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[MUSIC KUCHEZA]

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DAVID J. Malan: All wa kulia.

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Hii ni CS50.

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Hii ni wiki tano kuendelea, na sisi
kuwa na baadhi ya habari njema na baadhi ya habari mbaya.

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Hivyo habari njema ni kwamba CS50
lanserar Ijumaa hii.

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00:00:21,140 --> 00:00:24,430
Kama ungependa kujiunga na sisi,
kichwa na kawaida URL hapa.

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00:00:24,430 --> 00:00:28,670
Habari Hata bora, hakuna hotuba
huu kuja Jumatatu ya 13.

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00:00:28,670 --> 00:00:31,970
Kidogo kidogo habari bora,
Jaribio zero ni Jumatano ijayo.

10
00:00:31,970 --> 00:00:33,840
Maelezo zaidi yanaweza kuwa
kupatikana katika URL hii hapa.

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Na zaidi ya wanandoa siku
tutaweza kuwa na kujaza nafasi zilizoachwa wazi

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kwa upande wa vyumba
kwamba sisi kuwa zimehifadhiwa.

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Bora habari ni kwamba kuna itabidi
kuwa mapitio shaka kote

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00:00:41,400 --> 00:00:43,570
kikao hiki kuja
Jumatatu jioni.

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Stay tuned kwa kozi ya
tovuti kwa ajili ya eneo na maelezo.

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Sehemu, hata kama ni
likizo, pia kukutana na kama vizuri.

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00:00:49,290 --> 00:00:50,490

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Best habari, hotuba Ijumaa ijayo.

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Hivyo hii ni mila sisi
kuwa, kama per mtaala.

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Just-- ni kwenda kuwa ajabu.

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Wewe utaona vitu kama
miundo data wakati mara kwa mara

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na meza hash na miti na anajaribu.

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Na tutaweza majadiliano juu ya matatizo siku ya kuzaliwa.

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rundo zima ya mambo
watapata Ijumaa ijayo.

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OK.

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Hata hivyo.

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>> Hivyo kukumbuka kuwa sisi tumekuwa
kulenga picha hii ya nini

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ndani ya kumbukumbu ya kompyuta yetu.

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Hivyo kumbukumbu au RAM ni ambapo programu
kuwepo wakati wewe mbio yao.

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Kama wewe mara mbili-click
icon ya kuendesha mpango baadhi

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au mara mbili-click
icon kufungua baadhi ya faili,

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ni kubeba kutoka ngumu yako
kuendesha gari au gari hali imara

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ndani ya RAM, Random Access Memory, ambapo
ni maisha mpaka nguvu huenda mbali,

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mfuniko mbali kufunga,
au wewe kuacha mpango.

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>> Sasa kwa kuwa kumbukumbu, ya
ambayo pengine

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1 gigabyte siku hizi, 2
gigabytes, au hata zaidi,

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kwa ujumla kuweka nje
kwa mpango wa kupewa

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katika aina hii ya rectangular
mtindo wa dhana

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ambapo tuna stack chini
na rundo la mambo mengine kwa juu.

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Jambo saa ya juu sana
tumeona juu ya picha hii

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lakini kamwe kabla ya kuongelea
ni kinachojulikana Nakala sehemu.

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Nakala sehemu ni njia tu dhana
ya kusema zeros na wale ambao

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kutunga halisi compiled mpango wako.

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>> Hivyo wakati wewe mara mbili-click
Microsoft Word juu ya Mac au PC yako,

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au wakati wewe kukimbia dot kufyeka Mario juu ya
Linux kompyuta katika terminal dirisha yako,

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zeros na wale ambao kutunga
Neno au Mario ni kuhifadhiwa kwa muda

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katika RAM ya kompyuta yako katika kinachojulikana
Nakala sehemu kwa ajili ya mpango fulani.

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Chini kwamba huenda initialized
na data uninitialized.

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Hii ni mambo kama vigezo kimataifa,
kwamba tumekuwa si kutumika wengi wa,

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lakini juu ya tukio tumekuwa
alikuwa vigezo kimataifa

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au statically defined masharti kwamba
ni ngumu coded maneno kama "hello"

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ambayo si kuchukuliwa katika kutoka kwa mtumiaji
kuwa ni ngumu-coded katika mpango wako.

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>> Sasa, chini chini sisi
na kinachojulikana stack.

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Na stack, hivi sasa, tumekuwa
kutumia kwa ajili ya aina gani ya makusudi?

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00:02:37,665 --> 00:02:39,706

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Nini stack zimetumika kwa ajili ya?

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Yeah?

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>> Watazamaji: Kazi.

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>> DAVID J. Malan: Kwa kazi?

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Ni katika maana gani kwa ajili ya kazi?

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>> Watazamaji: Wakati wewe piga kazi,
hoja ni kunakiliwa kwenye stack.

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>> DAVID J. Malan: Hasa.

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Wakati wewe piga kazi, yake
hoja ni kunakiliwa kwenye stack.

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Hivyo X yoyote au Y au A au B ya
kwamba wewe ni kupita katika kazi

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ni muda kuweka juu ya
kinachojulikana stack,

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tu kama moja ya Annenberg
dining trays ukumbi, na pia mambo

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kama vigezo mitaa.

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Kama foo kazi yako au byta yako
kazi kuwa na vigezo mitaa,

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kama temp, wale wawili
kuishia juu ya stack.

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Sasa, sisi si kuzungumza sana kuhusu
yao, lakini vigezo hivi mazingira

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chini tuliona wakati iliyopita wakati
Mimi nilikuwa futzing katika keyboard siku moja

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na mimi kuanza kupata mambo
kama argv 100 au argv 1000,

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tu elements-- mimi kusahau
numbers-- lakini kwamba

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walikuwa si walidhani kuwa kupatikana kwa mimi.

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Sisi kuanza kuona baadhi
alama funky juu ya screen.

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Wale walikuwa kinachojulikana
mazingira vigezo

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kama mipangilio ya kwa ajili yangu
mpango au kwa kompyuta yangu, si

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lisilohusiana na ya hivi karibuni
mdudu kwamba sisi kujadiliwa,

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Shellshock, kwamba imekuwa
inayolikabili kompyuta chache kabisa.

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>> Sasa mwisho, katika mtazamo wa leo
tutaweza hatimaye kuwa juu ya lundo.

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Hii ni chunk nyingine ya kumbukumbu.

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Na kimsingi yote haya
kumbukumbu ni mambo sawa.

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Ni vifaa hivyo.

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Sisi ni tu aina ya
kutibu nguzo mbalimbali

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ya ka kwa malengo tofauti.

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chungu pia ni kwenda kuwa ambapo
vigezo na kumbukumbu kwamba wewe ombi

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kutoka mfumo wa uendeshaji
ni muda kuhifadhiwa.

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>> Lakini kuna aina ya tatizo
hapa, kama picha ina maana.

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Sisi aina ya wawili
meli juu ya collide.

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Kwa sababu kama wewe kutumia zaidi na zaidi
ya stack, na kama sisi kuona leo

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kuendelea, kama wewe kutumia zaidi na zaidi ya
chungu, hakika mambo mabaya yanaweza kutokea.

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Na hakika, sisi inaweza kutumika kwamba
makusudi au bila kukusudia.

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Hivyo cliffhanger mwisho
huo ilikuwa mpango huu,

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ambao hawakuwa kumtumikia yoyote kazi
kusudi wengine kuliko kuonyesha

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jinsi kama guy mbaya inaweza kweli kuchukua
faida ya mende katika mpango wa mtu

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na kuchukua juu ya mpango au hata
zima mfumo wa kompyuta au server.

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Hivyo tu kwa mtazamo kwa ufupi, wewe
taarifa kwamba kuu chini

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inachukua katika mstari amri
hoja, kama per argv.

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Na ina mwito wa kazi f,
kimsingi kazi Nameless kuitwa

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f, na ni kupita katika argv [1].

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>> Kwa hiyo chochote neno aina user katika saa
haraka baada ya jina mpango huu,

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na kisha kazi hii holela up
juu, f, inachukua katika kamba, AKA * Char,

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kama tumeanza kujadili,
na ni haki anaiita "bar."

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Lakini tunaweza kuiita kitu chochote.

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Na kisha anatangaza, ndani ya
ya f, safu ya wahusika

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kuitwa c-- 12 wahusika kama.

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>> Sasa, kwa hadithi mimi alikuwa akiwaambia
wakati iliyopita, ambapo katika kumbukumbu

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ni c, au ni wale 12
chars kwenda kuishia?

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Tu kuwa wazi.

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Yeah?

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>> Watazamaji: On stack.

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>> DAVID J. Malan: On stack.

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Hivyo c ni variable mitaa.

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Tunawaomba kwa chars 12 au ka 12.

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Wale ni kwenda kuishia
juu ya kile kinachoitwa stack.

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Sasa hatimaye ni kazi hii nyingine
hiyo ni kweli pretty muhimu,

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lakini tumekuwa si kweli kutumika
wenyewe, strncopy.

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Ina maana string nakala, lakini
tu n barua, n wahusika.

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Hivyo wahusika n itakuwa
kunakiliwa kutoka bar ndani ya c.

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Na jinsi wengi?

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urefu wa bar.

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Hivyo kwa maneno mengine, kwamba
mstari mmoja, strncopy,

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ni kwenda nakala
ufanisi bar katika kwa c.

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>> Sasa, tu aina ya wanatarajia
maadili ya hadithi hii,

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nini ni uwezekano wa matatizo hapa?

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Hata ingawa sisi ni kuangalia urefu
ya bar na kupita katika strncopy,

129
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kile gut wako akikuambia ni
bado kuvunjwa kuhusu mpango huu?

130
00:05:53,145 --> 00:05:54,410

131
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Yeah?

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00:05:55,220 --> 00:05:57,491
>> Watazamaji: Je, si ni pamoja na
chumba for null tabia.

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DAVID J. Malan: Je, si ni pamoja na
chumba for null tabia.

134
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Uwezekano, tofauti na katika
mitindo ya kizamani sisi kufanya hata

135
00:06:02,073 --> 00:06:04,810
kuwa na kiasi kama plus 1 kwa
malazi kwamba null tabia.

136
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Lakini ni mbaya zaidi kuliko hiyo.

137
00:06:06,649 --> 00:06:07,940
Nini kingine ni sisi kushindwa kufanya?

138
00:06:07,940 --> 00:06:08,432
Yeah?

139
00:06:08,432 --> 00:06:09,307
>> Watazamaji: [inaudible]

140
00:06:09,307 --> 00:06:15,440

141
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DAVID J. Malan: Perfect.

142
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Tumekuwa ngumu coded 12 pretty kiholela.

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00:06:18,490 --> 00:06:19,497

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Hiyo ni si sana
tatizo, lakini ukweli

145
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kwamba sisi siyo hata kuangalia kama
urefu wa bar ni chini ya 12,

146
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katika kesi ambayo ni kwenda kuwa
salama ya kuweka ndani ya kumbukumbu

147
00:06:28,530 --> 00:06:30,260
kuitwa c kwamba tumekuwa zilizotengwa.

148
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Hakika, kama bar ni kama
Wahusika 20 kwa muda mrefu,

149
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kazi hii inaonekana kuwa kuiga
Wahusika 20 kutoka bar ndani ya c, na hivyo

150
00:06:39,010 --> 00:06:41,310
kuchukua angalau 8 ka
kwamba ni lazima kuwa.

151
00:06:41,310 --> 00:06:42,690
Hiyo ni maana hapa.

152
00:06:42,690 --> 00:06:44,347
>> Hivyo katika muda mfupi, kuvunjwa mpango.

153
00:06:44,347 --> 00:06:45,180
Si kama mpango kubwa.

154
00:06:45,180 --> 00:06:46,360
Labda wewe kupata kosa segmentation.

155
00:06:46,360 --> 00:06:47,651
Tumekuwa wote walikuwa na mende katika programu.

156
00:06:47,651 --> 00:06:50,196
Sisi wote wapate kuwa na mende
katika programu hivi sasa.

157
00:06:50,196 --> 00:06:51,320
Lakini nini maana?

158
00:06:51,320 --> 00:06:54,390
Naam, hapa ni zoomed-katika toleo la
picha ya kumbukumbu ya kompyuta yangu.

159
00:06:54,390 --> 00:06:56,230
Hii ni chini ya stack yangu.

160
00:06:56,230 --> 00:06:59,644
Na hakika, chini sana ni nini
kuitwa mzazi wa mara kwa mara stack, dhana njia

161
00:06:59,644 --> 00:07:00,560
ya kusema kwamba kuu.

162
00:07:00,560 --> 00:07:03,772
Ili kila mtu aitwaye kazi
f kwamba sisi ni kuzungumza juu.

163
00:07:03,772 --> 00:07:05,230
Hivyo hii ni chini ya stack.

164
00:07:05,230 --> 00:07:06,640
Return anwani ni kitu kipya.

165
00:07:06,640 --> 00:07:08,810
Ni daima imekuwa pale,
daima imekuwa katika picha hiyo.

166
00:07:08,810 --> 00:07:10,440
Sisi tu kamwe kuitwa tahadhari hiyo.

167
00:07:10,440 --> 00:07:15,290
Kwa sababu ni zamu nje ya njia c kazi ni
kwamba wakati kazi moja wito mwingine,

168
00:07:15,290 --> 00:07:18,780
si tu kufanya hoja ya kwamba
kazi kupata kusukuma kwenye stack,

169
00:07:18,780 --> 00:07:22,470
si tu kufanya kazi ya ndani
vigezo kupata kusukuma kwenye stack,

170
00:07:22,470 --> 00:07:26,820
kitu kinachoitwa anwani kurudi
pia anapata kuweka kwenye stack.

171
00:07:26,820 --> 00:07:33,330
Hasa, kama wito kuu foo, ya kuu
mwenyewe anwani katika kumbukumbu, ng'ombe kitu,

172
00:07:33,330 --> 00:07:38,240
ufanisi anapata kuweka kwenye stack
hivyo kwamba wakati f ni kosa utekelezaji yake

173
00:07:38,240 --> 00:07:43,630
anajua wapi kuruka nyuma katika maandishi
sehemu ili kuendelea utekelezaji.

174
00:07:43,630 --> 00:07:47,760
>> Hivyo kama tuko hapa conceptually,
katika kuu, basi f anapata kuitwa.

175
00:07:47,760 --> 00:07:50,200
Jinsi gani f kujua ni nani
kwa mkono kudhibiti nyuma?

176
00:07:50,200 --> 00:07:52,020
Naam, hii kidogo
breadcrumb katika nyekundu hapa,

177
00:07:52,020 --> 00:07:54,978
kuitwa anwani kurudi, ni tu
hundi, nini ni kwamba kurudi anwani?

178
00:07:54,978 --> 00:07:57,039
Oh, napenda kuruka nyuma kwa kuu hapa.

179
00:07:57,039 --> 00:07:59,080
Na kwamba ni kidogo
ya kurahisisha,

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00:07:59,080 --> 00:08:00,750
kwa sababu zeros na ndio
kwa kuu ni kitaalam

181
00:08:00,750 --> 00:08:01,967
up hapa katika sehemu tech.

182
00:08:01,967 --> 00:08:03,800
Lakini hiyo ni wazo. f
tu ana kujua nini

183
00:08:03,800 --> 00:08:06,680
ambapo kudhibiti hatimaye inakwenda nyuma.

184
00:08:06,680 --> 00:08:09,790
>> Lakini kompyuta njia
kwa muda mrefu kuweka nje mambo

185
00:08:09,790 --> 00:08:12,320
kama vigezo mitaa na
hoja ni kama hii.

186
00:08:12,320 --> 00:08:17,180
Hivyo katika juu ya picha hii katika
bluu ni stack frame kwa f, hivyo wote

187
00:08:17,180 --> 00:08:19,630
ya kumbukumbu kwamba f
hasa ni kutumia.

188
00:08:19,630 --> 00:08:22,990
Hivyo ipasavyo, taarifa kwamba
bar ni katika picha hii.

189
00:08:22,990 --> 00:08:23,980
Bar ilikuwa hoja yake.

190
00:08:23,980 --> 00:08:27,240
Na sisi alidai kuwa hoja ya
kazi kupata kusukuma kwenye stack.

191
00:08:27,240 --> 00:08:29,910
Na c, bila shaka, ni
pia katika picha hii.

192
00:08:29,910 --> 00:08:33,520
>> Na tu kwa madhumuni ya notational,
taarifa juu upande wa kushoto kona

193
00:08:33,520 --> 00:08:37,020
ni nini itakuwa c bracket 0 na
kisha chini kidogo na haki

194
00:08:37,020 --> 00:08:38,220
ni c bracket 11.

195
00:08:38,220 --> 00:08:41,240
Hivyo kwa maneno mengine, unaweza kufikiria
kwamba kuna gridi ya taifa ya ka

196
00:08:41,240 --> 00:08:44,380
kuna ya kwanza ambayo ni
juu kushoto, chini ya ambayo

197
00:08:44,380 --> 00:08:48,360
ni mwisho wa wale ka 12.

198
00:08:48,360 --> 00:08:49,930
>> Lakini sasa kujaribu kufunga mbele.

199
00:08:49,930 --> 00:08:55,580
Nini ni kuhusu kutokea kama sisi kupita
katika kamba bar hiyo ni muda mrefu zaidi ya c?

200
00:08:55,580 --> 00:08:59,130
Na sisi ni si kuangalia kama
ni kweli kwa muda mrefu kuliko 12.

201
00:08:59,130 --> 00:09:03,146
Ambayo ni sehemu ya picha hii ni kwenda
kupata overwritten na ka 0, 1, 2, 3,

202
00:09:03,146 --> 00:09:07,890
dot dot dot, 11, na kisha
mbaya, 12, 13 kupitia 19?

203
00:09:07,890 --> 00:09:11,820
Nini kinaendelea kutokea hapa,
kama wewe infer kutoka kuagiza

204
00:09:11,820 --> 00:09:14,790
kwamba c bracket 0 ni juu
na c bracket 11 ni aina ya chini

205
00:09:14,790 --> 00:09:15,812
upande wa kulia?

206
00:09:15,812 --> 00:09:16,796
Yeah?

207
00:09:16,796 --> 00:09:19,260
>> Watazamaji: Naam, ni kwenda
overwrite * Char bar.

208
00:09:19,260 --> 00:09:22,260
>> DAVID J. Malan: Yeah, inaonekana kama
wewe ni kwenda overwrite * Char bar.

209
00:09:22,260 --> 00:09:26,245
Na mbaya zaidi, kama kutuma katika kweli kwa muda mrefu
kamba, unaweza hata overwrite nini?

210
00:09:26,245 --> 00:09:27,460

211
00:09:27,460 --> 00:09:28,570
anwani kurudi.

212
00:09:28,570 --> 00:09:31,380
Ambayo tena, ni tu kama
breadcrumb kwa kuwaambia mpango ambapo

213
00:09:31,380 --> 00:09:34,060
kwenda nyuma wakati f
ni kosa kuitwa.

214
00:09:34,060 --> 00:09:37,140
>> Hivyo kile wabaya kawaida ya kufanya
ni kama wao kuja hela mpango

215
00:09:37,140 --> 00:09:41,290
kwamba wao ni curious kama ni
exploitable, buggy kwa namna

216
00:09:41,290 --> 00:09:43,550
kwamba yeye au yeye anaweza kuchukua
faida ya kwamba mdudu,

217
00:09:43,550 --> 00:09:45,720
kwa ujumla hawana kupata
haki hii mara ya kwanza.

218
00:09:45,720 --> 00:09:48,590
Wao tu kuanza kutuma, kwa mfano,
masharti random katika mpango wako,

219
00:09:48,590 --> 00:09:50,260
iwe katika keyboard,
au kusema ukweli wao pengine

220
00:09:50,260 --> 00:09:52,740
kuandika mpango kidogo tu
moja kwa moja kuzalisha masharti,

221
00:09:52,740 --> 00:09:55,430
na kuanza banging juu ya mpango wako na
kutuma katika kura ya pembejeo mbalimbali

222
00:09:55,430 --> 00:09:56,340
katika urefu tofauti.

223
00:09:56,340 --> 00:09:58,990
>> Haraka kama shambulio mpango wako,
hiyo ni jambo la kushangaza.

224
00:09:58,990 --> 00:10:01,020
Kwa sababu ina maana yeye
au yeye ana aligundua

225
00:10:01,020 --> 00:10:02,660
nini pengine ni kweli mdudu.

226
00:10:02,660 --> 00:10:05,830
Na kisha wanaweza kupata zaidi wajanja
na kuanza kuelekeza nguvu zaidi narrowly

227
00:10:05,830 --> 00:10:07,420
juu ya jinsi ya kutumia kwamba mdudu.

228
00:10:07,420 --> 00:10:11,480
Hasa, nini yeye au anaweza
kufanya ni kutuma, katika kesi bora, hello.

229
00:10:11,480 --> 00:10:12,210
Hakuna mpango kubwa.

230
00:10:12,210 --> 00:10:14,750
Ni string kwamba ni kutosha short.

231
00:10:14,750 --> 00:10:18,100
Lakini nini kama yeye au yeye zituma,
na tutaweza kujumlisha ni kama,

232
00:10:18,100 --> 00:10:20,890
mashambulizi code-- hivyo zeros
na wale ambao kufanya mambo

233
00:10:20,890 --> 00:10:25,150
kama rm-rf, kwamba kuondoa kila kitu
kutoka gari ngumu au kutuma spam

234
00:10:25,150 --> 00:10:27,000
au kwa namna fulani kushambulia mashine?

235
00:10:27,000 --> 00:10:29,570
>> Hivyo kama kila moja ya haya
barua A tu inawakilisha,

236
00:10:29,570 --> 00:10:32,380
conceptually, mashambulizi, mashambulizi,
mashambulizi, mashambulizi, baadhi ya kanuni mbaya

237
00:10:32,380 --> 00:10:36,410
kwamba mtu mwingine aliandika, lakini
iwapo mtu huyo ni smart kutosha

238
00:10:36,410 --> 00:10:40,790
kwa si tu ni pamoja na kila
ya wale rm-RFS, lakini pia

239
00:10:40,790 --> 00:10:46,100
na ka yake michache iliyopita
kuwa idadi hiyo sambamba

240
00:10:46,100 --> 00:10:50,540
kwa anwani ya yake
au mashambulizi yake mwenyewe code

241
00:10:50,540 --> 00:10:53,820
kwamba yeye au yeye kupita katika tu
kwa kutoa hiyo kwa haraka,

242
00:10:53,820 --> 00:10:58,760
unaweza ufanisi hila kompyuta
ndani ya noticing wakati f ni kosa utekelezaji,

243
00:10:58,760 --> 00:11:02,400
oh, ni wakati kwa ajili yangu kuruka
nyuma nyekundu kurudi mahali.

244
00:11:02,400 --> 00:11:06,070
Lakini kwa sababu yeye au yeye ana namna fulani
walipishana kwamba kurudi anwani

245
00:11:06,070 --> 00:11:09,602
na idadi yao wenyewe,
na wao uko smart kutosha

246
00:11:09,602 --> 00:11:11,560
kwa uliyoisanidi kwamba
idadi ya rejea, kama wewe

247
00:11:11,560 --> 00:11:13,740
kuona katika top super
mkono wa kushoto kona kuna,

248
00:11:13,740 --> 00:11:18,020
anwani halisi katika kompyuta
kumbukumbu ya baadhi ya mashambulizi kanuni zao,

249
00:11:18,020 --> 00:11:21,740
guy mbaya inaweza hila kompyuta
ndani ya utekelezaji code yake mwenyewe.

250
00:11:21,740 --> 00:11:23,700
>> Na kwamba kanuni, tena, inaweza kuwa kitu chochote.

251
00:11:23,700 --> 00:11:26,120
Ni kwa ujumla aitwaye
shell code, ambayo ni tu

252
00:11:26,120 --> 00:11:29,030
njia ya kusema kwamba siyo
kwa ujumla kitu rahisi kama rm-rf.

253
00:11:29,030 --> 00:11:32,340
Ni kweli kitu kama Bash,
au mpango halisi kwamba inampa

254
00:11:32,340 --> 00:11:37,230
au kudhibiti yake programu kutekeleza
kitu kingine chochote kwamba wanataka.

255
00:11:37,230 --> 00:11:40,210
Hivyo katika muda mfupi, hii yote
inatokana na ukweli rahisi

256
00:11:40,210 --> 00:11:44,490
kwamba hii mdudu kushiriki si kuangalia
mipaka ya safu yako.

257
00:11:44,490 --> 00:11:47,250
Na kwa sababu njia
kompyuta kazi ni kwamba wao

258
00:11:47,250 --> 00:11:49,430
kutumia stack kutoka
ufanisi, conceptually,

259
00:11:49,430 --> 00:11:54,830
chini juu juu, lakini basi mambo
kushinikiza kwenye stack kukua juu chini,

260
00:11:54,830 --> 00:11:56,624
hii ni incredibly tatizo.

261
00:11:56,624 --> 00:11:58,290
Sasa, kuna njia ya kufanya kazi ya kuzunguka hili.

262
00:11:58,290 --> 00:12:00,800
Na kusema ukweli, kuna lugha
na ambayo kwa kazi ya kuzunguka hili.

263
00:12:00,800 --> 00:12:03,100
Java ni kinga, kwa mfano,
kwa hasa katika suala hili.

264
00:12:03,100 --> 00:12:04,110
Kwa sababu hawana kuwapa kuyatumia.

265
00:12:04,110 --> 00:12:05,943
Hawana kukupa
kumbukumbu anwani moja kwa moja.

266
00:12:05,943 --> 00:12:08,560
Hivyo kwa nguvu hii kwamba tuna
kwa kugusa kitu chochote katika kumbukumbu

267
00:12:08,560 --> 00:12:11,580
sisi wanataka kuja, admittedly, hatari kubwa.

268
00:12:11,580 --> 00:12:12,430
>> Hivyo kuweka jicho nje.

269
00:12:12,430 --> 00:12:14,596
Kama, kusema ukweli, katika kipindi cha miezi
au miaka ijayo, wakati wowote

270
00:12:14,596 --> 00:12:17,740
wewe kusoma kuhusu baadhi unyonyaji
ya mpango au server,

271
00:12:17,740 --> 00:12:22,370
kama wewe milele kuona ladha ya kitu
kama mashambulizi buffer kufurika,

272
00:12:22,370 --> 00:12:25,390
au stack kufurika ni aina nyingine
ya mashambulizi, sawa katika roho,

273
00:12:25,390 --> 00:12:28,770
vile kuwahamasisha tovuti ya
jina, kama wewe kujua,

274
00:12:28,770 --> 00:12:33,170
ni wote kuzungumza juu ya tu
wingi na ukubwa wa baadhi ya tabia

275
00:12:33,170 --> 00:12:36,200
safu au safu baadhi zaidi kwa ujumla.

276
00:12:36,200 --> 00:12:38,822
Maswali yoyote, basi, juu ya hili?

277
00:12:38,822 --> 00:12:39,780
Je, si kujaribu hili nyumbani.

278
00:12:39,780 --> 00:12:41,620

279
00:12:41,620 --> 00:12:42,300
>> Wote haki.

280
00:12:42,300 --> 00:12:47,270
Hivyo malloc hivi sasa imekuwa wetu mpya
rafiki katika kwamba tunaweza kutenga kumbukumbu

281
00:12:47,270 --> 00:12:50,540
kwamba hatuna lazima kujua katika
mapema kwamba tunataka hivyo hatuna

282
00:12:50,540 --> 00:12:52,920
na kanuni ngumu katika yetu
namba mpango kama 12.

283
00:12:52,920 --> 00:12:55,550
Mara baada ya user anatueleza jinsi gani
data yeye au yeye anataka kwa pembejeo,

284
00:12:55,550 --> 00:12:58,000
tunaweza malloc kumbukumbu kwamba mengi.

285
00:12:58,000 --> 00:13:01,484
>> Hivyo malloc ni zamu nje, kwa
kiwango tumekuwa kutumia hiyo,

286
00:13:01,484 --> 00:13:03,900
wazi mara ya mwisho, na kisha
nyie wamekuwa kutumia

287
00:13:03,900 --> 00:13:08,160
kwa GetString kutojua kwa
wiki kadhaa, yote ya kumbukumbu malloc ya

288
00:13:08,160 --> 00:13:09,820
linatokana na kinachojulikana chungu.

289
00:13:09,820 --> 00:13:13,852
Na hii ni kwa nini GetString, kwa mfano,
unaweza kutenga kumbukumbu dynamically

290
00:13:13,852 --> 00:13:16,060
bila kujua nini wewe ni
kwenda aina mapema,

291
00:13:16,060 --> 00:13:21,520
mkono wewe nyuma pointer kwa kuwa kumbukumbu,
na kwamba kumbukumbu ni bado yako ya kutunza,

292
00:13:21,520 --> 00:13:24,080
hata baada ya GetString anarudi.

293
00:13:24,080 --> 00:13:27,450
Kwa sababu kukumbuka baada ya yote
stack ni mara kwa mara kwenda juu na chini,

294
00:13:27,450 --> 00:13:27,950
juu na chini.

295
00:13:27,950 --> 00:13:30,230
Na kama hivi karibuni kama unaendelea
chini, hiyo ina maana yoyote kumbukumbu

296
00:13:30,230 --> 00:13:33,030
kazi hii kutumika lazima
si kutumiwa na mtu mwingine yeyote.

297
00:13:33,030 --> 00:13:34,570
Ni maadili takataka sasa.

298
00:13:34,570 --> 00:13:36,120
>> Lakini chungu ni up hapa.

299
00:13:36,120 --> 00:13:39,360
Na nini ni nzuri kuhusu malloc ni kwamba
wakati malloc kutenga kumbukumbu hadi hapa,

300
00:13:39,360 --> 00:13:42,070
ni si wanashikiliwa, kwa
sehemu kubwa, na stack.

301
00:13:42,070 --> 00:13:46,000
Na hivyo kazi yoyote wanaweza kupata
kumbukumbu ambayo imekuwa malloc'd,

302
00:13:46,000 --> 00:13:49,120
hata kwa kazi kama GetString,
hata baada ya kurudi huko.

303
00:13:49,120 --> 00:13:51,700
>> Sasa, kinyume cha malloc ni bure.

304
00:13:51,700 --> 00:13:53,900
Na hakika, utawala wewe
haja ya kuanza kupitisha

305
00:13:53,900 --> 00:13:58,950
ni yoyote, yoyote, wakati wowote wewe kutumia malloc
lazima wewe mwenyewe kutumia bure, hatimaye,

306
00:13:58,950 --> 00:14:00,280
juu ya kwamba pointer huo.

307
00:14:00,280 --> 00:14:03,289
Muda wote huu tumekuwa kuandika
buggy, buggy code, kwa sababu nyingi.

308
00:14:03,289 --> 00:14:05,580
Lakini moja ya ambayo imekuwa
kutumia maktaba CS50, ambayo

309
00:14:05,580 --> 00:14:09,010
yenyewe ni kwa makusudi
buggy, ni uvujaji kumbukumbu.

310
00:14:09,010 --> 00:14:11,410
Wakati wowote umetumia GetString
katika wiki chache zilizopita

311
00:14:11,410 --> 00:14:13,870
sisi ni kuuliza uendeshaji
mfumo, Linux, kwa ajili ya kumbukumbu.

312
00:14:13,870 --> 00:14:15,780
Na una kamwe mara moja kutokana na nyuma.

313
00:14:15,780 --> 00:14:17,730
Na hii si, katika
mazoezi, jambo zuri.

314
00:14:17,730 --> 00:14:20,330
>> Na Valgrind, mmoja wa
zana ilianzisha katika pset 4,

315
00:14:20,330 --> 00:14:22,900
ni wote kuhusu kusaidia
sasa kupata mende kama hiyo.

316
00:14:22,900 --> 00:14:27,060
Bali nashiriki kwa pset 4 huna haja ya
kutumia maktaba CS50 au GetString.

317
00:14:27,060 --> 00:14:31,220
Hivyo mende yoyote kuhusiana na kumbukumbu ni
hatimaye kwenda kuwa yako mwenyewe.

318
00:14:31,220 --> 00:14:34,060
>> Hivyo malloc ni zaidi ya
rahisi kwa ajili ya lengo hili.

319
00:14:34,060 --> 00:14:37,420
Tunaweza kweli sasa kutatua
matatizo kimsingi tofauti,

320
00:14:37,420 --> 00:14:41,640
na kimsingi kutatua matatizo zaidi
ufanisi kama kwa wiki zero ya ahadi.

321
00:14:41,640 --> 00:14:44,720
Hivi sasa hii ni sexiest
muundo data tumekuwa alikuwa.

322
00:14:44,720 --> 00:14:47,804
Na kwa muundo data I just maana
njia ya kufafanua kumbukumbu

323
00:14:47,804 --> 00:14:50,720
kwa njia ambayo inakwenda zaidi ya kusema tu,
hii ni int, hii ni char.

324
00:14:50,720 --> 00:14:52,930
Tunaweza kuanza nguzo mambo pamoja.

325
00:14:52,930 --> 00:14:54,460
>> Hivyo safu inaonekana kama hii.

326
00:14:54,460 --> 00:14:57,270
Na nini ilikuwa muhimu katika kuhusu
safu ni kwamba anatoa wewe

327
00:14:57,270 --> 00:14:59,724
nyuma-ya-nyuma chunks ya
kumbukumbu, ambayo kila mmoja

328
00:14:59,724 --> 00:15:02,765
ni kwenda kuwa ya aina moja, int,
int, int, int, au char, char, char,

329
00:15:02,765 --> 00:15:03,330
char.

330
00:15:03,330 --> 00:15:04,496
Lakini kuna downsides wachache.

331
00:15:04,496 --> 00:15:06,570
Hii kwa mfano, ni
safu ya ukubwa sita.

332
00:15:06,570 --> 00:15:10,650
Tuseme wewe kujaza safu hii na sita
namba na kisha, kwa sababu yoyote,

333
00:15:10,650 --> 00:15:13,187
user yako anataka kuwapa
wewe idadi ya saba.

334
00:15:13,187 --> 00:15:14,020
Ambapo gani unaweza kuweka it?

335
00:15:14,020 --> 00:15:15,490

336
00:15:15,490 --> 00:15:18,990
>> Nini suluhisho kama una
kuundwa safu juu ya stack,

337
00:15:18,990 --> 00:15:22,030
kwa mfano, tu na wiki
mbili nukuu kwamba sisi kuletwa,

338
00:15:22,030 --> 00:15:23,730
ya mabano mraba na idadi ndani?

339
00:15:23,730 --> 00:15:25,160

340
00:15:25,160 --> 00:15:27,260
Naam, nimepata sita
idadi katika masanduku hayo.

341
00:15:27,260 --> 00:15:28,530
Gani hisia zako kuwa?

342
00:15:28,530 --> 00:15:29,973
Ambapo unataka kuiweka?

343
00:15:29,973 --> 00:15:30,860
>> Watazamaji: [inaudible]

344
00:15:30,860 --> 00:15:31,315
>> DAVID J. Malan: Sorry?

345
00:15:31,315 --> 00:15:32,380
>> Watazamaji: Weka ya mwisho.

346
00:15:32,380 --> 00:15:33,796
>> DAVID J. Malan: Weka ya mwisho.

347
00:15:33,796 --> 00:15:35,880
Hivyo tu juu ya upande wa kulia,
nje ya boksi hii.

348
00:15:35,880 --> 00:15:38,710
Ambayo itakuwa nzuri, lakini
anarudi nje huwezi kufanya hivyo.

349
00:15:38,710 --> 00:15:41,350
Kwa sababu kama umefanya si aliuliza
kwa chunk hii ya kumbukumbu,

350
00:15:41,350 --> 00:15:44,490
inaweza kuwa kwa bahati mbaya kwamba hii
ni kutumiwa na baadhi variable nyingine

351
00:15:44,490 --> 00:15:45,030
kabisa.

352
00:15:45,030 --> 00:15:49,210
Fikiria nyuma wiki au hivyo wakati sisi kuweka
nje Zamyla na Davin na Gabe ya majina

353
00:15:49,210 --> 00:15:49,930
katika kumbukumbu.

354
00:15:49,930 --> 00:15:51,638
Walikuwa literally
nyuma kwa nyuma kwa nyuma.

355
00:15:51,638 --> 00:15:53,550
Hivyo tunaweza si lazima
imani kwamba kila ya

356
00:15:53,550 --> 00:15:55,800
zaidi ya hapa ni inapatikana kwa ajili yangu kutumia.

357
00:15:55,800 --> 00:15:56,990
>> Hivyo kile kingine inaweza kufanya nini?

358
00:15:56,990 --> 00:16:00,282
Naam, mara moja kutambua wewe
haja safu ya ukubwa saba,

359
00:16:00,282 --> 00:16:02,490
unaweza kujenga tu
safu ya ukubwa saba kisha kutumia

360
00:16:02,490 --> 00:16:05,950
a kwa kitanzi au kitanzi wakati,
nakala yake katika safu mpya,

361
00:16:05,950 --> 00:16:09,680
na kisha kwa namna fulani tu kujikwamua
safu hii au tu kuacha kutumia hiyo.

362
00:16:09,680 --> 00:16:12,130
Lakini si kwamba hasa ufanisi.

363
00:16:12,130 --> 00:16:15,340
Kwa kifupi, arrays si basi
wewe dynamically resize.

364
00:16:15,340 --> 00:16:17,900
>> Hivyo kwa upande mmoja, kupata
upatikanaji random, ambayo ni ya ajabu.

365
00:16:17,900 --> 00:16:20,108
Kwa sababu unatuwezesha kufanya mambo
kama kugawanya na kushinda,

366
00:16:20,108 --> 00:16:23,100
search binary, ambayo yote tumekuwa
aliyesema kuhusu juu ya screen hapa.

367
00:16:23,100 --> 00:16:24,950
Lakini wewe mwenyewe rangi katika kona.

368
00:16:24,950 --> 00:16:27,810
Haraka kama wewe hit
mwisho wa safu yako,

369
00:16:27,810 --> 00:16:29,980
una kufanya sana
operesheni ghali

370
00:16:29,980 --> 00:16:33,910
au kuandika rundo zima la code
kwa sasa kukabiliana na tatizo hilo.

371
00:16:33,910 --> 00:16:36,680
>> Basi nini kama badala tulikuwa
kitu kinachoitwa orodha,

372
00:16:36,680 --> 00:16:38,820
au wanaohusishwa orodha hasa?

373
00:16:38,820 --> 00:16:41,930
Nini kama badala ya kuwa
rectangles nyuma kwa nyuma kwa nyuma,

374
00:16:41,930 --> 00:16:45,730
tuna rectangles kwamba kuondoka kidogo
kidogo ya wiggle chumba katika kati yao?

375
00:16:45,730 --> 00:16:49,670
Na hata kama nimekuwa inayotolewa hii
picha au ilichukuliwa picha hii

376
00:16:49,670 --> 00:16:54,696
kutoka kwa mmoja wa maandiko hapa kuwa nyuma ya
nyuma kwa nyuma utaratibu sana, katika hali halisi,

377
00:16:54,696 --> 00:16:56,820
moja ya rectangles wale
inaweza kuwa hapa up katika kumbukumbu.

378
00:16:56,820 --> 00:16:58,028
Mmoja wao inaweza kuwa juu hapa.

379
00:16:58,028 --> 00:17:00,420
Mmoja wao inaweza kuwa juu hapa,
zaidi ya hapa, na kadhalika.

380
00:17:00,420 --> 00:17:02,910
>> Lakini nini kama sisi akauchomoa,
katika kesi hii, mishale

381
00:17:02,910 --> 00:17:05,650
kwamba kwa namna fulani kuhusisha haya
mistatili pamoja?

382
00:17:05,650 --> 00:17:08,170
Hakika, tumeona kiufundi
mwili wa mshale.

383
00:17:08,170 --> 00:17:09,839

384
00:17:09,839 --> 00:17:13,710
Nini sisi kutumika katika hivi karibuni
siku hiyo, chini ya Hood,

385
00:17:13,710 --> 00:17:15,210
ni mwakilishi wa arrow?

386
00:17:15,210 --> 00:17:16,290

387
00:17:16,290 --> 00:17:17,349
pointer, haki?

388
00:17:17,349 --> 00:17:19,780
>> Basi nini kama, badala ya
tu kuhifadhi namba,

389
00:17:19,780 --> 00:17:23,130
kama 9, 17, 22, 26, 34,
nini kama sisi kuhifadhiwa si

390
00:17:23,130 --> 00:17:27,079
tu idadi lakini pointer
karibu na kila idadi kama hiyo?

391
00:17:27,079 --> 00:17:30,690
Hivyo kwamba kiasi kama ungependa thread
sindano kwa njia ya rundo zima la kitambaa,

392
00:17:30,690 --> 00:17:32,950
mambo kwa namna fulani tying
pamoja, vile vile unaweza

393
00:17:32,950 --> 00:17:35,550
sisi na kuyatumia, kama
incarnated kwa mishale hapa,

394
00:17:35,550 --> 00:17:38,550
aina ya weave pamoja
rectangles haya ya mtu binafsi

395
00:17:38,550 --> 00:17:41,780
kwa kutumia vyema pointer
karibu na kila idadi hiyo

396
00:17:41,780 --> 00:17:46,065
anazungumzia baadhi ya idadi ya pili yake,
anazungumzia, kwa upande wake, baadhi ya idadi ijayo?

397
00:17:46,065 --> 00:17:47,940
Hivyo kwa maneno mengine, nini
kama sisi kweli alitaka

398
00:17:47,940 --> 00:17:49,820
kutekeleza kitu kama hii?

399
00:17:49,820 --> 00:17:53,610
Naam kwa bahati mbaya, mistatili haya,
angalau moja na 9, 17, 22,

400
00:17:53,610 --> 00:17:57,040
na kadhalika, haya ni tena
mraba nzuri na namba moja.

401
00:17:57,040 --> 00:17:59,960
chini, mstatili
chini 9, kwa mfano,

402
00:17:59,960 --> 00:18:04,330
inawakilisha kile lazima
kuwa pointer, 32 bits.

403
00:18:04,330 --> 00:18:09,460
Sasa, mimi nina bado na ufahamu wa aina yoyote data
katika C kwamba anatoa si tu int

404
00:18:09,460 --> 00:18:11,630
lakini pointer kabisa.

405
00:18:11,630 --> 00:18:15,020
>> Basi nini ufumbuzi kama tunataka
mzulia jibu yetu wenyewe na hii?

406
00:18:15,020 --> 00:18:15,760
Yeah?

407
00:18:15,760 --> 00:18:16,640
>> Watazamaji: [inaudible]

408
00:18:16,640 --> 00:18:17,360
>> DAVID J. Malan: Nini hiyo?

409
00:18:17,360 --> 00:18:17,880
>> Watazamaji: muundo mpya.

410
00:18:17,880 --> 00:18:19,590
>> DAVID J. Malan: Yeah, hivyo kwa nini
si sisi kujenga muundo mpya,

411
00:18:19,590 --> 00:18:20,920
au katika C, struct?

412
00:18:20,920 --> 00:18:25,990
Tumeona structs kabla ya, kama kwa ufupi,
ambapo sisi kushughulikiwa na muundo mwanafunzi

413
00:18:25,990 --> 00:18:27,780
kama huyo, ambaye alikuwa jina na nyumba.

414
00:18:27,780 --> 00:18:31,980
Katika pset 3 kuzuka unaweza kutumika zima
rundo la structs-- GRect na GOvals

415
00:18:31,980 --> 00:18:34,810
kwamba Stanford kuundwa kwa
habari nguzo ya pamoja.

416
00:18:34,810 --> 00:18:38,580
Basi nini kama sisi kuchukua wazo hili hili la
maneno "typedef" na "struct,"

417
00:18:38,580 --> 00:18:42,890
na kisha baadhi mwanafunzi maalum stuff,
na kufuka hii katika yafuatayo:

418
00:18:42,890 --> 00:18:46,210
typedef struct nodi node-- na ni
tu generic sana sayansi ya kompyuta

419
00:18:46,210 --> 00:18:49,980
mrefu kwa ajili ya kitu katika muundo data,
chombo katika muundo data.

420
00:18:49,980 --> 00:18:53,900
node mimi kudai ni kwenda kuwa na
int n, kabisa moja kwa moja,

421
00:18:53,900 --> 00:18:58,810
na kisha kidogo zaidi isiyoeleweka kirahisi,
line hii ya pili, struct nodi * ijayo.

422
00:18:58,810 --> 00:19:01,300
Lakini katika suala chini ya kiufundi,
ni nini kwamba mstari wa pili

423
00:19:01,300 --> 00:19:02,980
wa kanuni ndani ya braces curly?

424
00:19:02,980 --> 00:19:03,737
Yeah?

425
00:19:03,737 --> 00:19:04,851
>> Watazamaji: [inaudible]

426
00:19:04,851 --> 00:19:06,600
DAVID J. Malan: A
pointer nodi nyingine.

427
00:19:06,600 --> 00:19:09,910
Hivyo admittedly, syntax kidogo cryptic.

428
00:19:09,910 --> 00:19:13,250
Lakini kama wewe kusoma literally,
pili ni jina la kutofautiana.

429
00:19:13,250 --> 00:19:14,410
Ni aina yake data nini?

430
00:19:14,410 --> 00:19:18,206
Ni verbose kidogo wakati huu,
lakini ni ya aina struct nodi *.

431
00:19:18,206 --> 00:19:22,960
Wakati wowote tumeona kitu nyota, kwamba
ina maana ni pointer kwa ajili ya aina kwamba data.

432
00:19:22,960 --> 00:19:26,810
Hivyo ijayo ni inaonekana
pointer kwa struct nodi.

433
00:19:26,810 --> 00:19:28,310
>> Sasa, ni nini struct nodi?

434
00:19:28,310 --> 00:19:31,044
Naam, taarifa yenu kuona wale
maneno yale yale katika haki juu.

435
00:19:31,044 --> 00:19:33,960
Na hakika, wewe pia kuona neno
"Node" chini hapa chini kushoto.

436
00:19:33,960 --> 00:19:35,640
Na hii ni kweli tu urahisi.

437
00:19:35,640 --> 00:19:39,930
Taarifa kwamba katika yetu mwanafunzi ufafanuzi
kuna neno "mwanafunzi" mara moja tu.

438
00:19:39,930 --> 00:19:42,510
Na hiyo ni kwa sababu mwanafunzi
hicho kilikuwa ni si binafsi rejea.

439
00:19:42,510 --> 00:19:45,340
Kuna kitu ndani ya mwanafunzi
kwamba mahitaji kwa uhakika na mwanafunzi mwingine,

440
00:19:45,340 --> 00:19:45,610
persay.

441
00:19:45,610 --> 00:19:47,630
Hiyo itakuwa aina ya
weird katika ulimwengu wa kweli.

442
00:19:47,630 --> 00:19:50,880
>> Lakini pamoja na node katika wanaohusishwa
orodha, sisi kufanya unataka node

443
00:19:50,880 --> 00:19:53,970
kuwa rejea kwa sawa kitu.

444
00:19:53,970 --> 00:19:57,900
Na hivyo taarifa ya mabadiliko ya hapa ni si
tu nini ndani braces curly.

445
00:19:57,900 --> 00:20:00,800
Lakini sisi kuongeza neno "node"
saa ya juu kama vizuri kama

446
00:20:00,800 --> 00:20:02,930
akiongeza kuwa chini
badala ya "mwanafunzi."

447
00:20:02,930 --> 00:20:06,000
Na hii ni tu kina ya kiufundi
hivyo tena kuwa, muundo yako data

448
00:20:06,000 --> 00:20:11,380
inaweza kuwa self-rejea, ili
node unaweza kumweka kwa node mwingine vile.

449
00:20:11,380 --> 00:20:13,840
>> Hivyo ni nini hii hatimaye
kwenda maana kwa ajili yetu?

450
00:20:13,840 --> 00:20:17,560
Naam, moja, mambo haya ndani ya
ni yaliyomo ya node yetu.

451
00:20:17,560 --> 00:20:19,360
Jambo hili hapa juu,
haki ya juu, ni hivyo tu

452
00:20:19,360 --> 00:20:20,860
tena kuwa, tunaweza kutaja wenyewe.

453
00:20:20,860 --> 00:20:23,401
Na kisha mambo yttersta,
ingawa node ni mpya mrefu,

454
00:20:23,401 --> 00:20:25,500
labda, bado
huo kama mwanafunzi na kile

455
00:20:25,500 --> 00:20:27,520
Ilikuwa chini ya Hood katika SPL.

456
00:20:27,520 --> 00:20:31,095
>> Hivyo kama sisi sasa alitaka kuanza
utekelezaji wa orodha hii wanaohusishwa,

457
00:20:31,095 --> 00:20:33,220
jinsi gani sisi kutafsiri
kitu kama hii na kanuni?

458
00:20:33,220 --> 00:20:35,350
Naam, hebu tu kuona
mfano wa mpango huo

459
00:20:35,350 --> 00:20:36,840
kwa kweli matumizi ya orodha wanaohusishwa.

460
00:20:36,840 --> 00:20:40,870
Miongoni mwa leo usambazaji code
ni programu inayoitwa Orodha ya Zero.

461
00:20:40,870 --> 00:20:44,980
Na kama mimi kukimbia hii mimi umba super
GUI rahisi, Graphical User Interface,

462
00:20:44,980 --> 00:20:46,460
lakini ni kweli tu printf.

463
00:20:46,460 --> 00:20:50,930
Na sasa nimepata kutokana na mwenyewe menu chache
options-- Futa, Insert, Search,

464
00:20:50,930 --> 00:20:51,750
na Traverse.

465
00:20:51,750 --> 00:20:52,630
Na kuacha.

466
00:20:52,630 --> 00:20:55,970
Hizi ni shughuli ya kawaida tu juu ya
muundo data inayojulikana kama orodha ya kiungo.

467
00:20:55,970 --> 00:20:58,409
>> Sasa, Futa ni kwenda
kufuta idadi kutoka kwenye orodha.

468
00:20:58,409 --> 00:21:00,200
Insert kwenda kuongeza
idadi ya orodha.

469
00:21:00,200 --> 00:21:02,181
Search ni kwenda kuangalia
kwa idadi katika orodha.

470
00:21:02,181 --> 00:21:04,930
Na traverse ni njia tu dhana
ya kusema, kutembea kwa njia ya orodha,

471
00:21:04,930 --> 00:21:06,245
magazeti ya nje, lakini hiyo ni yake.

472
00:21:06,245 --> 00:21:07,720
Je, si mabadiliko hayo kwa njia yoyote.

473
00:21:07,720 --> 00:21:08,570
>> Basi hebu jaribu hii.

474
00:21:08,570 --> 00:21:10,160
Hebu kwenda mbele na aina 2.

475
00:21:10,160 --> 00:21:12,710
Na kisha mimi nina kwenda
kuingiza simu, kusema 9.

476
00:21:12,710 --> 00:21:13,620
Kuingia.

477
00:21:13,620 --> 00:21:17,480
Na sasa mpango wangu ni tu
iliyowekwa kusema, orodha ni sasa 9.

478
00:21:17,480 --> 00:21:20,190
Sasa, kama mimi kwenda mbele na
je Ingiza tena, basi

479
00:21:20,190 --> 00:21:23,680
mimi kwenda mbele na zoom nje na aina katika 17.

480
00:21:23,680 --> 00:21:25,770
Sasa orodha yangu ni 9, kisha 17.

481
00:21:25,770 --> 00:21:27,750
Kama mimi kufanya kuingiza tena, hebu ruka moja.

482
00:21:27,750 --> 00:21:32,400
Badala ya 22, kama per picha tumekuwa
wamekuwa kuangalia hapa, napenda kuruka mbele

483
00:21:32,400 --> 00:21:34,630
na kuingiza 26 ijayo.

484
00:21:34,630 --> 00:21:36,230
Hivyo mimi nina kwenda aina 26.

485
00:21:36,230 --> 00:21:37,755
orodha ni kama mimi kutarajia.

486
00:21:37,755 --> 00:21:40,630
Lakini sasa, tu kuona kama kanuni hii
ni kwenda kuwa rahisi, napenda sasa

487
00:21:40,630 --> 00:21:43,520
aina 22, ambayo angalau
conceptually, kama sisi ni

488
00:21:43,520 --> 00:21:46,520
kushika hii namna, ambayo ni kweli
kwenda kuwa lengo lingine sasa hivi,

489
00:21:46,520 --> 00:21:48,690
anatakiwa kwenda katika kati ya 17 na 26.

490
00:21:48,690 --> 00:21:50,270
Hivyo mimi hit Enter.

491
00:21:50,270 --> 00:21:51,380
Hakika, kwamba kazi.

492
00:21:51,380 --> 00:21:54,950
Na hivyo sasa napenda kuingiza
mwisho, kwa picha, 34.

493
00:21:54,950 --> 00:21:55,450
>> Wote haki.

494
00:21:55,450 --> 00:21:58,980
Hivyo kwa sasa napenda inasema kuwa
Kufuta na Traverse na Tafuta kufanya,

495
00:21:58,980 --> 00:21:59,760
kwa kweli, kazi.

496
00:21:59,760 --> 00:22:04,180
Kwa kweli, kama mimi kufanya kukimbia Search, hebu
kutafuta namba 22, kuingia.

497
00:22:04,180 --> 00:22:05,010
Ni kupatikana 22.

498
00:22:05,010 --> 00:22:07,580
Hivyo kwamba ni nini hii
mpango Orodha ya Zero gani.

499
00:22:07,580 --> 00:22:10,230
>> Lakini nini ni kweli kwenda
juu ya kwamba zana hii?

500
00:22:10,230 --> 00:22:14,530
Naam, kwanza nipate kuwa, na kwa kweli
Mimi kuwa, faili inayoitwa list0.h.

501
00:22:14,530 --> 00:22:16,540

502
00:22:16,540 --> 00:22:20,690
Na mahali fulani katika kuna hii
line, typedef, struct nodi,

503
00:22:20,690 --> 00:22:24,850
basi nina braces yangu curly, int n, na
kisha struct-- nini ilikuwa ufafanuzi?

504
00:22:24,850 --> 00:22:26,530

505
00:22:26,530 --> 00:22:28,545
Struct nodi ijayo.

506
00:22:28,545 --> 00:22:29,920

507
00:22:29,920 --> 00:22:31,045
Hivyo tunahitaji nyota.

508
00:22:31,045 --> 00:22:33,420
Sasa kitaalam sisi kupata katika
tabia ya kuchora hapa.

509
00:22:33,420 --> 00:22:35,670
Unaweza kuona vitabu vya kiada na
marejeo online kufanya hivyo huko.

510
00:22:35,670 --> 00:22:36,660
Ni functionally sawa.

511
00:22:36,660 --> 00:22:37,980
Kwa kweli, hii ni kidogo zaidi ya kawaida.

512
00:22:37,980 --> 00:22:40,563
Lakini mimi itabidi kuwa thabiti na kile
sisi alifanya mara ya mwisho na kufanya hili.

513
00:22:40,563 --> 00:22:42,350
Na kisha mwisho, mimi nina kwenda kufanya hivyo.

514
00:22:42,350 --> 00:22:45,550
>> Hivyo katika header ya faili
mahali fulani, katika list0.h

515
00:22:45,550 --> 00:22:49,200
leo ni hii ufafanuzi struct,
na labda baadhi ya mambo mengine.

516
00:22:49,200 --> 00:22:52,580
Wakati huo huo katika list0c kuna
kwenda kuwa mambo kadhaa.

517
00:22:52,580 --> 00:22:54,740
Lakini sisi ni kwenda tu
kuanza na si kumaliza hii.

518
00:22:54,740 --> 00:22:59,690
List0.h ni faili nataka
ni pamoja na katika wangu C file.

519
00:22:59,690 --> 00:23:03,910
Na kisha wakati fulani mimi nina
kwenda na int, kuu, utupu.

520
00:23:03,910 --> 00:23:06,530
Na kisha mimi nina kwenda
na baadhi ya-do hapa.

521
00:23:06,530 --> 00:23:10,620
Mimi pia kwenda na
mfano, kama batili, search, int,

522
00:23:10,620 --> 00:23:13,610
n, kusudi lake katika maisha ni
kutafuta kipengele.

523
00:23:13,610 --> 00:23:18,310
Na kisha chini hapa mimi kudai katika
code ya leo, batili, search, int, n,

524
00:23:18,310 --> 00:23:21,020
hakuna semicolon lakini wazi braces curly.

525
00:23:21,020 --> 00:23:25,049
Na sasa mimi nataka namna fulani kutafuta
kwa kipengele katika orodha hii.

526
00:23:25,049 --> 00:23:27,340
Lakini hatuna kutosha
habari juu ya screen bado.

527
00:23:27,340 --> 00:23:29,800
Nina si kweli
kuwakilishwa orodha yenyewe.

528
00:23:29,800 --> 00:23:33,070
Hivyo njia moja tunaweza kutekeleza
orodha wanaohusishwa katika mpango

529
00:23:33,070 --> 00:23:37,520
ni mimi aina ya kutaka kufanya kitu
kama kutangaza wanaohusishwa orodha hapa.

530
00:23:37,520 --> 00:23:40,520
Kwa unyenyekevu, mimi nina kwenda kufanya
hii ya kimataifa, ingawa kwa ujumla sisi

531
00:23:40,520 --> 00:23:41,645
haipaswi kufanya hii sana.

532
00:23:41,645 --> 00:23:43,260
Lakini itakuwa kurahisisha mfano huu.

533
00:23:43,260 --> 00:23:45,890
Hivyo nataka kutangaza
orodha wanaohusishwa hapa.

534
00:23:45,890 --> 00:23:47,010
Sasa, jinsi gani mimi kufanya hivyo?

535
00:23:47,010 --> 00:23:48,810

536
00:23:48,810 --> 00:23:50,750
>> Hapa ni picha ya orodha wanaohusishwa.

537
00:23:50,750 --> 00:23:53,030
Na mimi si kweli
kujua wakati jinsi

538
00:23:53,030 --> 00:23:56,710
Mimi nina kwenda juu anayewakilisha
mambo mengi na moja tu

539
00:23:56,710 --> 00:23:58,040
variable katika kumbukumbu.

540
00:23:58,040 --> 00:23:59,160
Lakini kufikiri nyuma sasa.

541
00:23:59,160 --> 00:24:00,830
Muda wote huu tulikuwa na
masharti, ambayo sisi basi

542
00:24:00,830 --> 00:24:02,913
umebaini kuwa arrays ya
wahusika, ambayo sisi kisha

543
00:24:02,913 --> 00:24:05,740
umebaini kuwa tu pointer
kwa tabia ya kwanza

544
00:24:05,740 --> 00:24:08,890
katika safu ya wahusika
hiyo null terminated.

545
00:24:08,890 --> 00:24:13,530
Hivyo kwa mantiki hiyo, na kwa hili
picha aina ya mbegu mawazo yenu,

546
00:24:13,530 --> 00:24:17,964
nini haja ya sisi kweli kuandika katika yetu
code kwa kuwakilisha orodha wanaohusishwa?

547
00:24:17,964 --> 00:24:21,130
Ni kiasi gani cha habari hii tunahitaji
kukamata katika C code, ungeweza kusema?

548
00:24:21,130 --> 00:24:22,654

549
00:24:22,654 --> 00:24:23,154
Yeah?

550
00:24:23,154 --> 00:24:24,738
>> Watazamaji: Tunahitaji pointer nodi.

551
00:24:24,738 --> 00:24:26,237
DAVID J. Malan: pointer nodi.

552
00:24:26,237 --> 00:24:29,320
Hasa, ambayo node ingekuwa yako
hisia kuwa kuweka pointer kwa?

553
00:24:29,320 --> 00:24:30,026
>> Watazamaji: node kwanza.

554
00:24:30,026 --> 00:24:31,942
>> DAVID J. Malan: Yeah,
pengine tu kwanza.

555
00:24:31,942 --> 00:24:34,030
Na taarifa, kwanza
node ni sura tofauti.

556
00:24:34,030 --> 00:24:37,690
Ni tu nusu ya ukubwa wa struct,
kwa sababu ni kweli tu pointer.

557
00:24:37,690 --> 00:24:44,650
Basi nini unaweza kweli kufanya ni kutangaza
orodha wanaohusishwa na kuwa ya aina nodi *.

558
00:24:44,650 --> 00:24:47,780
Na hebu tu kuiita kwanza
na initialize kwa null.

559
00:24:47,780 --> 00:24:49,910
Hivyo null, tena, ni kuja
katika picha hapa.

560
00:24:49,910 --> 00:24:53,620
Si tu ni null kutumika kama kama maalum
thamani ya kurudi kwa mambo kama GetString

561
00:24:53,620 --> 00:24:57,770
na malloc, null ni pia zero
pointer, ukosefu wa pointer,

562
00:24:57,770 --> 00:24:58,430
kama wewe.

563
00:24:58,430 --> 00:25:00,309
Ni tu ina maana hakuna kitu bado hapa.

564
00:25:00,309 --> 00:25:02,100
Sasa kwanza, mimi naweza wameweza
kuitwa kitu huu.

565
00:25:02,100 --> 00:25:04,200
Mimi naweza kuwa na kuitwa kuwa ni "orodha"
au idadi yoyote ya mambo mengine.

566
00:25:04,200 --> 00:25:06,960
Lakini nina wito ni "kwanza" ili
hayo yanaendana na picha hii.

567
00:25:06,960 --> 00:25:10,280
Hivyo tu kama kamba inaweza kuwakilishwa
na anwani ya Byte wake wa kwanza,

568
00:25:10,280 --> 00:25:11,280
hivyo unaweza orodha wanaohusishwa.

569
00:25:11,280 --> 00:25:13,480
Na tutaweza kuona data nyingine
miundo kuwa kuwakilishwa

570
00:25:13,480 --> 00:25:16,700
na pointer moja tu,
32-bit mshale, akizungumzia

571
00:25:16,700 --> 00:25:18,740
nodi kwanza sana katika muundo.

572
00:25:18,740 --> 00:25:20,340
>> Lakini sasa hebu wanatarajia tatizo.

573
00:25:20,340 --> 00:25:23,230
Kama mimi nina tu kukumbuka
katika mpango wangu anwani

574
00:25:23,230 --> 00:25:27,220
ya nodi ya kwanza, kwanza
Mstatili katika muundo huu data,

575
00:25:27,220 --> 00:25:31,760
nini alikuwa bora kuwa kesi kuhusu
utekelezaji wa mapumziko ya orodha yangu?

576
00:25:31,760 --> 00:25:35,820
Nini undani muhimu kwamba kinaendelea
kuhakikisha hii kwa kweli kazi?

577
00:25:35,820 --> 00:25:39,250
Na kwa "kweli kazi" Mimi
maana, kiasi kama kamba,

578
00:25:39,250 --> 00:25:42,180
unatufanya kwenda kutoka tabia ya kwanza
katika jina Davin ya pili,

579
00:25:42,180 --> 00:25:44,755
kwa wa tatu, mpaka
nne, na mwisho sana,

580
00:25:44,755 --> 00:25:47,880
jinsi gani sisi kujua wakati tuko mwishoni
ya orodha wanaohusishwa kwamba inaonekana kama hii?

581
00:25:47,880 --> 00:25:50,035

582
00:25:50,035 --> 00:25:50,660
Wakati ni null.

583
00:25:50,660 --> 00:25:53,640
Na nimepata kuwakilishwa aina hii ya kama
kama nguvu ya umeme mhandisi,

584
00:25:53,640 --> 00:25:56,420
na kutuliza kidogo
ishara, ya kila aina.

585
00:25:56,420 --> 00:25:58,246
Lakini kwamba tu maana null katika kesi hii.

586
00:25:58,246 --> 00:26:00,370
Unaweza kuteka ni idadi yoyote
ya njia, lakini mwandishi huyu

587
00:26:00,370 --> 00:26:02,800
kilichotokea kwa kutumia alama hii hapa.

588
00:26:02,800 --> 00:26:06,260
>> Hiyo kwa muda mrefu kama sisi ni stringing
wote wa nodes hizi pamoja,

589
00:26:06,260 --> 00:26:08,600
tu kukumbuka ambapo
moja ya kwanza ni, hivyo muda mrefu

590
00:26:08,600 --> 00:26:11,760
kama sisi kuweka alama maalum katika
node mwisho sana katika orodha,

591
00:26:11,760 --> 00:26:15,130
na tutaweza kutumia null, kwa sababu hiyo
nini tuna inapatikana kwa sisi,

592
00:26:15,130 --> 00:26:16,480
orodha hii ni kamili.

593
00:26:16,480 --> 00:26:20,190
Na hata kama mimi tu kukupa pointer kwa
kipengele kwanza, wewe, programu,

594
00:26:20,190 --> 00:26:22,486
Unaweza shaka kupata mapumziko ya yake.

595
00:26:22,486 --> 00:26:24,360
Lakini hebu basi akili yako
tanga kidogo,

596
00:26:24,360 --> 00:26:26,140
kama uko tayari
kabisa wandered-- nini

597
00:26:26,140 --> 00:26:28,723
kwenda kuwa wakati mbio ya
kutafuta kitu chochote katika orodha hii?

598
00:26:28,723 --> 00:26:30,450

599
00:26:30,450 --> 00:26:33,470
Damn hilo, ni O kubwa ya n,
ambayo si mbaya, katika haki.

600
00:26:33,470 --> 00:26:34,800
Lakini ni linear.

601
00:26:34,800 --> 00:26:37,980
Sisi wameacha kipengele kile
ya arrays na kusonga zaidi

602
00:26:37,980 --> 00:26:43,130
kuelekea picha hii ya dynamically
kusuka pamoja au wanaohusishwa nodes?

603
00:26:43,130 --> 00:26:44,970

604
00:26:44,970 --> 00:26:46,687
Tumekuwa aliyopewa up upatikanaji random.

605
00:26:46,687 --> 00:26:48,770
safu ni nzuri kwa sababu
mathematically kila kitu

606
00:26:48,770 --> 00:26:50,340
ni nyuma kwa nyuma kwa nyuma kwa nyuma.

607
00:26:50,340 --> 00:26:52,370
Hata ingawa picha hii
inaonekana pretty, na hata

608
00:26:52,370 --> 00:26:55,830
ingawa inaonekana kama nodes hizi
ni nicely spaced mbali, katika hali halisi

609
00:26:55,830 --> 00:26:56,830
wao inaweza kuwa mahali popote.

610
00:26:56,830 --> 00:27:01,590
OX1, Ox50, Ox123, Ox99, hizi
nodes inaweza kuwa mahali popote.

611
00:27:01,590 --> 00:27:05,960
Kwa sababu gani malloc kutenga kumbukumbu
kutoka chungu, lakini mahali popote katika chungu.

612
00:27:05,960 --> 00:27:09,080
Wewe si lazima kujua kwamba ni
kwenda kuwa nyuma kwa nyuma kwa nyuma.

613
00:27:09,080 --> 00:27:12,460
Na hivyo picha hii katika hali halisi ya
si kwenda kuwa kabisa hii pretty.

614
00:27:12,460 --> 00:27:16,140
>> Hivyo ni kwenda kuchukua kidogo ya
kazi ili kutekeleza kazi hii.

615
00:27:16,140 --> 00:27:17,880
Basi hebu kutekeleza tafuta sasa.

616
00:27:17,880 --> 00:27:20,250
Na tutaweza kuona aina ya
njia wajanja wa kufanya hivyo.

617
00:27:20,250 --> 00:27:24,660
Hivyo kama mimi ni kutafuta kazi na
Mimi nina aliyopewa variable, integer n

618
00:27:24,660 --> 00:27:28,490
kwa kuangalia, mimi haja ya kujua
syntax mpya kwa ajili ya kuangalia ndani ya

619
00:27:28,490 --> 00:27:32,400
ya muundo hiyo ni
alisema kwa, ili kupata n.

620
00:27:32,400 --> 00:27:33,210
Basi hebu kufanya hili.

621
00:27:33,210 --> 00:27:36,030
>> Hivyo kwanza mimi nina kwenda
mbele na kutangaza nodi *.

622
00:27:36,030 --> 00:27:39,400
Na mimi nina kwenda kumwita
pointer, tu kwa mkataba.

623
00:27:39,400 --> 00:27:41,710
Na mimi nina kwenda initialize kwa kwanza.

624
00:27:41,710 --> 00:27:43,770
Na sasa siwezi kufanya hivyo
katika idadi ya njia.

625
00:27:43,770 --> 00:27:45,436
Lakini nina kwenda kuchukua njia ya kawaida.

626
00:27:45,436 --> 00:27:50,180
Wakati pointer ni si sawa na
null, na kwamba ni halali syntax.

627
00:27:50,180 --> 00:27:54,550
Na ni tu ina maana kufanya yafuatayo, hivyo
muda mrefu kama wewe si akionyesha chochote.

628
00:27:54,550 --> 00:27:55,800
Nini nataka kufanya?

629
00:27:55,800 --> 00:28:01,939
>> Kama pointer dot n, basi mimi kuja nyuma
na kwamba, equals-- sawa na nini?

630
00:28:01,939 --> 00:28:03,105
Nini thamani mimi kuangalia kwa?

631
00:28:03,105 --> 00:28:04,920

632
00:28:04,920 --> 00:28:06,590
n halisi kwamba ilipitishwa katika.

633
00:28:06,590 --> 00:28:09,020
Hivyo hapa ni kipengele mwingine
ya C na lugha nyingi.

634
00:28:09,020 --> 00:28:13,705
Hata ingawa muundo kuitwa node
ina thamani n, kabisa halali

635
00:28:13,705 --> 00:28:17,530
na pia kuwa na hoja za mitaa
au variable kuitwa n.

636
00:28:17,530 --> 00:28:20,085
Kwa sababu hata sisi, pamoja na
macho ya binadamu, wanaweza kutofautisha

637
00:28:20,085 --> 00:28:22,087
kwamba hii ni labda n
tofauti na n huu.

638
00:28:22,087 --> 00:28:23,420
Kwa sababu syntax ni tofauti.

639
00:28:23,420 --> 00:28:26,211
Nimepata dot na pointer,
ambapo hii moja ina hakuna kitu kama hicho.

640
00:28:26,211 --> 00:28:27,290
Hivyo hii ni sawa.

641
00:28:27,290 --> 00:28:29,120
Hiyo ni sawa kuwaita mambo sawa.

642
00:28:29,120 --> 00:28:32,380
>> Kama mimi kupata hii, mimi nina
kwenda wanataka kufanya kitu

643
00:28:32,380 --> 00:28:35,000
kama kutangaza kwamba sisi kupatikana n.

644
00:28:35,000 --> 00:28:37,930
Na tutaweza kuondoka kwamba kama
maoni au pseudocode code.

645
00:28:37,930 --> 00:28:40,190
Mwingine, na hapa ni
kuvutia sehemu, nini

646
00:28:40,190 --> 00:28:47,320
kufanya mimi wanataka kufanya kama nodi sasa
si vyenye n kwamba mimi huduma ya juu?

647
00:28:47,320 --> 00:28:50,700
Je, mimi kufikia yafuatayo?

648
00:28:50,700 --> 00:28:53,710
Kama kidole yangu katika
sasa ni PTR, na ni

649
00:28:53,710 --> 00:28:55,920
akionyesha chochote
kwanza ni akizungumzia katika,

650
00:28:55,920 --> 00:28:59,290
jinsi gani mimi hoja kidole yangu
kwa node ya pili katika kanuni?

651
00:28:59,290 --> 00:29:01,915
Naam, nini breadcrumb tuko
kwenda kufuata katika kesi hii?

652
00:29:01,915 --> 00:29:03,464

653
00:29:03,464 --> 00:29:04,380
Watazamaji: [inaudible].

654
00:29:04,380 --> 00:29:05,630
DAVID J. Malan: Yeah, hivyo ijayo.

655
00:29:05,630 --> 00:29:06,640

656
00:29:06,640 --> 00:29:09,824
Hivyo kama mimi kwenda nyuma yangu
code hapa, kwa kweli, mimi nina

657
00:29:09,824 --> 00:29:12,990
kwenda mbele na kusema pointer, ambayo
ni tu variable-- muda ni

658
00:29:12,990 --> 00:29:15,320
jina weird, PTR, lakini
ni tu kama temp--

659
00:29:15,320 --> 00:29:19,234
Mimi nina kwenda kuweka pointer
sawa na chochote pointer is--

660
00:29:19,234 --> 00:29:22,150
na tena, hii ni kwenda kuwa
buggy kidogo kwa ajili ya moment-- dot ijayo.

661
00:29:22,150 --> 00:29:23,551

662
00:29:23,551 --> 00:29:26,550
Kwa maneno mengine, mimi nina kwenda kuchukua yangu
kidole hiyo akionyesha node hii

663
00:29:26,550 --> 00:29:31,247
hapa na mimi nina kwenda kusema, unajua
nini, kuangalia uwanja ijayo

664
00:29:31,247 --> 00:29:33,330
na hoja kidole kwa
chochote ni akizungumzia katika.

665
00:29:33,330 --> 00:29:35,163
Na hii ni kwenda
kurudia, kurudia, kurudia.

666
00:29:35,163 --> 00:29:37,630
Lakini wakati gani kidole yangu
kuacha kufanya kitu chochote wakati wote?

667
00:29:37,630 --> 00:29:40,095
Haraka kama nini mstari wa kanuni mateke katika?

668
00:29:40,095 --> 00:29:40,970
Watazamaji: [inaudible]

669
00:29:40,970 --> 00:29:43,060
DAVID J. Malan: Kama hatua wakati
pointer ni si sawa na null.

670
00:29:43,060 --> 00:29:44,900
Wakati fulani kidole yangu
kwenda kuwa akionyesha null

671
00:29:44,900 --> 00:29:47,070
na mimi nina kwenda kwa kutambua
hiyo ni mwisho wa orodha hii.

672
00:29:47,070 --> 00:29:48,910
Sasa, hii ni kidogo
uongo nyeupe kwa urahisi.

673
00:29:48,910 --> 00:29:51,580
Ni zinageuka kuwa hata kama sisi
tu kujifunza dot nukuu hii

674
00:29:51,580 --> 00:29:55,220
kwa ajili ya miundo, pointer ni si struct.

675
00:29:55,220 --> 00:29:56,580
PTR ni nini?

676
00:29:56,580 --> 00:29:58,350
Tu kuwa zaidi nitpicky.

677
00:29:58,350 --> 00:29:59,720

678
00:29:59,720 --> 00:30:01,360
Ni pointer nodi.

679
00:30:01,360 --> 00:30:03,120
Siyo node yenyewe.

680
00:30:03,120 --> 00:30:06,650
Kama sikuwa na nyota hapa, pointer
absolutely-- ni nodi.

681
00:30:06,650 --> 00:30:08,650
Hii ni kama wiki moja
tamko la variable,

682
00:30:08,650 --> 00:30:10,120
ingawa neno "node" ni mpya.

683
00:30:10,120 --> 00:30:13,860
>> Lakini kwa haraka kama sisi kuanzisha
nyota, ni sasa pointer nodi.

684
00:30:13,860 --> 00:30:17,960
Na kwa bahati mbaya huwezi kutumia
dot nukuu kwa pointer.

685
00:30:17,960 --> 00:30:21,070
Una kutumia mshale
nukuu, ambayo, strikingly,

686
00:30:21,070 --> 00:30:23,470
ni mara ya kwanza kipande yoyote
ya syntax inaonekana Intuitive.

687
00:30:23,470 --> 00:30:25,245
Hii ina inaonekana kama mshale.

688
00:30:25,245 --> 00:30:26,370
Na hivyo kwamba ni jambo jema.

689
00:30:26,370 --> 00:30:28,995
Na hapa chini literally
inaonekana kama mshale.

690
00:30:28,995 --> 00:30:31,870
Hivyo nadhani hiyo ni la-- mimi si
kufikiri mimi nina juu-kufanya here-- mimi

691
00:30:31,870 --> 00:30:34,120
nadhani hiyo ni mwisho mpya kipande
ya syntax tunakwenda kuona.

692
00:30:34,120 --> 00:30:36,500
Na nashiriki, ni kweli
kidogo Intuitive zaidi.

693
00:30:36,500 --> 00:30:40,090
>> Sasa, kwa wale ambao
kingependa njia ya zamani,

694
00:30:40,090 --> 00:30:42,550
bado unaweza kutumia dot nukuu.

695
00:30:42,550 --> 00:30:45,380
Lakini kama per Jumatatu
mazungumzo, sisi kwanza

696
00:30:45,380 --> 00:30:50,530
haja ya kwenda huko, kwenda kuwa
kushughulikia, na kisha kupata shamba.

697
00:30:50,530 --> 00:30:51,897
Hivyo hii ni pia sahihi.

698
00:30:51,897 --> 00:30:53,730
Na kusema ukweli, hii ni
kidogo zaidi pedantic.

699
00:30:53,730 --> 00:30:56,530
Wewe ni literally akisema, dereference
pointer na kwenda huko.

700
00:30:56,530 --> 00:30:59,320
Kisha kunyakua .n, shamba iitwayo n.

701
00:30:59,320 --> 00:31:01,370
Lakini kusema ukweli, hakuna mtu anataka
aina au kusoma hii.

702
00:31:01,370 --> 00:31:03,620
Na hivyo dunia zuliwa
arrow nukuu, ambayo

703
00:31:03,620 --> 00:31:06,980
ni sawa, kufanana,
ni tu Kiwango cha kisintaksia sukari.

704
00:31:06,980 --> 00:31:10,570
Hivyo njia dhana ya kusema hii
inaonekana zaidi, au inaonekana rahisi.

705
00:31:10,570 --> 00:31:12,296
>> Hivyo sasa mimi nina kwenda kufanya jambo moja nyingine.

706
00:31:12,296 --> 00:31:15,420
Mimi nina kwenda kusema "kuvunja" mara moja nimekuwa
kupatikana hivyo mimi si kuendelea kutafuta kwa ajili yake.

707
00:31:15,420 --> 00:31:17,620
Lakini hii ni kiini
ya kazi ya utafutaji.

708
00:31:17,620 --> 00:31:21,710
Lakini ni rahisi sana, katika
mwisho, si kwa kutembea kwa njia ya kificho.

709
00:31:21,710 --> 00:31:25,570
Hii ni kweli utekelezaji rasmi
ya kutafuta katika leo usambazaji code.

710
00:31:25,570 --> 00:31:30,530
Mimi kuthubutu kusema kwamba Insert ni si
hasa furaha kwa kutembea kwa njia ya

711
00:31:30,530 --> 00:31:33,180
kuibua, wala ni kufuta, hata
ingawa mwisho wa siku

712
00:31:33,180 --> 00:31:35,460
wao jipu chini kwa haki
rahisi heuristics.

713
00:31:35,460 --> 00:31:36,330
>> Basi hebu kufanya hili.

714
00:31:36,330 --> 00:31:39,250
Kama wewe utakuwa ucheshi mimi hapa, mimi
kuleta rundo la mipira stress.

715
00:31:39,250 --> 00:31:40,620
Mimi kuletwa rundo la idadi.

716
00:31:40,620 --> 00:31:46,562
Na tunaweza kupata kujitolea chache tu
kuwakilisha 9, 17, 20, 22, 29, na 34?

717
00:31:46,562 --> 00:31:48,270
Hivyo kimsingi kila mtu
ambaye ni hapa leo.

718
00:31:48,270 --> 00:31:50,170

719
00:31:50,170 --> 00:31:52,760
Hiyo ilikuwa moja, mbili, tatu,
nne, tano, sita watu.

720
00:31:52,760 --> 00:31:55,740
Na nimekuwa aliuliza kwa go-- kuona, hakuna
moja katika nyuma huwafufua mikono yao.

721
00:31:55,740 --> 00:32:01,910
OK, moja, mbili, tatu, nne,
five-- napenda mzigo balance-- sita.

722
00:32:01,910 --> 00:32:03,051
OK, wewe sita kuja juu up.

723
00:32:03,051 --> 00:32:04,050
Tutaweza haja watu wengine.

724
00:32:04,050 --> 00:32:05,460
Sisi kuletwa mipira ya ziada stress.

725
00:32:05,460 --> 00:32:08,200
Na kama unaweza, kwa
muda tu, line

726
00:32:08,200 --> 00:32:10,490
maisha yenu juu tu
kama picha hii hapa.

727
00:32:10,490 --> 00:32:15,200

728
00:32:15,200 --> 00:32:15,959
>> Wote haki.

729
00:32:15,959 --> 00:32:17,125
Hebu angalia, nini jina lako?

730
00:32:17,125 --> 00:32:17,550
>> Watazamaji: Andrew.

731
00:32:17,550 --> 00:32:18,800
>> DAVID J. Malan: Andrew,
wewe ni namba 9.

732
00:32:18,800 --> 00:32:19,540
Nice kukutana na wewe.

733
00:32:19,540 --> 00:32:20,400
Hapa kwenda.

734
00:32:20,400 --> 00:32:21,593

735
00:32:21,593 --> 00:32:22,176
Watazamaji: Jen.

736
00:32:22,176 --> 00:32:22,662
DAVID J. Malan: Jen.

737
00:32:22,662 --> 00:32:23,162
Daudi.

738
00:32:23,162 --> 00:32:23,765
Namba 17.

739
00:32:23,765 --> 00:32:24,950

740
00:32:24,950 --> 00:32:25,450
Ndiyo?

741
00:32:25,450 --> 00:32:26,400
>> Watazamaji: Mimi nina Julia.

742
00:32:26,400 --> 00:32:26,980
>> DAVID J. Malan: Julia, David.

743
00:32:26,980 --> 00:32:27,545
Idadi 20.

744
00:32:27,545 --> 00:32:28,507

745
00:32:28,507 --> 00:32:29,340
Watazamaji: Christian.

746
00:32:29,340 --> 00:32:30,715
DAVID J. Malan: Christian, David.

747
00:32:30,715 --> 00:32:31,541
Idadi 22.

748
00:32:31,541 --> 00:32:32,040
Na?

749
00:32:32,040 --> 00:32:32,649
>> Watazamaji: JP.

750
00:32:32,649 --> 00:32:33,440
DAVID J. Malan: JP.

751
00:32:33,440 --> 00:32:34,880
Idadi 29.

752
00:32:34,880 --> 00:32:37,080
Hivyo kwenda mbele na kupata in-- Uh oh.

753
00:32:37,080 --> 00:32:38,486

754
00:32:38,486 --> 00:32:38,985
Uh oh.

755
00:32:38,985 --> 00:32:39,650

756
00:32:39,650 --> 00:32:40,150
Kusubiri.

757
00:32:40,150 --> 00:32:41,360

758
00:32:41,360 --> 00:32:42,390
20.

759
00:32:42,390 --> 00:32:43,682
Je, mtu yeyote kuwa na marker?

760
00:32:43,682 --> 00:32:44,890
Watazamaji: Mimi nimepata Sharpie.

761
00:32:44,890 --> 00:32:45,660
DAVID J. Malan: You got Sharpie?

762
00:32:45,660 --> 00:32:46,159
OK.

763
00:32:46,159 --> 00:32:47,577

764
00:32:47,577 --> 00:32:49,160
Na je, mtu yeyote kuwa na kipande cha karatasi?

765
00:32:49,160 --> 00:32:51,562

766
00:32:51,562 --> 00:32:52,270
Ila hotuba.

767
00:32:52,270 --> 00:32:53,810

768
00:32:53,810 --> 00:32:55,362
Kuja juu.

769
00:32:55,362 --> 00:32:56,320
Watazamaji: Sisi tumepewa yake.

770
00:32:56,320 --> 00:32:57,600
DAVID J. Malan: Sisi got it?

771
00:32:57,600 --> 00:32:58,577
Zote haki, asante.

772
00:32:58,577 --> 00:33:01,380

773
00:33:01,380 --> 00:33:02,520
Hapa sisi kwenda.

774
00:33:02,520 --> 00:33:03,582
Ilikuwa hii kutoka kwenu?

775
00:33:03,582 --> 00:33:04,540
Wewe tu kuokolewa siku.

776
00:33:04,540 --> 00:33:05,670

777
00:33:05,670 --> 00:33:07,220
Hivyo 29.

778
00:33:07,220 --> 00:33:10,510

779
00:33:10,510 --> 00:33:11,110
Wote haki.

780
00:33:11,110 --> 00:33:13,360

781
00:33:13,360 --> 00:33:14,890
Mimi misspelled 29, lakini OK.

782
00:33:14,890 --> 00:33:15,720
Kwenda mbele.

783
00:33:15,720 --> 00:33:18,114
Haki wote, mimi nitakupa
kalamu yako nyuma momentarily.

784
00:33:18,114 --> 00:33:19,280
Hivyo tuna folks hizi hapa.

785
00:33:19,280 --> 00:33:20,330
Hebu kuwa na mtu mwingine.

786
00:33:20,330 --> 00:33:23,750
Gabe, je, unataka kucheza
kipengele kwanza hapa?

787
00:33:23,750 --> 00:33:25,705
Tutaweza haja ya wewe kwa uhakika
hizi folks faini.

788
00:33:25,705 --> 00:33:26,930

789
00:33:26,930 --> 00:33:31,030
Hivyo 9, 17, 20, 22, aina
ya 29, na kisha 34.

790
00:33:31,030 --> 00:33:32,160

791
00:33:32,160 --> 00:33:33,325
Je, sisi kupoteza mtu?

792
00:33:33,325 --> 00:33:33,950
Mimi kufanya kuwa 34.

793
00:33:33,950 --> 00:33:36,730
Ambapo did-- OK, ambaye anataka kuwa 34?

794
00:33:36,730 --> 00:33:37,605
OK, kuja juu juu, 34.

795
00:33:37,605 --> 00:33:39,280

796
00:33:39,280 --> 00:33:41,220
Zote haki, hii itakuwa
pamoja na thamani ya kilele.

797
00:33:41,220 --> 00:33:41,550
Nini jina lako?

798
00:33:41,550 --> 00:33:42,040
>> Watazamaji: Peter.

799
00:33:42,040 --> 00:33:43,456
>> DAVID J. Malan: Peter, kuja juu up.

800
00:33:43,456 --> 00:33:46,810
Haki wote, hivyo hapa ni
rundo zima la nodes.

801
00:33:46,810 --> 00:33:49,060
Kila mmoja wenu guys inawakilisha
moja ya rectangles haya.

802
00:33:49,060 --> 00:33:51,930
Na Gabe, kidogo isiyo ya kawaida
mtu nje, inawakilisha kwanza.

803
00:33:51,930 --> 00:33:54,850
Hivyo pointer yake ni kidogo kidogo
juu ya screen kuliko mtu mwingine.

804
00:33:54,850 --> 00:33:58,120
Na katika kesi hii, kila mmoja wa wako wa kushoto
mikono ni kwenda aidha uhakika chini,

805
00:33:58,120 --> 00:34:01,085
hivyo anayewakilisha null, hivyo
tu kukosekana kwa pointer,

806
00:34:01,085 --> 00:34:03,210
au ni kwenda akizungumzia
nodi karibu na wewe.

807
00:34:03,210 --> 00:34:05,440
>> Hivyo sasa hivi kama wewe kupamba
wenyewe kama picha

808
00:34:05,440 --> 00:34:07,585
hapa, kwenda mbele na hatua
kwa kila mmoja, na Gabe

809
00:34:07,585 --> 00:34:11,030
katika akizungumzia hasa katika
namba 9 ya kuwakilisha orodha.

810
00:34:11,030 --> 00:34:14,050
OK, na idadi 34, mkono wako wa kushoto
lazima tu akizungumzia katika sakafu.

811
00:34:14,050 --> 00:34:15,750
>> OK, hivyo hii ni orodha wanaohusishwa.

812
00:34:15,750 --> 00:34:17,580
Hivyo hii ni mazingira katika swali.

813
00:34:17,580 --> 00:34:20,210
Na hakika, hii ni mwakilishi
wa darasa la matatizo

814
00:34:20,210 --> 00:34:21,929
kwamba unaweza kujaribu kutatua na kanuni.

815
00:34:21,929 --> 00:34:25,020
Unataka hatimaye kuingiza
kipengele mpya katika orodha.

816
00:34:25,020 --> 00:34:27,494
Katika kesi hiyo, tunakwenda
kujaribu kuingiza idadi 55.

817
00:34:27,494 --> 00:34:28,500

818
00:34:28,500 --> 00:34:30,860
Lakini kuna kwenda kuwa
matukio mbalimbali ya kuzingatia.

819
00:34:30,860 --> 00:34:34,409
Na hakika, hii ni kwenda kuwa moja
ya big-picha Takeaways hapa, ni,

820
00:34:34,409 --> 00:34:35,659
nini ni kesi tofauti.

821
00:34:35,659 --> 00:34:39,120
Je, ni tofauti kama hali au
matawi kwamba mpango wako wanaweza kuwa na?

822
00:34:39,120 --> 00:34:42,024
>> Naam, idadi wewe ni kujaribu
Insert, ambayo sisi kujua sasa kuwa 55,

823
00:34:42,024 --> 00:34:44,650
lakini kama wewe hakujua
mapema, mimi daresay

824
00:34:44,650 --> 00:34:47,840
unaingia angalau tatu
inawezekana hali.

825
00:34:47,840 --> 00:34:49,717
Ambapo wanaweza kipengele mpya kuwa?

826
00:34:49,717 --> 00:34:51,050
Watazamaji: Na mwisho au katikati.

827
00:34:51,050 --> 00:34:54,150
DAVID J. Malan: Mwishoni, katika
katikati, au mwanzoni.

828
00:34:54,150 --> 00:34:56,650
Hivyo mimi kudai kuna angalau
matatizo matatu sisi haja ya kutatua.

829
00:34:56,650 --> 00:34:58,691
Hebu kuchagua nini labda
arguably rahisi

830
00:34:58,691 --> 00:35:01,090
moja, ambapo kipengele mpya
mali mwanzoni.

831
00:35:01,090 --> 00:35:04,040
Hivyo nina kwenda kuwa na code kabisa
kama kutafuta, ambayo mimi tu aliandika.

832
00:35:04,040 --> 00:35:07,670
Na mimi nina kwenda kuwa na PTR, ambayo
Mimi itabidi kuwakilisha hapa kwa kidole yangu,

833
00:35:07,670 --> 00:35:08,370
kama kawaida.

834
00:35:08,370 --> 00:35:12,430
>> Na kumbuka thamani, nini
gani sisi initialize PTR kwa?

835
00:35:12,430 --> 00:35:15,300
Hivyo sisi initialized kwa null awali.

836
00:35:15,300 --> 00:35:16,410

837
00:35:16,410 --> 00:35:19,770
Lakini basi nini sisi kufanya mara moja sisi
walikuwa ndani ya kutafuta kazi yetu?

838
00:35:19,770 --> 00:35:20,940

839
00:35:20,940 --> 00:35:24,870
Sisi kuweka sawa na ya kwanza,
ambayo haina maana kufanya hivyo.

840
00:35:24,870 --> 00:35:25,890

841
00:35:25,890 --> 00:35:30,570
Kama mimi kuweka PTR sawa na kwanza, nini
lazima mkono wangu kweli kuwa akionyesha?

842
00:35:30,570 --> 00:35:31,070
Haki.

843
00:35:31,070 --> 00:35:33,290
Hivyo kama Gabe na mimi ni kwenda
kuwa na maadili sawa hapa,

844
00:35:33,290 --> 00:35:34,760
tunahitaji wote wawili uhakika katika namba 9.

845
00:35:34,760 --> 00:35:36,420
>> Hivyo hii ilikuwa mwanzo wa hadithi yetu.

846
00:35:36,420 --> 00:35:38,700
Na sasa hii ni moja kwa moja,
ingawa syntax ni mpya.

847
00:35:38,700 --> 00:35:40,580
Conceptually hii ni search linear.

848
00:35:40,580 --> 00:35:42,750
Ni 55 sawa na 9?

849
00:35:42,750 --> 00:35:45,559
Au tuseme, hebu sema chini ya 9.

850
00:35:45,559 --> 00:35:47,600
Kwa sababu mimi nina kujaribu
kufikiri mahali pa kuweka 55.

851
00:35:47,600 --> 00:35:51,270
Chini ya 9, chini ya 17, chini ya
ya 20, chini ya 22, chini ya 29,

852
00:35:51,270 --> 00:35:52,510
chini ya 34, hakuna.

853
00:35:52,510 --> 00:35:55,080
Hivyo sasa tuko katika kesi
moja ya angalau tatu.

854
00:35:55,080 --> 00:35:59,910
>> Kama mimi nataka kuingiza 55 zaidi ya hapa, nini
mstari wa kanuni haja ya kupata kuuawa?

855
00:35:59,910 --> 00:36:01,890
Ni kwa jinsi gani picha hii ya
binadamu haja ya kubadili?

856
00:36:01,890 --> 00:36:03,181
Je, mimi kufanya na mkono wangu wa kushoto?

857
00:36:03,181 --> 00:36:04,530

858
00:36:04,530 --> 00:36:07,360
Hii inapaswa kuwa null awali,
kwa sababu mimi nina mwishoni mwa orodha.

859
00:36:07,360 --> 00:36:09,318
Na kile lazima kutokea
hapa pamoja na Petro, kwa nani?

860
00:36:09,318 --> 00:36:10,520

861
00:36:10,520 --> 00:36:12,430
Yeye ni wazi kwenda kwa uhakika na mimi.

862
00:36:12,430 --> 00:36:15,580
Hivyo mimi kudai kuna mistari angalau mbili
wa kanuni katika sampuli kificho kutoka leo

863
00:36:15,580 --> 00:36:18,570
kwamba kinaendelea kutekeleza hili
mazingira ya kuongeza 55 katika mkia.

864
00:36:18,570 --> 00:36:20,950
Na naweza kuwa na mtu hop
up na tu kuwakilisha 55?

865
00:36:20,950 --> 00:36:22,200
Haki wote, wewe ni mpya 55.

866
00:36:22,200 --> 00:36:23,580

867
00:36:23,580 --> 00:36:27,054
>> Hivyo sasa nini kama ya
mazingira huja pamoja,

868
00:36:27,054 --> 00:36:29,720
na tunataka kuingiza katika
mwanzo au mkuu wa orodha hii?

869
00:36:29,720 --> 00:36:31,100
Na nini jina lako, idadi ya 55?

870
00:36:31,100 --> 00:36:31,420
>> Watazamaji: Jack.

871
00:36:31,420 --> 00:36:32,295
>> DAVID J. Malan: Jack?

872
00:36:32,295 --> 00:36:33,585
OK, nzuri ya kukutana na wewe.

873
00:36:33,585 --> 00:36:34,210
Karibu ndani.

874
00:36:34,210 --> 00:36:36,640
Hivyo sasa sisi ni kwenda
kuingiza, kusema, namba 5.

875
00:36:36,640 --> 00:36:39,840
Hapa ni kesi ya pili ya
tatu sisi kuja na kabla ya.

876
00:36:39,840 --> 00:36:43,050
Hivyo kama 5 yanakuwa mwanzoni,
hebu angalia jinsi sisi kupata kwamba nje.

877
00:36:43,050 --> 00:36:46,310
Mimi initialize PTR yangu
pointer kwa namba 9 tena.

878
00:36:46,310 --> 00:36:49,140
Na mimi barabara, oh, 5 ni chini ya 9.

879
00:36:49,140 --> 00:36:50,880
Hivyo kurekebisha picha hii kwa ajili yetu.

880
00:36:50,880 --> 00:36:54,820
Ambao mikono, Gabe au Daudi
or-- namba 9 ya jina ni nini?

881
00:36:54,820 --> 00:36:55,740
>> Watazamaji: Jen.

882
00:36:55,740 --> 00:36:58,406
>> DAVID J. Malan: hands-- Jen ya
ambayo ya mikono yetu haja ya kubadili?

883
00:36:58,406 --> 00:36:58,905

884
00:36:58,905 --> 00:37:00,970
OK, hivyo Gabe anasema nini sasa?

885
00:37:00,970 --> 00:37:01,640
Saa yangu.

886
00:37:01,640 --> 00:37:02,750
Mimi ni node mpya.

887
00:37:02,750 --> 00:37:04,870
Hivyo mimi itabidi tu aina ya hoja
hapa kuona kuibua.

888
00:37:04,870 --> 00:37:06,435
Na wakati huo huo je, mimi uhakika kwamba?

889
00:37:06,435 --> 00:37:07,910

890
00:37:07,910 --> 00:37:09,020
Bado ambapo mimi nina akizungumzia.

891
00:37:09,020 --> 00:37:10,000
Hivyo hiyo ni yake.

892
00:37:10,000 --> 00:37:13,717
Hivyo tu kweli line moja ya kanuni fixes
hasa katika suala hili, ingekuwa kuonekana.

893
00:37:13,717 --> 00:37:14,800
Haki zote, hivyo hiyo ni nzuri.

894
00:37:14,800 --> 00:37:17,580
Na mtu anaweza kuwa placeholder kwa 5?

895
00:37:17,580 --> 00:37:18,080
Kuja juu juu.

896
00:37:18,080 --> 00:37:20,270

897
00:37:20,270 --> 00:37:21,320
Sisi itabidi kupata wewe mara ya pili.

898
00:37:21,320 --> 00:37:24,280
>> Haki zote, hivyo now-- na
kama kando, majina

899
00:37:24,280 --> 00:37:28,510
Mimi si kufanya wazi kutaja ya haki
sasa, pred pointer, mtangulizi pointer

900
00:37:28,510 --> 00:37:31,260
na pointer mpya, hiyo ni
tu majina aliyopewa

901
00:37:31,260 --> 00:37:35,280
katika sampuli kificho kwa kuyatumia au
mikono yangu hiyo ni aina ya kuonyesha kote.

902
00:37:35,280 --> 00:37:36,060
Nini jina lako?

903
00:37:36,060 --> 00:37:36,700
>> Watazamaji: Christine.

904
00:37:36,700 --> 00:37:37,100
>> DAVID J. Malan: Christine.

905
00:37:37,100 --> 00:37:38,090
Karibu ndani.

906
00:37:38,090 --> 00:37:42,180
Haki zote, hivyo hebu fikiria sasa
kidogo zaidi annoying mazingira,

907
00:37:42,180 --> 00:37:46,350
ambapo mimi unataka Insert
kitu kama 26 katika hili.

908
00:37:46,350 --> 00:37:47,090
20?

909
00:37:47,090 --> 00:37:47,590
Nini?

910
00:37:47,590 --> 00:37:50,510
Hizi are-- jambo zuri tuna kalamu hii.

911
00:37:50,510 --> 00:37:51,955
Zote haki, 20.

912
00:37:51,955 --> 00:37:53,640

913
00:37:53,640 --> 00:37:57,570
Kama mtu anaweza kupata kipande kingine cha
karatasi tayari, tu katika case-- haki yote.

914
00:37:57,570 --> 00:37:58,370
Oh, kuvutia.

915
00:37:58,370 --> 00:37:59,760

916
00:37:59,760 --> 00:38:02,390
Naam hii ni mfano
ya hotuba mdudu.

917
00:38:02,390 --> 00:38:03,894
OK hivyo nini jina yako tena?

918
00:38:03,894 --> 00:38:04,560
Watazamaji: Julia.

919
00:38:04,560 --> 00:38:07,559
DAVID J. Malan: Julia, unaweza pop
nje na kujifanya wewe walikuwa kamwe huko?

920
00:38:07,559 --> 00:38:09,040
OK, hii kamwe kilichotokea.

921
00:38:09,040 --> 00:38:09,680
Asante.

922
00:38:09,680 --> 00:38:12,180
Hivyo tuseme tunataka kuingiza
Julia katika orodha hii wanaohusishwa.

923
00:38:12,180 --> 00:38:13,780
Yeye ni namba 20.

924
00:38:13,780 --> 00:38:15,530
Na bila shaka yeye ni
kwenda ni katika

925
00:38:15,530 --> 00:38:17,521
begin-- hawana uhakika katika chochote bado.

926
00:38:17,521 --> 00:38:20,020
Hivyo mkono wako unaweza aina ya kuwa
chini null au baadhi thamani takataka.

927
00:38:20,020 --> 00:38:21,210
Hebu kuwaambia hadithi ya haraka.

928
00:38:21,210 --> 00:38:22,980
Mimi nina akionyesha namba 5 wakati huu.

929
00:38:22,980 --> 00:38:23,880
Kisha mimi kuangalia 9.

930
00:38:23,880 --> 00:38:25,130
Kisha mimi kuangalia 17.

931
00:38:25,130 --> 00:38:26,247
Kisha mimi kuangalia 22.

932
00:38:26,247 --> 00:38:27,650

933
00:38:27,650 --> 00:38:32,485
Na mimi kutambua, ooh, Julia
mahitaji ya kwenda kabla ya 22.

934
00:38:32,485 --> 00:38:33,580

935
00:38:33,580 --> 00:38:34,660
Basi nini mahitaji ya kutokea?

936
00:38:34,660 --> 00:38:35,786

937
00:38:35,786 --> 00:38:36,910
Ambao mikono haja ya kubadili?

938
00:38:36,910 --> 00:38:38,360
Julia ya, yangu, or--
nini jina yako tena?

939
00:38:38,360 --> 00:38:39,230
>> Watazamaji: Christian.

940
00:38:39,230 --> 00:38:40,060
>> DAVID J. Malan: Christian au?

941
00:38:40,060 --> 00:38:40,560
>> Watazamaji: Andy.

942
00:38:40,560 --> 00:38:40,905
>> DAVID J. Malan: Andy.

943
00:38:40,905 --> 00:38:41,654
Mkristo au Andy?

944
00:38:41,654 --> 00:38:44,280

945
00:38:44,280 --> 00:38:45,690
Andy mahitaji ya kumweka katika?

946
00:38:45,690 --> 00:38:46,780

947
00:38:46,780 --> 00:38:47,341
Julia.

948
00:38:47,341 --> 00:38:47,840
Wote haki.

949
00:38:47,840 --> 00:38:48,960
Hivyo Andy, unataka kumweka katika Julia?

950
00:38:48,960 --> 00:38:50,120
Lakini kusubiri dakika.

951
00:38:50,120 --> 00:38:53,260
Katika hadithi hivi sasa,
Mimi nina aina ya moja

952
00:38:53,260 --> 00:38:56,800
katika malipo, kwa maana kwamba
pointer ni jambo kwamba

953
00:38:56,800 --> 00:38:57,850
kuhamia kwa njia ya orodha.

954
00:38:57,850 --> 00:39:00,800
Tuweze kuwa na jina kwa Andy, lakini
hakuna variable kuitwa Andy.

955
00:39:00,800 --> 00:39:04,320
tu variable mwingine tuna ni
kwanza, ambaye ni kuwakilishwa na Gabe.

956
00:39:04,320 --> 00:39:07,690
>> Hivyo hii ni kweli kwa nini hivyo
mbali tumekuwa si zinahitajika huu.

957
00:39:07,690 --> 00:39:10,846
Lakini sasa juu ya screen kuna
kutaja tena ya pred pointer.

958
00:39:10,846 --> 00:39:11,970
Hivyo basi mimi kuwa wazi zaidi.

959
00:39:11,970 --> 00:39:14,820
Kama hii ni pointer, mimi alikuwa bora
kupata akili kidogo zaidi

960
00:39:14,820 --> 00:39:15,950
kuhusu iteration yangu.

961
00:39:15,950 --> 00:39:19,580
Kama huna akili yangu kwenda kwa njia ya hapa
tena, akizungumzia hapa, akizungumzia hapa.

962
00:39:19,580 --> 00:39:22,500
Lakini ngoja na pointer pred,
mtangulizi pointer, hiyo ni

963
00:39:22,500 --> 00:39:24,740
aina ya akionyesha
kipengele Mimi mara tu saa.

964
00:39:24,740 --> 00:39:27,330
Hivyo wakati mimi kwenda hapa, sasa
mkono wangu wa kushoto updates.

965
00:39:27,330 --> 00:39:29,370
Wakati mimi kwenda hapa wangu updates mkono wa kushoto.

966
00:39:29,370 --> 00:39:33,090
Na sasa nina si tu pointer kwa
kipengele kwamba huenda baada ya Julia,

967
00:39:33,090 --> 00:39:36,300
Mimi bado wana pointer kwa
Andy, kipengele kabla ya.

968
00:39:36,300 --> 00:39:39,430
Hivyo unaweza kupata, kimsingi,
breadcrumbs, kama wewe,

969
00:39:39,430 --> 00:39:41,500
yote ya kuyatumia zinazohitajika.

970
00:39:41,500 --> 00:39:43,710
>> Hivyo kama mimi nina akionyesha
Andy na mimi nina pia akizungumzia

971
00:39:43,710 --> 00:39:47,105
Christian, ambaye mikono
lazima sasa kuwa alisema mahali pengine?

972
00:39:47,105 --> 00:39:48,770

973
00:39:48,770 --> 00:39:51,960
Hivyo Andy sasa wanaweza kumweka katika Julia.

974
00:39:51,960 --> 00:39:54,460
Julia sasa wanaweza kumweka katika Kikristo.

975
00:39:54,460 --> 00:39:56,950
Kwa sababu yeye anaweza nakala yangu
upande wa kulia ya pointer.

976
00:39:56,950 --> 00:40:00,044
Na kwamba kwa ufanisi unaweka
nyuma katika nafasi hii hapa.

977
00:40:00,044 --> 00:40:02,460
Hivyo katika muda mfupi, hata ingawa hii
ni kuchukua us aina ya milele

978
00:40:02,460 --> 00:40:04,510
kwa kweli update
wanaohusishwa orodha, kutambua

979
00:40:04,510 --> 00:40:06,580
kwamba shughuli za
ni rahisi kiasi.

980
00:40:06,580 --> 00:40:10,030
Ni ya moja, mbili, tatu
mstari wa kanuni hatimaye.

981
00:40:10,030 --> 00:40:12,780
Lakini kung'ata wale
mstari wa kanuni labda

982
00:40:12,780 --> 00:40:16,350
ni kidogo ya mantiki kwamba ufanisi
anauliza swali, ambapo ni sisi?

983
00:40:16,350 --> 00:40:18,970
Je, sisi mwanzoni,
katikati, au mwisho?

984
00:40:18,970 --> 00:40:21,890
>> Sasa, kuna shaka baadhi ya wengine
shughuli tupate kutekeleza.

985
00:40:21,890 --> 00:40:24,880
Na picha hizi hapa depict tu
kile sisi tu alivyofanya kwa binadamu.

986
00:40:24,880 --> 00:40:26,080
Nini juu ya kuondolewa?

987
00:40:26,080 --> 00:40:30,650
Kama mimi nataka, kwa mfano,
kuondoa namba 34 au 55,

988
00:40:30,650 --> 00:40:34,680
Nipate kuwa aina hiyo ya kificho,
lakini mimi nina kwenda haja ya hatua moja au mbili.

989
00:40:34,680 --> 00:40:36,110
Kwa sababu nini mpya?

990
00:40:36,110 --> 00:40:40,460
Kama mimi kuondoa mtu mwishoni,
kama idadi ya 55 na kisha 34,

991
00:40:40,460 --> 00:40:42,995
nini pia ina mabadiliko kama mimi kufanya hivyo?

992
00:40:42,995 --> 00:40:44,870
Nina si evict--
nini jina yako tena?

993
00:40:44,870 --> 00:40:45,380
>> Watazamaji: Jack.

994
00:40:45,380 --> 00:40:46,255
>> DAVID J. Malan: Jack.

995
00:40:46,255 --> 00:40:49,770
Nina si tu evict-- bure Jack,
hivyo literally wito bure Jack, au angalau

996
00:40:49,770 --> 00:40:53,530
pointer huko pia, lakini sasa
nini inahitaji mabadiliko na Petro?

997
00:40:53,530 --> 00:40:55,510
Mkono wake bora kuanza akizungumzia chini.

998
00:40:55,510 --> 00:40:59,300
Sababu kwa haraka kama mimi wito bure juu ya
Jack, kama Petro bado akionyesha Jack

999
00:40:59,300 --> 00:41:02,530
na mimi hivyo kuweka apitaye
orodha na upatikanaji pointer hii,

1000
00:41:02,530 --> 00:41:05,650
kwamba wakati wetu wa kale rafiki segmentation
kosa ili kweli kick katika.

1001
00:41:05,650 --> 00:41:07,860
Kwa sababu tumekuwa aliyopewa
kumbukumbu nyuma Jack.

1002
00:41:07,860 --> 00:41:10,760
>> Unaweza kukaa huko
awkwardly kwa muda tu.

1003
00:41:10,760 --> 00:41:13,410
Kwa sababu tuna michache tu
shughuli ya mwisho ya kuzingatia.

1004
00:41:13,410 --> 00:41:15,600
Kuondoa mkuu wa orodha,
au beginning-- na hii moja ya

1005
00:41:15,600 --> 00:41:16,349
kidogo annoying.

1006
00:41:16,349 --> 00:41:19,640
Kwa sababu tuna kujua kwamba Gabe
ni aina ya pekee katika mpango huu.

1007
00:41:19,640 --> 00:41:21,440
Kwa sababu kwa kweli, yeye ana pointer yake mwenyewe.

1008
00:41:21,440 --> 00:41:24,860
Yeye si tu kuwa alisema katika,
kama ni karibu kila mtu mwingine hapa.

1009
00:41:24,860 --> 00:41:28,112
>> Hivyo wakati mkuu wa orodha ni
kuondolewa, ambao mikono haja ya kubadili sasa?

1010
00:41:28,112 --> 00:41:29,070
Nini jina yako tena?

1011
00:41:29,070 --> 00:41:29,450
>> Watazamaji: Christine.

1012
00:41:29,450 --> 00:41:31,408
>> DAVID J. Malan: Mimi nina kubwa
katika majina, inaonekana.

1013
00:41:31,408 --> 00:41:34,011
Hivyo Christine na Gabe,
ambao mikono haja ya kubadili

1014
00:41:34,011 --> 00:41:36,510
wakati sisi kujaribu kuondoa Christine,
namba 5, kutoka picha?

1015
00:41:36,510 --> 00:41:37,550

1016
00:41:37,550 --> 00:41:38,820
OK, hivyo hebu kufanya Gabe.

1017
00:41:38,820 --> 00:41:40,950
Gabe kinaendelea kwa uhakika,
labda, katika namba 9.

1018
00:41:40,950 --> 00:41:42,230

1019
00:41:42,230 --> 00:41:44,642
Lakini nini ijayo lazima kutokea?

1020
00:41:44,642 --> 00:41:46,600
Watazamaji: Christine lazima
kuwa null [inaudible].

1021
00:41:46,600 --> 00:41:50,244
DAVID J. Malan: Sawa, sisi lazima pengine
make-- nikasikia "null" mahali fulani.

1022
00:41:50,244 --> 00:41:51,410
Watazamaji: Null na bure yake.

1023
00:41:51,410 --> 00:41:51,855
DAVID J. Malan: null nini?

1024
00:41:51,855 --> 00:41:53,074
Watazamaji: Null na bure yake.

1025
00:41:53,074 --> 00:41:54,490
DAVID J. Malan: Null na bure yake.

1026
00:41:54,490 --> 00:41:55,422
Hivyo hii ni rahisi sana.

1027
00:41:55,422 --> 00:41:58,380
Na ni kamili kwamba wewe ni sasa aina
ya amesimama pale, si wa mali.

1028
00:41:58,380 --> 00:42:00,430
Kwa sababu tumekuwa
frikopplas kutoka kwenye orodha.

1029
00:42:00,430 --> 00:42:02,820
Ve ufanisi imekuwa
yatima kutoka kwenye orodha.

1030
00:42:02,820 --> 00:42:07,770
Na hivyo sisi alikuwa bora wito bure sasa juu ya
Christine kutoa kwamba kumbukumbu nyuma.

1031
00:42:07,770 --> 00:42:10,240
Vinginevyo kila wakati sisi
kufuta nodi kutoka orodha

1032
00:42:10,240 --> 00:42:14,230
tupate kuwa maamuzi orodha
mfupi, lakini si kweli kupungua

1033
00:42:14,230 --> 00:42:15,096
ukubwa katika kumbukumbu.

1034
00:42:15,096 --> 00:42:17,720
Na hivyo kama sisi kuendelea kuongeza na
kuongeza, akiongeza mambo kwenye orodha,

1035
00:42:17,720 --> 00:42:19,280
kompyuta yangu ili kupata polepole
na polepole na polepole,

1036
00:42:19,280 --> 00:42:21,740
kwa sababu mimi nina mbio nje ya
kumbukumbu, hata kama nina si kweli

1037
00:42:21,740 --> 00:42:25,580
kutumia ka Christine ya
ya kumbukumbu tena.

1038
00:42:25,580 --> 00:42:28,500
>> Hivyo katika mwisho kuna wengine
matukio, ya course-- kuondolewa

1039
00:42:28,500 --> 00:42:30,640
katikati, kuondolewa
mwishoni, kama sisi kuona.

1040
00:42:30,640 --> 00:42:32,348
Lakini zaidi ya kuvutia
Changamoto sasa ni

1041
00:42:32,348 --> 00:42:34,770
kwenda kuwa kwa kuzingatia hasa
nini wakati mbio ni.

1042
00:42:34,770 --> 00:42:36,640
Hivyo si tu unaweza kuweka yako
vipande vya karatasi, kama, Gabe,

1043
00:42:36,640 --> 00:42:38,640
isingekuwa akili kutoa
kila mtu stress mpira.

1044
00:42:38,640 --> 00:42:42,100
Asante sana kwa orodha yetu wanaohusishwa
wa kujitolea hapa, kama unaweza.

1045
00:42:42,100 --> 00:42:45,320
>> [Makofi]

1046
00:42:45,320 --> 00:42:46,700
>> DAVID J. Malan: All wa kulia.

1047
00:42:46,700 --> 00:42:51,110
Hivyo wanandoa wa uchambuzi
maswali basi, kama mimi naweza.

1048
00:42:51,110 --> 00:42:59,670
Tumeona nukuu hii kabla,
O kubwa na Omega, mipaka juu

1049
00:42:59,670 --> 00:43:02,520
na mipaka ya chini juu ya
mbio wakati wa baadhi ya algorithm.

1050
00:43:02,520 --> 00:43:04,950
Hivyo hebu fikiria tu
wanandoa wa maswali.

1051
00:43:04,950 --> 00:43:07,090
>> Moja, na sisi alisema
kabla ya, nini mbio

1052
00:43:07,090 --> 00:43:10,647
wakati wa kutafuta kwa
orodha katika suala la kubwa O?

1053
00:43:10,647 --> 00:43:13,480
Nini amefungwa juu ya kuendesha
wakati wa kutafuta orodha wanaohusishwa

1054
00:43:13,480 --> 00:43:16,340
kama kutekelezwa na kujitolea yetu hapa?

1055
00:43:16,340 --> 00:43:17,820
Ni O kubwa ya n, linear.

1056
00:43:17,820 --> 00:43:20,630
Kwa sababu katika hali mbaya zaidi,
kipengele, kama 55,

1057
00:43:20,630 --> 00:43:23,830
sisi kuwa na kuangalia kwa inaweza kuwa ambapo
Jack alikuwa, njia yote mwishoni.

1058
00:43:23,830 --> 00:43:28,250
Na kwa bahati mbaya, tofauti na safu
hatuwezi kupata dhana wakati huu.

1059
00:43:28,250 --> 00:43:31,820
Hata ingawa yote ya binadamu wetu walikuwa
sorted kutoka mambo madogo, 5,

1060
00:43:31,820 --> 00:43:35,900
njia yote hadi kipengele kubwa,
55, hiyo ni kawaida jambo zuri.

1061
00:43:35,900 --> 00:43:38,815
Lakini ni nini dhana kwamba
tena kuruhusu sisi kufanya nini?

1062
00:43:38,815 --> 00:43:39,775

1063
00:43:39,775 --> 00:43:40,650
Watazamaji: [inaudible]

1064
00:43:40,650 --> 00:43:40,920
DAVID J. Malan: Sema tena?

1065
00:43:40,920 --> 00:43:41,800
Watazamaji: Random upatikanaji.

1066
00:43:41,800 --> 00:43:43,049
DAVID J. Malan: Random upatikanaji.

1067
00:43:43,049 --> 00:43:46,330
Na kwa upande hiyo ina maana tunaweza hakuna
tena kutumia zeros dhaifu, Intuition,

1068
00:43:46,330 --> 00:43:49,365
na udhahiri wa kutumia binary
kutafuta na kugawanya na kushinda.

1069
00:43:49,365 --> 00:43:51,240
Kwa sababu hata kama sisi
binadamu inaweza wazi

1070
00:43:51,240 --> 00:43:54,610
kuona kwamba Andy au Kikristo walikuwa
takribani katikati ya orodha,

1071
00:43:54,610 --> 00:43:57,670
sisi tu kujua kwamba kama
kompyuta na skimming orodha

1072
00:43:57,670 --> 00:43:59,029
tangu mwanzo.

1073
00:43:59,029 --> 00:44:00,570
Hivyo tumekuwa wamekata kwamba upatikanaji random.

1074
00:44:00,570 --> 00:44:04,380
>> O Hivyo kubwa ya n sasa ni juu
amefungwa juu ya search wakati wetu.

1075
00:44:04,380 --> 00:44:07,920
Nini juu ya omega ya search yetu?

1076
00:44:07,920 --> 00:44:11,535
Nini chini amefungwa juu ya kutafuta
kwa baadhi ya idadi katika orodha hii?

1077
00:44:11,535 --> 00:44:12,410
Watazamaji: [inaudible]

1078
00:44:12,410 --> 00:44:13,040
DAVID J. Malan: Sema tena?

1079
00:44:13,040 --> 00:44:13,420
Watazamaji: One.

1080
00:44:13,420 --> 00:44:13,800
DAVID J. Malan: One.

1081
00:44:13,800 --> 00:44:14,760
Hivyo wakati mara kwa mara.

1082
00:44:14,760 --> 00:44:17,020
Katika kesi bora, Christine ni
kweli mwanzoni mwa orodha.

1083
00:44:17,020 --> 00:44:19,020
Na sisi ni kuangalia kwa
namba 5, hivyo sisi kupatikana yake.

1084
00:44:19,020 --> 00:44:19,787
Hivyo hakuna mpango kubwa.

1085
00:44:19,787 --> 00:44:22,370
Lakini yeye ni got kuwa katika
mwanzo wa orodha katika kesi hii.

1086
00:44:22,370 --> 00:44:23,745
Nini juu ya kitu kama Futa?

1087
00:44:23,745 --> 00:44:24,717

1088
00:44:24,717 --> 00:44:26,300
Nini kama unataka kufuta kipengele?

1089
00:44:26,300 --> 00:44:29,200
Nini amefungwa juu na chini amefungwa
juu ya kufuta kitu kutoka wanaohusishwa

1090
00:44:29,200 --> 00:44:29,699
orodha?

1091
00:44:29,699 --> 00:44:35,195

1092
00:44:35,195 --> 00:44:36,070
Watazamaji: [inaudible]

1093
00:44:36,070 --> 00:44:36,420
DAVID J. Malan: Sema tena?

1094
00:44:36,420 --> 00:44:37,067
Watazamaji: n.

1095
00:44:37,067 --> 00:44:38,900
DAVID J. Malan: n ni
kweli juu amefungwa.

1096
00:44:38,900 --> 00:44:41,700
Kwa sababu katika kesi mbaya sisi kujaribu
kufuta Jack, kama sisi tu hawakuwa.

1097
00:44:41,700 --> 00:44:43,050
Yeye ni njia yote mwishoni.

1098
00:44:43,050 --> 00:44:45,419
Inachukua sisi milele, au
n hatua ya kumpata.

1099
00:44:45,419 --> 00:44:46,460
Hivyo hiyo ni amefungwa juu.

1100
00:44:46,460 --> 00:44:47,430
Hiyo ni linear, uhakika.

1101
00:44:47,430 --> 00:44:50,970
Na kesi bora mbio wakati, au
mipaka ya chini katika kesi bora

1102
00:44:50,970 --> 00:44:51,975
itakuwa ni mara ya mara kwa mara.

1103
00:44:51,975 --> 00:44:54,600
Kwa sababu labda sisi kujaribu kufuta
Christine, na sisi tu kupata bahati

1104
00:44:54,600 --> 00:44:55,558
yeye ni mwanzoni.

1105
00:44:55,558 --> 00:44:56,350
Sasa kusubiri dakika.

1106
00:44:56,350 --> 00:44:59,370
Gabe mara mwanzoni pia,
na sisi pia alikuwa na update Gabe.

1107
00:44:59,370 --> 00:45:01,150
Hivyo hiyo haikuwa hatua moja tu.

1108
00:45:01,150 --> 00:45:04,210
Hivyo ni kweli mara kwa mara
wakati, katika kesi bora,

1109
00:45:04,210 --> 00:45:06,345
kuondoa kipengele madogo?

1110
00:45:06,345 --> 00:45:07,360

1111
00:45:07,360 --> 00:45:10,960
Ni, hata ingawa inaweza kuwa mbili,
tatu, au hata 100 mstari wa kanuni,

1112
00:45:10,960 --> 00:45:14,000
kama ni idadi sawa ya
mistari, si katika baadhi kitanzi,

1113
00:45:14,000 --> 00:45:16,577
na uhuru wa ukubwa
ya orodha, kabisa.

1114
00:45:16,577 --> 00:45:18,660
Kufuta kipengele katika
mwanzo wa orodha,

1115
00:45:18,660 --> 00:45:21,940
hata kama sisi kuwa na kushughulika na
Gabe, ni wakati wa mara kwa mara bado.

1116
00:45:21,940 --> 00:45:24,220
>> Hivyo hii inaonekana kama
hatua kubwa nyuma.

1117
00:45:24,220 --> 00:45:27,000
Na nini kupoteza muda
kama, katika wiki moja na wiki

1118
00:45:27,000 --> 00:45:30,250
zero tulikuwa si tu
pseudocode code lakini code halisi

1119
00:45:30,250 --> 00:45:35,780
kutekeleza kitu ambacho ni logi
msingi n, au kuingia, badala yake, ya n, msingi 2,

1120
00:45:35,780 --> 00:45:37,150
katika suala la mbio yake wakati.

1121
00:45:37,150 --> 00:45:40,710
Hivyo kwa nini heck ingekuwa tunataka kuanza
kutumia kitu kama orodha wanaohusishwa?

1122
00:45:40,710 --> 00:45:41,517
Yeah.

1123
00:45:41,517 --> 00:45:44,022
>> Watazamaji: Hivyo unaweza kuongeza
mambo ya safu.

1124
00:45:44,022 --> 00:45:46,230
DAVID J. Malan: Hivyo unaweza
kuongeza mambo kwa safu.

1125
00:45:46,230 --> 00:45:47,550
Na hii pia ni ufadhili.

1126
00:45:47,550 --> 00:45:49,740
Na tutaweza kuendelea kuona
hii, biashara-off, kiasi

1127
00:45:49,740 --> 00:45:51,573
kama tumeona
biashara-off na kuunganisha aina.

1128
00:45:51,573 --> 00:45:54,606
Tunaweza kweli kasi ya
kutafuta au kuchagua, badala yake,

1129
00:45:54,606 --> 00:45:57,480
kama sisi kutumia nafasi kidogo zaidi na
na chunk ya ziada ya kumbukumbu

1130
00:45:57,480 --> 00:45:58,760
au safu kwa kuunganisha aina.

1131
00:45:58,760 --> 00:46:01,270
Lakini sisi kutumia zaidi
nafasi, lakini sisi kuokoa muda.

1132
00:46:01,270 --> 00:46:04,820
Katika kesi hiyo, sisi ni
kutoa up wakati lakini sisi ni

1133
00:46:04,820 --> 00:46:08,170
kupata mabadiliko,
mabadiliko kama wewe,

1134
00:46:08,170 --> 00:46:10,280
ambayo ni arguably kipengele chanya.

1135
00:46:10,280 --> 00:46:11,520
>> Sisi ni pia kutumia nafasi.

1136
00:46:11,520 --> 00:46:13,710
Ni katika maana gani ni wanaohusishwa
orodha ghali zaidi

1137
00:46:13,710 --> 00:46:15,700
katika suala la nafasi zaidi safu?

1138
00:46:15,700 --> 00:46:18,379

1139
00:46:18,379 --> 00:46:19,920
Ambapo ni nafasi ya ziada kuja kutoka?

1140
00:46:19,920 --> 00:46:20,460
Yeah?

1141
00:46:20,460 --> 00:46:21,800
>> Watazamaji: [inaudible] pointer.

1142
00:46:21,800 --> 00:46:23,310
>> DAVID J. Malan: Yeah, sisi
pia kuwa pointer.

1143
00:46:23,310 --> 00:46:25,560
Hivyo hii ni minorly annoying
kwa kuwa sipo

1144
00:46:25,560 --> 00:46:27,780
Mimi kuhifadhi tu int
kuwakilisha int.

1145
00:46:27,780 --> 00:46:30,990
Mimi nina kuhifadhi int na a
pointer, ambayo pia ni 32 bits.

1146
00:46:30,990 --> 00:46:33,470
Hivyo mimi nina literally mara mbili
kiasi cha nafasi ya kushiriki.

1147
00:46:33,470 --> 00:46:36,040
Hivyo hiyo ni biashara-off, lakini
hiyo ni katika kesi ya int.

1148
00:46:36,040 --> 00:46:39,580
Tuseme kwamba wewe si kuhifadhi int,
lakini nadhani kila mmoja wa rectangles haya

1149
00:46:39,580 --> 00:46:43,290
au kila mmoja wa hawa binadamu mara anayewakilisha
neno, neno la Kiingereza kuwa

1150
00:46:43,290 --> 00:46:46,430
inaweza kuwa wahusika tano, 10
wahusika, labda hata zaidi.

1151
00:46:46,430 --> 00:46:49,940
Kisha kuongeza bits 32 tu zaidi
inaweza kuwa chini ya mpango kubwa.

1152
00:46:49,940 --> 00:46:52,160
>> Nini kama kila mmoja wa wanafunzi
katika maandamano

1153
00:46:52,160 --> 00:46:55,107
walikuwa literally mwanafunzi structs kwamba
kuwa na majina na nyumba na labda

1154
00:46:55,107 --> 00:46:57,065
namba za simu na Twitter
Hushughulikia na kadhalika.

1155
00:46:57,065 --> 00:46:59,564
Basi wote wa mashamba tulianza
kuzungumza juu ya siku nyingine,

1156
00:46:59,564 --> 00:47:02,410
kiasi kidogo ya mpango kubwa kama
nodes wetu kupata zaidi ya kuvutia

1157
00:47:02,410 --> 00:47:05,972
na kubwa kwa kutumia, eh, ziada
pointer tu kwa kiungo wao pamoja.

1158
00:47:05,972 --> 00:47:07,180
Lakini kwa kweli, ni biashara-off.

1159
00:47:07,180 --> 00:47:09,560
Na hakika, kanuni na ni
zaidi tata, kama wewe utakuwa

1160
00:47:09,560 --> 00:47:11,770
kuona kwa kupitia skimming
kuwa mfano fulani.

1161
00:47:11,770 --> 00:47:14,302
Lakini nini kama kulikuwa na
baadhi grail takatifu hapa.

1162
00:47:14,302 --> 00:47:17,010
Nini kama hatuwezi kuchukua hatua
nyuma lakini hatua kubwa mbele

1163
00:47:17,010 --> 00:47:19,180
na kutekeleza data
muundo kupitia ambayo sisi

1164
00:47:19,180 --> 00:47:22,870
Unaweza kupata mambo kama Jack au
Christine au mambo mengine yoyote

1165
00:47:22,870 --> 00:47:25,870
katika safu hii katika wakati kweli mara kwa mara?

1166
00:47:25,870 --> 00:47:26,920
Search ni mara kwa mara.

1167
00:47:26,920 --> 00:47:28,320
Kufuta ni mara kwa mara.

1168
00:47:28,320 --> 00:47:29,570
Insert ni mara kwa mara.

1169
00:47:29,570 --> 00:47:32,260
Wote wa shughuli hizo ni mara kwa mara.

1170
00:47:32,260 --> 00:47:33,750
Hiyo itakuwa grail zetu takatifu.

1171
00:47:33,750 --> 00:47:36,690
Na kwamba ni wapi sisi
pick up wakati ujao.

1172
00:47:36,690 --> 00:47:38,600
Tazama wewe hapo.

1173
00:47:38,600 --> 00:47:39,371