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>> [Music kucheza]

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DOUG LLOYD: Linear
search ni algorithm sisi

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unaweza kutumia ili kupata kipengele katika safu.

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Wanakumbuka algorithm
ni hatua kwa hatua ya kuweka

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maelekezo kwa ajili ya kukamilisha kazi.

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>> Tafuta linear
algorithm kazi kama ifuatavyo.

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Iterate hela safu kutoka kushoto kwenda
haki, kuangalia kwa kipengele maalum.

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>> Katika pseudocode, ambayo ni zaidi
distilled toleo la hukumu hii,

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kama kitu cha kwanza ni kile
wewe kutafuta, unaweza kuacha.

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Vinginevyo, hoja ya kipengele ijayo na
kuendelea tena na tena mpaka kupata

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kipengele, au huna.

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Ili tuweze kutumia linear
search algorithm, kwa mfano,

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kupata thamani Lengo
tisa katika safu hii.

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Naam sisi kuanza mwanzoni.

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Kama ni nini tuko
kutafuta, tunaweza kuacha.

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Siyo, sisi siyo kuangalia kwa 11.

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Hivyo vinginevyo, hoja ya kipengele ijayo.

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>> Hivyo sisi kuangalia 23.

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Ni 23 nini sisi ni kuangalia kwa?

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Naam hakuna, hivyo sisi kuhamia kwenye ijayo
kipengele, na kipengele ijayo,

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na sisi kuendelea kwenda kwa
mchakato huu tena na tena

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na tena, mpaka sisi ardhi
juu ya hali kama hii.

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>> Tisa ni nini sisi ni kuangalia kwa,
na kipengele hiki cha safu

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yaani, thamani yake ni tisa.

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Na hivyo sisi kupatikana nini tuko
kutafuta, na tunaweza kuacha.

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Tafuta linear ina
kukamilika, kwa mafanikio.

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>> Lakini nini kuhusu kama sisi ni kuangalia kwa
kipengele kwamba si katika safu yetu.

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Je, linear la bado kazi?

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Naam uhakika.

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Kwa hiyo sisi kurudia utaratibu huu
kuanzia saa kipengele kwanza.

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Kama ni nini tuko
kutafuta, tunaweza kuacha.

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Sio.

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Vinginevyo, sisi hoja ya kipengele ijayo.

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>> Lakini tunaweza kuendelea kurudia utaratibu huu,
kuchunguza kila kipengele kwa upande wake,

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matumaini kwamba sisi kupata idadi 50.

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Lakini hatutaweza kujua kama
tumekuwa kupatikana idadi 50

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au kama hatukuwa, mpaka tumekuwa kupitiwa
juu ya kila kipengele moja ya safu.

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>> Tu mara moja tumefanya
kuwa na kuja mfupi,

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Tunaweza kuhitimisha kwamba
50 siyo katika safu.

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Na hivyo tafuta linear
algorithm, vizuri alishindwa, per se.

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Lakini si kwa maana kwamba
hakufaulu katika kufanya yaliyo

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sisi aliuliza kufanya.

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>> Ilikuwa ni aliyeshindwa katika kama
vile ni hawakuona 50,

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lakini 50 hakuwa katika safu.

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Lakini sisi vyema msako
kupitia kila kipengele moja

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na hivyo, wakati sisi hawakuona
kitu chochote, tafuta linear bado

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inafanikiwa hata kama
kipengele ni si katika safu.

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>> Basi nini hali mbaya
mazingira na tafuta linear?

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Vizuri inabidi kuangalia njia
kila kipengele moja,

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ama kwa sababu lengo kipengele
ni kipengele mwisho wa safu,

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au kipengele sisi ni kuangalia kwa hana
kweli zipo katika safu wakati wote.

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Nini bora kesi mazingira?

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Naam tunaweza kukuta
kipengele mara moja.

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Na jinsi mambo mengi
Je, sisi kisha kuwa na kuangalia

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katika katika kesi bora,
kama sisi ni kuangalia kwa ajili yake

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na tunapata ni mwanzoni kabisa?

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Tunaweza kuacha mara moja.

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>> Je, hii inasema nini kuhusu
utata wa tafuta linear?

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Vizuri katika hali mbaya zaidi, tuna
kuangalia kila kipengele moja.

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Na hivyo ni anaendesha katika O wa
n, katika hali mbaya zaidi.

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>> Katika kesi bora, sisi ni gonna
kupata kipengele mara moja.

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Na hivyo anaendesha katika omega ya 1.

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>> Mimi nina Doug Lloyd.

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Hii ni CS50.

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