeweza lazima kuwa na kufuata viungo hizo,

885
00:49:53,000 --> 00:49:56,000
kuhesabu njia yake mpaka yeye kupatikana takribani katikati,

886
00:49:56,000 --> 00:49:58,000
na hata basi, yeye si kwenda kujua wakati yeye kufikiwa katikati

887
00:49:58,000 --> 00:50:01,000
isipokuwa yeye anakwenda njia yote ya mwisho kwa kufikiri jinsi wengi kuna,

888
00:50:01,000 --> 00:50:05,000
kisha backtracks, na kwamba pia itakuwa ngumu kama huna

889
00:50:05,000 --> 00:50:07,000
orodha doubly wanaohusishwa wa aina fulani.

890
00:50:07,000 --> 00:50:10,000
>> Kutatua matatizo ya baadhi ya leo, lakini kuanzisha wengine.

891
00:50:10,000 --> 00:50:12,000
Je kuhusu muundo tofauti kabisa data?

892
00:50:12,000 --> 00:50:15,000
Hii ni picha ya trays katika Mather House,

893
00:50:15,000 --> 00:50:19,000
na katika kesi hii, tuna muundo data tumekuwa pia aina ya tayari kuzungumza juu.

894
00:50:19,000 --> 00:50:22,000
Kuongelea stack katika muktadha wa kumbukumbu,

895
00:50:22,000 --> 00:50:26,000
na kwamba aina ya makusudi jina lake kwa sababu stack katika suala la kumbukumbu

896
00:50:26,000 --> 00:50:31,000
ni ufanisi muundo data ambayo ina zaidi na zaidi stuff layered juu yake.

897
00:50:31,000 --> 00:50:35,000
Lakini jambo kuvutia kuhusu stack, kama ilivyo katika hali halisi,

898
00:50:35,000 --> 00:50:38,000
ni kwamba ni aina maalum ya muundo data.

899
00:50:38,000 --> 00:50:42,000
Ni muundo data ambapo kipengele kwanza katika

900
00:50:42,000 --> 00:50:46,000
ni kipengele mwisho nje.

901
00:50:46,000 --> 00:50:50,000
Kama wewe ni tray kwanza kuwekwa kwenye stack,

902
00:50:50,000 --> 00:50:53,000
wewe ni kwenda kuwa kwa bahati mbaya tray mwisho kuchukuliwa mbali stack,

903
00:50:53,000 --> 00:50:55,000
na kwamba si lazima jambo jema.

904
00:50:55,000 --> 00:50:58,000
Kinyume, unaweza kufikiri juu yake kwa njia nyingine kote,

905
00:50:58,000 --> 00:51:02,000
mwisho katika ni nje ya kwanza.

906
00:51:02,000 --> 00:51:05,000
>> Sasa, je yoyote matukio kuja akili ambapo baada ya stack

907
00:51:05,000 --> 00:51:08,000
data muundo ambapo una kwamba mali

908
00:51:08,000 --> 00:51:13,000
ya mwisho katika, nje ya kwanza, ni kweli kulazimisha?

909
00:51:13,000 --> 00:51:16,000
Ni kwamba jambo zuri? Ni kwamba jambo baya?

910
00:51:16,000 --> 00:51:19,000
Ni dhahiri kitu mbaya kama trays walikuwa si wote kufanana

911
00:51:19,000 --> 00:51:21,000
na wote walikuwa maalum rangi tofauti au whatnot,

912
00:51:21,000 --> 00:51:24,000
na rangi unataka ni njia yote chini.

913
00:51:24,000 --> 00:51:26,000
Bila shaka, huwezi kupata kwamba bila juhudi kubwa.

914
00:51:26,000 --> 00:51:28,000
Una kuanza kutoka juu na kufanya kazi kwa njia yako chini.

915
00:51:28,000 --> 00:51:31,000
Vile vile, nini kama ungekuwa mmoja wa wavulana hawa mashabiki

916
00:51:31,000 --> 00:51:34,000
angojaye hadi usiku wote kujaribu kupata iPhone mistari na hadi

917
00:51:34,000 --> 00:51:36,000
katika mahali kama hii?

918
00:51:36,000 --> 00:51:40,000
Je, si ni kuwa nzuri kama Apple kuhifadhi

919
00:51:40,000 --> 00:51:42,000
walikuwa data stack muundo?

920
00:51:42,000 --> 00:51:44,000
Yay? Bali?

921
00:51:44,000 --> 00:51:47,000
Ni nzuri tu kwa watu ambao show up katika dakika ya mwisho iwezekanavyo

922
00:51:47,000 --> 00:51:50,000
na kisha kupata amelitunda foleni.

923
00:51:50,000 --> 00:51:52,000
Na kwa kweli, ukweli kwamba nilikuwa hivyo kutega kusema foleni

924
00:51:52,000 --> 00:51:56,000
ni kweli sambamba na nini tunataka kuwaita aina hii ya muundo data,

925
00:51:56,000 --> 00:51:59,000
moja katika ukweli ambapo utaratibu gani jambo,

926
00:51:59,000 --> 00:52:02,000
na unataka moja ya kwanza katika kuwa moja ya kwanza nje

927
00:52:02,000 --> 00:52:04,000
kama tu kwa ajili ya haki za binadamu.

928
00:52:04,000 --> 00:52:07,000
Tutaweza ujumla wito kwamba data foleni muundo.

929
00:52:07,000 --> 00:52:11,000
>> Ni zinageuka badala orodha wanaohusishwa, tunaweza kuanza kutumia hizi sawa mawazo ya msingi

930
00:52:11,000 --> 00:52:15,000
na kuanza kujenga aina mpya na tofauti ya ufumbuzi wa matatizo.

931
00:52:15,000 --> 00:52:19,000
Kwa mfano, katika kesi ya stack, tunaweza kuwakilisha stack

932
00:52:19,000 --> 00:52:22,000
kutumia muundo data kama hii, napenda kupendekeza.

933
00:52:22,000 --> 00:52:26,000
Katika kesi hiyo, nimekuwa alitangaza struct, na nimekuwa alisema ndani ya muundo huu

934
00:52:26,000 --> 00:52:30,000
ni safu ya idadi na kisha kuitwa variable kawaida,

935
00:52:30,000 --> 00:52:33,000
na mimi naenda kuwaita jambo hili stack.

936
00:52:33,000 --> 00:52:35,000
Sasa, kwa nini hii kweli kazi?

937
00:52:35,000 --> 00:52:43,000
Katika kesi ya stack, mimi naweza kuchora hili kwa ufanisi kwenye screen kama safu.

938
00:52:43,000 --> 00:52:47,000
Hapa ni stack yangu. Wale ni namba yangu.

939
00:52:47,000 --> 00:52:50,000
Na tutaweza kuteka yao kama hii, hii, hii, hii, hii.

940
00:52:50,000 --> 00:52:53,000
Na kisha mimi na baadhi nyingine data mwanachama hapa,

941
00:52:53,000 --> 00:52:58,000
iitwayo kawaida, hivyo hii ni kawaida, na hii ni idadi,

942
00:52:58,000 --> 00:53:02,000
na kwa pamoja, iPad zima hapa inawakilisha moja stack muundo.

943
00:53:02,000 --> 00:53:07,000
Sasa, kwa default, ukubwa ina ikatengeneza got kuwa initialized 0,

944
00:53:07,000 --> 00:53:11,000
na nini ndani ya safu ya idadi ya awali

945
00:53:11,000 --> 00:53:14,000
wakati mimi kwanza kutenga safu?

946
00:53:14,000 --> 00:53:16,000
Takataka. Nani anajua? Na si kweli jambo.

947
00:53:16,000 --> 00:53:20,000
Haijalishi kama hii ni 1, 2, 3, 4, 5, kabisa nasibu

948
00:53:20,000 --> 00:53:25,000
kwa bahati mbaya kuhifadhiwa katika muundo wangu kwa sababu ya muda mrefu kama mimi kujua kwamba ukubwa wa stack

949
00:53:25,000 --> 00:53:29,000
ni 0, basi mimi kujua programmatically, si kuangalia yoyote ya vipengele katika safu.

950
00:53:29,000 --> 00:53:31,000
Haijalishi nini huko.

951
00:53:31,000 --> 00:53:34,000
Je, si kuangalia yao, kama itakuwa na maana ya kawaida ya 0.

952
00:53:34,000 --> 00:53:38,000
>> Lakini tuseme sasa mimi kwenda mbele na kuingiza kitu kwenye mkusanyiko.

953
00:53:38,000 --> 00:53:42,000
Mimi nataka kuingiza namba 5, hivyo mimi kuweka namba 5 hapa,

954
00:53:42,000 --> 00:53:45,000
na kisha nini mimi kuweka chini hapa?

955
00:53:45,000 --> 00:53:48,000
Sasa mimi ingekuwa kweli kuweka chini 1 kwa ukubwa,

956
00:53:48,000 --> 00:53:50,000
na sasa stack ni ya kawaida ya 1.

957
00:53:50,000 --> 00:53:53,000
Nini kama mimi kwenda mbele na kuingiza namba, hebu sema, 7 ijayo?

958
00:53:53,000 --> 00:53:57,000
Hii basi anapata updated 2, na kisha tutaweza kufanya 9,

959
00:53:57,000 --> 00:54:02,000
na kisha hii anapata updated 3.

960
00:54:02,000 --> 00:54:05,000
Lakini jambo la kuvutia sasa ya stack hii ni kwamba

961
00:54:05,000 --> 00:54:09,000
Natakiwa kuondoa kipengele ambayo kama nataka pop

962
00:54:09,000 --> 00:54:12,000
kitu mbali ya stack, hivyo kusema?

963
00:54:12,000 --> 00:54:14,000
9 itakuwa jambo la kwanza kwenda.

964
00:54:14,000 --> 00:54:18,000
Jinsi lazima picha kubadilika kama nataka pop kipengele mbali stack,

965
00:54:18,000 --> 00:54:20,000
kiasi kama tray katika Mather?

966
00:54:20,000 --> 00:54:22,000
Yeah >> [Mwanafunzi] Set ukubwa wa 2..

967
00:54:22,000 --> 00:54:27,000
Hasa, wote mimi kufanya ni kuweka ukubwa wa 2, na nini mimi na safu?

968
00:54:27,000 --> 00:54:29,000
Sina kufanya kitu chochote.

969
00:54:29,000 --> 00:54:32,000
Mimi naweza, tu kuwa anal, kuweka 0 huko au -1 au kitu kwa ishara ya

970
00:54:32,000 --> 00:54:34,000
kuwa hii si thamani legit, lakini haijalishi kwa sababu

971
00:54:34,000 --> 00:54:37,000
Naweza kurekodi nje ya safu yenyewe ni muda gani

972
00:54:37,000 --> 00:54:41,000
hivyo kwamba mimi kujua tu kuangalia mambo mawili ya kwanza katika safu hii.

973
00:54:41,000 --> 00:54:47,000
Sasa, kama mimi kwenda na kuongeza idadi ya 8 na safu hii, jinsi gani picha kubadili ijayo?

974
00:54:47,000 --> 00:54:50,000
Hii inakuwa 8, na hii inakuwa 3.

975
00:54:50,000 --> 00:54:52,000
Mimi kukata pembe chache hapa.

976
00:54:52,000 --> 00:54:56,000
Sasa tuna 5, 7, 8, na tuko nyuma na ukubwa wa 3.

977
00:54:56,000 --> 00:54:58,000
Hii ni pretty rahisi kutekeleza,

978
00:54:58,000 --> 00:55:06,000
lakini wakati ni sisi kwenda kwa majuto uamuzi huu design?

979
00:55:06,000 --> 00:55:09,000
Wakati kufanya mambo kuanza kwenda sana, vibaya sana? Yeah.

980
00:55:09,000 --> 00:55:11,000
[Inaudible mwanafunzi majibu]

981
00:55:11,000 --> 00:55:13,000
Wakati unataka kwenda nyuma na kupata kipengele kwanza kuweka in

982
00:55:13,000 --> 00:55:18,000
>> Ni zinageuka hapa hata ingawa stack ni safu chini ya Hood,

983
00:55:18,000 --> 00:55:21,000
miundo haya data tumekuwa kuanza kuzungumza kuhusu pia ujumla inayojulikana kama

984
00:55:21,000 --> 00:55:25,000
abstract data miundo ambapo jinsi re kutekelezwa

985
00:55:25,000 --> 00:55:27,000
ni kabisa badala ya uhakika.

986
00:55:27,000 --> 00:55:31,000
muundo data kama stack zinatakiwa kuongeza msaada

987
00:55:31,000 --> 00:55:35,000
shughuli kama vile kushinikiza, ambayo inasukuma kwenye tray stack,

988
00:55:35,000 --> 00:55:39,000
na pop, ambayo kuondosha kipengele kutoka stack, na hiyo ni yake.

989
00:55:39,000 --> 00:55:43,000
Kama ungekuwa na download code za mtu mwingine ambaye tayari kutekelezwa

990
00:55:43,000 --> 00:55:46,000
jambo hili aitwaye stack, mtu kwamba ingekuwa imeandikwa

991
00:55:46,000 --> 00:55:49,000
mbili tu kazi kwa ajili yenu, kushinikiza na pop, ambao lengo pekee katika maisha

992
00:55:49,000 --> 00:55:51,000
itakuwa kwa kufanya hasa kwamba.

993
00:55:51,000 --> 00:55:54,000
Wewe au kwake ambaye kutekelezwa kwamba mpango

994
00:55:54,000 --> 00:55:58,000
ingekuwa kabisa moja ya kuamua jinsi ya kutekeleza

995
00:55:58,000 --> 00:56:00,000
semantiki ya kusukuma na popping chini ya Hood

996
00:56:00,000 --> 00:56:03,000
au utendaji wa kusukuma na popping.

997
00:56:03,000 --> 00:56:07,000
Na mimi kuwa alifanya uamuzi fulani shortsighted hapa

998
00:56:07,000 --> 00:56:10,000
kwa kutekeleza stack yangu na muundo huu rahisi data kwa nini?

999
00:56:10,000 --> 00:56:12,000
Wakati gani data hii kuvunja muundo?

1000
00:56:12,000 --> 00:56:18,000
Katika hatua gani unataka Mimi kurudi kosa wakati mtumiaji wito kushinikiza, kwa mfano?

1001
00:56:18,000 --> 00:56:20,000
[Mwanafunzi] Kama hakuna nafasi zaidi.

1002
00:56:20,000 --> 00:56:23,000
Hasa, ikiwa hakuna nafasi zaidi, ikiwa nimepata ulizidi uwezo,

1003
00:56:23,000 --> 00:56:27,000
ambayo ni wote kofia kwa sababu inaashiria kwamba ni baadhi ya aina ya mara kwa mara kimataifa.

1004
00:56:27,000 --> 00:56:30,000
Vizuri, basi Mimi tu kwenda na kusema, "Samahani, siwezi kushinikiza thamani nyingine

1005
00:56:30,000 --> 00:56:32,000
kwenye stack, "kiasi kama katika Mather.

1006
00:56:32,000 --> 00:56:36,000
>> Katika hatua nyingine, wao wanaenda kupiga sehemu ya juu ya baraza la mawaziri kuwa kidogo.

1007
00:56:36,000 --> 00:56:39,000
Hakuna nafasi zaidi au uwezo katika stack, ambapo kiwango kuna baadhi ya aina ya makosa.

1008
00:56:39,000 --> 00:56:42,000
Wanapaswa kuweka kipengele mahali pengine, tray mahali pengine,

1009
00:56:42,000 --> 00:56:44,000
au mahali pa wakati wote.

1010
00:56:44,000 --> 00:56:47,000
Sasa, pamoja na foleni, tunaweza kutekeleza tofauti kidogo.

1011
00:56:47,000 --> 00:56:50,000
foleni ni tofauti kidogo katika kuwa chini ya Hood, inaweza kutekelezwa

1012
00:56:50,000 --> 00:56:54,000
kama safu, lakini kwa nini, katika kesi hii, mimi kupendekeza

1013
00:56:54,000 --> 00:56:59,000
na pia kuwa na kipengele kichwa kichwa anayewakilisha ya orodha,

1014
00:56:59,000 --> 00:57:06,000
mbele ya orodha, mtu wa kwanza katika mstari katika kuhifadhi Apple, kwa kuongeza ukubwa?

1015
00:57:06,000 --> 00:57:14,000
Kwa nini nahitaji kipande ziada ya data hapa?

1016
00:57:14,000 --> 00:57:16,000
Fikiria nyuma kwa nini idadi ni

1017
00:57:16,000 --> 00:57:18,000
ikiwa nimepata inayotolewa ni kama ifuatavyo.

1018
00:57:18,000 --> 00:57:21,000
Tuseme hii ni sasa foleni badala ya stack,

1019
00:57:21,000 --> 00:57:24,000
tofauti kuwa-tu kama foleni kuhifadhi-Apple ni haki.

1020
00:57:24,000 --> 00:57:27,000
mtu wa kwanza katika mstari katika mwanzo wa orodha, idadi 5 katika kesi hii,

1021
00:57:27,000 --> 00:57:30,000
yeye au yeye ni kwenda basi katika kuhifadhi kwanza.

1022
00:57:30,000 --> 00:57:32,000
Hebu kufanya hivyo.

1023
00:57:32,000 --> 00:57:35,000
Tuseme kwamba hii ni hali ya foleni yangu katika wakati huu katika muda, na sasa kuhifadhi Apple

1024
00:57:35,000 --> 00:57:39,000
kuufungua na mtu wa kwanza, namba 5, ni kuongozwa katika kuhifadhi.

1025
00:57:39,000 --> 00:57:43,000
Ninawezaje kubadilisha picha sasa kwamba mimi de-queued mtu wa kwanza

1026
00:57:43,000 --> 00:57:47,000
mbele ya mstari?

1027
00:57:47,000 --> 00:57:50,000
Nini kwamba? >> [Mwanafunzi] Mabadiliko ya foleni.

1028
00:57:50,000 --> 00:57:52,000
Mabadiliko ya kichwa, hivyo 5 kutoweka.

1029
00:57:52,000 --> 00:57:56,000
Katika hali halisi, ni kama ingawa-jinsi bora ya kufanya hivyo?

1030
00:57:56,000 --> 00:58:00,000
Katika hali halisi, ni kana kwamba hii guy kutoweka.

1031
00:58:00,000 --> 00:58:03,000
Nini idadi 7 kufanya katika duka halisi?

1032
00:58:03,000 --> 00:58:05,000
Wangeweza kuchukua hatua kubwa mbele.

1033
00:58:05,000 --> 00:58:08,000
>> Lakini nini sisi kuja kufahamu linapokuja arrays

1034
00:58:08,000 --> 00:58:10,000
na kusonga mambo kote?

1035
00:58:10,000 --> 00:58:12,000
Hiyo ni aina ya kupoteza muda wako, sawa?

1036
00:58:12,000 --> 00:58:16,000
Kwa nini wewe kuwa hivyo anal kama kuwa na mtu wa kwanza

1037
00:58:16,000 --> 00:58:21,000
katika mwanzo wa mstari katika mwanzo wa kimwili chunk ya kumbukumbu?

1038
00:58:21,000 --> 00:58:23,000
Hiyo kabisa lazima. Kwa nini?

1039
00:58:23,000 --> 00:58:26,000
Je, inaweza mimi kumbuka tu badala? >> [Inaudible mwanafunzi majibu]

1040
00:58:26,000 --> 00:58:30,000
Hasa, mimi naweza kumbuka tu na hii kichwa data mwanachama ziada

1041
00:58:30,000 --> 00:58:34,000
kwamba sasa ni mkuu wa orodha ni tena 0, ambayo ilikuwa ni wakati iliyopita.

1042
00:58:34,000 --> 00:58:39,000
Sasa ni kweli namba 1. Kwa njia hii, mimi kupata optimization kidogo.

1043
00:58:39,000 --> 00:58:44,000
Kwa sababu tu nimepata de-queued mtu kutoka mstari katika mwanzo wa mstari katika kuhifadhi Apple

1044
00:58:44,000 --> 00:58:47,000
haina maana kila mtu ana kuhama, ambayo wanakumbuka ni operesheni linear.

1045
00:58:47,000 --> 00:58:50,000
Naweza kutumia muda badala ya mara kwa mara tu

1046
00:58:50,000 --> 00:58:53,000
na kufikia basi majibu kwa kasi zaidi.

1047
00:58:53,000 --> 00:58:56,000
Lakini mimi nina bei kulipa ni nini kupata kwamba utendaji ziada

1048
00:58:56,000 --> 00:58:58,000
na si kuwa na kuhama kila mtu?

1049
00:58:58,000 --> 00:59:01,000
Yeah. >> [Inaudible mwanafunzi majibu]

1050
00:59:01,000 --> 00:59:04,000
Anaweza kuongeza watu zaidi, vizuri, tatizo kwamba ni orthogonal

1051
00:59:04,000 --> 00:59:07,000
na ukweli kwamba sisi siyo shifting watu duniani.

1052
00:59:07,000 --> 00:59:11,000
Ni bado safu, hivyo kama au sisi kuhama kila mtu au si-

1053
00:59:11,000 --> 00:59:13,000
oh, mimi kuona nini maana, sawa.

1054
00:59:13,000 --> 00:59:16,000
Kweli, mimi kukubaliana na unachosema kwa kuwa karibu kama ingawa

1055
00:59:16,000 --> 00:59:19,000
tuko sasa kamwe kwenda kutumia mwanzo wa safu hii tena

1056
00:59:19,000 --> 00:59:22,000
kwa sababu kama mimi kuondoa 5, basi mimi kuondoa 7.

1057
00:59:22,000 --> 00:59:24,000
Lakini mimi tu kuweka watu kwa haki.

1058
00:59:24,000 --> 00:59:28,000
>> Ni anahisi kama mimi nina kupoteza nafasi, na hatimaye foleni yangu disintegrates ndani ya kitu!

1059
00:59:28,000 --> 00:59:31,000
hivyo tunaweza tu watu iliyomficha

1060
00:59:31,000 --> 00:59:35,000
na tunaweza kufikiri wa safu hii kwa kweli kama baadhi ya aina ya muundo mviringo,

1061
00:59:35,000 --> 00:59:38,000
lakini sisi kutumia nini operator katika C kufanya aina hiyo ya iliyomficha?

1062
00:59:38,000 --> 00:59:40,000
[Inaudible mwanafunzi majibu] >> operator modulo.

1063
00:59:40,000 --> 00:59:43,000
Itakuwa annoying kidogo kufikiri kwa jinsi gani unaweza kufanya iliyomficha

1064
00:59:43,000 --> 00:59:46,000
lakini tunaweza kufanya hivyo, na sisi inaweza kuanza kuweka watu katika kile kutumika kuwa mbele ya mstari,

1065
00:59:46,000 --> 00:59:52,000
lakini sisi kumbuka tu na hii variable kichwa kichwa ambaye halisi ya mstari kweli ni.

1066
00:59:52,000 --> 00:59:57,000
Je, iwapo, badala yake, lengo letu hatimaye, ingawa,

1067
00:59:57,000 --> 01:00:00,000
ilikuwa kuangalia namba, kama tulivyofanya hapa juu ya hatua kwa Anita,

1068
01:00:00,000 --> 01:00:02,000
lakini kweli tunataka bora ya walimwengu wote hawa?

1069
01:00:02,000 --> 01:00:05,000
Tunataka zaidi kuliko sophistication safu inaruhusu

1070
01:00:05,000 --> 01:00:09,000
sababu tunataka uwezo wa dynamically kukua muundo data.

1071
01:00:09,000 --> 01:00:12,000
Lakini hatutaki kuwa na mapumziko kwa kitu ambacho sisi alidokeza

1072
01:00:12,000 --> 01:00:15,000
katika hotuba ya kwanza ilikuwa si algorithm mojawapo,

1073
01:00:15,000 --> 01:00:17,000
ile ya utafutaji linear.

1074
01:00:17,000 --> 01:00:21,000
Ni zinageuka kuwa unaweza, kwa kweli, kufikia

1075
01:00:21,000 --> 01:00:24,000
au angalau karibu na wakati mara kwa mara, ambapo mtu kama Anita,

1076
01:00:24,000 --> 01:00:27,000
kama yeye configures data wake muundo si kwa kuwa orodha zilizounganishwa,

1077
01:00:27,000 --> 01:00:30,000
si kwa kuwa stack, si kwa kuwa foleni, anaweza, kwa kweli,

1078
01:00:30,000 --> 01:00:33,000
kuja na muundo data kwamba unamruhusu kuangalia juu ya mambo,

1079
01:00:33,000 --> 01:00:37,000
hata maneno, si tu idadi, katika kile Tutamwita wakati mara kwa mara.

1080
01:00:37,000 --> 01:00:40,000
>> Na kwa kweli, kuangalia mbele, mmoja wa psets katika darasa hili ni karibu daima

1081
01:00:40,000 --> 01:00:43,000
utekelezaji wa spellchecker, ambapo

1082
01:00:43,000 --> 01:00:46,000
sisi kukupa tena baadhi 150,000 maneno ya Kiingereza na lengo ni

1083
01:00:46,000 --> 01:00:51,000
mzigo wale katika kumbukumbu na kwa kasi na uwezo wa kujibu maswali ya aina

1084
01:00:51,000 --> 01:00:54,000
ni neno hili yameendelezwa vizuri?

1085
01:00:54,000 --> 01:00:58,000
Na ingekuwa kweli Suck kama alikuwa na iterate kupitia maneno yote 150,000 kujibu.

1086
01:00:58,000 --> 01:01:02,000
Lakini, kwa kweli, tutaweza kuona kwamba tunaweza kufanya hivyo katika muda sana, ya haraka sana.

1087
01:01:02,000 --> 01:01:06,000
Na itakuja kuhusisha kutekeleza kitu kinachoitwa meza hash,

1088
01:01:06,000 --> 01:01:09,000
na hata kama katika mtazamo wa kwanza jambo hili aitwaye meza hash ni kwenda

1089
01:01:09,000 --> 01:01:12,000
hebu kufikia haya super mwitikio wa haraka wakati,

1090
01:01:12,000 --> 01:01:18,000
zinageuka kuwa kuna ukweli katika tatizo.

1091
01:01:18,000 --> 01:01:23,000
Linapokuja wakati wa kutekeleza jambo hili aitwaye-tena, mimi nina kufanya hivyo tena.

1092
01:01:23,000 --> 01:01:25,000
Mimi nina moja tu hapa.

1093
01:01:25,000 --> 01:01:28,000
Linapokuja wakati wa kutekeleza jambo hili aitwaye meza hash,

1094
01:01:28,000 --> 01:01:30,000
sisi itawabidi kufanya uamuzi.

1095
01:01:30,000 --> 01:01:32,000
Jinsi kubwa lazima jambo hili kweli kuwa?

1096
01:01:32,000 --> 01:01:36,000
Na wakati sisi kuanza idadi ya kuingiza katika meza hii hash,

1097
01:01:36,000 --> 01:01:38,000
jinsi sisi kwenda kuhifadhi yao katika namna

1098
01:01:38,000 --> 01:01:42,000
kwamba tunaweza kupata yao nyuma nje kwa haraka kama sisi got yao katika?

1099
01:01:42,000 --> 01:01:45,000
Lakini tutaweza kuona kabla ya muda mrefu kwamba swali hili

1100
01:01:45,000 --> 01:01:48,000
wakati siku ya kuzaliwa ya kila mtu ni katika darasa itakuwa kabisa germane.

1101
01:01:48,000 --> 01:01:51,000
Ni zinageuka kuwa katika nafasi hii, sisi tumepewa watu mia kadhaa,

1102
01:01:51,000 --> 01:01:56,000
hivyo tabia mbaya kwamba sisi wawili kuwa na siku ya kuzaliwa huo pengine ni pretty juu.

1103
01:01:56,000 --> 01:01:58,000
Nini kama kulikuwa na 40 tu ya sisi katika chumba hii?

1104
01:01:58,000 --> 01:02:02,000
Je, ni tabia mbaya ya watu wawili kuzaliwa sawa?

1105
01:02:02,000 --> 01:02:04,000
[Wanafunzi] Zaidi ya 50%.

1106
01:02:04,000 --> 01:02:06,000
Yeah, zaidi ya 50%. Kwa kweli, mimi hata kuletwa chati.

1107
01:02:06,000 --> 01:02:08,000
Ni zinageuka-na hii ni kweli tu sneak preview-

1108
01:02:08,000 --> 01:02:12,000
kama kuna 58 tu ya sisi katika nafasi hii, uwezekano wa 2 wa kwetu

1109
01:02:12,000 --> 01:02:16,000
kuwa na siku ya kuzaliwa huo ni hugely juu, karibu 100%,

1110
01:02:16,000 --> 01:02:20,000
na ambayo inaenda kusababisha rundo zima la kuumiza kwa ajili yetu juu ya Jumatano.

1111
01:02:20,000 --> 01:02:24,000
>> Kwa kuwa alisema, hebu kuahirishwa hapa. Tutaweza kuona juu ya Jumatano.

1112
01:02:24,000 --> 01:02:28,000
[Applause]

1113
01:02:28,000 --> 01:02:30,000
[CS50.TV]