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DOUG LLOYD: zote haki.

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Hivyo sasa hebu kukabiliana na
mada kweli kubwa, kazi.

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Hadi sasa katika mwendo, kila
mipango ambayo sisi tumekuwa kuandika

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vimeandikwa ndani ya kuu.

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Wao ni mipango pretty rahisi.

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Huna haja ya kuwa na haya yote
matawi na mambo kinachoendelea.

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Tunaweza tu fit yote
ndani ya kuu na

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haina kupata sana balaa.

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Lakini kama kozi unaendelea na
kama wewe kuanza kuendeleza mipango

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kujitegemea, wao pengine wewe kwenda
kuanza kwa kupata kura zaidi ya 10

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au mistari 15.

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Unaweza kupata mamia au maelfu
au maelfu ya mstari wa kanuni.

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Na ni kweli si
kwamba mambo mawazo.

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Kama vile, ni pengine si wazo nzuri
kuweka kila kitu ndani ya kuu.

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Inaweza kupata ngumu kidogo kupata
nini wewe kutafuta kwa kama wewe kufanya hivyo.

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>> Kwa bahati nzuri, ingawa C, na pretty much
kila mmoja lugha ya programu kwamba

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inaweza kufanya kazi kwa, inaruhusu
sisi kuandika kazi.

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Na mimi nina kwenda tu kwa
kuchukua haraka kando hapa

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kutaja kwamba kazi ni
eneo moja ya sayansi ya kompyuta.

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Na utaona watu wengi zaidi miongoni mwao katika
maeneo mbalimbali katika mwenendo

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na kama wewe kuendelea.

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Ambapo kuna mengi ya
visawe kwa neno moja.

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Hivyo tunatoa wito kazi.

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Lakini unaweza pia kuwasikia
inajulikana kama taratibu,

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au mbinu, hasa, kama wameweza milele
amefanya kitu oriented programu yoyote

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kabla, na msiwe na wasiwasi
kama una si, si

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deal-- kubwa lakini katika
Lugha ukaguzi oriented

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ni mara nyingi aitwaye mbinu.

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Wakati mwingine wao ni kuitwa subroutines.

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Lakini kwa kweli zote rejea
kwa hiyo wazo la msingi.

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>> Hebu kuona nini wazo kwamba ni.

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Ni kazi gani?

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Vizuri kazi ni kweli
kitu zaidi kuliko sanduku nyeusi.

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Sanduku nyeusi ambayo ina seti ya sifuri
au pembejeo zaidi na pato moja.

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Hivyo kwa mfano, hii
inaweza kuwa kazi.

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Hii ni kazi kuitwa func.

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Na inachukua pembejeo tatu, b, na c.

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Na ndani ya kwamba sanduku nyeusi, sisi
sijui nini hasa itakuwa hivyo,

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lakini taratibu pembejeo
katika baadhi ya njia na kisha

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inatoa pato moja, katika kesi hii, z.

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Sasa kwa kufanya hivyo kidogo
chini ya kufikirika, sisi

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naweza kusema kwamba labda sisi
na kazi kuitwa

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kuongeza kwamba inachukua pembejeo tatu, b, na
c na michakato pato katika baadhi ya njia

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ndani ya boksi nyeusi kwa
kuzalisha pato moja.

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Hivyo katika kesi hii, kama
kuongeza inachukua 3, 6, na 7.

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Mahali fulani ndani
kuongeza kazi, tunataka

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wao wanatarajia kuongezwa kwa pamoja
kuzalisha pato, ambayo

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ni pamoja na 3 6 pamoja na 7 au 16.

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>> Vile vile, una kazi kuitwa
mult kwamba inachukua pembejeo mbili, a na b,

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michakato yao kwa njia baadhi kama
kwamba pato la kazi

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ni matokeo ya pembejeo hizo mbili.

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Pembejeo mbili kuyagawa kwa pamoja.

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4 na 5 kuwa alipita katika mult,
kitu kinachotokea, pato tunatarajia

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ni 20.

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Kwa nini sisi kuiita sanduku nyeusi?

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Vizuri kama sisi si kuandika
kazi zake wenyewe, ambayo

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tumefanya kidogo kabisa hadi sasa cs50.

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Tumeona magazeti f, kwa mfano, ambayo
ni kazi ambayo hatukuwa kuandika

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sisi wenyewe, lakini hatuwezi kutumia muda wote.

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Kama sisi si kuandika
kazi wenyewe,

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sisi si kweli wanahitaji kujua jinsi ni
kweli kutekelezwa chini ya kofia.

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>> Hivyo kwa mfano nyeusi sanduku mimi
tu ilionyesha wewe kwa kuzidisha,

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Mult, b inaweza kuwa
defined-- na hii ni

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baadhi pseudocode inaweza kuwa
kuelezwa kama mara pato a b.

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Hiyo mantiki, haki.

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Kama tuna kazi kuitwa
mult kwamba inachukua pembejeo hizo mbili.

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Tungetarajia kuwa pato ingekuwa
kuwa pembejeo mbili kuyagawa kwa pamoja,

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mara b.

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Lakini mult pia inaweza kuwa
kutekelezwa kama hii,

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tuna kutofautiana kinyume na
kupata kuweka ndani ya mult kwa 0.

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Na kisha sisi kurudia utaratibu huu
b nyakati kuongeza kukabiliana.

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Kwa mfano, kama sisi kuzidisha 3a na
5b, tunaweza kusema kuweka kinyume na 0,

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kurudia mara tano, kuongeza 3 kwa kukabiliana.

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Hivyo sisi kuanza saa 0 na kisha sisi kufanya
hii mara tano 3, 6, 9, 12, 15.

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Ni matokeo hayo. Sisi
bado kupata 3 mara 5 tu

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utekelezaji ni tofauti.

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>> Hiyo ni nini maana sisi
wakati tunasema sanduku nyeusi.

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Ni tu ina maana sisi si kweli huduma
jinsi gani kutekelezwa chini ya kofia

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muda mrefu kama pato ni mategemeo yetu.

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Kwa kweli, hiyo ni sehemu ya mkataba
ya kutumia kazi, hasa

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kazi ambayo watu wengine kuandika.

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Tabia ni daima kwenda
kuwa kawaida, haitabiriki

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kulingana na jina la kazi.

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Na hii ndiyo maana ni kweli
muhimu wakati wewe kuandika kazi

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au wakati watu wengine kuandika
kazi ambayo unaweza kutumia,

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kuwa kazi hizo na
wazi, kiasi dhahiri majina,

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na ni vizuri kumbukumbu.

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Ambayo ni hakika kesi
kwa kazi kama magazeti f.

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>> Hivyo kwa nini sisi kutumia kazi?

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Naam kama nilivyosema awali, kama sisi kuandika
wote wa kificho wetu ndani ya vitu kuu

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unaweza kupata kweli mbaya
na kwa kweli ngumu.

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Kazi kuruhusu sisi uwezo
kuandaa mambo na kuvunja

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Tatizo ngumu sana katika
mengi zaidi manageable sehemu ndogo.

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Kazi pia kuruhusu sisi
kurahisisha mchakato coding.

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Ni rahisi sana kwa Debug 10
mstari kazi dhidi ya 100 mstari

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kazi au 1,000 mstari kazi.

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Kama sisi tu na utatuzi
vipande vidogo wakati huo,

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au kuandika vipande vidogo wakati huo,
inafanya kuwa uzoefu wa programu

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mengi zaidi.

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Matumaini yangu juu ya kwamba moja.

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>> Mwisho, kama sisi kuandika kazi sisi
kutumia tena sehemu hizo mbalimbali.

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Kazi inaweza kuwa recycled.

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Wao inaweza kutumika katika
Mpango moja au nyingine.

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Umefanya tayari imeandikwa
kazi, wote

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unahitaji kufanya ni kuwaambia mpango huo
ambapo kupata kazi hiyo.

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Tumekuwa kusindika na kutumia
magazeti f kwa zaidi ya miaka 40.

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Lakini ilikuwa tu imeandikwa mara moja.

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Pretty muhimu, haki.

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Sawa.

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Hivyo kazi ni kubwa.

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Tunajua kwamba.

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Sasa hebu kuanza kuandika yao.

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Hebu kuanza kupata
yao katika mipango yetu.

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Ili kufanya hivyo, kwanza
Jambo sisi kufanya ni kutangaza kazi.

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Wakati kutangaza kazi
nini wewe kimsingi kufanya

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ni kuwaambia compiler,
hey, ili tu kujua,

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Mimi ni kwenda kuwa kuandika
kazi baadaye

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na hapa ni nini ni kwenda kuangalia kama.

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Sababu hii ni
kwa sababu compilers Unaweza

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kufanya baadhi ya mambo weird kama
wao kuona seti ya alama

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kwamba wao ni wala ukoo na.

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Hivyo sisi kutoa tu compiler a
anaongoza, mimi nina kujenga kazi

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na ni kwenda kufanya hivyo.

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Kazi maazimio ujumla ikiwa
wewe ni kuandaa kanuni yako kwa njia

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kwamba wengine wataweza
kuelewa na kufanya matumizi ya,

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wewe ujumla wanataka kuweka yote
ya kazi yako maazimio

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katika sana juu ya kanuni yako, haki
kabla ya kuanza kuandika kuu hata.

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Na kwa urahisi, kuna
fomu ya kiwango sana

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kwamba kila tamko kazi ifuatavyo.

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Wote pretty much kuangalia kama hii.

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Kuna sehemu tatu kwa kazi
tamko, aina ya kurudi, jina,

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na hoja orodha.

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>> Sasa ni aina ya kurudi ni aina gani ya
kutofautiana kazi mapenzi pato.

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Hivyo kwa mfano, kama tunafikiri nyuma
dakika iliyopita kwa kuzidisha mbili

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nambari kazi, je, sisi kutarajia kama
sisi kuzidisha integer na integer

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pato itakuwa
pengine integer, haki.

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Kuyagawa integers mbili
pamoja, unaweza kupata integer.

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Hivyo aina ya kurudi kwamba
kazi itakuwa int.

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Jina ni nini unataka
kuwaita kazi yako.

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Hii pengine ni angalau muhimu
sehemu ya kazi tamko,

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katika masuala ya utendaji.

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Lakini ni kweli pengine ni moja
ya sehemu muhimu

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ya kazi tamko katika suala
ya kujua nini kazi kweli

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gani.

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Kama wewe jina kazi yako f au g au
h au siri au kitu kama hicho,

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pengine wewe kwenda kupata
kidogo tripped up kujaribu

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kukumbuka nini kazi hizo kufanya.

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Hivyo ni muhimu kutoa yako
maana majina ya kazi ya.

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>> Mwisho, orodha Hoja ni
comma kutengwa orodha

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ya pembejeo zote kwa kazi yako,
ambayo kila mmoja ina aina na jina.

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Hivyo si tu kufanya una
kutaja ni aina gani ya kutofautiana

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kazi mapenzi pato,
wewe pia wanataka bayana

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aina ya vigezo ni aina gani na
kazi itakuwa kukubali kama pembejeo.

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Basi hebu kufanya mfano hapa.

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00:07:08,860 --> 00:07:10,220
Hebu tu kuangalia
saa moja thabiti zaidi.

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Hivyo hapa ni mfano wa kazi
Tamko kwa kazi ambayo

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ataongeza integers mbili pamoja.

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Jumla ya integers mbili ni kwenda
kuwa integer pia, kama sisi tu

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kujadiliwa.

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Na hivyo aina ya kurudi,
hapa katika kijani, itakuwa int.

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Hiyo anatueleza kwamba kuongeza ints mbili tu
ni kwenda, mwisho wa siku,

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pato, au mate nyuma
nje kwa sisi, integer.

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Kutokana na kile kazi hii haina sisi
wanataka kuwapa jina maana.

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Kuongeza ints mbili inaonekana
sahihi, kwa kuzingatia

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sisi ni kuchukua integers mbili kama pembejeo
na hopefully kuongeza yao pamoja.

167
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Ni inaweza kuwa kidogo ya usumbufu
jina na kusema ukweli kazi hii

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pengine ni si lazima
kwa kuwa tuna Mbali

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operator, kama unakumbuka kutoka wetu
mjadala wa waendeshaji, hapo awali.

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Lakini hebu sema tu kwa ajili ya
hoja kuwa kazi hii ni muhimu

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na hivyo tutaweza simu yake kuongeza ints mbili.

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Mwisho, kazi hii inachukua pembejeo hizo mbili.

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Kila mmoja ni integer.

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Hivyo tuna koma huu
kutengwa orodha ya pembejeo.

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Sasa sisi ujumla wanataka
kutoa jina kwa kila mmoja wao

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ili waweze kutumiwa
ndani ya kazi.

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Majina yao ni si sana muhimu.

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>> Katika kesi hiyo, sisi si lazima
maana yoyote masharti yao.

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Ili tuweze tu kuwaita na b.

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Hiyo ni kabisa faini.

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Kama hata hivyo, unakuta
mwenyewe katika hali

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ambapo majina ya vigezo
ili kweli kuwa muhimu,

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unaweza kutaka kuwaita
kitu kingine zaidi na b

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kwa kuwapa kitu zaidi
mfano maana.

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Lakini katika kesi hii, sisi si kweli
kujua kitu kingine chochote kuhusu kazi.

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Sisi tu wanataka kuongeza integers mbili.

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Hivyo tutaweza wito tu
wale integers a na b.

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Hiyo ni mfano mmoja.

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>> Mbona wewe kuchukua pili
kufikiri juu ya hili,

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jinsi gani unaweza kuandika kazi
Tamko kwa kazi ambayo

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00:08:38,870 --> 00:08:42,940
hulizidisha mbili yaliyo hatua namba?

192
00:08:42,940 --> 00:08:45,910
Je, unakumbuka kile a
hatua yaliyo idadi ni?

193
00:08:45,910 --> 00:08:48,120
Ingekuwa kazi hii nini
Tamko kuangalia kama?

194
00:08:48,120 --> 00:08:53,330
Mimi kwa kweli kupendekeza pause video
hapa na kuchukua muda kiasi gani unahitaji.

195
00:08:53,330 --> 00:08:55,521
Fikiria juu ya nini hii
kazi tamko itakuwa?

196
00:08:55,521 --> 00:08:56,770
Kitu gani aina ya kurudi kuwa?

197
00:08:56,770 --> 00:08:58,103
Kitu gani jina maana kuwa?

198
00:08:58,103 --> 00:08:59,580
Kitu gani pembejeo kuwa?

199
00:08:59,580 --> 00:09:03,190
Hivyo kwa nini wewe pause video hapa
na kuandika-up kazi tamko

200
00:09:03,190 --> 00:09:07,640
kwa kazi ambayo ingeweza kuzidisha
mbili yaliyo hatua nambari pamoja.

201
00:09:07,640 --> 00:09:09,330
Hopefully paused video.

202
00:09:09,330 --> 00:09:12,950
>> Basi hebu tuangalie mfano
ya tamko moja iwezekanavyo.

203
00:09:12,950 --> 00:09:17,340
Kuelea mult reals mbili kuelea x, y kuelea.

204
00:09:17,340 --> 00:09:19,090
Bidhaa ya mbili
yaliyo idadi hatua,

205
00:09:19,090 --> 00:09:21,710
ambayo wanakumbuka ni jinsi sisi
kuwakilisha idadi halisi

206
00:09:21,710 --> 00:09:26,770
au namba na maadili alisema katika c,
ni kwenda kuwa hatua yaliyo idadi.

207
00:09:26,770 --> 00:09:28,570
Wakati kuzidisha
alisema na alisema,

208
00:09:28,570 --> 00:09:30,460
pengine wewe kwenda kupata alisema.

209
00:09:30,460 --> 00:09:31,960
Unataka kuwapa jina sahihi.

210
00:09:31,960 --> 00:09:33,810
Kuzidisha reals mbili inaonekana faini.

211
00:09:33,810 --> 00:09:36,620
Lakini unaweza kweli kuiita
mult ikifungwa mbili, au ikifungwa mult.

212
00:09:36,620 --> 00:09:39,540
Kitu kama hicho, kwa muda mrefu kama
alitoa wengine maana halisi ya kile

213
00:09:39,540 --> 00:09:41,469
hii sanduku nyeusi alikuwa anaenda kufanya.

214
00:09:41,469 --> 00:09:44,260
Na tena, katika kesi hii, hatufanyi
wanaonekana kuwa na maana yoyote masharti

215
00:09:44,260 --> 00:09:46,390
kwa majina ya
vigezo sisi ni kupita katika,

216
00:09:46,390 --> 00:09:48,645
hivyo sisi tu kuwaita x na y.

217
00:09:48,645 --> 00:09:51,020
Sasa kama wewe kuwaita kitu
mwingine, hiyo ni kabisa faini.

218
00:09:51,020 --> 00:09:53,310
Kwa kweli, kama alivyofanya
tamko hili badala

219
00:09:53,310 --> 00:09:55,450
kutumia mara mbili badala
ya ikifungwa, kama unakumbuka

220
00:09:55,450 --> 00:09:59,100
kuwa mara mbili ni tofauti
njia ya usahihi

221
00:09:59,100 --> 00:10:02,330
kutaja idadi halisi au
hatua yaliyo vigezo.

222
00:10:02,330 --> 00:10:03,620
Hiyo ni kabisa faini pia.

223
00:10:03,620 --> 00:10:04,670
Aidha mmoja wa wale itakuwa nzuri.

224
00:10:04,670 --> 00:10:06,711
Kwa kweli, kuna kadhaa
michanganyiko tofauti

225
00:10:06,711 --> 00:10:08,410
njia ya kutangaza kazi hii.

226
00:10:08,410 --> 00:10:10,884
Lakini haya ni wawili ndio nzuri sana.

227
00:10:10,884 --> 00:10:12,550
Tumekuwa alitangaza kazi, hiyo ni kubwa.

228
00:10:12,550 --> 00:10:15,700
Tumekuwa aliiambia compiler nini
ni nini tunakwenda kufanya.

229
00:10:15,700 --> 00:10:17,630
Sasa hebu kweli kuandika kazi hiyo.

230
00:10:17,630 --> 00:10:20,750
Hebu kuwapa ufafanuzi,
ili ndani ya boksi nyeusi

231
00:10:20,750 --> 00:10:22,840
tabia kutabirika kinachotokea.

232
00:10:22,840 --> 00:10:26,270
Kwa kweli, sisi ni kuzidisha mbili halisi
nambari pamoja, au namba kuongeza

233
00:10:26,270 --> 00:10:29,760
pamoja, au kufanya chochote ni
kwamba sisi aliuliza kazi yetu ya kufanya.

234
00:10:29,760 --> 00:10:32,780
>> Hivyo kwa kweli, hebu jaribu na kufafanua
kuzidisha reals mawili ambayo sisi tu

235
00:10:32,780 --> 00:10:35,350
kuongelea pili iliyopita.

236
00:10:35,350 --> 00:10:38,560
Sasa mwanzoni mwa
ufafanuzi kazi

237
00:10:38,560 --> 00:10:41,720
inaonekana karibu sawa
kama kazi tamko hilo.

238
00:10:41,720 --> 00:10:43,170
Nina wote wawili hapa.

239
00:10:43,170 --> 00:10:47,770
Juu ni kazi tamko,
aina, jina, comma kutengwa hoja

240
00:10:47,770 --> 00:10:49,410
orodha, semicolon.

241
00:10:49,410 --> 00:10:53,800
Semicolon inaonyesha kwamba
kuwa ni kazi tamko.

242
00:10:53,800 --> 00:10:57,060
Mwanzo wa kazi
ufafanuzi inaonekana karibu hasa

243
00:10:57,060 --> 00:11:03,790
huo huo, aina, jina, comma kutengwa
orodha hoja, hakuna semicolon,

244
00:11:03,790 --> 00:11:05,206
kufungua curly brace.

245
00:11:05,206 --> 00:11:07,580
Wazi curly brace, kama vile
tumekuwa kufanya na kuu,

246
00:11:07,580 --> 00:11:09,540
maana yake ni kwamba sasa tuko
mwanzo kufafanua

247
00:11:09,540 --> 00:11:14,567
nini kinatokea ndani ya boksi nyeusi kwamba
tumekuwa aliamua kuita mult reals mbili.

248
00:11:14,567 --> 00:11:15,900
Hapa ni njia mojawapo ya kutekeleza.

249
00:11:15,900 --> 00:11:20,370
Tunaweza kusema, tunaweza kutangaza mpya
kutofautiana wa aina kuelea inaitwa bidhaa

250
00:11:20,370 --> 00:11:24,020
na kuwapa kwamba kutofautiana
kwa mara thamani x y.

251
00:11:24,020 --> 00:11:27,306
Na kisha kurudi bidhaa.

252
00:11:27,306 --> 00:11:28,430
Je kurudi maana hapa.

253
00:11:28,430 --> 00:11:31,090
Vizuri kurudi ni njia
sisi zinaonyesha kwamba ni jinsi gani

254
00:11:31,090 --> 00:11:33,400
sisi ni kupita pato nyuma nje.

255
00:11:33,400 --> 00:11:38,160
Hivyo kurudi kitu, ni sawa na,
hii ni matokeo ya sanduku nyeusi.

256
00:11:38,160 --> 00:11:40,732
Hivyo hiyo ni jinsi ya kufanya hivyo.

257
00:11:40,732 --> 00:11:42,190
Hapa ni njia nyingine ya kutekeleza.

258
00:11:42,190 --> 00:11:45,050
Tunaweza tu kurudi mara x y.

259
00:11:45,050 --> 00:11:45,870
x ni kuelea.

260
00:11:45,870 --> 00:11:46,660
y ni kuelea.

261
00:11:46,660 --> 00:11:48,490
Hivyo x mara y pia ni kuelea.

262
00:11:48,490 --> 00:11:50,750
Hatuwezi hata haja ya
kujenga mwingine kutofautiana.

263
00:11:50,750 --> 00:11:56,750
Hivyo hiyo ni njia tofauti kwa
kutekeleza exact nyeusi sanduku.

264
00:11:56,750 --> 00:11:58,570
>> Sasa kuchukua muda,
pause video tena,

265
00:11:58,570 --> 00:12:01,680
na kujaribu na kufafanua kuongeza ints mbili,
ambayo ni kazi nyingine ambazo sisi

266
00:12:01,680 --> 00:12:03,090
kuongelea wakati iliyopita.

267
00:12:03,090 --> 00:12:06,440
Tena hapa, nimekuwa kuweka kazi
tamko, na hivyo semicolon,

268
00:12:06,440 --> 00:12:08,420
na wazi curly brace
na kufungwa curly

269
00:12:08,420 --> 00:12:12,080
Brace zinaonyesha ambapo tutakuwa kujaza
katika maudhui ya kuongeza ints mbili,

270
00:12:12,080 --> 00:12:15,530
ili tuweze kufafanua hasa
Tabia ndani ya boksi nyeusi.

271
00:12:15,530 --> 00:12:16,380
Hivyo pause video.

272
00:12:16,380 --> 00:12:18,790
Na kuchukua muda mwingi kama
unahitaji kujaribu na kufafanua

273
00:12:18,790 --> 00:12:25,040
utekelezaji wa kuongeza ints mbili, kama
kwamba wakati kazi matokeo thamani,

274
00:12:25,040 --> 00:12:29,209
ni gani, kwa kweli, kurudi
Jumla ya pembejeo hizo mbili.

275
00:12:29,209 --> 00:12:32,000
Hivyo tu kama mfano uliopita,
kuna njia kadhaa tofauti

276
00:12:32,000 --> 00:12:34,210
kwamba unaweza kutekeleza kuongeza ints mbili.

277
00:12:34,210 --> 00:12:35,130
Hapa ni moja.

278
00:12:35,130 --> 00:12:37,172
Katika hapa katika machungwa nimekuwa
tu alikuwa na baadhi ya comments--

279
00:12:37,172 --> 00:12:38,880
Nimekuwa tu aliongeza baadhi
maoni zinaonyesha

280
00:12:38,880 --> 00:12:41,400
nini kinatokea kwenye kila mstari wa kanuni.

281
00:12:41,400 --> 00:12:45,430
Hivyo mimi kutangaza kutofautiana
kuitwa jumla ya aina int.

282
00:12:45,430 --> 00:12:47,279
Nasema Jumla sawa na pamoja b.

283
00:12:47,279 --> 00:12:50,070
Hiyo ambapo sisi ni kweli kufanya
kazi na kuongeza na b pamoja.

284
00:12:50,070 --> 00:12:51,850
Na mimi kurudi jibu.

285
00:12:51,850 --> 00:12:56,460
Na kwamba inafanya hisia kwa sababu
Jumla ni kutofautiana wa aina int.

286
00:12:56,460 --> 00:13:00,180
Na nini data aina kwamba hii
kazi anasema mimi ni kwenda pato?

287
00:13:00,180 --> 00:13:00,680
Int.

288
00:13:00,680 --> 00:13:03,072
Hivyo mimi nina kurudi kiasi, ambayo
ni integer kutofautiana.

289
00:13:03,072 --> 00:13:06,030
Na kwamba inafanya hisia kutokana na kile tumekuwa
alitangaza na kuelezwa kazi yetu

290
00:13:06,030 --> 00:13:07,320
cha kufanya.

291
00:13:07,320 --> 00:13:09,700
>> Sasa unaweza pia kufafanua
kazi kwa njia hii,

292
00:13:09,700 --> 00:13:15,260
int Jumla sawa na pamoja na b-- ruka kwamba
kwanza step-- na kisha, kurudi jibu.

293
00:13:15,260 --> 00:13:17,760
Sasa unaweza kuwa na pia
kutekelezwa kwa njia hii,

294
00:13:17,760 --> 00:13:19,180
ambayo mimi sana si kupendekeza.

295
00:13:19,180 --> 00:13:22,540
Hii ni style mbaya kwa moja
Jambo na kubuni ni mbaya,

296
00:13:22,540 --> 00:13:24,420
lakini haina, kwa kweli, kazi.

297
00:13:24,420 --> 00:13:30,199
Kama wewe kuchukua kanuni hii, ambayo ni int
kuongeza mbaya fira nukta c, na matumizi yake.

298
00:13:30,199 --> 00:13:31,990
Ni kweli haina kuongeza
mbili integers pamoja.

299
00:13:31,990 --> 00:13:37,632
Ni utekelezaji maskini sana
ya tabia fulani.

300
00:13:37,632 --> 00:13:38,340
Lakini haina kazi.

301
00:13:38,340 --> 00:13:41,200
Ni tu hapa kuonyesha
hatua hiyo sisi si kweli

302
00:13:41,200 --> 00:13:44,530
huduma nini kinatokea ndani ya
sanduku nyeusi, kwa muda mrefu

303
00:13:44,530 --> 00:13:46,510
kama ina pato kwamba tunatarajia.

304
00:13:46,510 --> 00:13:48,870
Hii ni hafifu iliyoundwa sanduku nyeusi.

305
00:13:48,870 --> 00:13:53,801
Lakini mwishoni mwa siku, ni gani
bado pato Jumla ya pamoja b.

306
00:13:53,801 --> 00:13:54,300
Sawa.

307
00:13:54,300 --> 00:13:56,320
Hivyo tumekuwa alitangaza utendaji.

308
00:13:56,320 --> 00:13:57,490
Na tumekuwa inavyoelezwa kazi.

309
00:13:57,490 --> 00:13:58,540
Hivyo hiyo ni nzuri kwa kweli.

310
00:13:58,540 --> 00:14:03,020
Sasa hebu kuanza kutumia kazi
kwamba tumekuwa alitangaza na tumekuwa inavyoelezwa.

311
00:14:03,020 --> 00:14:05,960
Kuwaita function-- ni kweli
pretty easy-- wote unahitaji kufanya

312
00:14:05,960 --> 00:14:09,070
ni kupita hoja sahihi,
hoja za aina data

313
00:14:09,070 --> 00:14:11,600
kwamba anatarajia, na
kisha kuwapa kurudi

314
00:14:11,600 --> 00:14:15,190
thamani ya kazi ambayo
na udhuru Haya ME

315
00:14:15,190 --> 00:14:19,390
kuwapa thamani ya kurudi kwa kazi ambayo
na kitu cha aina sahihi.

316
00:14:19,390 --> 00:14:22,410
>> Basi hebu kuwa na kuangalia
hii kwa vitendo katika faili

317
00:14:22,410 --> 00:14:27,730
aitwaye fira 1 nukta c, ambayo
Nina katika cs50 yangu IDE.

318
00:14:27,730 --> 00:14:31,042
Hivyo hapa ni fira 1 nukta c.

319
00:14:31,042 --> 00:14:33,500
Mwanzoni mwa mnionavyo
yangu ni pamoja na, chupa ni pamoja na,

320
00:14:33,500 --> 00:14:35,460
kiwango cha IO, na cs50 nukta h.

321
00:14:35,460 --> 00:14:37,700
Na kisha mimi kuwa na kazi yangu tamko hilo.

322
00:14:37,700 --> 00:14:39,570
Hii ni pale ambapo mimi nina
kuwaambia compiler mimi nina

323
00:14:39,570 --> 00:14:42,850
kwenda kuwa kuandika
kazi kuitwa kuongeza ints mbili.

324
00:14:42,850 --> 00:14:45,780
Ni kwenda pato an
integer aina kutofautiana.

325
00:14:45,780 --> 00:14:47,360
Hiyo ni nini sehemu hii ni haki hapa.

326
00:14:47,360 --> 00:14:51,950
Na kisha mimi na pembejeo mbili hiyo
na b, ambayo kila mmoja ni integer.

327
00:14:51,950 --> 00:14:58,250
Ndani ya kuu, mimi kuuliza mtumiaji kwa ajili
pembejeo kwa kusema, nipe integer.

328
00:14:58,250 --> 00:15:01,040
Nao ni ilisababisha kusahau
int, ambayo ni kazi ambayo

329
00:15:01,040 --> 00:15:03,240
ni pamoja na katika maktaba cs50.

330
00:15:03,240 --> 00:15:07,660
Na kwamba anapata kuhifadhiwa katika
x, integer kutofautiana.

331
00:15:07,660 --> 00:15:09,886
>> Kisha sisi kuwashawishi kwa integer mwingine.

332
00:15:09,886 --> 00:15:13,070
Sisi kupata integer nyingine
na kuhifadhi kwamba katika y.

333
00:15:13,070 --> 00:15:17,990
Na kisha, hapa kwenye mstari 28, ni
ambapo sisi kufanya kazi yetu wito.

334
00:15:17,990 --> 00:15:23,770
Tunasema, int z sawa
kuongeza 2 ints x comma y.

335
00:15:23,770 --> 00:15:25,980
Je, unaweza kuona nini hii hufanya akili?

336
00:15:25,980 --> 00:15:29,710
x ni aina integer kutofautiana na
y ni aina integer kutofautiana.

337
00:15:29,710 --> 00:15:31,220
Hivyo hiyo ni nzuri.

338
00:15:31,220 --> 00:15:34,570
Hiyo mantiki kwa nini kazi yetu
tamko juu ya mstari 17 inaonekana kama.

339
00:15:34,570 --> 00:15:38,300
Comma kutengwa pembejeo orodha
anatarajia integers mbili, a na b.

340
00:15:38,300 --> 00:15:40,300
Katika kesi hiyo, tunaweza kuwaita
nao chochote tunataka.

341
00:15:40,300 --> 00:15:42,300
Ni tu anatarajia integers mbili.

342
00:15:42,300 --> 00:15:44,930
Na x ni integer na y ni integer.

343
00:15:44,930 --> 00:15:45,640
Kwamba kazi.

344
00:15:45,640 --> 00:15:48,680
>> Na tunajua kazi hiyo ni kwenda
pato integers pia.

345
00:15:48,680 --> 00:15:51,290
Na hivyo sisi ni hifadhi
pato la kazi,

346
00:15:51,290 --> 00:15:56,050
kuongeza ints mbili, katika aina integer
kutofautiana, ambayo sisi ni wito z.

347
00:15:56,050 --> 00:16:01,980
Na kisha tunaweza kusema, jumla ya
asilimia i na asilimia i ni asilimia i.

348
00:16:01,980 --> 00:16:06,210
x, y na z mtiririko
kujaza katika wale asilimia i ya.

349
00:16:06,210 --> 00:16:08,334
Ni nini maana ya kile
kuongeza ints mbili kuangalia kama?

350
00:16:08,334 --> 00:16:09,125
Ni pretty rahisi.

351
00:16:09,125 --> 00:16:11,270
Ni mmoja wa wale sisi
tu kuona pili iliyopita,

352
00:16:11,270 --> 00:16:14,390
int Jumla sawa na pamoja na b kurudi jibu.

353
00:16:14,390 --> 00:16:15,420
Gani kazi hii?

354
00:16:15,420 --> 00:16:17,270
Hebu kuokoa faili.

355
00:16:17,270 --> 00:16:22,080
Na kisha chini hapa juu ya wastaafu yangu
Mimi nina kwenda kufanya fira 1,

356
00:16:22,080 --> 00:16:23,000
na mimi wazi screen yangu.

357
00:16:23,000 --> 00:16:25,791
Mimi nina kwenda kuvuta kwa sababu najua
ni kidogo vigumu kuona.

358
00:16:25,791 --> 00:16:31,520

359
00:16:31,520 --> 00:16:33,770
>> Kwa hiyo sisi kukusanya mpango huu kama fira 1.

360
00:16:33,770 --> 00:16:37,910
Hivyo tunaweza kufanya dot slash fira 1.

361
00:16:37,910 --> 00:16:40,060
Nipe integer, 10.

362
00:16:40,060 --> 00:16:42,380
Nipe integer mwingine, 20.

363
00:16:42,380 --> 00:16:45,200
Jumla ya 10 na 20 ni 30.

364
00:16:45,200 --> 00:16:47,615
Hivyo tukiwa na mafanikio kazi simu.

365
00:16:47,615 --> 00:16:55,820
Unaweza kukimbia kazi tena, hasi
10, 17 Jumla ya hasi 10 na 17 ni 7.

366
00:16:55,820 --> 00:16:57,120
Kazi hii kazi.

367
00:16:57,120 --> 00:16:59,240
Ina tabia
kwamba sisi kutarajia kwa.

368
00:16:59,240 --> 00:17:03,610
Na hivyo tumekuwa alifanya mafanikio
kazi, ufafanuzi, tamko,

369
00:17:03,610 --> 00:17:07,288
na mafanikio kazi simu.

370
00:17:07,288 --> 00:17:09,079
Wanandoa miscellaneous
pointi kuhusu kazi

371
00:17:09,079 --> 00:17:10,611
kabla ya sisi kuhitimisha sehemu hii.

372
00:17:10,611 --> 00:17:12,319
Kumbuka kutoka wetu
mjadala wa aina data,

373
00:17:12,319 --> 00:17:16,109
hapo awali, kwamba kazi
wakati mwingine kuchukua hakuna pembejeo.

374
00:17:16,109 --> 00:17:17,930
Kama hiyo kesi, sisi
kutangaza kazi

375
00:17:17,930 --> 00:17:19,788
kama kuwa na orodha hoja batili.

376
00:17:19,788 --> 00:17:21,579
Je, unakumbuka kile
kazi ya kawaida

377
00:17:21,579 --> 00:17:25,036
tumeona hadi sasa kwamba inachukua
utupu hoja orodha ni?

378
00:17:25,036 --> 00:17:27,300
Ni kuu.

379
00:17:27,300 --> 00:17:30,850
Kumbuka pia kwamba wakati mwingine kazi
si kweli kuwa pato.

380
00:17:30,850 --> 00:17:34,210
Katika kesi hiyo, sisi kutangaza kazi
kama kuwa na aina batili kurudi.

381
00:17:34,210 --> 00:17:37,880
Hebu kuhitimisha sehemu hii kwa
kukabiliana na tatizo mazoezi.

382
00:17:37,880 --> 00:17:39,900
>> Hivyo hapa ni tatizo kuweka nje.

383
00:17:39,900 --> 00:17:43,630
Mimi nataka wewe kuandika kazi
aitwaye halali pembe tatu.

384
00:17:43,630 --> 00:17:47,410
Nini kazi hii ni lazima kufanya
ni kuchukua tatu idadi halisi

385
00:17:47,410 --> 00:17:51,930
kwamba kuwakilisha urefu wa tatu
pande mbili za pembe kama vigezo wake,

386
00:17:51,930 --> 00:17:54,550
au hoja yake, au wake
inputs-- mwingine seti ya visawe

387
00:17:54,550 --> 00:17:57,340
kwamba unaweza kukutana.

388
00:17:57,340 --> 00:18:01,120
Kazi hii lazima
ama pato kweli au uongo

389
00:18:01,120 --> 00:18:04,960
kutegemea kama wale umbali wa tatu
ni uwezo wa kufanya pembe tatu.

390
00:18:04,960 --> 00:18:09,930
Unakumbuka aina data kwamba
sisi kutumika kuonyesha kweli au uongo?

391
00:18:09,930 --> 00:18:11,436
Sasa ni jinsi gani unaweza kutekeleza hili?

392
00:18:11,436 --> 00:18:13,810
Vizuri kujua kuna wanandoa
ya sheria kuhusu pembetatu

393
00:18:13,810 --> 00:18:15,480
ambazo ni muhimu kujua kweli.

394
00:18:15,480 --> 00:18:18,292
Pembe tatu inaweza tu kuwa
Pande na urefu chanya.

395
00:18:18,292 --> 00:18:19,000
Kwamba inafanya hisia.

396
00:18:19,000 --> 00:18:21,432
Pengine wewe kusema, duh.

397
00:18:21,432 --> 00:18:23,390
Jambo jingine kutambua
ingawa, ni kwamba jumla

398
00:18:23,390 --> 00:18:25,484
ya urefu wa yeyote
pande mbili za pembe tatu

399
00:18:25,484 --> 00:18:27,650
ina kuwa kubwa kuliko
urefu wa upande wa tatu.

400
00:18:27,650 --> 00:18:28,690
Hiyo ni kweli kweli.

401
00:18:28,690 --> 00:18:34,150
Huwezi kuwa na pembe ya pande 1,
2 na 4, kwa mfano, kwa sababu 1 plus 2

402
00:18:34,150 --> 00:18:36,270
si mkuu zaidi kuliko 4.

403
00:18:36,270 --> 00:18:38,870
Basi hizo sheria kwamba
au kuamua kama si tatu

404
00:18:38,870 --> 00:18:42,740
pembejeo unaweza conceivably kuunda pembe tatu.

405
00:18:42,740 --> 00:18:46,360
Hivyo kuchukua dakika kadhaa
na kutangaza na kisha kufafanua

406
00:18:46,360 --> 00:18:49,810
kazi hii inaitwa halali
pembe tatu, kama kwamba ni kweli

407
00:18:49,810 --> 00:18:51,650
ina tabia maalum hapa.

408
00:18:51,650 --> 00:18:57,030
>> Itakuwa pato kweli kama pande zile tatu
wana uwezo wa inahusu pembe tatu,

409
00:18:57,030 --> 00:19:01,950
na uongo vinginevyo
Tayari kuona jinsi gani alifanya?

410
00:19:01,950 --> 00:19:04,650
Hapa ni utekelezaji moja
ya halali pembe tatu.

411
00:19:04,650 --> 00:19:05,770
Siyo mmoja tu.

412
00:19:05,770 --> 00:19:07,770
Wako ili kutofautiana kidogo.

413
00:19:07,770 --> 00:19:11,040
Lakini hii mtu gani, kwa kweli, na
tabia ambayo tunatarajia.

414
00:19:11,040 --> 00:19:14,450
Sisi kutangaza kazi zetu katika
juu sana, bool halali pembe tatu

415
00:19:14,450 --> 00:19:16,630
kuelea x kuelea y kuelea z.

416
00:19:16,630 --> 00:19:18,930
Hivyo tena, kazi hii
inachukua tatu idadi halisi

417
00:19:18,930 --> 00:19:22,280
kama hoja yake, yaliyo
thamani hatua vigezo,

418
00:19:22,280 --> 00:19:26,510
na matokeo ya kweli au uongo
thamani, ambayo ni Boolean, kukumbuka.

419
00:19:26,510 --> 00:19:28,660
Hivyo ndiyo sababu ni aina ya kurudi bool.

420
00:19:28,660 --> 00:19:30,016
Kisha sisi kufafanua kazi.

421
00:19:30,016 --> 00:19:33,140
Jambo la kwanza sisi kufanya ni kuangalia kuhakikisha
kwamba wote wa pande ni mazuri.

422
00:19:33,140 --> 00:19:37,010
Kama x ni chini ya au sawa
0, au kama y ni sawa na 0,

423
00:19:37,010 --> 00:19:41,050
au kama z ni chini ya au sawa na 0,
kwamba hawawezi kuwa pembe tatu.

424
00:19:41,050 --> 00:19:42,380
Hawana pande chanya.

425
00:19:42,380 --> 00:19:45,790
Na ili tuweze kurudi
uongo katika hali hiyo.

426
00:19:45,790 --> 00:19:49,010
Next, sisi kuangalia kuhakikisha
kwamba kila jozi wa pembejeo

427
00:19:49,010 --> 00:19:51,830
ni mkubwa kuliko theluthi moja.

428
00:19:51,830 --> 00:19:54,530
>> Hivyo kama x plus y ni chini
kuliko au sawa na z,

429
00:19:54,530 --> 00:19:57,060
au kama x plus z ni chini
kuliko au sawa na y,

430
00:19:57,060 --> 00:20:01,730
au kama y pamoja na z ni chini ya au sawa na
x, kwamba pia hawezi kuwa pembe tatu halali.

431
00:20:01,730 --> 00:20:03,800
Hivyo sisi kurudi uongo tena.

432
00:20:03,800 --> 00:20:06,900
Kutokana sisi kupita wote wawili wa hundi
ingawa, basi tunaweza kurudi kweli.

433
00:20:06,900 --> 00:20:09,440
Kwa sababu pande hizo tatu
wana uwezo wa returning--

434
00:20:09,440 --> 00:20:11,647
ya kujenga pembe tatu halali.

435
00:20:11,647 --> 00:20:12,230
Na hiyo ni yake.

436
00:20:12,230 --> 00:20:13,830
Umefanya sasa alitangaza na kuelezwa.

437
00:20:13,830 --> 00:20:17,330
Na unaweza kuwa na uwezo wa sasa
kutumia na kuwaita kazi hii.

438
00:20:17,330 --> 00:20:19,470
Kazi kubwa.

439
00:20:19,470 --> 00:20:20,650
Mimi nina Doug Lloyd.

440
00:20:20,650 --> 00:20:22,820
Hii ni cs50.

441
00:20:22,820 --> 00:20:24,340