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>> DAVID Malan: Kull dritt.

3
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Aħna lura.

4
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Allura f'dan is-segment dwar il-programmazzjoni dak
Ħsibt aħna'd tagħmel huwa taħlita ta 'affarijiet.

5
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Wieħed, tagħmel ftit
ta 'xi ħaġa Hands-on,

6
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għalkemm bl-użu ta aktar jilgħab
environment-- ipprogrammar

7
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waħda li hija dimostrattiv ta
eżattament it-tipi ta 'ideat

8
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aħna kont qed jitkellem dwar,
iżda ftit aktar formali.

9
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Tnejn, tħares lejn uħud mill
-modi aktar tekniċi

10
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li programmer fil-fatt ssolvi
problemi bħall-problema tiftix

11
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li ħarisna lejn qabel u
ukoll iżjed fundamentali

12
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problema interessanti tal-għażla.

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>> Aħna biss assumiet mill-nikseb go
li dak il-ktieb tat-telefon kien magħżula,

14
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iżda li waħdu huwa attwalment tip ta '
problema iebsa ma 'bosta modi differenti

15
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biex issolviha.

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Allura aħna ser tuża dawn bħala
klassi ta 'problemi

17
00:00:34,366 --> 00:00:36,740
rappreżentant ta 'affarijiet li
jista 'jiġi solvuti b'mod ġenerali.

18
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U allura aħna ser nitkellmu
dwar f'ċertu dettall liema

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huma msejħa dejta structures--
modi fancier bħal listi marbuta

20
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u t-tabelli hash u siġar li
programmer kieku attwalment

21
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użu u ġeneralment jużaw
fuq whiteboard li żebgħa

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stampa ta 'dak li hu jew hi
envisions għall-implimentazzjoni

23
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xi biċċa ta 'softwer.

24
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>> Mela ejja jagħmlu l--idejn fuq porzjon ewwel.

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Hekk biss tikseb idejk maħmuġ ma '
ambjent imsejħa scratch.mit.edu.

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Din hija għodda li nużaw
fil-klassi undergraduate tagħna.

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Anki jekk huwa ddisinjat
għall-etajiet 12 u sa,

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nużawha għall-up
parti minn dak pjuttost ftit

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peress li huwa sabiħ, gost
Mod grafika ta 'tagħlim

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ftit xi ħaġa dwar l-ipprogrammar.

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Allura ras għal dak URL, fejn inti
għandha tara paġna pjuttost bħal dan,

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u jimxi 'l quddiem u kklikkja
Ingħaqad Scratch fil kantuniera

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u jagħżlu username u
password u finalment nikseb yourself

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l scratch.mit.edu account--.

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Ħsibt I d jużaw dan bħala
opportunità ewwel biex juru din.

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A kwistjoni ħarāu il-mistrieħ
dwar dak Kodiċi attwalment tidher qiesha.

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U konna nitkellmu
il-mistrieħ dwar Ċ,

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fi particular-- partikolarment
livell aktar baxx f'lingwa anzjani.

40
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U jien biss għamlet a quick
Google Tfittxija biex isibu kodiċi C

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għal tfittxija binarja, l-algoritmu li aħna
użati biex tfittex dak il-ktieb tat-telefon qabel.

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Dan l-eżempju partikolari, naturalment,
ma tfittxija ktieb tat-telefon.

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Hija biss tfittxijiet mazz sħiħ ta '
numri fil-memorja tal-kompjuter.

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Imma jekk inti tixtieq li biss jiksbu viżwali
sens ta 'dak l-ipprogrammar attwali

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lingwa Dehra, jidher
ftit xi ħaġa bħal din.

46
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Allura huwa madwar 20-plus,
30 jew hekk linji ta 'kodiċi,

47
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iżda l-konverżazzjoni aħna
wara li kienu fuq waqfa

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kien dwar kif dan fil-fatt
gets morphed fis żero u dawk

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u jekk inti ma tistax sempliċement imorru lura li
proċess u jmorru minn żero u dawk

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lura għall-kodiċi.

51
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>> Sfortunatament, il-proċess
hija tant trasformattiv

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li huwa ħafna aktar faċli minn qal jsir.

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I marru quddiem u effettivament warrab
dak il-programm, Binarju Tfittxija,

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fis żero u dawk permezz ta '
programm imsejjaħ The kompilatur li I

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jiġri li jkollhom hawn dritt fuq Mac tiegħi.

56
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U jekk inti tħares lejn l-iskrin
hawn, li jiffoka speċifikament

57
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fuq dawn nofs sitt kolonni biss,
tkun taf tara biss żerijiet u dawk.

58
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U dawk huma l-żerijiet u dawk li
compose eżattament dak il-programm tiftix.

59
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>> U għalhekk kull blokki ta 'ħames bits,
kull byte ta 'żero u dawk hawn,

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jirrapreżentaw xi istruzzjoni
tipikament ġewwa ta 'kompjuter.

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U fil-fatt, jekk inti widnejna l
kummerċjalizzazzjoni islogan "Intel ġewwa" - li,

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naturalment, ifisser biss għandek
CPU Intel jew moħħ ġewwa l-kompjuter.

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U dak li jfisser li tkun CPU hu
li inti għandek sett istruzzjoni,

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biex ngħidu hekk.

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>> Kull CPU fid-dinja, ħafna
minnhom magħmula minn Intel dawn il-ġranet,

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jifhem finit
numru ta 'struzzjonijiet.

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U dawk l-istruzzjonijiet huma f'livell tant baxx
kif żid dawn iż-żewġ numri flimkien,

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immultiplika dawn iż-żewġ numri flimkien,
jimxu din il-biċċa ta 'data minn hawn

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li hawn fil-memorja, ħlief din il
informazzjoni minn hawn hawn fil-memorja,

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u għalhekk forth-- hekk ħafna, ħafna
Livell baxx, dettalji kważi elettroniċi.

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Iżda ma 'dawk matematiċi
operazzjonijiet akkoppjat

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ma 'dak li aħna diskussa aktar kmieni,
-rappreżentazzjoni tad-data

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kif żerijiet u dawk, jistgħu
inti tibni up kollox

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li l-kompjuter tista 'tagħmel illum, kemm jekk
huwa testwali, grafika, mużikali,

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jew mod ieħor.

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>> Allura dan huwa faċli ħafna li tinkiseb
mitlufa fil-ħaxix ħażin ta 'malajr.

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U hemm ħafna ta '
isfidi sintattiċi

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li biha jekk inti tagħmel l-aktar sempliċi,
stupidest ta typos ebda wieħed mill-programm

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se taħdem tkun xi tkun.

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U hekk minflok li jużaw
lingwa bħal Ċ dalgħodu,

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Ħsibt li jkun
aktar divertenti biex fil-fatt jagħmlu

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xi ħaġa aktar viżwali, li
filwaqt iddisinjati għat-tfal

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huwa attwalment manifestazzjoni perfetta
ta 'programmazzjoni attwali

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language-- jiġri biss li
tuża r-ritratti minflok test

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li jirrappreżentaw dawk l-ideat.

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>> Allura ladarba inti tabilħaqq jkollhom
kont fuq scratch.mit.edu,

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ikklikkja l-Oħloq buttuna
fil-quċċata xellug tas-sit.

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U inti għandek tara ambjent bħal
l-waħda li jien ser tara fuq l-iskrin tiegħi

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hawn.

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U aħna ser jonfqu biss ftit
ftit ta 'ħin jilagħbu hawn.

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Ejja naraw jekk aħna ma tistax kollox isolvu xi
problemi flimkien fil-mod li ġej.

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>> Allura dak li int ser tara fi ħdan dan
environment-- u fil-fatt biss let

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lili nieqaf.

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Huwa kwalunkwe persuna mhux hawn?

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Mhux hawn?

96
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KOLLOX SEW.

97
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So let me punt ftit
karatteristiċi ta 'dan l-ambjent.

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>> Allura fil-quċċata xellug tal-iskrin, aħna
għandhom stadju Scratch, l biex ngħidu hekk.

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Scratch mhux biss l-isem
ta din il-lingwa ta 'programmar;

100
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huwa wkoll l-isem tal-qattus li
tara b'mankanza hemmhekk fil oranġjo.

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Huwa fuq stadju, hekk
ferm simili I deskritti

102
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il-fekruna qabel li huwa fi
rettangolari ambjent bord abjad.

103
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dinja kapaċi jaħdmu f'din qattus huwa limitat għal kollox
għal dak rettangolu top up hemm.

104
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>> Sadanittant, dwar id-dritt
naħa tal-lemin hawn, huwa

105
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biss żona skripts, ta '
lavanja vojt jekk inti se.

106
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Dan huwa fejn aħna qed tmur biex jiktbu
Programmi tagħna fil ftit mument.

107
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U l-blokki tal-bini li aħna għandhom
użu li tikteb din program---puzzle

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biċċiet, jekk inti will-- l
dawk dritt hawn fin-nofs,

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u dawn qed kategorizzata
billi funzjonalità.

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Allura, per eżempju, jien ser jimxi 'l quddiem
u juru mill-inqas wieħed minn dawn.

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Jien ser jimxi 'l quddiem u kklikkja
il-kategorija ta 'Kontroll top up.

112
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>> Allura dawn huma l-kategoriji up quċċata.

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Jien ser ikklikkja l-kategorija ta 'Kontroll.

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Pjuttost, jien ser ikklikkja l-Avvenimenti
kategorija, l-ewwel waħda top up.

115
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U jekk inti tixtieq li ssegwi tul anke
kif nagħmlu dan, int pjuttost jilqgħu biex.

116
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Jien ser ikklikkja u drag din l
ewwel wieħed, "meta bandiera aħdar għafast."

117
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U mbagħad jien ser qatra hija biss
bejn wieħed u ieħor fil-quċċata tal lavanji vojta tiegħi.

118
00:05:58,410 --> 00:06:01,450
>> U x'hemm sbieħ dwar Scratch
hija li din il-biċċa puzzle, meta

119
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mrikkba ma 'puzzle ieħor
biċċiet, huwa se jagħmel litteralment

120
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liema dawk il-biċċiet puzzle jgħidu li jagħmlu.

121
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Allura, per eżempju, Scratch huwa dritt
issa fin-nofs tad-dinja tiegħu.

122
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Jien ser jimxi 'l quddiem u jagħżlu
Issa, ejja ngħidu, il-kategorija Mozzjoni,

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jekk inti tixtieq li tagħmel l-
same-- kategorija Mozzjoni.

124
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U issa Avviż għandi sħiħ
mazz ta 'biċċiet puzzle hawn

125
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li, għal darb'oħra, it-tip ta jagħmlu dak li jgħidu.

126
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U jien ser jimxi 'l quddiem u drag u
qatra l-blokk mixja dritt fuq hawn.

127
00:06:28,110 --> 00:06:31,860
>> U tinnota li malli ikollok
qrib il-qiegħ tal-"bandiera aħdar

128
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għafast "buttuna, avviż
kif linja bajda jidher,

129
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bħallikieku huwa kważi
manjetiċi, hija trid tmur hemmhekk.

130
00:06:36,950 --> 00:06:43,070
Just let go, u se snap
flimkien u l-forom se jaqblu.

131
00:06:43,070 --> 00:06:46,620
U issa inti tista 'forsi kważi
raden fejn aħna qed tmur ma 'dan.

132
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>> Jekk inti tħares lejn l-istadju Scratch
minn hawn u jfittxu għall-quċċata ta 'dan,

133
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tkun taf tara dawl aħmar, li
stop sinjal, u bandiera aħdar.

134
00:06:55,142 --> 00:06:57,100
U jien ser jimxi 'l quddiem
u watch screen-- tiegħi

135
00:06:57,100 --> 00:06:58,460
għal ftit mument, jekk inti tista '.

136
00:06:58,460 --> 00:07:01,960
Jien ser ikklikkja l-
bandiera aħdar dritt issa,

137
00:07:01,960 --> 00:07:07,850
u huwa mċaqlaq dak li jidher li jkun ta '10 passi
jew 10 pixel, 10 tikek, fuq l-iskrin.

138
00:07:07,850 --> 00:07:13,390
>> U hekk mhux li eċċitanti,
iżda let me tipproponi

139
00:07:13,390 --> 00:07:17,440
anki mingħajr tagħlim dan, biss
użu tal-stess let intuition-- tiegħek stess

140
00:07:17,440 --> 00:07:22,560
me nipproponi li inti figura kif
jagħmlu Scratch mixja dritt off-istadju.

141
00:07:22,560 --> 00:07:28,700
Have lilu jagħmlu mod għall-lemin tal
l-iskrin, it-triq kollha lejn il-lemin.

142
00:07:28,700 --> 00:07:32,200
Ħalli nagħtikom mument
jew hekk biex wrestle ma 'dak.

143
00:07:32,200 --> 00:07:37,681
Inti tista 'tixtieq li tagħti ħarsa
fil-kategoriji oħra ta 'blokki.

144
00:07:37,681 --> 00:07:38,180
Kull dritt.

145
00:07:38,180 --> 00:07:41,290
Hekk biss biex terġa, meta jkollna
il-bandiera aħdar għafast hawn

146
00:07:41,290 --> 00:07:44,850
u jimxu 10 passi qed l
istruzzjoni biss, kull darba I

147
00:07:44,850 --> 00:07:46,720
ikklikkja l-bandiera aħdar, dak li qed jiġri?

148
00:07:46,720 --> 00:07:50,070
Ukoll, li l-ġirja programm tiegħi.

149
00:07:50,070 --> 00:07:52,450
So I jistgħu jagħmlu dan
forsi 10 darbiet manwalment,

150
00:07:52,450 --> 00:07:55,130
iżda dan iħoss ftit
bit hackish, biex ngħidu hekk,

151
00:07:55,130 --> 00:07:57,480
li permezz tagħha Jien ma verament
tissolva l-problema.

152
00:07:57,480 --> 00:08:00,530
Jien biss tipprova mill-ġdid u
ġdid u għal darb'oħra u għal darb'oħra

153
00:08:00,530 --> 00:08:03,180
sal I sort tal aċċidentalment
jinkiseb id-direttiva

154
00:08:03,180 --> 00:08:05,560
li I stabbiliti biex jinkiseb aktar kmieni.

155
00:08:05,560 --> 00:08:08,200
>> Imma nafu mill tagħna
pseudocode qabel li hemm

156
00:08:08,200 --> 00:08:11,870
dan il-kunċett fil-programmazzjoni ta 'looping,
tagħmel xi ħaġa mill-ġdid u għal darb'oħra.

157
00:08:11,870 --> 00:08:14,888
U hekk rajt li mazz ta 'inti
li ntlaħaq għall-biċċa liema puzzle?

158
00:08:14,888 --> 00:08:17,870

159
00:08:17,870 --> 00:08:18,730
Irrepeti sakemm.

160
00:08:18,730 --> 00:08:21,400
Allura nistgħu nagħmlu xi ħaġa
bħal irrepeti sakemm.

161
00:08:21,400 --> 00:08:23,760
U dak did you jirrepetu sal eżattament?

162
00:08:23,760 --> 00:08:27,720

163
00:08:27,720 --> 00:08:28,540
>> KOLLOX SEW.

164
00:08:28,540 --> 00:08:31,974
U let me go ma 'wieħed li l-
kemmxejn aktar sempliċi għal ftit mument.

165
00:08:31,974 --> 00:08:33,140
Let me imorru quddiem u tagħmel dan.

166
00:08:33,140 --> 00:08:35,559
Avviż li, kif jista 'jkollok
skoperti taħt Kontroll,

167
00:08:35,559 --> 00:08:38,409
hemm dan il-blokk ripetuta, li
ma look like huwa li l-kbar.

168
00:08:38,409 --> 00:08:41,039
Hemm Ma tantx spazju fil
bejn dawn iż-żewġ linji sofor.

169
00:08:41,039 --> 00:08:43,539
Imma kif xi wħud minnkom jista 'jkollok
ndunat, jekk inti drag u qatra,

170
00:08:43,539 --> 00:08:45,150
avviż kif tikber biex timla l-forma.

171
00:08:45,150 --> 00:08:46,274
>> U inti tista 'anki CRAM aktar.

172
00:08:46,274 --> 00:08:48,670
Hija ser biss jibqgħu jikbru jekk
inti drag u imbagħad jerġgħu jsiru fuq dan.

173
00:08:48,670 --> 00:08:51,110
U jien ma nafx x'hemm
aħjar hawn, so let

174
00:08:51,110 --> 00:08:54,760
lili mill-inqas irrepeti ħames darbiet, għal
Pereżempju, u mbagħad mur lura għall-istadju

175
00:08:54,760 --> 00:08:56,720
u kklikkja l-bandiera aħdar.

176
00:08:56,720 --> 00:08:59,110
U issa avviż huwa pjuttost mhux hemm.

177
00:08:59,110 --> 00:09:02,400
>> Issa xi wħud minnkom proposta, kif
Victoria biss ma, irrepeti 10 darbiet.

178
00:09:02,400 --> 00:09:05,140
U li ġeneralment ma
nikseb lilu-triq kollha,

179
00:09:05,140 --> 00:09:10,510
iżda kieku ma jkun hemm l-iktar b'saħħitha
Mod arbitrarju jidhru

180
00:09:10,510 --> 00:09:12,640
kemm jiċċaqlaq biex jagħmlu?

181
00:09:12,640 --> 00:09:17,680
Liema jista 'jkun blokk aħjar
minn irrepeti 10 darbiet jkun?

182
00:09:17,680 --> 00:09:20,380
>> Yeah, hekk għaliex ma tagħmel xi ħaġa għal dejjem?

183
00:09:20,380 --> 00:09:24,390
U issa let me jimxu din il-biċċa puzzle
hemm ġewwa u jeħles ta 'dan wieħed.

184
00:09:24,390 --> 00:09:28,300
Issa avviż irrispettivament minn fejn Scratch
jibda, imur mat-tarf.

185
00:09:28,300 --> 00:09:30,700
U Thankfully MIT,
li jagħmel Scratch, biss

186
00:09:30,700 --> 00:09:33,190
jagħmel żgur li hu qatt ma
tisparixxi kompletament.

187
00:09:33,190 --> 00:09:35,360
Inti tista 'dejjem grab denb tiegħu.

188
00:09:35,360 --> 00:09:37,680
>> U biss intuwittivament,
għaliex ma hu jżomm miexja?

189
00:09:37,680 --> 00:09:38,892
Dak li qed jiġri hawn?

190
00:09:38,892 --> 00:09:41,440

191
00:09:41,440 --> 00:09:43,824
Huwa jidher li jkunu waqfu, iżda
imbagħad jekk I pick up u drag

192
00:09:43,824 --> 00:09:45,240
hu jżomm jixtiequ li jmorru hemmhekk.

193
00:09:45,240 --> 00:09:46,123
Għaliex huwa li?

194
00:09:46,123 --> 00:09:51,610

195
00:09:51,610 --> 00:09:54,360
Tassew, kompjuter huwa litteralment
se tagħmel dak li għid li tagħmel.

196
00:09:54,360 --> 00:09:58,380
Mela jekk inti told qabel tagħmel l-
segwenti ħaġa dejjem, jimxu 10 passi,

197
00:09:58,380 --> 00:10:01,860
li għaddej biex iżommu għaddejjin u għaddejjin
sal I hit-sinjal ta 'waqfien aħmar

198
00:10:01,860 --> 00:10:04,620
u twaqqaf il-programm għal kollox.

199
00:10:04,620 --> 00:10:06,610
>> Għalhekk anki jekk inti ma
tagħmel dan, kif jista I

200
00:10:06,610 --> 00:10:09,510
jagħmlu Scratch jħaffu aktar
madwar l-iskrin?

201
00:10:09,510 --> 00:10:12,060

202
00:10:12,060 --> 00:10:13,280
Aktar passi, id-dritt?

203
00:10:13,280 --> 00:10:15,710
Allura minflok tagħmel 10
fi żmien, għaliex ma we

204
00:10:15,710 --> 00:10:20,100
imorru quddiem u l-bidla to--
dak li għandek propose-- 50?

205
00:10:20,100 --> 00:10:24,410
Allura issa jien ser ikklikkja l-aħdar
bandiera, u fil-fatt, imur verament mgħaġġel.

206
00:10:24,410 --> 00:10:27,180
>> U dan, naturalment, huwa biss
manifestazzjoni ta 'animazzjoni.

207
00:10:27,180 --> 00:10:28,060
X'inhi animazzjoni?

208
00:10:28,060 --> 00:10:33,090
Huwa biss turi li inti l-bniedem
mazz sħiħ ta 'immaġni fissi tassew,

209
00:10:33,090 --> 00:10:34,160
tassew, tassew mgħaġġel.

210
00:10:34,160 --> 00:10:36,500
U hekk jekk aħna qed biss javżak
lilu li jimxu aktar passi,

211
00:10:36,500 --> 00:10:39,750
aħna qed biss li jkollhom l-effett ikun li
-bidla fejn huwa fuq l-iskrin

212
00:10:39,750 --> 00:10:42,900
l-unità aktar malajr għal kull ta 'żmien.

213
00:10:42,900 --> 00:10:46,454
>> Issa l-isfida li jmiss li jiena pproponejt
kien li jkollhom lilu bounce off-tarf.

214
00:10:46,454 --> 00:10:49,120
U mingħajr ma jkunu jafu liema puzzle
biċċiet exist-- għaliex dan huwa multa

215
00:10:49,120 --> 00:10:53,030
jekk inti ma tieħux il-
istadju tal-challenge-- dak

216
00:10:53,030 --> 00:10:54,280
tridu li tagħmel intuwittivament?

217
00:10:54,280 --> 00:10:58,030
Kif għandna lilu bounce back u
raba, bejn ix-xellug u tal-lemin?

218
00:10:58,030 --> 00:11:02,630

219
00:11:02,630 --> 00:11:03,810
>> Yeah.

220
00:11:03,810 --> 00:11:05,680
Allura għandna bżonn xi tip
tal-kondizzjoni, u aħna

221
00:11:05,680 --> 00:11:09,710
jidhru li jkollhom conditionals, hekk li
jitkellmu, taħt il-kategorija ta 'Kontroll.

222
00:11:09,710 --> 00:11:14,110
Liema minn dawn il-blokok
għandna probabilment tixtieq?

223
00:11:14,110 --> 00:11:15,200
Yeah, forsi "jekk, imbagħad."

224
00:11:15,200 --> 00:11:18,780
Allura tinnota li fost l-blokki isfar
għandna hawnhekk, hemm dan il- "jekk"

225
00:11:18,780 --> 00:11:23,920
jew dan "jekk, inkella" blokk li se
inessu biex jagħmlu deċiżjoni biex jagħmlu dan

226
00:11:23,920 --> 00:11:25,000
jew biex tagħmel dan.

227
00:11:25,000 --> 00:11:27,380
U inti tista 'anki bejta tagħhom
biex tagħmel affarijiet multipli.

228
00:11:27,380 --> 00:11:34,910
Jew jekk inti ħadthom ma marret hawn għadhom,
imorru quddiem għall-kategorija Sensing

229
00:11:34,910 --> 00:11:39,612
and-- ejja ara jekk huwa hawnhekk.

230
00:11:39,612 --> 00:11:43,050

231
00:11:43,050 --> 00:11:52,050
>> Allura dak li blokk jista 'jkun utli hawnhekk
biex tiskopri jekk hu barra mill-istadju?

232
00:11:52,050 --> 00:11:56,740
Yeah, avviż li xi wħud minn dawn il-blokok
jista 'jiġi parametrized, biex ngħidu hekk.

233
00:11:56,740 --> 00:12:00,706
Huma jistgħu jkunu tip ta 'personalizzata, mhux
b'differenza HTML bieraħ b'attributi,

234
00:12:00,706 --> 00:12:03,330
fejn dawk l-attributi tip ta
customize-imġiba ta 'tag.

235
00:12:03,330 --> 00:12:08,880
Bl-istess mod hawnhekk, nista grab din jmissu
blokk u l-bidla u titlob il-kwistjoni,

236
00:12:08,880 --> 00:12:11,500
huma inti tmiss il-mouse
werrej bħall-cursor

237
00:12:11,500 --> 00:12:13,250
jew li huma inti jmiss it-tarf?

238
00:12:13,250 --> 00:12:15,210
>> So let me jmorru fi u jagħmlu dan.

239
00:12:15,210 --> 00:12:18,130
Jien ser zoom out għal mument.

240
00:12:18,130 --> 00:12:21,320
Let me grab din il-biċċa puzzle
hawn, din il-biċċa puzzle dan,

241
00:12:21,320 --> 00:12:24,570
u jien ser jumble
up għal ftit mument.

242
00:12:24,570 --> 00:12:27,620
Jien ser jimxu dan,
tbiddel dan li tarf jmissu,

243
00:12:27,620 --> 00:12:38,590
u jien ser mozzjoni tagħmel dan.

244
00:12:38,590 --> 00:12:40,490
Allura hawn huma xi ingredjenti.

245
00:12:40,490 --> 00:12:42,570
I think stajt ltqajna kollox irrid.

246
00:12:42,570 --> 00:12:47,710
>> Kieku xi ħadd jixtieq jipproponi kif I
jistgħu jgħaqqdu dawn forsi fuq għal isfel

247
00:12:47,710 --> 00:12:52,020
sabiex tissolva l-problema ta 'wara
Scratch lemin għax-xellug għal-lemin biex jimxu

248
00:12:52,020 --> 00:12:57,020
xellug għal-lemin għax-xellug, kull
ħin eżatt bouncing barra mill-ħajt?

249
00:12:57,020 --> 00:12:58,050
What do I trid tagħmel?

250
00:12:58,050 --> 00:13:01,097
Liema blokk għandi jaqbdu mal-
"Bandiera meta jkunu ħodor għafast ewwel"?

251
00:13:01,097 --> 00:13:04,060

252
00:13:04,060 --> 00:13:06,200
>> OK, so ejja tibda bil-"għal dejjem."

253
00:13:06,200 --> 00:13:07,170
Dak li jmur ġewwa jmiss?

254
00:13:07,170 --> 00:13:10,290
Xi ħadd ieħor.

255
00:13:10,290 --> 00:13:11,850
OK, jimxu passi.

256
00:13:11,850 --> 00:13:12,350
Kull dritt.

257
00:13:12,350 --> 00:13:14,470
Imbagħad dak?

258
00:13:14,470 --> 00:13:15,120
Mela allura l-, jekk.

259
00:13:15,120 --> 00:13:17,720
U avviż, anki jekk jidher
mgħaffeġ flimkien sewwa,

260
00:13:17,720 --> 00:13:19,500
se biss jikber biex jimlew.

261
00:13:19,500 --> 00:13:21,500
Hija se jaqbżu biss fil fejn I jriduhom.

262
00:13:21,500 --> 00:13:25,920
>> U dak li nressaq bejn
l jekk u l mbagħad?

263
00:13:25,920 --> 00:13:27,180
Probabbilment "jekk jmissu tarf."

264
00:13:27,180 --> 00:13:31,800
U l-avviż, għal darb'oħra, huwa kbir wisq
għal dan, iżda se jikbru biex timla.

265
00:13:31,800 --> 00:13:35,002
U imbagħad ixgħel 15-il grad?

266
00:13:35,002 --> 00:13:35,710
Kemm gradi?

267
00:13:35,710 --> 00:13:38,800

268
00:13:38,800 --> 00:13:41,196
Yeah, hekk 180 se spin
me-triq kollha madwar.

269
00:13:41,196 --> 00:13:42,570
Mela ejja ara jekk sibt dan id-dritt.

270
00:13:42,570 --> 00:13:43,930
Let me zoom out.

271
00:13:43,930 --> 00:13:45,130
>> Let me drag scratch up.

272
00:13:45,130 --> 00:13:50,030
Hekk hu l-ftit mgħawġa
issa, iżda li l-multa.

273
00:13:50,030 --> 00:13:52,231
Kif nista reset lilu faċilment?

274
00:13:52,231 --> 00:13:59,879

275
00:13:59,879 --> 00:14:01,045
Jien ser iqarrqu ftit.

276
00:14:01,045 --> 00:14:04,074

277
00:14:04,074 --> 00:14:05,990
Hekk jien żżid ieħor
blokk, just biex tkun ċara.

278
00:14:05,990 --> 00:14:08,424
Irrid lilu għall-punt 90 grad
lejn il-lemin fil-kontumaċja,

279
00:14:08,424 --> 00:14:10,840
hekk jien biss ser tgħidlu
biex tagħmel dan programmatically.

280
00:14:10,840 --> 00:14:11,632
U here we go.

281
00:14:11,632 --> 00:14:14,740

282
00:14:14,740 --> 00:14:15,740
Aħna jidhru li għamlu dan.

283
00:14:15,740 --> 00:14:19,980
Huwa ftit stramb, għaliex
hu mixi rasu 'l isfel.

284
00:14:19,980 --> 00:14:21,250
Ejja sejħa dan bug.

285
00:14:21,250 --> 00:14:22,120
Li żball.

286
00:14:22,120 --> 00:14:27,320
A bug huwa żball fi programm,
żball loġiku li jien, il-bniedem, magħmul.

287
00:14:27,320 --> 00:14:28,985
Għaliex huwa hu għaddej isfel?

288
00:14:28,985 --> 00:14:33,560

289
00:14:33,560 --> 00:14:35,250
Did MIT screw up jew ma I?

290
00:14:35,250 --> 00:14:38,840

291
00:14:38,840 --> 00:14:42,550
>> Yeah, I mean, mhuwiex s-MIT
tort. Huma tatni biċċa puzzle

292
00:14:42,550 --> 00:14:44,970
li tgħid dawran xi numru ta 'gradi.

293
00:14:44,970 --> 00:14:47,672
U fl suġġeriment Victoria,
Jien tidwir 180 grad,

294
00:14:47,672 --> 00:14:48,880
li hija l-intwizzjoni tajba.

295
00:14:48,880 --> 00:14:53,700
Iżda tidwir 180 gradi litteralment
tfisser tidwir 180 grad,

296
00:14:53,700 --> 00:14:55,860
u li mhux verament
dak li nixtieq, apparentement.

297
00:14:55,860 --> 00:14:58,026
Minħabba li mill-inqas hu fil
din id-dinja żewġ dimensjonijiet,

298
00:14:58,026 --> 00:15:00,740
hekk tidwir hu verament għaddejjin
flip lilu rasu 'l isfel.

299
00:15:00,740 --> 00:15:04,030
>> I probabbilment jridu jużaw dak blokk
minflok, ibbażati fuq dak li tara hawn?

300
00:15:04,030 --> 00:15:11,890

301
00:15:11,890 --> 00:15:14,790
Kif tista infasslu dan?

302
00:15:14,790 --> 00:15:18,380
Yeah, hekk aħna jista 'punt
fid-direzzjoni opposta.

303
00:15:18,380 --> 00:15:22,300
U fil-fatt anki dan huwa
mhux ser ikun biżżejjed,

304
00:15:22,300 --> 00:15:26,410
għaliex nistgħu biss kodiċi iebsa
li tipponta xellug jew il-lemin.

305
00:15:26,410 --> 00:15:27,920
>> Inti taf dak li stajna nagħmlu?

306
00:15:27,920 --> 00:15:30,160
Jidher qisu għandna
blokk konvenjenza hawn.

307
00:15:30,160 --> 00:15:32,987
Jekk I zoom fi, ara
xi ħaġa li aħna nixtiequ hawn?

308
00:15:32,987 --> 00:15:36,120

309
00:15:36,120 --> 00:15:40,020
Allura jidher qisu MIT għandu
estrazzjoni mibnija fil hawn.

310
00:15:40,020 --> 00:15:45,440
Dan il-blokk jidher li huwa ekwivalenti
li blokki oħra, plural?

311
00:15:45,440 --> 00:15:49,510
>> Dan il-blokk wieħed jidher li jkun ekwivalenti
għal dan trio kollu ta 'blokki

312
00:15:49,510 --> 00:15:50,880
li għandna hawnhekk.

313
00:15:50,880 --> 00:15:54,670
Għalhekk jirriżulta li I jista 'jissimplifika tiegħi
programm billi jwarrbu kollha ta 'dak

314
00:15:54,670 --> 00:15:58,270
u biss jitqiegħed dan fil hawn.

315
00:15:58,270 --> 00:16:01,620
U issa hu għadu ftit
Buggy, u li l-multa għal issa.

316
00:16:01,620 --> 00:16:03,370
Aħna ser jitlaq minn dak jkun.

317
00:16:03,370 --> 00:16:06,000
Iżda programm tiegħi huwa saħansitra
aktar sempliċi, u dan, wisq,

318
00:16:06,000 --> 00:16:09,060
ikun rappreżentattiv
ta 'gowl fil programming--

319
00:16:09,060 --> 00:16:13,430
huwa li idealment jagħmel kodiċi tiegħek kif
sempliċi, kemm kompatti kemm jista 'jkun,

320
00:16:13,430 --> 00:16:15,650
filwaqt li jkunu kif
li tinqara 'jkun malajr.

321
00:16:15,650 --> 00:16:20,310
Inti ma tridx li tagħmel dan hekk konċiż
li huwa diffiċli li wieħed jifhem.

322
00:16:20,310 --> 00:16:22,826
>> Imma avviż stajt mibdula
tliet blokki ma 'wieħed,

323
00:16:22,826 --> 00:16:24,200
u li l forsi ħaġa tajba.

324
00:16:24,200 --> 00:16:27,280
Stajt estratt bogħod l-kunċett
ta 'verifika jekk int

325
00:16:27,280 --> 00:16:29,120
fuq it-tarf biss blokka waħda.

326
00:16:29,120 --> 00:16:31,520
Issa nistgħu jieħdu pjaċir bil dan, fil-fatt.

327
00:16:31,520 --> 00:16:35,790
Dan ma jżid tant
valur intellettwali iżda valur jilgħab.

328
00:16:35,790 --> 00:16:39,730
Jien ser jimxi 'l quddiem
u grab dan il-ħoss hawn.

329
00:16:39,730 --> 00:16:42,900

330
00:16:42,900 --> 00:16:46,420
So let me jimxi 'l quddiem, u let me
twaqqaf il-programm għal mument.

331
00:16:46,420 --> 00:16:52,070
Jien ser jirreġistra dan li ġej,
jippermettu aċċess għal mikrofonu tiegħi.

332
00:16:52,070 --> 00:16:53,181
>> Here we go.

333
00:16:53,181 --> 00:16:53,680
Ouch.

334
00:16:53,680 --> 00:16:58,710

335
00:16:58,710 --> 00:17:01,140
Ejja nippruvaw nerġgħu.

336
00:17:01,140 --> 00:17:02,279
Here we go.

337
00:17:02,279 --> 00:17:03,570
OK, I rreġistrati l-ħaġa ħażina.

338
00:17:03,570 --> 00:17:04,580
Here we go.

339
00:17:04,580 --> 00:17:05,080
Ouch.

340
00:17:05,080 --> 00:17:07,910

341
00:17:07,910 --> 00:17:08,800
Ouch.

342
00:17:08,800 --> 00:17:09,300
Kull dritt.

343
00:17:09,300 --> 00:17:10,791
Issa għandi bżonn biex teħles minn dik.

344
00:17:10,791 --> 00:17:11,290
Kull dritt.

345
00:17:11,290 --> 00:17:13,950
>> Allura issa għandi
reġistrazzjoni ta 'ftit "Ouch."

346
00:17:13,950 --> 00:17:18,040
Allura issa jien se jmorru
quddiem u sejħa dan "Ouch."

347
00:17:18,040 --> 00:17:20,270
Jien se jmorru lura
li skripts tiegħi, u issa

348
00:17:20,270 --> 00:17:25,460
Avviż hemm dan il-blokk li sejjaħ
play ħoss "meow" jew play ħoss "Ouch."

349
00:17:25,460 --> 00:17:28,920
Jien ser drag dan, u fejn
għandi tpoġġi din għall-effett komiku?

350
00:17:28,920 --> 00:17:31,740

351
00:17:31,740 --> 00:17:37,860
Yeah, hekk issa huwa tip ta
Buggy, għaliex issa dan block--

352
00:17:37,860 --> 00:17:42,050
Avviż kif dan "jekk fit-tarf,
bounce "huwa tip ta 'self-contained.

353
00:17:42,050 --> 00:17:43,704
So I bżonn biex jiffissaw dan.

354
00:17:43,704 --> 00:17:44,870
Let me imorru quddiem u tagħmel dan.

355
00:17:44,870 --> 00:17:48,630
Let me jeħles ta 'dan u jmorru lura
li oriġinali tagħna, aktar deliberata

356
00:17:48,630 --> 00:17:49,870
funzjonalità.

357
00:17:49,870 --> 00:18:01,080
Mela "jekk jmissu tarf, allura" Irrid
li jduru, kif Rabat proposta,

358
00:18:01,080 --> 00:18:02,480
180 gradi.

359
00:18:02,480 --> 00:18:05,497
U ma nixtieq li play
il-ħoss "Ouch" hemmhekk?

360
00:18:05,497 --> 00:18:11,800

361
00:18:11,800 --> 00:18:15,580
>> Yeah, avviż huwa barra
li blokka isfar.

362
00:18:15,580 --> 00:18:17,680
Allura dan, ukoll, ikun
bug, imma stajt ndunat dan.

363
00:18:17,680 --> 00:18:21,290
Hekk jien ser jkaxkru up hawn,
u avviż issa huwa ġewwa l-"jekk".

364
00:18:21,290 --> 00:18:24,250
Allura l-"jekk" huwa dan it-tip
ta 'prodotti simili blot-driegħ simili

365
00:18:24,250 --> 00:18:26,260
thats biss ser
nagħmlu dak li hu ġewwa ta 'dan.

366
00:18:26,260 --> 00:18:30,216
Mela issa jekk jien zoom fil
ir-riskju ta annoying--

367
00:18:30,216 --> 00:18:32,860

368
00:18:32,860 --> 00:18:36,470
>> KOMPJUTER: Ouch, Ouch, Ouch.

369
00:18:36,470 --> 00:18:39,910
>> DAVID Malan: U
se biss jmorru fuq għal dejjem.

370
00:18:39,910 --> 00:18:44,160
Issa biss biex iħaffu l-affarijiet
hawn, let me imorru quddiem u tiftaħ,

371
00:18:44,160 --> 00:18:50,460
ejja say-- let me go għal xi
ta 'għalf tiegħi stess mill-klassi.

372
00:18:50,460 --> 00:18:53,000

373
00:18:53,000 --> 00:19:00,220
U let me jiftħu, ejja ngħidu, dan
waħda magħmula minn wieħed mill fellows tagħlim tagħna

374
00:19:00,220 --> 00:19:01,500
ftit ta 'snin ilu.

375
00:19:01,500 --> 00:19:04,732
Allura xi wħud minnkom jista recall
din il-logħba mill-imgħoddi,

376
00:19:04,732 --> 00:19:05,940
u huwa attwalment notevoli.

377
00:19:05,940 --> 00:19:08,190
Anki jekk aħna ghamilt l
aktar sempliċi ta 'programmi dritt issa,

378
00:19:08,190 --> 00:19:09,980
ejja jikkunsidraw liema dan
attwalment tidher qiesha.

379
00:19:09,980 --> 00:19:10,650
Let me hit play.

380
00:19:10,650 --> 00:19:14,210

381
00:19:14,210 --> 00:19:18,980
>> Allura f'dan il-logħba, aħna għandna
Żrinġ, u jużaw il-vleġġa keys--

382
00:19:18,980 --> 00:19:23,340
hu jieħu passi akbar minn I remember--
I jkollhom kontroll fuq din il Żrinġ.

383
00:19:23,340 --> 00:19:29,630
U l-għan huwa li tikseb madwar il busy
triq mingħajr ma tinkorri fis-karozzi.

384
00:19:29,630 --> 00:19:34,735
U ejja see-- jekk immur up here, I
għandek tistenna għal log li tiskrollja permezz.

385
00:19:34,735 --> 00:19:38,130

386
00:19:38,130 --> 00:19:39,274
Din il iħoss bħal bug.

387
00:19:39,274 --> 00:19:42,240

388
00:19:42,240 --> 00:19:43,495
Din hija tip ta 'bug.

389
00:19:43,495 --> 00:19:45,980

390
00:19:45,980 --> 00:19:46,480
Kull dritt.

391
00:19:46,480 --> 00:19:51,550
Jien fuq dan hawn,
hemm, u allura inti żżomm

392
00:19:51,550 --> 00:19:54,100
għaddejjin sakemm ikollok kollha
l żrinġijiet għall-pads lily.

393
00:19:54,100 --> 00:19:55,920
Issa dan jista 'tfittex
l-aktar kumplessi,

394
00:19:55,920 --> 00:19:57,840
imma ejja jippruvaw jiksru
din tinqasam mentalment

395
00:19:57,840 --> 00:20:00,040
u verbalment fi blokki komponenti tiegħu.

396
00:20:00,040 --> 00:20:03,910
Allura hemm probabilment puzzle
biċċa li ma rajniex s'issa

397
00:20:03,910 --> 00:20:07,440
iżda li jirrispondu għall keystrokes,
affarijiet I hit fuq it-tastiera.

398
00:20:07,440 --> 00:20:11,660
>> Allura hemm probabbilment xi tip ta '
blokk li tgħid, jekk ċavetta huwa daqs up,

399
00:20:11,660 --> 00:20:15,965
imbagħad tagħmel xi ħaġa ma Scratch--
forsi jġorrhom 10 passi b'dan il-mod.

400
00:20:15,965 --> 00:20:20,240
Jekk ċavetta isfel hija ppressata, jimxu 10 passi
B'dan il-mod, jew ċavetta xellug, jimxu 10 passi

401
00:20:20,240 --> 00:20:21,710
B'dan il-mod, 10 passi dik.

402
00:20:21,710 --> 00:20:23,644
Stajt daru ċar l-qattus fi Żrinġ.

403
00:20:23,644 --> 00:20:26,060
Allura li jinsab biss meta l-
kostum, kif sejħiet Scratch it-- aħna

404
00:20:26,060 --> 00:20:28,440
biss importati stampa ta 'l-Żrinġ.

405
00:20:28,440 --> 00:20:29,570
>> Imma dak li inkella qed jiġri?

406
00:20:29,570 --> 00:20:32,794
Liema linji oħra ta 'kodiċi,
liema biċċiet puzzle oħrajn

407
00:20:32,794 --> 00:20:35,460
ma Blake, sħabi tagħlim tagħna,
użu f'dan il-programm, apparentement?

408
00:20:35,460 --> 00:20:38,320

409
00:20:38,320 --> 00:20:42,730
X'hemm teħid kollox move--
liema programmazzjoni tibni?

410
00:20:42,730 --> 00:20:44,950
>> Mozzjoni, sure-- hekk il
jimxu blokk, għall-żgur.

411
00:20:44,950 --> 00:20:49,330
U x'hemm dan blokka mossa
ġewwa ta ', x'aktarx?

412
00:20:49,330 --> 00:20:52,850
Yeah, xi tip ta 'linja, forsi
dejjem blokk, forsi irrepeti block--

413
00:20:52,850 --> 00:20:54,070
irrepeti sakemm blokk.

414
00:20:54,070 --> 00:20:57,330
U dan huwa dak li jagħmlu l-zkuk u
-pads lily u kollox mossa ħaġa oħra

415
00:20:57,330 --> 00:20:57,990
quddiem u lura.

416
00:20:57,990 --> 00:21:00,270
Huwa biss jiġri endlessly.

417
00:21:00,270 --> 00:21:03,180
>> Għaliex huma xi wħud mill-karozzi
jiċċaqilqu aktar mgħaġġla mill-oħrajn?

418
00:21:03,180 --> 00:21:06,607
Dak li hu differenti dwar dawk il-programmi?

419
00:21:06,607 --> 00:21:09,690
Yeah, probabbilment xi wħud minnhom qed tieħu
aktar passi f'daqqa u xi wħud minnhom

420
00:21:09,690 --> 00:21:10,690
inqas passi f'daqqa.

421
00:21:10,690 --> 00:21:14,670
U l-effett viżwali
huwa mgħaġġel kontra kajman.

422
00:21:14,670 --> 00:21:16,030
>> What do you think ġara?

423
00:21:16,030 --> 00:21:19,700
Meta sirt Żrinġ tiegħi it-triq kollha
fl-triq u l-xmara

424
00:21:19,700 --> 00:21:23,560
fuq il-kuxxinett lily, xi ħaġa
notevoli ġara.

425
00:21:23,560 --> 00:21:26,540
Dak li ġara hekk kif għamilt dan?

426
00:21:26,540 --> 00:21:27,210
Hija waqfet.

427
00:21:27,210 --> 00:21:29,680
Dik Żrinġ waqfet, u
Sibt tieni Żrinġ.

428
00:21:29,680 --> 00:21:33,155
Allura dak li jibnu irid ikun
użati hemmhekk, liema karatteristika?

429
00:21:33,155 --> 00:21:36,020

430
00:21:36,020 --> 00:21:38,660
>> Yeah, hekk hemm xi tip ta '
"Jekk" jiġi kkundizzjonat up hemm, wisq.

431
00:21:38,660 --> 00:21:41,909
U jirriżulta out-- aħna ma tara this--
imma hemm blokki oħra fil hemmhekk li

432
00:21:41,909 --> 00:21:45,300
tista 'tgħid, jekk inti tmiss
ħaġa oħra fuq l-iskrin,

433
00:21:45,300 --> 00:21:47,720
jekk int jmissu l-kuxxinett lily, "imbagħad."

434
00:21:47,720 --> 00:21:50,810
U allura li meta aħna
jagħmlu t-tieni Żrinġ jidhru.

435
00:21:50,810 --> 00:21:54,969
Għalhekk anki jekk din il-logħba hija ċertament
ħafna datat, anki jekk l-ewwel daqqa t'għajn

436
00:21:54,969 --> 00:21:58,010
hemm daqstant għaddej Blake on-- u
ma Whip dan up f'żewġ minuti,

437
00:21:58,010 --> 00:22:00,390
hija probabbilment ħadet lilu diversi
siegħa biex joħolqu din il-logħba

438
00:22:00,390 --> 00:22:03,850
ibbażata fuq il-memorja jew videos tiegħu
tal-verżjoni imgħoddi ta 'dan.

439
00:22:03,850 --> 00:22:07,940
Imma kollha ta 'dawn l-affarijiet ftit
għaddejjin fuq l-iskrin b'mod iżolat

440
00:22:07,940 --> 00:22:11,550
jsarrafx biss fl dawn sempliċi ħafna
movimenti constructs-- jew dikjarazzjonijiet

441
00:22:11,550 --> 00:22:15,519
bħal konna diskussi, loops u
kondizzjonijiet, u li dwar dan.

442
00:22:15,519 --> 00:22:17,060
Hemm ftit karatteristiċi oħra fancier.

443
00:22:17,060 --> 00:22:19,130
Xi wħud minnhom huma purament
estetiċi jew akustiku,

444
00:22:19,130 --> 00:22:20,964
bħall-ħsejjes I biss lagħbu.

445
00:22:20,964 --> 00:22:23,380
Iżda għall-parti l-kbira, inti
għandhom f'din il-lingwa, Scratch,

446
00:22:23,380 --> 00:22:25,350
kollha ta 'l fundamentali
blokki tal-bini li inti

447
00:22:25,350 --> 00:22:29,280
jkollhom fis-C, Java, JavaScript,
PHP, Ruby, Python,

448
00:22:29,280 --> 00:22:32,960
u kull numru ta 'lingwi oħra.

449
00:22:32,960 --> 00:22:36,720
Kwalunkwe mistoqsijiet dwar Scratch?

450
00:22:36,720 --> 00:22:37,220
Kull dritt.

451
00:22:37,220 --> 00:22:40,303
Allura aħna mhux se adsa fis-fond għall Scratch,
għalkemm inti qed jilqgħu dan il-weekend,

452
00:22:40,303 --> 00:22:42,860
speċjalment jekk ikollok tfal jew
nieces u nephews u bħal dawn,

453
00:22:42,860 --> 00:22:44,220
li jintroduċuhom lil scratch.

454
00:22:44,220 --> 00:22:47,960
Huwa fil-fatt wonderfully jilgħab
ambjent ma ', bħala awturi tagħha say,

455
00:22:47,960 --> 00:22:49,120
limiti għolja ħafna.

456
00:22:49,120 --> 00:22:51,670
Anki jekk aħna beda bil
ħafna dettalji ta 'livell baxx,

457
00:22:51,670 --> 00:22:54,890
inti tista 'verament tagħmel pjuttost ftit
magħha, u dan huwa forsi

458
00:22:54,890 --> 00:22:57,360
dimostrazzjoni ta 'eżattament dak.

459
00:22:57,360 --> 00:23:02,920
>> Imma ejja issa transizzjoni għal ftit aktar
problemi sofistikati, jekk inti se,

460
00:23:02,920 --> 00:23:05,870
magħrufa bħala "tiftix" u
"Issortjar," b'mod aktar ġenerali.

461
00:23:05,870 --> 00:23:09,500
Kellna dan il-ktieb tat-telefon earlier-- hawn
xulxin biss għall discussion--

462
00:23:09,500 --> 00:23:13,460
li konna kapaċi li jfittxu
b'mod aktar effiċjenti minħabba li

463
00:23:13,460 --> 00:23:15,270
ta 'suppożizzjoni sinifikanti.

464
00:23:15,270 --> 00:23:17,655
U biss li tkun ċara, liema
suppożizzjoni kienet I jagħmlu

465
00:23:17,655 --> 00:23:19,280
meta titfittex permezz ta 'dan il-ktieb tat-telefon?

466
00:23:19,280 --> 00:23:23,342

467
00:23:23,342 --> 00:23:25,300
Dak Mike Smith kien fl
-ktieb tat-telefon, għalkemm I

468
00:23:25,300 --> 00:23:27,410
jkunu jistgħu jimmaniġġjaw
-xenarju mingħajrha

469
00:23:27,410 --> 00:23:30,720
hemm jekk I biss waqfet qabel iż-żmien.

470
00:23:30,720 --> 00:23:31,806
Il-ktieb huwa alfabetiku.

471
00:23:31,806 --> 00:23:33,930
U li l-ħafna ġenerużi
suppożizzjoni, peress li

472
00:23:33,930 --> 00:23:36,580
tfisser someone-- Jien xorta
ta 'tqattigħ Minn corner,

473
00:23:36,580 --> 00:23:40,580
bħal I am aktar malajr minħabba xi ħadd
inkella għamilt ħafna xogħol iebes għalija.

474
00:23:40,580 --> 00:23:43,120
>> Imma x'jiġri jekk il-phone
ktieb kienu mhux magħżul?

475
00:23:43,120 --> 00:23:47,050
Forsi Verizon ltqajna għażżien, biss threw
ismijiet u n-numri ta 'kulħadd fil hemm

476
00:23:47,050 --> 00:23:50,120
forsi fl-ordni li fih ikunu
iffirmaw għal servizz tat-telefon.

477
00:23:50,120 --> 00:23:54,570
U kemm ħin ma jieħdu me
li ssib xi ħadd bħal Mike Smith?

478
00:23:54,570 --> 00:23:58,160
1000 telefon paġna book-- kemm
paġni għandi tfittex permezz?

479
00:23:58,160 --> 00:23:58,905
>> Kollha kemm huma.

480
00:23:58,905 --> 00:24:00,030
Inti xorta ta 'barra ta' xortih.

481
00:24:00,030 --> 00:24:03,420
Inti litteralment għandek tħares lejn kull
paġna jekk il-ktieb tat-telefon huwa biss

482
00:24:03,420 --> 00:24:04,450
saltwarjament magħżula.

483
00:24:04,450 --> 00:24:06,910
Inti tista 'tikseb xortik tajba u jsibu Mike
fuq l-ewwel paġna, għaliex huwa

484
00:24:06,910 --> 00:24:08,826
kienet l-ewwel klijent
għall-ordni servizz tat-telefon.

485
00:24:08,826 --> 00:24:10,760
Imma hu seta 'kien l-aħħar, wisq.

486
00:24:10,760 --> 00:24:12,500
>> Allura sabiex każwali mhix tajba.

487
00:24:12,500 --> 00:24:16,750
Allura jissoponi għandna biex issolvi l-
ktieb tat-telefon jew fid-dejta xorta ġenerali

488
00:24:16,750 --> 00:24:18,520
li aħna kont qed tingħata.

489
00:24:18,520 --> 00:24:19,440
Kif nistgħu nagħmlu dan?

490
00:24:19,440 --> 00:24:21,360
>> Well, let me biss jippruvaw
eżempju sempliċi hawn.

491
00:24:21,360 --> 00:24:24,290
Let me imorru quddiem u toss
Ftit numri fuq il-bord.

492
00:24:24,290 --> 00:24:35,480
Ejja ngħidu n-numri li għandna huma,
ejja ngħidu, erba ', tnejn, waħda, u tlieta.

493
00:24:35,480 --> 00:24:38,390
U, Ben, sort dawn in-numri għalina.

494
00:24:38,390 --> 00:24:39,017
>> OK tajjeb.

495
00:24:39,017 --> 00:24:39,850
Kif sirt tagħmel dan?

496
00:24:39,850 --> 00:24:42,731

497
00:24:42,731 --> 00:24:43,230
Kull dritt.

498
00:24:43,230 --> 00:24:44,710
Allura tibda bl-iżgħar
valur u l-ogħla,

499
00:24:44,710 --> 00:24:46,084
u li tassew intwizzjoni tajba.

500
00:24:46,084 --> 00:24:48,080
U tirrealizza li aħna
bnedmin huma attwalment pretty

501
00:24:48,080 --> 00:24:49,913
tajba fuq soluzzjoni ta 'problemi
bħal din hija, għallinqas

502
00:24:49,913 --> 00:24:51,810
meta d-data hija relattivament żgħir.

503
00:24:51,810 --> 00:24:54,860
Hekk kif tibda jkollha mijiet
ta 'numri, eluf ta' numri,

504
00:24:54,860 --> 00:24:58,440
miljuni ta 'numri, Ben probabbilment
ma setgħux jagħmlu dan pjuttost li mgħaġġel,

505
00:24:58,440 --> 00:25:00,620
jekk wieħed jassumi li kien hemm
nuqqasijiet fil-numri.

506
00:25:00,620 --> 00:25:03,450
Pjuttost faċli biex għodd sa miljun
xort'oħra, biss jieħdu ħafna ħin.

507
00:25:03,450 --> 00:25:07,150
>> Allura l-algoritmu li ħsejjes
bħal Ben użat biss issa

508
00:25:07,150 --> 00:25:08,930
kien tfittxija għall-iżgħar numru.

509
00:25:08,930 --> 00:25:12,900
Allura anke jekk aħna bnedmin jistgħu jieħdu
fil-lott ta 'informazzjoni viżwalment,

510
00:25:12,900 --> 00:25:14,830
kompjuter huwa attwalment
ftit aktar limitata.

511
00:25:14,830 --> 00:25:17,560
Il-kompjuter jista 'biss
tħares lejn byte wieħed kull darba

512
00:25:17,560 --> 00:25:20,770
jew forsi erba 'bytes fi time--
dawn il-jiem forsi 8 bytes bi time--

513
00:25:20,770 --> 00:25:24,450
iżda numru żgħir ħafna
ta bytes fi żmien partikolari.

514
00:25:24,450 --> 00:25:28,480
>> Allura peress li aħna verament ikollhom
erba 'valuri separati here--

515
00:25:28,480 --> 00:25:32,440
u inti tista 'taħseb Ben bħala li
blinders fuq li kieku kien il-kompjuter tali

516
00:25:32,440 --> 00:25:36,450
li ma jistax jara xi ħaġa oħra
minn numru wieħed kull time--

517
00:25:36,450 --> 00:25:39,720
hekk aħna ġeneralment se tassumi, bħal fil
Ingliż, aħna ser jinqara mill-lemin għax-xellug.

518
00:25:39,720 --> 00:25:42,870
Allura l-ewwel numru Ben probabbilment ħares
lejn kienet erba 'u mbagħad malajr ħafna

519
00:25:42,870 --> 00:25:44,770
induna li l-pretty big
number-- let me ikompli jfittex.

520
00:25:44,770 --> 00:25:45,357
>> Hemm tnejn.

521
00:25:45,357 --> 00:25:45,940
Stenna minuta.

522
00:25:45,940 --> 00:25:47,070
Tnejn huwa iżgħar minn erbgħa.

523
00:25:47,070 --> 00:25:47,986
Jien ser tiftakar.

524
00:25:47,986 --> 00:25:49,070
Żewġ issa huwa l-iżgħar.

525
00:25:49,070 --> 00:25:50,417
Issa one-- li, anki aħjar.

526
00:25:50,417 --> 00:25:51,250
C'est saħansitra iżgħar.

527
00:25:51,250 --> 00:25:54,000
Jien ser tinsa dwar żewġ
u biss ftakar wieħed issa.

528
00:25:54,000 --> 00:25:56,550
>> U jista 'hu tieqaf tfittex?

529
00:25:56,550 --> 00:25:58,360
Ukoll, huwa jista ibbażata
din l-informazzjoni,

530
00:25:58,360 --> 00:26:00,477
imma hu d-tfittxija aħjar
il-bqija tal-lista.

531
00:26:00,477 --> 00:26:02,060
Minħabba dak li jekk żero kienu fil-lista?

532
00:26:02,060 --> 00:26:03,643
X'jiġri jekk negattiv wieħed kellu fil-lista?

533
00:26:03,643 --> 00:26:07,720
Huwa biss jaf ir-risposta tiegħu
hija korretta jekk hu b'mod eżawrjenti

534
00:26:07,720 --> 00:26:08,729
ċċekkjati l-lista kollha.

535
00:26:08,729 --> 00:26:10,020
Allura aħna nħarsu lejn il-bqija ta 'dan il-.

536
00:26:10,020 --> 00:26:11,394
Three-- li kien ħela ta 'ħin.

537
00:26:11,394 --> 00:26:13,540
Ghandek unlucky, imma jien kien
xorta korrett li jagħmlu hekk.

538
00:26:13,540 --> 00:26:17,857
U hekk issa hu probabbilment
magħżula l-iżgħar numru

539
00:26:17,857 --> 00:26:20,440
u biss jitqiegħed fil-bidu
tal-lista, kif jien ser nagħmlu hawnhekk.

540
00:26:20,440 --> 00:26:23,480
Issa ux'għamiltu jmiss, anki jekk
inti ma taħseb dwarha kważi

541
00:26:23,480 --> 00:26:25,962
sa dan il-punt?

542
00:26:25,962 --> 00:26:27,670
Irrepeti l-proċess,
hekk xi tip ta 'linja.

543
00:26:27,670 --> 00:26:28,920
Hemm idea familjari.

544
00:26:28,920 --> 00:26:30,860
Allura hawnhekk huwa erbgħa.

545
00:26:30,860 --> 00:26:32,110
Li bħalissa hija l-iżgħar.

546
00:26:32,110 --> 00:26:33,220
Li l-kandidat.

547
00:26:33,220 --> 00:26:33,900
Mhux iktar.

548
00:26:33,900 --> 00:26:34,770
Issa stajt tidher tnejn.

549
00:26:34,770 --> 00:26:36,630
Dik hija l-iżgħar li jiġi element.

550
00:26:36,630 --> 00:26:40,800
Three-- li mhux iżgħar, hekk
issa ben jistgħu ġewwieni l-tnejn.

551
00:26:40,800 --> 00:26:44,510
>> U issa aħna irrepeti l-proċess, u
naturalment tlieta gets miġbud 'il barra li jmiss.

552
00:26:44,510 --> 00:26:45,420
Irrepeti l-proċess.

553
00:26:45,420 --> 00:26:46,990
Erba gets miġbud 'il barra.

554
00:26:46,990 --> 00:26:50,140
U issa aħna qed barra ta 'numri,
sabiex il-lista għandha tiġi magħżula.

555
00:26:50,140 --> 00:26:51,960
>> U fil-fatt, dan huwa algoritmu formali.

556
00:26:51,960 --> 00:26:56,610
A xjentist kompjuter ikun
sejħa dan "it-tip ta 'għażla,"

557
00:26:56,610 --> 00:27:00,880
l-idea li jkun tip ta '
lista iteratively-- darb'oħra

558
00:27:00,880 --> 00:27:03,807
u għal darb'oħra u għal darb'oħra tagħżel
l-iżgħar numru.

559
00:27:03,807 --> 00:27:06,140
U x'hemm sbieħ dwar dan huwa
huwa biss hekk darn intuwittivi.

560
00:27:06,140 --> 00:27:07,470
Huwa tant sempliċi.

561
00:27:07,470 --> 00:27:11,100
U inti tista 'tirrepeti l-istess
operazzjoni mill-ġdid u għal darb'oħra.

562
00:27:11,100 --> 00:27:12,150
Huwa sempliċi.

563
00:27:12,150 --> 00:27:17,170
>> F'dan il-każ kien mgħaġġel, iżda
kemm żmien ma attwalment jieħdu?

564
00:27:17,170 --> 00:27:19,880
Ejja jagħmilha jidhru u
tħoss ftit aktar tedious.

565
00:27:19,880 --> 00:27:24,150
Allura wieħed, tnejn, tlieta, erba ', ħames sitta,
seba ', tmien, disa', 10, 11, 12, 13, 14,

566
00:27:24,150 --> 00:27:26,160
15, 16-- numru arbitrarju.

567
00:27:26,160 --> 00:27:28,780
I biss riedu aktar din il
żmien minn sempliċiment il-erbgħa.

568
00:27:28,780 --> 00:27:30,780
Mela jekk stajt ltqajna kollha
mazz ta 'numri now-- dan

569
00:27:30,780 --> 00:27:32,420
lanqas ma jimpurtax
dak li are-- tal let

570
00:27:32,420 --> 00:27:34,380
jaħsbu dwar dak li dan
algoritmu verament huwa simili.

571
00:27:34,380 --> 00:27:35,857
>> Ejja ngħidu li jeżistu numri hemmhekk.

572
00:27:35,857 --> 00:27:38,190
Għal darb'oħra, ma jimpurtax liema
dawn huma, iżda dawn qed każwali.

573
00:27:38,190 --> 00:27:39,679
I am li tapplika algoritmu Ben.

574
00:27:39,679 --> 00:27:41,220
I bżonn li jagħżlu l-iżgħar numru.

575
00:27:41,220 --> 00:27:41,761
X 'nagħmel?

576
00:27:41,761 --> 00:27:44,240
U jien ser fiżikament
tagħmel dan il-ħin li jaġixxu out.

577
00:27:44,240 --> 00:27:46,099
Looking, tfittex,
tfittex, tfittex, tfittex.

578
00:27:46,099 --> 00:27:48,140
Biss mill-ħin I nikseb biex
l-aħħar tal-lista jista

579
00:27:48,140 --> 00:27:51,230
Nifhem l-iżgħar
in-numru kien żewġ dan iż-żmien.

580
00:27:51,230 --> 00:27:52,720
Wieħed mhux fil-lista.

581
00:27:52,720 --> 00:27:54,400
So I stabbilixxit tnejn.

582
00:27:54,400 --> 00:27:55,590
>> What do I do jmiss?

583
00:27:55,590 --> 00:27:58,600
Looking, tfittex, tfittex, tfittex.

584
00:27:58,600 --> 00:28:02,250
Issa sibt in-numru sebgħa, għaliex
hemm lakuni f'dawn numbers--

585
00:28:02,250 --> 00:28:03,300
iżda biss arbitrarja.

586
00:28:03,300 --> 00:28:03,800
Kull dritt.

587
00:28:03,800 --> 00:28:06,030
Allura issa I tista 'tpoġġi isfel sebgħa.

588
00:28:06,030 --> 00:28:08,860
Looking tfittex, tfittex.

589
00:28:08,860 --> 00:28:11,030
>> Issa jien jekk wieħed jassumi, ta
Naturalment, li Ben ma

590
00:28:11,030 --> 00:28:14,780
għandhom RAM żejda, extra
memorja, minħabba li, naturalment,

591
00:28:14,780 --> 00:28:16,080
Jien tħares lejn l-istess numru.

592
00:28:16,080 --> 00:28:18,246
Żgur I setgħet mfakkar
kollha ta 'dawn in-numri,

593
00:28:18,246 --> 00:28:19,930
u li assolutament veru.

594
00:28:19,930 --> 00:28:22,610
Imma jekk Ben jiftakar kollha
tan-numri hu jidher,

595
00:28:22,610 --> 00:28:24,430
hu ma verament magħmula
progress bażiku

596
00:28:24,430 --> 00:28:26,170
għaliex huwa jkun diġa jaf
il-kapaċità ta 'tiftix

597
00:28:26,170 --> 00:28:27,540
permezz tan-numri fuq il-bord.

598
00:28:27,540 --> 00:28:29,373
Ftakar kollha tal-
numri ma jgħinx,

599
00:28:29,373 --> 00:28:32,490
għax xorta tista bħala kompjuter
tħares biss lejn, konna qal, numru wieħed

600
00:28:32,490 --> 00:28:33,080
kull darba.

601
00:28:33,080 --> 00:28:35,760
Hekk hemm ebda tip ta 'iqarrqu
hemmhekk li inti tista 'lieva.

602
00:28:35,760 --> 00:28:39,170
>> Allura fir-realtà, kif
iżommu tiftix il-lista,

603
00:28:39,170 --> 00:28:44,200
I litteralment għandek biss iżommu għaddejjin
quddiem u lura permezz tagħha, tnittif out

604
00:28:44,200 --> 00:28:45,710
-iżgħar li jiġi numru.

605
00:28:45,710 --> 00:28:48,810
U kif inti tista 'tip ta' jiddeduċu
minn movimenti iblah tiegħi,

606
00:28:48,810 --> 00:28:50,860
dan biss gets ħafna
tedious malajr ħafna,

607
00:28:50,860 --> 00:28:54,850
u I jidhru li jkunu għaddejjin lura u
raba, quddiem u lura pjuttost ftit.

608
00:28:54,850 --> 00:29:03,220
Issa biex ikunu ġusti, I ma jkollhom imorru
daqshekk, ukoll, ejja see-- li tkun ġusta,

609
00:29:03,220 --> 00:29:06,310
I ma jkollhom jimxu pjuttost
kif ħafna passi kull darba.

610
00:29:06,310 --> 00:29:09,200
Minħabba, naturalment, kif
tagħżel numri mil-lista,

611
00:29:09,200 --> 00:29:11,860
il-lista li jifdal huwa jkollna iqsar.

612
00:29:11,860 --> 00:29:14,240
>> U hekk ejja jaħsbu dwar
kif ħafna passi jien attwalment

613
00:29:14,240 --> 00:29:16,010
traipsing permezz ta 'kull darba.

614
00:29:16,010 --> 00:29:18,950
Fl-ewwel sitwazzjoni
kellna 16 numri,

615
00:29:18,950 --> 00:29:22,210
u għalhekk maximally-- ejja biss
tagħmel dan għal discussion--

616
00:29:22,210 --> 00:29:25,640
I kellha tfittex permezz 16
numri li ssib l-iżgħar.

617
00:29:25,640 --> 00:29:28,420
Imma ladarba I mnittfa l
l-iżgħar numru, kif

618
00:29:28,420 --> 00:29:30,590
twil kien l-lista li jifdal, tal-kors?

619
00:29:30,590 --> 00:29:31,420
Biss 15.

620
00:29:31,420 --> 00:29:34,670
Allura kemm-numri ma 'Ben jew għandi
tfittex permezz-tieni darba madwar?

621
00:29:34,670 --> 00:29:36,832
15, biss biex tmur u ssib l-iżgħar.

622
00:29:36,832 --> 00:29:39,540
Imma issa, naturalment, il-lista hija,
wisq, iżgħar milli kienet qabel.

623
00:29:39,540 --> 00:29:42,540
Allura kif ħafna passi ma I
għandek tieħu l-ħin li jmiss?

624
00:29:42,540 --> 00:29:49,970
14 u mbagħad 13 u mbagħad 12, kif ukoll dot,
dot, dot, sakemm jien xellug ma biss wieħed.

625
00:29:49,970 --> 00:29:53,146
Allura issa xjenzat kompjuter kieku
jistaqsu, ukoll, dak ma dan kollu indaqs?

626
00:29:53,146 --> 00:29:55,770
Hija fil-fatt ekwilvalenti għal bejn konkreti
numru li nistgħu ċertament

627
00:29:55,770 --> 00:30:00,490
do aritmetikament, iżda rridu nitkellmu
dwar l-effiċjenza ta 'algoritmi

628
00:30:00,490 --> 00:30:04,940
ftit aktar formulaically,
indipendenti mill kemm żmien il-lista hija.

629
00:30:04,940 --> 00:30:06,240
>> U għalhekk inti taf liema?

630
00:30:06,240 --> 00:30:09,860
Dan huwa 16, imma bħal I said qabel,
ejja biss sejħa-daqs tal-problema

631
00:30:09,860 --> 00:30:10,970
n, fejn n hija xi numru.

632
00:30:10,970 --> 00:30:13,220
Forsi huwa 16, forsi huwa
tlieta, forsi huwa miljun.

633
00:30:13,220 --> 00:30:13,761
I do not know.

634
00:30:13,761 --> 00:30:14,390
I do not care.

635
00:30:14,390 --> 00:30:16,520
What I verament irridu huwa
formula li nista

636
00:30:16,520 --> 00:30:19,420
jużaw biex iqabblu din algoritmu
kontra algoritmi oħra

637
00:30:19,420 --> 00:30:22,350
li xi ħadd jista 'pretensjoni
huma aħjar jew agħar.

638
00:30:22,350 --> 00:30:25,430
>> Għalhekk jirriżulta li, u jien biss
jafu dan mill-iskola grad,

639
00:30:25,430 --> 00:30:34,790
li dan attwalment xogħlijiet biex l-istess
ħaġa bħala n tul n flimkien waħda fuq tnejn.

640
00:30:34,790 --> 00:30:40,020
U dan jiġri li jkun daqs, ta '
Naturalment, n kwadrat miżjud b'n fuq tnejn.

641
00:30:40,020 --> 00:30:43,250
Mela jekk jien ridt formula
għal kemm ħafna passi

642
00:30:43,250 --> 00:30:46,330
kienu involuti fil tħares lejn kollha
ta 'dawk in-numri mill-ġdid u għal darb'oħra

643
00:30:46,330 --> 00:30:52,681
u għal darb'oħra u għal darb'oħra, nixtieq ngħid
huwa n kwadrat miżjud b'n fuq tnejn.

644
00:30:52,681 --> 00:30:53,430
Imma inti taf liema?

645
00:30:53,430 --> 00:30:54,500
Dan biss jistenna messy.

646
00:30:54,500 --> 00:30:56,470
I biss verament irridu
sens ġenerali ta 'affarijiet.

647
00:30:56,470 --> 00:30:58,810
U inti tista 'recall minn
iskola għolja li hemm

648
00:30:58,810 --> 00:31:00,660
hija l-kunċett ta 'ogħla terminu ordni.

649
00:31:00,660 --> 00:31:05,300
Liema minn dawn it-termini, il-n
kwadrat, n, jew in-nofs,

650
00:31:05,300 --> 00:31:07,550
għandha l-aktar impatt matul iż-żmien?

651
00:31:07,550 --> 00:31:11,920
Ln ikbar gets, li
dawn il-materji l-aktar?

652
00:31:11,920 --> 00:31:15,560
>> Fi kliem ieħor, jekk I plug
fil-miljun, n kwadrat

653
00:31:15,560 --> 00:31:17,900
se tkun aktar probabbli
il-fattur dominanti,

654
00:31:17,900 --> 00:31:21,670
għaliex miljun darba
nnifisha hija ħafna akbar

655
00:31:21,670 --> 00:31:23,682
minn bejn wieħed u waħda addizzjonali miljun.

656
00:31:23,682 --> 00:31:24,390
Allura inti taf liema?

657
00:31:24,390 --> 00:31:27,305
Dan huwa tali darn kbir
Numru jekk inti kwadru numru.

658
00:31:27,305 --> 00:31:28,430
Dan ma verament kwistjoni.

659
00:31:28,430 --> 00:31:30,596
Aħna biss jmorru transkonfinali li
out u tinsieh.

660
00:31:30,596 --> 00:31:34,250
U hekk xjenzat kompjuter ngħid
li l-effiċjenza ta 'din l-algoritmu

661
00:31:34,250 --> 00:31:37,850
huwa fuq l-ordni ta 'n squared--
I tfisser verament approssimazzjoni.

662
00:31:37,850 --> 00:31:40,810
Huwa tip ta 'bejn wieħed u ieħor n kwadrat.

663
00:31:40,810 --> 00:31:44,130
Maż-żmien, l-akbar
u n akbar gets, dan

664
00:31:44,130 --> 00:31:47,610
hija stima tajba għal dak l-
effiċjenza jew nuqqas ta 'effiċjenza

665
00:31:47,610 --> 00:31:49,400
ta 'dan algoritmu fil-fatt hu.

666
00:31:49,400 --> 00:31:52,040
U jien jidderivaw li, naturalment,
mill-fatt jagħmlu l-matematika.

667
00:31:52,040 --> 00:31:54,040
Imma issa jien biss waving
idejn tiegħi, minħabba I biss

668
00:31:54,040 --> 00:31:55,790
jridu sens ġenerali ta 'dan algoritmu.

669
00:31:55,790 --> 00:31:58,850
>> Hekk billi tuża l-istess loġika, sadanittant,
ejja jikkunsidraw algoritmu ieħor

670
00:31:58,850 --> 00:32:01,162
aħna diġà ħares at-- tfittxija lineari.

671
00:32:01,162 --> 00:32:02,870
Meta I kien it-tiftix
għall-book-- telefon

672
00:32:02,870 --> 00:32:05,980
mhux issortjar dan, it-tiftix
permezz tat-book-- telefon

673
00:32:05,980 --> 00:32:09,197
aħna miżmuma qal li kien
1,000 passi, jew 500 passi.

674
00:32:09,197 --> 00:32:10,280
Imma ejja jiġġeneralizza din.

675
00:32:10,280 --> 00:32:12,860
Jekk hemm n paġni fil
-ktieb tat-telefon, x'hemm

676
00:32:12,860 --> 00:32:17,250
il running time jew l-
effiċjenza tat-tfittxija lineari?

677
00:32:17,250 --> 00:32:19,750
Huwa fuq l-ordni ta '
kemm passi li ssib

678
00:32:19,750 --> 00:32:24,210
Mike Smith jużaw tfittxija lineari, il-
ewwel algoritmu, jew saħansitra t-tieni?

679
00:32:24,210 --> 00:32:27,240

680
00:32:27,240 --> 00:32:31,710
>> Fl-agħar każ, Mike
hija fl-aħħar tal-ktieb.

681
00:32:31,710 --> 00:32:35,590
Allura jekk il-ktieb tat-telefon tkun 1,000 paġni,
għidna aħħar darba, fl-agħar każ,

682
00:32:35,590 --> 00:32:38,380
jista 'jieħu bejn wieħed u ieħor kif
bosta paġni li ssib Mike?

683
00:32:38,380 --> 00:32:38,990
Bħall 1000.

684
00:32:38,990 --> 00:32:39,830
Huwa ta 'rbit superjuri.

685
00:32:39,830 --> 00:32:41,790
Huwa sitwazzjoni agħar possibbli.

686
00:32:41,790 --> 00:32:44,410
Iżda għal darb'oħra, aħna qed jitbiegħdu
minn numri bħall 1,000 issa.

687
00:32:44,410 --> 00:32:45,730
Huwa biss n.

688
00:32:45,730 --> 00:32:47,470
>> Allura x'inhu l-konklużjoni loġika?

689
00:32:47,470 --> 00:32:50,210
Tfittxija Mike fil-telefon
ktieb li għandu paġni n

690
00:32:50,210 --> 00:32:55,280
tista 'tieħu, fil-ħafna agħar każ,
kemm passi dwar l-ordni ta 'n?

691
00:32:55,280 --> 00:32:58,110
U fil-fatt kompjuter
xjentist ngħid

692
00:32:58,110 --> 00:33:02,340
li l-ħin taħdem, jew il-
prestazzjoni jew effiċjenza

693
00:33:02,340 --> 00:33:07,470
jew ineffiċjenza, ta 'algoriżmu simili
tfittxija lineari huwa fuq l-ordni ta 'n.

694
00:33:07,470 --> 00:33:10,010
U nistgħu japplikaw l-istess
loġika tal-qsim xi ħaġa barra

695
00:33:10,010 --> 00:33:13,170
kif I biss għamlet għat-tieni
algoritmu kellna mal-ktieb tat-telefon,

696
00:33:13,170 --> 00:33:16,040
fejn aħna marru żewġ paġni kull darba.

697
00:33:16,040 --> 00:33:20,120
>> Allura 1000 paġna telefon ktieb jista
jqarrbuna 500 paġna dawriet, u wieħed

698
00:33:20,120 --> 00:33:21,910
jekk irridu doppju lura daqsxejn.

699
00:33:21,910 --> 00:33:26,590
Mela jekk ktieb tat-telefon tkun paġni n, iżda
li aħna qed tagħmel żewġ paġni fi żmien,

700
00:33:26,590 --> 00:33:28,900
dan huwa bejn wieħed u ieħor dak?

701
00:33:28,900 --> 00:33:33,190
N fuq tnejn, b'tali mod li huwa simili nru fuq tnejn.

702
00:33:33,190 --> 00:33:38,490
Imma I għamel it-talba ta '
mument ilu li n matul two--

703
00:33:38,490 --> 00:33:41,060
dak l-tip ta 'l-istess biss bħala n.

704
00:33:41,060 --> 00:33:44,050
Huwa biss fattur kostanti,
xjenzjati tal-kompjuter ngħid.

705
00:33:44,050 --> 00:33:45,970
Ejja biss jiffoka fuq
il-varjabbli, really--

706
00:33:45,970 --> 00:33:47,780
-akbar varjabbli fil-ekwazzjoni.

707
00:33:47,780 --> 00:33:52,530
>> tfittxija Allura lineari, kemm jekk isir wieħed
paġna fi żmien jew żewġ paġni fi żmien,

708
00:33:52,530 --> 00:33:54,810
huwa tip ta fundamentalment l-istess.

709
00:33:54,810 --> 00:33:56,880
Huwa għadu fuq l-ordni ta 'n.

710
00:33:56,880 --> 00:34:01,930
Imma jien tellgħu ma 'stampa tiegħi qabel
li t-tielet algoritmu ma kienx

711
00:34:01,930 --> 00:34:02,480
lineari.

712
00:34:02,480 --> 00:34:03,605
Ma kienx linja dritta.

713
00:34:03,605 --> 00:34:08,659
Kien dik il-linja mgħawġa, u l-
formola alġebrajka hemm kien dak?

714
00:34:08,659 --> 00:34:11,812
Log ta n-- hekk log bażi tnejn n.

715
00:34:11,812 --> 00:34:14,520
U aħna ma jkollhom imorru fis wisq
Dettall ħafna fuq logaritmi illum,

716
00:34:14,520 --> 00:34:17,394
imma ħafna xjenzjati tal-kompjuter ma jkunux jistgħu
anki jgħidlek liema l-bażi hija.

717
00:34:17,394 --> 00:34:20,639
Minħabba dan kollu biss
Fatturi kostanti, biex ngħidu hekk,

718
00:34:20,639 --> 00:34:22,659
biss differenzi numeriċi żgħar.

719
00:34:22,659 --> 00:34:31,179
U għalhekk dan ikun komuni ħafna
triq għal kompjuter partikolarment formali

720
00:34:31,179 --> 00:34:33,949
xjentisti fi abbord jew
programmaturi fuq bord abjad

721
00:34:33,949 --> 00:34:36,889
fil-fatt argumenta li
algoritmu huma se jużaw

722
00:34:36,889 --> 00:34:39,500
jew dak l-effiċjenza
tal algoritmu tagħhom hu.

723
00:34:39,500 --> 00:34:42,960
>> U dan mhux neċessarjament xi ħaġa
int tiddiskuti fid-dettall ħafna,

724
00:34:42,960 --> 00:34:47,889
iżda programmer tajba hija xi ħadd
li jkollha solidu, l-isfond formali.

725
00:34:47,889 --> 00:34:50,120
Hu jista 'jitkellem għal
inti f'dan it-tip ta 'passaġġ

726
00:34:50,120 --> 00:34:53,350
u fil-fatt jagħmlu
argumenti kwalitattivi kif

727
00:34:53,350 --> 00:34:56,870
li tispjega għaliex algoritmu waħda jew
biċċa waħda ta 'softwer

728
00:34:56,870 --> 00:35:00,165
huwa superjuri b'xi mod għall-ieħor.

729
00:35:00,165 --> 00:35:02,540
Għaliex inti tista 'ċertament
biss run program persuna waħda

730
00:35:02,540 --> 00:35:04,980
u jgħodd in-numru ta 'sekonda
li tieħu biex issolvi xi numri,

731
00:35:04,980 --> 00:35:06,710
u inti tista 'taħdem xi
programm persuna l-oħra

732
00:35:06,710 --> 00:35:08,418
u jgħodd in-numru
ta 'sekonda li tieħu.

733
00:35:08,418 --> 00:35:12,840
Iżda dan huwa mod aktar ġenerali li
inti tista 'tuża biex tanalizza algoritmi,

734
00:35:12,840 --> 00:35:15,520
jekk inti se, biss fuq
karta jew biss verbalment.

735
00:35:15,520 --> 00:35:18,430
Anki mingħajr ma ġestjoni tiegħu, mingħajr
saħansitra jippruvaw inputs kampjun,

736
00:35:18,430 --> 00:35:20,180
inti tista 'sempliċement raġuni permezz tiegħu.

737
00:35:20,180 --> 00:35:24,670
U hekk ma kiri iżviluppatur jew jekk
wara lilu jew lilha tip ta jargumentaw għalik

738
00:35:24,670 --> 00:35:28,460
għaliex algoritmu tagħhom, sigrieti tagħhom
zalza għat-tiftix biljuni

739
00:35:28,460 --> 00:35:30,580
ta 'paġni tal-web għall-tiegħek
kumpanija hija aħjar, dawn

740
00:35:30,580 --> 00:35:33,302
huma t-tipi ta 'argumenti li
għandhom idealment ikunu jistgħu jagħmlu.

741
00:35:33,302 --> 00:35:35,010
Jew għall-inqas dawn huma
-tipi ta 'affarijiet

742
00:35:35,010 --> 00:35:40,211
li ser toħroġ fid-diskussjoni, fi
inqas f'diskussjoni formali ħafna.

743
00:35:40,211 --> 00:35:40,710
Kull dritt.

744
00:35:40,710 --> 00:35:44,400
Allura Ben propost xi ħaġa
imsejħa sort għażla.

745
00:35:44,400 --> 00:35:48,200
Imma jien ser nipproponi li hemm
modi oħra ta 'kif isir dan, wisq.

746
00:35:48,200 --> 00:35:50,400
What I ma verament simili
dwar algoritmu Ben

747
00:35:50,400 --> 00:35:54,400
huwa li hu miżmum mixi, jew
wara li lili jimxu, quddiem u lura

748
00:35:54,400 --> 00:35:56,930
u quddiem u lura u quddiem u lura.

749
00:35:56,930 --> 00:36:04,130
X'jiġri jekk minflok jien kienu jagħmlu
xi ħaġa bħal dawn in-numri hawn

750
00:36:04,130 --> 00:36:08,200
u jien kienu biss jittrattaw ma 'kull
Numru mbagħad kif jien taha?

751
00:36:08,200 --> 00:36:10,780
>> Fi kliem ieħor, hawn
Lista tiegħi ta 'numri.

752
00:36:10,780 --> 00:36:12,944
Erba, wieħed, tlieta, tnejn.

753
00:36:12,944 --> 00:36:14,360
U jien ser jagħmlu dan li ġej.

754
00:36:14,360 --> 00:36:17,230
Jien ser daħħal in-numri
fejn huma jappartjenu pjuttost

755
00:36:17,230 --> 00:36:18,980
milli tagħżel minnhom wieħed kull darba.

756
00:36:18,980 --> 00:36:20,820
Fi kliem ieħor, hawnhekk l-numru erbgħa.

757
00:36:20,820 --> 00:36:22,430
>> Hawn lista oriġinali tiegħi.

758
00:36:22,430 --> 00:36:25,290
U jien ser iżommu
essenzjalment lista ġdida hawn.

759
00:36:25,290 --> 00:36:26,710
Allura dan huwa l-lista antika.

760
00:36:26,710 --> 00:36:28,560
Din hija l-lista l-ġdida.

761
00:36:28,560 --> 00:36:30,220
Nara l-għadd erbgħa ewwel.

762
00:36:30,220 --> 00:36:34,500
lista ġdida tiegħi hija inizjalment vojta,
għalhekk huwa trivially il-każ

763
00:36:34,500 --> 00:36:36,410
li erba issa huwa assortiti lista.

764
00:36:36,410 --> 00:36:39,560
Jien biss tieħu l-għadd jien mogħti,
u jien poġġietha fil-lista l-ġdida tiegħi.

765
00:36:39,560 --> 00:36:41,460
>> Huwa din il-lista l-ġdida magħżula?

766
00:36:41,460 --> 00:36:41,990
Yeah.

767
00:36:41,990 --> 00:36:45,090
Huwa stupid għaliex hemm biss wieħed
Element, iżda huwa assolutament magħżula.

768
00:36:45,090 --> 00:36:46,390
M'hemm xejn barra mill-post.

769
00:36:46,390 --> 00:36:49,290
Huwa aktar interessanti, dan algoritmu,
meta nimxi għall-pass li jmiss.

770
00:36:49,290 --> 00:36:50,550
>> Issa I jkollhom waħda.

771
00:36:50,550 --> 00:36:55,430
Allura wieħed, naturalment, tappartjeni fl-
bidu jew it-tmiem ta 'din il-lista l-ġdida?

772
00:36:55,430 --> 00:36:56,360
Il-bidu.

773
00:36:56,360 --> 00:36:58,530
So I jkollhom jagħmlu xi xogħol issa.

774
00:36:58,530 --> 00:37:01,410
Stajt ilhom jieħdu xi
libertajiet ma markatur tiegħi

775
00:37:01,410 --> 00:37:03,120
bi ftit tpinġija affarijiet
fejn irrid minnhom,

776
00:37:03,120 --> 00:37:05,320
iżda li mhux verament
preċiż fil-kompjuter.

777
00:37:05,320 --> 00:37:08,530
A kompjuter, kif nafu, għandha
RAM, jew Random Access Memory,

778
00:37:08,530 --> 00:37:12,411
u li l-byte wieħed u
byte ieħor u byte ieħor.

779
00:37:12,411 --> 00:37:14,910
U jekk ikollok gigabyte ta '
RAM, inti għandek biljun bytes,

780
00:37:14,910 --> 00:37:16,680
iżda dawn qed fiżikament f'post wieħed.

781
00:37:16,680 --> 00:37:19,540
Inti ma tistax biss jiċċaqalqu Jittieħed madwar
billi tinġibed fuq il-bord

782
00:37:19,540 --> 00:37:20,750
fejn trid.

783
00:37:20,750 --> 00:37:24,090
Mela jekk lista l-ġdida tiegħi
erba 'postijiet fil-memorja,

784
00:37:24,090 --> 00:37:27,480
sfortunatament il-erbgħa huwa
diġà fil-post żbaljat.

785
00:37:27,480 --> 00:37:30,410
>> Allura biex daħħal in-numru wieħed
I tista 'mhux biss tiġbed hawn.

786
00:37:30,410 --> 00:37:31,901
Dan il-post Memorja ma teżistix.

787
00:37:31,901 --> 00:37:35,150
Dan ikun qerq, u I ġew
qerq pictorially għal ftit minuti

788
00:37:35,150 --> 00:37:35,800
hawn.

789
00:37:35,800 --> 00:37:40,950
Allura verament, jekk jien tixtieq li tqiegħed wieħed hawn,
Għandi biex temporanjament kopja l-erba '

790
00:37:40,950 --> 00:37:43,030
u mbagħad iwettqu l-waħda hemm.

791
00:37:43,030 --> 00:37:45,500
>> Dik il-multa, li l-korretta,
dan huwa teknikament possibbli,

792
00:37:45,500 --> 00:37:48,410
imma tirrealizza li l-ħidma żejda.

793
00:37:48,410 --> 00:37:50,460
I ma biss jitqiegħed in-numru fil-post.

794
00:37:50,460 --> 00:37:53,026
I l-ewwel kellha timxi għal
numru, mbagħad titqiegħed fil-post,

795
00:37:53,026 --> 00:37:54,650
so I tip ta 'irdoppja ammont tax-xogħol tiegħi.

796
00:37:54,650 --> 00:37:55,660
Sabiex iżommu dan f'moħħhom.

797
00:37:55,660 --> 00:37:57,120
>> Imma jien issa isir ma 'dan l-element.

798
00:37:57,120 --> 00:37:59,056
Issa nixtieq li grab-numru tlieta.

799
00:37:59,056 --> 00:38:00,430
Fejn, naturalment, ma jappartjenix?

800
00:38:00,430 --> 00:38:01,480
Bejn.

801
00:38:01,480 --> 00:38:03,650
I ma jistgħux iqarrqu jibqgħalu
u biss jitqiegħed hemmhekk,

802
00:38:03,650 --> 00:38:06,770
minħabba li, għal darb'oħra, dan il-memorja
huwa fil-postijiet fiżiċi.

803
00:38:06,770 --> 00:38:10,900
So I jkollhom kopja tal-erba '
u tpoġġi l-tlieta minn hawn.

804
00:38:10,900 --> 00:38:11,550
Mhux a big deal.

805
00:38:11,550 --> 00:38:14,610
Huwa biss pass wieħed addizzjonali
again-- iħoss ħafna rħas.

806
00:38:14,610 --> 00:38:16,445
>> Imma issa I jimxu fuq il-tnejn.

807
00:38:16,445 --> 00:38:17,820
It-tnejn, naturalment, tappartjeni hawn.

808
00:38:17,820 --> 00:38:20,990
Issa tibda biex tara kif
-xogħol jista 'pile up.

809
00:38:20,990 --> 00:38:23,520
Issa dak li nagħmel?

810
00:38:23,520 --> 00:38:28,570
Yeah, I għandhom jimxu l-erbgħa,
I mbagħad ikollhom li kopja tal-tlieta,

811
00:38:28,570 --> 00:38:31,200
u issa I tista 'daħħal it-tnejn.

812
00:38:31,200 --> 00:38:34,460
U l-qabda ma 'dan
algoritmu, interessanti biżżejjed,

813
00:38:34,460 --> 00:38:41,050
huwa li jissoponi għandna aktar estremi
każ fejn huwa ejja ngħidu tmienja, seba,

814
00:38:41,050 --> 00:38:45,150
sitta, ħames, erba, tlieta, tnejn, waħda.

815
00:38:45,150 --> 00:38:49,450
Dan huwa, f'ħafna kuntesti,
il agħar xenarju possibbli,

816
00:38:49,450 --> 00:38:51,570
minħabba li l-ħaġa darn
huwa litteralment lura.

817
00:38:51,570 --> 00:38:53,670
>> Hija ma verament
jaffettwaw algoritmu Ben,

818
00:38:53,670 --> 00:38:55,940
minħabba fl-għażla Ben
sort hu għaddej biex iżommu

819
00:38:55,940 --> 00:38:58,359
jmorru quddiem u lura permezz tal-lista.

820
00:38:58,359 --> 00:39:01,150
U għaliex kien dejjem infittxu
permezz tal-lista sħiħa jifdal,

821
00:39:01,150 --> 00:39:02,858
ma jimpurtax
fejn l-elementi jkunu.

822
00:39:02,858 --> 00:39:05,630
Iżda f'dan il-każ ma ddaħħal tiegħi
approach-- ejja tipprova dan.

823
00:39:05,630 --> 00:39:08,616
>> Allura wieħed, tnejn, tlieta, erba,
ħames, sitt, seba ', tmien.

824
00:39:08,616 --> 00:39:11,630
Wieħed, tnejn, tlieta, erba,
ħames, sitt, seba ', tmien.

825
00:39:11,630 --> 00:39:14,320
Jien ser tieħu l-tmien,
u fejn ma nressaq dan?

826
00:39:14,320 --> 00:39:17,260
Ukoll, fil-bidu tal-lista tiegħi,
għaliex din il-lista l-ġdida huwa magħżul.

827
00:39:17,260 --> 00:39:18,760
U jien jaqsmu out.

828
00:39:18,760 --> 00:39:20,551
>> Fejn nista 'tpoġġi l-seba?

829
00:39:20,551 --> 00:39:21,050
Darn dan.

830
00:39:21,050 --> 00:39:23,174
Jeħtieġ li jmorru hemm, hekk
Għandi biex jagħmlu xi ikkupjar.

831
00:39:23,174 --> 00:39:26,820

832
00:39:26,820 --> 00:39:28,480
U issa l-seba tmur hawn.

833
00:39:28,480 --> 00:39:29,860
Issa jien jimxu fuq il-sitta.

834
00:39:29,860 --> 00:39:30,980
Issa huwa saħansitra aktar xogħol.

835
00:39:30,980 --> 00:39:32,570
>> Tmienja irid imur hawn.

836
00:39:32,570 --> 00:39:33,920
Sebgħa irid imur hawn.

837
00:39:33,920 --> 00:39:35,450
Issa sitt tista 'tmur hawn.

838
00:39:35,450 --> 00:39:37,950
Now I grab-ħamsa.

839
00:39:37,950 --> 00:39:40,560
Issa l-tmien irid imur
hawn, seba irid imur hawn,

840
00:39:40,560 --> 00:39:43,650
sitta irid imur hawn, u
issa l-ħames u ripetuti.

841
00:39:43,650 --> 00:39:46,610
U jien pretty ħafna
jmexxuh kontinwament.

842
00:39:46,610 --> 00:39:52,950
>> Għalhekk fl-aħħar, din il algorithm-- aħna ser
sejħa hija inserzjoni sort-- attwalment

843
00:39:52,950 --> 00:39:55,020
għandha ħafna ta 'xogħol, wisq.

844
00:39:55,020 --> 00:39:56,970
Huwa biss differenti
tip ta 'xogħol minn Ben.

845
00:39:56,970 --> 00:40:00,090
xogħol Ben kellu me going
quddiem u lura l-ħin kollu,

846
00:40:00,090 --> 00:40:03,510
għażla tal-iżgħar li jiġi wara
Element ġdid u għal darb'oħra.

847
00:40:03,510 --> 00:40:06,660
Allura kien dan it-tip ħafna viżwali ta 'xogħol.

848
00:40:06,660 --> 00:40:10,600
>> Dan il algoritmu ieħor, li għadu
correct-- dan se x-xogħol done--

849
00:40:10,600 --> 00:40:12,800
biss bidliet l-ammont ta 'xogħol.

850
00:40:12,800 --> 00:40:15,420
Jidher qisu inizjalment int
iffrankar, għax int biss

851
00:40:15,420 --> 00:40:19,190
jittrattaw ma 'kull element
bil-quddiem mingħajr mixi kollha

852
00:40:19,190 --> 00:40:20,930
-triq permezz tal-lista simili Ben kien.

853
00:40:20,930 --> 00:40:25,300
Iżda l-problema hija, speċjalment f'dawn
F'każijiet crazy fejn dan kollu lura,

854
00:40:25,300 --> 00:40:27,830
int biss tip ta '
jipposponi x-xogħol iebes

855
00:40:27,830 --> 00:40:30,360
sakemm ikollok biex jiffissaw iżbalji tiegħek.

856
00:40:30,360 --> 00:40:33,919
>> U hekk jekk inti tista 'timmaġina dan il
tmienja u sebgħa u sitt u ħames

857
00:40:33,919 --> 00:40:36,710
u aktar tard erba 'u tlieta u tnejn
jiċċaqilqu mod tagħhom permezz tal-lista,

858
00:40:36,710 --> 00:40:39,060
konna biss biddel il-
tip ta 'xogħol li aħna qed tagħmel.

859
00:40:39,060 --> 00:40:42,340
Minflok tagħmel dan fil-
bidu ta 'iterazzjoni tiegħi,

860
00:40:42,340 --> 00:40:45,250
Jien biss tagħmel dan fil-
aħħar ta 'kull iterazzjoni.

861
00:40:45,250 --> 00:40:50,550
Għalhekk jirriżulta li dan algoritmu,
wisq, ġeneralment imsejħa sort inserzjoni,

862
00:40:50,550 --> 00:40:52,190
huwa wkoll fuq l-ordni ta 'n kwadrat.

863
00:40:52,190 --> 00:40:56,480
Huwa fil-fatt ebda aħjar,
ebda aħjar fil-livelli kollha.

864
00:40:56,480 --> 00:41:00,810
>> Madankollu, hemm it-tielet approċċ
Nixtieq jinkoraġġixi lilna biex tikkunsidra,

865
00:41:00,810 --> 00:41:02,970
li hija din.

866
00:41:02,970 --> 00:41:07,850
Allura jissoponi lista tiegħi, għas-sempliċità
darb'oħra, huwa erba, wieħed, tlieta,

867
00:41:07,850 --> 00:41:11,080
two-- biss erba 'numri.

868
00:41:11,080 --> 00:41:13,300
Ben kellhom intwizzjoni tajba,
intwizzjoni bniedem tajjeb

869
00:41:13,300 --> 00:41:16,340
qabel, li permezz tiegħu aħna fiss kollu
lista eventually-- sort inserzjoni.

870
00:41:16,340 --> 00:41:18,020
I coaxed magħna flimkien.

871
00:41:18,020 --> 00:41:22,530
Imma ejja jikkunsidraw il-
Mod sempliċi biex jiffissaw din il-lista.

872
00:41:22,530 --> 00:41:24,110
>> Din il-lista mhix riżolta.

873
00:41:24,110 --> 00:41:26,130
Għaliex?

874
00:41:26,130 --> 00:41:31,920
Bl-Ingliż, spjega għaliex
mhuwiex fil-fatt magħżula.

875
00:41:31,920 --> 00:41:33,400
Xi jfisser li ma għandux magħżula?

876
00:41:33,400 --> 00:41:34,220
>> STUDENT: Mhuwiex sekwenzali.

877
00:41:34,220 --> 00:41:34,990
>> DAVID Malan: Mhux sekwenzjali.

878
00:41:34,990 --> 00:41:35,822
Agħti me eżempju.

879
00:41:35,822 --> 00:41:37,180
>> STUDENT: Tpoġġihom fl-ordni.

880
00:41:37,180 --> 00:41:37,440
>> DAVID Malan: OK.

881
00:41:37,440 --> 00:41:38,790
Agħti me eżempju aktar speċifiku.

882
00:41:38,790 --> 00:41:39,832
>> STUDENT: f'ordni axxendenti.

883
00:41:39,832 --> 00:41:41,206
DAVID Malan: Mhux axxendenti ordni.

884
00:41:41,206 --> 00:41:42,100
Ikunu aktar preċiżi.

885
00:41:42,100 --> 00:41:45,190
I do not know dak li jfisser minn axxendenti.

886
00:41:45,190 --> 00:41:47,150
X'hemm ħażin?

887
00:41:47,150 --> 00:41:49,930
>> STUDENT: L-iżgħar ta 'l-
numri mhuwiex fl-ewwel ispazju.

888
00:41:49,930 --> 00:41:51,140
>> DAVID Malan:-iżgħar numru ta
mhux fl-ewwel ispazju.

889
00:41:51,140 --> 00:41:52,120
Tkun aktar speċifika.

890
00:41:52,120 --> 00:41:55,000
Jien jibdew qabda.

891
00:41:55,000 --> 00:41:59,470
Aħna qed isserraħ, iżda
x'hemm barra ta 'ordni hawn?

892
00:41:59,470 --> 00:42:00,707
>> STUDENT: sekwenza numerika.

893
00:42:00,707 --> 00:42:02,040
DAVID Malan: sekwenza numerika.

894
00:42:02,040 --> 00:42:04,248
tip 'kulħadd ta' żamma
dan here-- livell għoli ħafna.

895
00:42:04,248 --> 00:42:07,450
Biss litteralment tell me x'hemm
ħażin bħal-jista 'ħames snin qodma.

896
00:42:07,450 --> 00:42:08,310
>> STUDENT: Plus wieħed.

897
00:42:08,310 --> 00:42:08,750
>> DAVID Malan: X'hemm li?

898
00:42:08,750 --> 00:42:09,610
>> STUDENT: Plus wieħed.

899
00:42:09,610 --> 00:42:11,235
>> DAVID Malan: X'tifhem u wieħed?

900
00:42:11,235 --> 00:42:12,754

901
00:42:12,754 --> 00:42:14,170
Agħti me differenti ħames snin qodma.

902
00:42:14,170 --> 00:42:16,840

903
00:42:16,840 --> 00:42:18,330
X'hemm ħażin, mom?

904
00:42:18,330 --> 00:42:19,940
X'hemm ħażin, dad?

905
00:42:19,940 --> 00:42:22,808
X'tifhem dan mhux magħżula?

906
00:42:22,808 --> 00:42:24,370
>> STUDENT: Mhuwiex l-post it-tajjeb.

907
00:42:24,370 --> 00:42:25,580
>> DAVID Malan: X'hemm
mhux fil-post it-tajjeb?

908
00:42:25,580 --> 00:42:26,174
>> STUDENT: Erba.

909
00:42:26,174 --> 00:42:27,090
DAVID Malan: OK, tajba.

910
00:42:27,090 --> 00:42:29,110
Allura erba mhuwiex meta dan għandu jkun.

911
00:42:29,110 --> 00:42:30,590
B'mod partikolari, huwa dan id-dritt?

912
00:42:30,590 --> 00:42:33,000
Erba u wieħed, l-ewwel
żewġ numri nara.

913
00:42:33,000 --> 00:42:34,930
Huwa dan id-dritt?

914
00:42:34,930 --> 00:42:36,427
Le, dawn qed out of order, id-dritt?

915
00:42:36,427 --> 00:42:38,135
Fil-fatt, naħseb issa
dwar kompjuter, wisq.

916
00:42:38,135 --> 00:42:40,824
Hija tista 'tħares biss lejn forsi waħda,
forsi żewġ affarijiet fil once--

917
00:42:40,824 --> 00:42:43,240
u fil-fatt biss ħaġa waħda
fi żmien, iżda jista 'mill-inqas

918
00:42:43,240 --> 00:42:45,790
tħares lejn ħaġa waħda allura l-
Ħaġa li jmiss dritt li jmiss lilu.

919
00:42:45,790 --> 00:42:47,380
>> Allura huma dawn fl-ordni?

920
00:42:47,380 --> 00:42:48,032
Mhux ovvja li le.

921
00:42:48,032 --> 00:42:48,740
Allura inti taf liema?

922
00:42:48,740 --> 00:42:51,020
Għaliex ma nieħdu tarbija
passi li jiffissaw din il-problema

923
00:42:51,020 --> 00:42:53,410
minflok tagħmel dawn fancy
algoritmi bħal Ben, fejn

924
00:42:53,410 --> 00:42:56,440
hu tip ta 'iffissar dan billi
looping permezz tal-lista

925
00:42:56,440 --> 00:42:59,670
minflok tagħmel dak li għamilt, fejn
I biss tip ta 'iffissat kif immorru?

926
00:42:59,670 --> 00:43:03,650
Ejja biss litteralment tkisser il
kunċett ta 'ordni numeriku order--,

927
00:43:03,650 --> 00:43:06,990
sejħa hija tkun xi tkun want--
f'dawn il-paraguni pairwise.

928
00:43:06,990 --> 00:43:07,590
>> Erba 'u wieħed.

929
00:43:07,590 --> 00:43:09,970
Huwa dan l-ordni korretta?

930
00:43:09,970 --> 00:43:11,310
Mela ejja jiffissaw dak.

931
00:43:11,310 --> 00:43:14,700
Wieħed u erba, u mbagħad
aħna ser biss kopja dak.

932
00:43:14,700 --> 00:43:15,560
Kull dritt, tajba.

933
00:43:15,560 --> 00:43:17,022
I fiss wieħed u erbgħa.

934
00:43:17,022 --> 00:43:18,320
Tliet u żewġ?

935
00:43:18,320 --> 00:43:18,820
No

936
00:43:18,820 --> 00:43:21,690
Ħalli kliem tiegħi jaqblu swaba tiegħi.

937
00:43:21,690 --> 00:43:23,695
Erba 'u tliet?

938
00:43:23,695 --> 00:43:27,930
>> Mhuwiex sabiex, hekk jien ser
biex jagħmlu waħda, tlieta, erba ', tnejn.

939
00:43:27,930 --> 00:43:28,680
OK tajjeb.

940
00:43:28,680 --> 00:43:32,310
Issa erba 'u tnejn?

941
00:43:32,310 --> 00:43:33,370
Għandna bżonn biex jiffissaw dan, wisq.

942
00:43:33,370 --> 00:43:36,700
Allura wieħed, tlieta, tnejn, erbgħa.

943
00:43:36,700 --> 00:43:39,820
Allura huwa magħżul?

944
00:43:39,820 --> 00:43:43,170
Le, imma huwa eqreb lejn magħżula?

945
00:43:43,170 --> 00:43:48,930
>> Huwa, għaliex aħna fissi din il
żball, aħna fiss dan l-iżball,

946
00:43:48,930 --> 00:43:50,370
u aħna fissi dan l-iżball.

947
00:43:50,370 --> 00:43:52,420
Allura aħna fiss tliet żbalji forsi.

948
00:43:52,420 --> 00:43:58,100
Still ma verament tħares magħżula, iżda
huwa oġġettivament eqreb li mifthiema

949
00:43:58,100 --> 00:44:00,080
għaliex aħna fiss xi wħud minn dawk l-iżbalji.

950
00:44:00,080 --> 00:44:02,047
>> Issa x'għandi nagħmel jmiss?

951
00:44:02,047 --> 00:44:03,630
I tip ta 'laħqu t-tmiem tal-lista.

952
00:44:03,630 --> 00:44:05,680
I deher li iffissaw
l-iżbalji, iżda l-ebda.

953
00:44:05,680 --> 00:44:08,510
Minħabba f'dan il-każ, xi numri
setgħet effervexxentement up eqreb

954
00:44:08,510 --> 00:44:10,410
għal numri oħra li
għadhom out of order.

955
00:44:10,410 --> 00:44:12,951
Mela ejja tagħmel dan mill-ġdid, u jien ser
biss tagħmel dan fil-post f'dan il-ħin.

956
00:44:12,951 --> 00:44:14,170
Wieħed u tlieta?

957
00:44:14,170 --> 00:44:14,720
Huwa tal-multa.

958
00:44:14,720 --> 00:44:16,070
Tliet u żewġ?

959
00:44:16,070 --> 00:44:17,560
Naturalment l-ebda, so ejja jibdlu din.

960
00:44:17,560 --> 00:44:19,160
Allura tnejn, tlieta.

961
00:44:19,160 --> 00:44:21,340
Tlieta u erbgħa?

962
00:44:21,340 --> 00:44:24,370
U issa ejja biss ikunu
partikolarment pedantic hawn.

963
00:44:24,370 --> 00:44:26,350
Huwa magħżula?

964
00:44:26,350 --> 00:44:29,280
Inti bnedmin taf huwa riżolta.

965
00:44:29,280 --> 00:44:30,400
>> I għandu erġa 'pprova.

966
00:44:30,400 --> 00:44:31,900
Allura Olivia qed tipproponi I erġa 'pprova.

967
00:44:31,900 --> 00:44:32,530
Għaliex?

968
00:44:32,530 --> 00:44:35,810
Minħabba kompjuter m'għandux għalfejn
l-lussu ta għajnejn tal-bniedem tagħna

969
00:44:35,810 --> 00:44:38,080
ta 'ftit glancing back-- OK, jien jsir.

970
00:44:38,080 --> 00:44:41,610
Kif il-kompjuter jiddetermina
li l-lista issa huwa magħżul?

971
00:44:41,610 --> 00:44:44,590
Mekkanikament.

972
00:44:44,590 --> 00:44:47,650
>> I għandhom jgħaddu
għal darba oħra, u biss jekk I

973
00:44:47,650 --> 00:44:51,190
ma jagħmlu / issib xi żbalji nista
imbagħad tikkonkludi bħala l-kompjuter, Yep,

974
00:44:51,190 --> 00:44:51,980
aħna qed tajba biex tmur.

975
00:44:51,980 --> 00:44:54,850
Allura wieħed u tnejn, tnejn u
tlieta, tlieta u erbgħa.

976
00:44:54,850 --> 00:44:58,030
Issa nista 'ngħid definittiv li dan huwa
magħżula, minħabba I għamel l-ebda tibdil.

977
00:44:58,030 --> 00:45:01,940
Issa ikun bug u biss
foolish jekk I, il-kompjuter,

978
00:45:01,940 --> 00:45:05,640
staqsa dawk l-istess domandi mill-ġdid
jistennew tweġibiet differenti.

979
00:45:05,640 --> 00:45:07,110
Jekk ma jiġri.

980
00:45:07,110 --> 00:45:08,600
>> U għalhekk issa l-lista magħżula.

981
00:45:08,600 --> 00:45:12,630
Sfortunatament, running time ta
din il algoritmu huwa wkoll n kwadrat.

982
00:45:12,630 --> 00:45:13,130
Għaliex?

983
00:45:13,130 --> 00:45:19,520
Minħabba li għandek numri n, u fil-
agħar każ għandek timxi n-numri

984
00:45:19,520 --> 00:45:23,637
n drabi għax għandek biex jibqgħu għaddejjin
lura biex jiċċekkja u potenzjalment tiffissa

985
00:45:23,637 --> 00:45:24,220
dawn in-numri.

986
00:45:24,220 --> 00:45:26,280
U nistgħu nagħmlu aktar
analiżi formali, wisq.

987
00:45:26,280 --> 00:45:29,530
>> Allura din hija kollha li ngħidu aħna ħadt
tliet approċċi differenti, wieħed

988
00:45:29,530 --> 00:45:32,210
minnhom immedjatament intuwittivi
barra l-BAT minn Ben

989
00:45:32,210 --> 00:45:35,170
biex inserzjoni ssuġġerit tiegħi
sort għal dan wieħed

990
00:45:35,170 --> 00:45:38,540
fejn inti tip ta nitilfu
l-foresti, għas-siġar inizjalment.

991
00:45:38,540 --> 00:45:41,760
Imma mbagħad jekk inti tieħu pass lura,
voila, konna ffissati l-kunċett issortjar.

992
00:45:41,760 --> 00:45:43,824
Allura dan huwa, DARE ngħidu,
livell aktar baxx forsi

993
00:45:43,824 --> 00:45:45,740
minn xi wħud minn dawk l-oħra
algoritmi, imma ejja

994
00:45:45,740 --> 00:45:48,550
ara jekk ma nkunux nistgħu Ħares
dawn permezz ta 'dan il-.

995
00:45:48,550 --> 00:45:51,450
>> Allura dan huwa xi sympathique
software li xi ħadd

996
00:45:51,450 --> 00:45:56,110
kiteb jużaw bars mlewna C'est
se jagħmlu dan li ġej għalina.

997
00:45:56,110 --> 00:45:57,736
Kull wieħed minn dawn il-vireg jirrappreżenta għadd.

998
00:45:57,736 --> 00:46:00,026
Taller il-bar, l-akbar
in-numru, iżgħar fost il-bar,

999
00:46:00,026 --> 00:46:00,990
l-iżgħar numru.

1000
00:46:00,990 --> 00:46:05,880
Allura idealment rridu piramida sympathique
fejn hija tibda żgħar u gets kbar,

1001
00:46:05,880 --> 00:46:08,330
u dan ikun ifisser li
dawn il-vireg huma magħżula.

1002
00:46:08,330 --> 00:46:11,200
Hekk jien ser jimxi 'l quddiem u jagħżlu,
per eżempju, algoritmu Ben

1003
00:46:11,200 --> 00:46:13,990
sort għażla first--.

1004
00:46:13,990 --> 00:46:16,220
>> U avviż dak li qed jagħmel.

1005
00:46:16,220 --> 00:46:18,670
Il-mod li ħadthom għażlu li
Ħares din il algoritmu

1006
00:46:18,670 --> 00:46:22,090
hija li, bħad I kien
mixi permezz ta 'lista tiegħi,

1007
00:46:22,090 --> 00:46:24,710
dan il-programm huwa mixi
permezz ta 'lista tagħha ta' numri,

1008
00:46:24,710 --> 00:46:28,160
tenfasizza b'mod roża f'kull
numru li huwa tħares lejn.

1009
00:46:28,160 --> 00:46:32,360
U x'hemm sejjer iseħħ id-dritt issa?

1010
00:46:32,360 --> 00:46:35,154
>> L-iżgħar numru li
I jew Ben misjuba f'daqqa

1011
00:46:35,154 --> 00:46:36,820
gets jiċċaqalqu lejn il-bidu tal-lista.

1012
00:46:36,820 --> 00:46:40,037
U bl-Avviż huma għamlu tkeċċi
in-numru li kien hemm,

1013
00:46:40,037 --> 00:46:41,120
u li l-perfettament multa.

1014
00:46:41,120 --> 00:46:42,600
I ma jsibu rwieħhom dak il-livell ta 'dettall.

1015
00:46:42,600 --> 00:46:44,308
Iżda neħtieġu npoġġu
dak in-numru x'imkien,

1016
00:46:44,308 --> 00:46:47,775
hekk aħna biss mċaqalqa lill-
post miftuħ li nħolqot.

1017
00:46:47,775 --> 00:46:49,900
Hekk jien ser iħaffu dan il
up, għax inkella

1018
00:46:49,900 --> 00:46:51,871
isir ħafna tedious malajr.

1019
00:46:51,871 --> 00:46:55,800

1020
00:46:55,800 --> 00:46:58,600
Animazzjoni speed-- hemm immorru.

1021
00:46:58,600 --> 00:47:01,850
Allura issa istess prinċipju
I kien qed japplika, imma int

1022
00:47:01,850 --> 00:47:06,540
tista 'tibda tħossok l-algoritmu, jekk inti
se, jew jarawha ftit aktar ċar.

1023
00:47:06,540 --> 00:47:13,190
U dan algoritmu għandha l-effett li
għażla tal-element li jkun imiss iżgħar,

1024
00:47:13,190 --> 00:47:16,422
hekk int ser jibdew
jarah rampa fuq ix-xellug.

1025
00:47:16,422 --> 00:47:19,130
U fuq kull iterazzjoni, kif jien
proposta, ma 'xogħol ftit inqas.

1026
00:47:19,130 --> 00:47:21,921
Huwa ma jkollu li jmorru it-triq kollha
lura għall-aħħar tax-xellug tal-lista,

1027
00:47:21,921 --> 00:47:23,900
għaliex diġà
jaf dawk huma magħżula.

1028
00:47:23,900 --> 00:47:28,129
Għalhekk tip ta jħoss simili huwa
aċċellerazzjoni, anki jekk kull pass huwa

1029
00:47:28,129 --> 00:47:29,420
tieħu l-istess ammont ta 'ħin.

1030
00:47:29,420 --> 00:47:31,600
Hemm passi biss inqas fadal.

1031
00:47:31,600 --> 00:47:35,240
U issa inti tista 'tip ta' jħossu l-
algoritmu tindif tal-aħħar ta 'dan,

1032
00:47:35,240 --> 00:47:37,040
u tabilħaqq issa huwa magħżula.

1033
00:47:37,040 --> 00:47:41,620
>> Allura tip inserzjoni huwa magħmul.

1034
00:47:41,620 --> 00:47:43,600
I-ħtieġa li terġa 'randomize l-array.

1035
00:47:43,600 --> 00:47:45,940
U Avviż nista biss
iżommu randomizing dan,

1036
00:47:45,940 --> 00:47:50,630
u aħna ser jiksbu approssimazzjoni tal
l-istess approċċ, sort inserzjoni.

1037
00:47:50,630 --> 00:47:55,050
Let me bil-mod l-isfel sa hawn.

1038
00:47:55,050 --> 00:47:56,915
Nibdew dan fuq.

1039
00:47:56,915 --> 00:47:57,414
Stop.

1040
00:47:57,414 --> 00:48:00,662

1041
00:48:00,662 --> 00:48:02,410
>> Ejja skip erbgħa.

1042
00:48:02,410 --> 00:48:03,200
Hemm immorru.

1043
00:48:03,200 --> 00:48:04,190
Randomize huma firxa.

1044
00:48:04,190 --> 00:48:05,555
U hawn aħna go-- tip inserzjoni.

1045
00:48:05,555 --> 00:48:10,260

1046
00:48:10,260 --> 00:48:12,800
Play.

1047
00:48:12,800 --> 00:48:17,280
Avviż li huwa li jittrattaw ma 'kull
Element dan jiltaqa dritt bogħod,

1048
00:48:17,280 --> 00:48:20,282
imma jekk jappartjeni fl
l-avviż post żbaljat

1049
00:48:20,282 --> 00:48:21,740
kollha tal-ħidma li għandu jiġri.

1050
00:48:21,740 --> 00:48:24,700
Irridu iżommu ċaqliq aktar
u aktar elementi li jagħmlu kamra

1051
00:48:24,700 --> 00:48:27,340
l-waħda aħna tixtieq li tqiegħed fis-seħħ.

1052
00:48:27,340 --> 00:48:30,740
>> Allura aħna qed jiffokaw fuq il-
tmiem tax-xellug tal-lista biss.

1053
00:48:30,740 --> 00:48:34,460
Avviż aħna lanqas biss ħarsu at-- aħna
ma enfasizzati fil-xejn roża

1054
00:48:34,460 --> 00:48:35,610
lejn il-lemin.

1055
00:48:35,610 --> 00:48:38,180
Aħna biss jittrattaw
il-problemi kif immorru,

1056
00:48:38,180 --> 00:48:40,430
imma aħna qed joħolqu ħafna ta '
xogħol għalina għadu.

1057
00:48:40,430 --> 00:48:44,410
U hekk jekk aħna iħaffu dan up
issa biex tmur tlestija,

1058
00:48:44,410 --> 00:48:46,210
hija għandu jħossu differenti għaliha tabilħaqq.

1059
00:48:46,210 --> 00:48:50,150
Huwa sempliċement jiffukaw fuq l-aħħar xellug imma
tagħmel xogħol ftit aktar bħala needed--

1060
00:48:50,150 --> 00:48:53,230
tip ta 'affarijiet twittija
fuq, li jiffissa l-affarijiet,

1061
00:48:53,230 --> 00:48:58,350
iżda jittrattaw fl-aħħar ma
kull element wieħed fi żmien

1062
00:48:58,350 --> 00:49:07,740
sakemm aħna jiksbu l the-- sew, aħna
lkoll nafu kif dan se jispiċċaw,

1063
00:49:07,740 --> 00:49:09,700
għalhekk huwa underwhelming ftit forsi.

1064
00:49:09,700 --> 00:49:12,830
>> Iżda l-lista fil-end--
spoiler-- se jiġu magħżula.

1065
00:49:12,830 --> 00:49:15,300
Mela ejja nħarsu lejn l-aħħar wieħed wieħed.

1066
00:49:15,300 --> 00:49:16,840
Ma nistgħux sempliċement skip issa.

1067
00:49:16,840 --> 00:49:18,000
Aħna kważi hemm.

1068
00:49:18,000 --> 00:49:19,980
Żewġ tmur, wieħed li jmorru.

1069
00:49:19,980 --> 00:49:22,680
U voila.

1070
00:49:22,680 --> 00:49:23,450
Eċċellenti.

1071
00:49:23,450 --> 00:49:27,220
>> Allura issa ejja nagħmlu aħħar wieħed wieħed,
jerġa 'randomizing ma bużżieqa tip.

1072
00:49:27,220 --> 00:49:31,690
U avviż hawn, speċjalment jekk jien bil-mod l
isfel, dan ma jżomm swooping permezz.

1073
00:49:31,690 --> 00:49:36,830
Iżda avviż hija biss jagħmel pairwise
tip comparisons-- ta 'soluzzjonijiet lokali.

1074
00:49:36,830 --> 00:49:39,050
Iżda hekk kif aħna nikseb biex
l-aħħar tal-lista fl-roża,

1075
00:49:39,050 --> 00:49:40,690
x'inhu għaddej li jkollhom jerġa 'jiġri?

1076
00:49:40,690 --> 00:49:44,539

1077
00:49:44,539 --> 00:49:46,830
Yeah, li għaddej biex ikollhom
tibda fuq, għaliex biss

1078
00:49:46,830 --> 00:49:49,870
żbalji fissi pairwise.

1079
00:49:49,870 --> 00:49:53,120
U li jista wrew saħansitra f'oħrajn.

1080
00:49:53,120 --> 00:49:58,950
U hekk jekk inti tħaffef dan up, inti ser
tara li, kemm jista 'jimplika l-isem,

1081
00:49:58,950 --> 00:50:01,870
l-iżgħar elements-- jew aħjar,
l elements-- akbar qed jibdew

1082
00:50:01,870 --> 00:50:03,740
bużżieqa sal-quċċata, jekk inti se.

1083
00:50:03,740 --> 00:50:07,380
U l-elementi iżgħar huma
jibdew bużżieqa isfel lejn ix-xellug.

1084
00:50:07,380 --> 00:50:10,780
U fil-fatt, dan huwa tip ta '
l-effett viżwali kif ukoll.

1085
00:50:10,780 --> 00:50:17,150
U hekk dan se jispiċċaw irfinar
b'mod simili ħafna, wisq.

1086
00:50:17,150 --> 00:50:19,160
>> Aħna ma jkollhom biex nitkellem
fuq dan wieħed partikolari.

1087
00:50:19,160 --> 00:50:21,010
Let me tiftaħ dan issa, wisq.

1088
00:50:21,010 --> 00:50:24,040
Hemm ftit algoritmi oħra issortjar
fid-dinja, xi ftit minnhom

1089
00:50:24,040 --> 00:50:25,580
jinqabdu hawn.

1090
00:50:25,580 --> 00:50:29,960
U speċjalment għal studenti li mhumiex
neċessarjament viżwali jew matematiċi,

1091
00:50:29,960 --> 00:50:31,930
kif għamilna qabel, nistgħu
ukoll tagħmel dan audially

1092
00:50:31,930 --> 00:50:34,210
jekk aħna jassoċjaw ħoss ma 'dan.

1093
00:50:34,210 --> 00:50:36,990
U biss għall-gost, Heres
algoritmi differenti ftit,

1094
00:50:36,990 --> 00:50:40,950
u wieħed minnhom b'mod partikolari int
ser avviż huwa msejjaħ "tip jingħaqdu."

1095
00:50:40,950 --> 00:50:43,250
>> Hija fil-fatt huwa fundamentalment
algoritmu aħjar,

1096
00:50:43,250 --> 00:50:45,860
b'tali mod li jingħaqdu sort, wieħed mill
dawk int ser tara,

1097
00:50:45,860 --> 00:50:49,170
mhuwiex ordni ta 'n kwadrat.

1098
00:50:49,170 --> 00:50:57,280
Huwa fuq l-ordni ta 'n darbiet log ta
n, li huwa attwalment iżgħar u għalhekk

1099
00:50:57,280 --> 00:50:58,940
aktar mgħaġġla minn dawk it-tliet ieħor.

1100
00:50:58,940 --> 00:51:00,670
U hemm koppja oħra
dawk iblah li aħna ser tara.

1101
00:51:00,670 --> 00:51:01,933
>> Allura here we go ma 'xi ħoss.

1102
00:51:01,933 --> 00:51:06,620

1103
00:51:06,620 --> 00:51:10,490
Dan huwa tip inserzjoni, hekk darb'oħra
huwa biss jittrattaw l-elementi

1104
00:51:10,490 --> 00:51:13,420
kif dawn jidħlu.

1105
00:51:13,420 --> 00:51:17,180
Dan huwa bużżieqa tip, dan huwa
tqishom pari kull darba.

1106
00:51:17,180 --> 00:51:22,030

1107
00:51:22,030 --> 00:51:24,490
U għal darb'oħra, l-akbar elementi
huma tbaqbieq sal-quċċata.

1108
00:51:24,490 --> 00:51:38,098

1109
00:51:38,098 --> 00:51:41,710
>> Issa jmiss sort għażla.

1110
00:51:41,710 --> 00:51:45,420
Dan huwa algoritmu Ben, fejn
darb'oħra hu għażla iteratively

1111
00:51:45,420 --> 00:51:46,843
-iżgħar li jiġi element.

1112
00:51:46,843 --> 00:51:49,801

1113
00:51:49,801 --> 00:51:53,900
U għal darb'oħra, issa inti tista 'verament tisma li
huwa tħaffif imma biss safejn

1114
00:51:53,900 --> 00:51:58,230
kif huwa qed jagħmel inqas u inqas
xogħol fuq kull iterazzjoni.

1115
00:51:58,230 --> 00:52:04,170
Dan huwa l-aktar mgħaġġel waħda, jingħaqdu sort,
li hija l-għażla gruppi ta 'numri

1116
00:52:04,170 --> 00:52:05,971
flimkien u mbagħad jingħaqdu.

1117
00:52:05,971 --> 00:52:07,720
Allura look-- ix-xellug
nofs huwa diġà magħżula.

1118
00:52:07,720 --> 00:52:14,165
>> Issa huwa l-issortjar in-nofs id-dritt, u
issa li għaddej biex jinġabru flimkien f'waħda.

1119
00:52:14,165 --> 00:52:19,160
Din hija xi ħaġa imsejħa "Gnome tip."

1120
00:52:19,160 --> 00:52:23,460
U inti tista 'tip ta' tara li
li għaddej quddiem u lura,

1121
00:52:23,460 --> 00:52:27,950
iffissar xogħol ftit hawn u
hemm qabel ma tipproċedi għat tax-xogħol ġdid.

1122
00:52:27,950 --> 00:52:32,900

1123
00:52:32,900 --> 00:52:33,692
U li hu.

1124
00:52:33,692 --> 00:52:36,400
Hemm tip ieħor, li hija
verament ftit għal skopijiet akkademiċi,

1125
00:52:36,400 --> 00:52:40,980
imsejħa "tip stupid," li tieħu
data tiegħek, xorta huwa saltwarjament,

1126
00:52:40,980 --> 00:52:43,350
u mbagħad tiċċekkja jekk ikun magħżul.

1127
00:52:43,350 --> 00:52:47,880
U jekk ma jkunx, għandu jerġa 'xorta li
saltwarjament, kontrolli jekk huwa magħżula,

1128
00:52:47,880 --> 00:52:49,440
u jekk mhux jirrepeti.

1129
00:52:49,440 --> 00:52:52,660
U fit-teorija, probabilistically
dan se jitlesta,

1130
00:52:52,660 --> 00:52:54,140
iżda wara pjuttost ftit ta 'żmien.

1131
00:52:54,140 --> 00:52:56,930
Mhuwiex l-aktar
effiċjenti ta 'algoritmi.

1132
00:52:56,930 --> 00:53:02,550
Allura xi mistoqsijiet dwar dawk
Algoritmi partikolari jew xejn

1133
00:53:02,550 --> 00:53:04,720
relatat hemm, wisq?

1134
00:53:04,720 --> 00:53:09,430
>> Ukoll, ejja issa tease apparti dak kollu
dawn il-linji huma li stajt ġiet tfassil

1135
00:53:09,430 --> 00:53:15,090
u dak li jien jassumi l-kompjuter
tista 'tagħmel taħt il-barnuża.

1136
00:53:15,090 --> 00:53:18,650
Nixtieq jargumentaw li kollha ta 'dawn in-numri
I iżommu drawing-- li għandhom bżonn biex jiksbu

1137
00:53:18,650 --> 00:53:21,330
maħżuna x'imkien fil-memorja.

1138
00:53:21,330 --> 00:53:24,130
Aħna ser teħles minn dan Guy issa, wisq.

1139
00:53:24,130 --> 00:53:30,110
>> Allura biċċa ta 'memorja fil-
computer-- hekk RAM DIMM huwa

1140
00:53:30,110 --> 00:53:35,480
dak li aħna mfittxija bieraħ, doppju
Memorja inline module-- tidher bħal dan.

1141
00:53:35,480 --> 00:53:39,370
U kull wieħed minn dawn iċ-ċipep iswed ftit
hija xi numru ta 'bytes, tipikament.

1142
00:53:39,370 --> 00:53:44,380
U allura l-labar deheb huma simili l-
wajers li jgħaqqdu lill-kompjuter,

1143
00:53:44,380 --> 00:53:47,521
u l-bord tas-silikon aħdar huwa biss
dak li jżomm kollox kollha flimkien.

1144
00:53:47,521 --> 00:53:48,770
Allura dak li jfisser dan verament tfisser?

1145
00:53:48,770 --> 00:53:53,180
Jekk I tip ta tiġbed dan l-istess stampa,
ejja nassumu għas-sempliċità

1146
00:53:53,180 --> 00:53:55,280
li dan DIMM, doppju
modulu tal-memorja inline,

1147
00:53:55,280 --> 00:54:00,530
huwa gigabyte wieħed ta 'RAM, gigabyte wieħed mill
memorja, li hija kemm bytes totali?

1148
00:54:00,530 --> 00:54:02,100
Wieħed gigabyte huwa kemm bytes?

1149
00:54:02,100 --> 00:54:04,860

1150
00:54:04,860 --> 00:54:06,030
Aktar minn dak.

1151
00:54:06,030 --> 00:54:09,960
1124 hija kilo, 1000.

1152
00:54:09,960 --> 00:54:11,730
Mega hija miljun.

1153
00:54:11,730 --> 00:54:14,570
Giga hija biljun.

1154
00:54:14,570 --> 00:54:15,070
>> Am I li tinsab?

1155
00:54:15,070 --> 00:54:16,670
Nistgħu anke taqra t-tikketta?

1156
00:54:16,670 --> 00:54:19,920
Dan huwa attwalment 128
gigabytes, dan huwa aktar.

1157
00:54:19,920 --> 00:54:22,130
Iżda aħna ser nippretendu din il
huwa biss wieħed gigabyte.

1158
00:54:22,130 --> 00:54:25,640
Allura dan ifisser hemm biljun
bytes ta 'memorja disponibbli għalija

1159
00:54:25,640 --> 00:54:29,770
jew 8 biljun bits, iżda aħna qed tmur
li nitkellmu f'termini ta 'bytes issa,

1160
00:54:29,770 --> 00:54:30,750
miexja 'l quddiem.

1161
00:54:30,750 --> 00:54:36,330
>> Allura dak li jfisser hu li dan huwa
byte wieħed, dan huwa byte ieħor,

1162
00:54:36,330 --> 00:54:38,680
dan huwa byte ieħor,
u jekk aħna verament riedu

1163
00:54:38,680 --> 00:54:43,280
li jkunu speċifiċi rridu naraw li
jiġbed biljun kwadri ftit.

1164
00:54:43,280 --> 00:54:44,320
Imma dak ma jfisser?

1165
00:54:44,320 --> 00:54:46,420
Well, let me biss zoom
fil dwar din l-istampa.

1166
00:54:46,420 --> 00:54:50,900
Jekk Stajt ltqajna xi ħaġa li tidher
bħal dan issa, li l-erba 'bytes.

1167
00:54:50,900 --> 00:54:53,710
>> U hekk I tista 'tpoġġi erba' numri hawn.

1168
00:54:53,710 --> 00:54:54,990
Wieħed, tnejn, tlieta, erba '.

1169
00:54:54,990 --> 00:55:00,170
Jew I tista 'tpoġġi erba' ittri jew simboli.

1170
00:55:00,170 --> 00:55:02,620
"Ħej!" tista 'tmur hemm dritt,
minħabba kull waħda mill-ittri,

1171
00:55:02,620 --> 00:55:04,370
aħna diskussa aktar kmieni,
jista 'jkun rappreżentat

1172
00:55:04,370 --> 00:55:06,650
bi tmien bits jew ASCII jew byte.

1173
00:55:06,650 --> 00:55:09,370
Allura fi kliem ieħor, inti tista '
jitqiegħdu 8 biljun affarijiet ġewwa

1174
00:55:09,370 --> 00:55:11,137
ta 'dan stick wieħed ta' memorja.

1175
00:55:11,137 --> 00:55:14,345
Issa dak ma jfisser li l-affarijiet lura
biex lura biex lura fil-memorja bħal din?

1176
00:55:14,345 --> 00:55:17,330
Dan huwa dak programmer
kieku ssejjaħ għal "matriċi."

1177
00:55:17,330 --> 00:55:21,250
Fi programm tal-kompjuter, inti ma naħsibx
dwar il-hardware sottostanti, per se.

1178
00:55:21,250 --> 00:55:24,427
Inti biss jaħsbu ta 'lilek innifsek bħala li
aċċess għal total biljun bytes,

1179
00:55:24,427 --> 00:55:26,010
u inti tista 'xi ħaġa li trid magħha.

1180
00:55:26,010 --> 00:55:27,880
Iżda għall-konvenjenza
huwa ġeneralment utli

1181
00:55:27,880 --> 00:55:31,202
li jżomm id-dritt memorja tiegħek
ħdejn xulxin bħal dan.

1182
00:55:31,202 --> 00:55:33,660
Mela jekk jien zoom fl fuq this--
għaliex aħna qed ċertament mhux ser

1183
00:55:33,660 --> 00:55:39,310
tiġbed biljun squares-- ftit
ejja nassumu li dan il-bord jirrappreżenta

1184
00:55:39,310 --> 00:55:40,610
li twaħħal tal-memorja issa.

1185
00:55:40,610 --> 00:55:43,800
U jien ser biss jiġbed daqs tiegħi
markatur jispiċċa tajtu lili hawn.

1186
00:55:43,800 --> 00:55:46,420

1187
00:55:46,420 --> 00:55:52,300
Allura issa għandna stick
tal-memorja fuq il-bord

1188
00:55:52,300 --> 00:55:56,400
li ltqajna wieħed, tnejn, tlieta, erba ', ħames,
sitta, wieħed, tnejn, tlieta, erba ', ħames, sitt,

1189
00:55:56,400 --> 00:56:01,130
seven-- hekk 42 bytes ta
memorja fuq it-total iskrin.

1190
00:56:01,130 --> 00:56:01,630
Grazzi.

1191
00:56:01,630 --> 00:56:02,838
Iva, kont aritmetika tiegħi dritt.

1192
00:56:02,838 --> 00:56:05,120
Allura 42 bytes ta 'memorja hawn.

1193
00:56:05,120 --> 00:56:06,660
Allura dak li jfisser dan fil-fatt jfisser?

1194
00:56:06,660 --> 00:56:09,830
Ukoll, programmer kompjuter
fil-fatt ġeneralment

1195
00:56:09,830 --> 00:56:12,450
think ta 'dan memorja bħala indirizzabbli.

1196
00:56:12,450 --> 00:56:16,630
Fi kliem ieħor, kull wieħed minn dawn
postijiet fil-memorja, fil-hardware,

1197
00:56:16,630 --> 00:56:18,030
għandu indirizz uniku.

1198
00:56:18,030 --> 00:56:22,020
>> Mhuwiex daqshekk kumplessa bħal Wieħed BRATTLE
Pjazza, Cambridge, Mass., 02138.

1199
00:56:22,020 --> 00:56:23,830
Minflok, huwa biss numru.

1200
00:56:23,830 --> 00:56:27,930
Dan huwa byte in-numru żero, dan huwa
wieħed, dan huwa tnejn, dan huwa tlieta,

1201
00:56:27,930 --> 00:56:30,327
u dan huwa 41.

1202
00:56:30,327 --> 00:56:30,910
Stenna minuta.

1203
00:56:30,910 --> 00:56:32,510
Ħsibt I said 42 mument ilu.

1204
00:56:32,510 --> 00:56:35,050

1205
00:56:35,050 --> 00:56:37,772
I bdew jingħaddu għal żero,
b'tali mod li l-fatt korretta.

1206
00:56:37,772 --> 00:56:40,980
Issa aħna ma jkollhomx biex effettivament tiġbed
bħala grilja, u jekk inti tiġbed bħala grilja

1207
00:56:40,980 --> 00:56:43,520
Naħseb affarijiet attwalment
jiksbu daqsxejn qarrieqa.

1208
00:56:43,520 --> 00:56:46,650
Liema programmer ikun,
fil-memorja tiegħu jew tagħha stess,

1209
00:56:46,650 --> 00:56:50,310
ġeneralment jaħsbu ta 'dan il-
memorja kif huwa biss bħal tejp,

1210
00:56:50,310 --> 00:56:53,340
bħal biċċa ta 'masking tejp
li biss tmur fuq u fuq għal dejjem

1211
00:56:53,340 --> 00:56:54,980
jew sakemm inti jispiċċaw ta 'memorja.

1212
00:56:54,980 --> 00:56:59,200
Allura mod aktar komuni biex tiġbed
u biss jaħsbu dwar memorja

1213
00:56:59,200 --> 00:57:03,710
ikun li dan huwa byte żero, wieħed,
tnejn, tlieta, u mbagħad dot, dot, dot.

1214
00:57:03,710 --> 00:57:07,650
U inti għandek 42 bytes tali totali, anke
għalkemm fiżikament għandu mnejn attwalment

1215
00:57:07,650 --> 00:57:09,480
tkun xi ħaġa aktar bħal din.

1216
00:57:09,480 --> 00:57:12,850
>> Mela jekk inti issa taħseb tiegħek
memorja peress li dan, bħad tejp,

1217
00:57:12,850 --> 00:57:17,640
dan huwa dak programmer ġdid
kieku ssejjaħ firxa ta 'memorja.

1218
00:57:17,640 --> 00:57:20,660
U meta inti tixtieq li attwalment jaħżnu
xi ħaġa fil-memorja tal-kompjuter,

1219
00:57:20,660 --> 00:57:23,290
inti ġeneralment tagħmel taħżen affarijiet
Back-to-back lill-back-to-back.

1220
00:57:23,290 --> 00:57:25,010
Allura aħna kont qed jitkellem dwar in-numri.

1221
00:57:25,010 --> 00:57:30,880
U meta jien ridt li ssolvi l-problemi
bħal erbgħa, wieħed, tlieta, tnejn,

1222
00:57:30,880 --> 00:57:33,820
anki jekk I kien biss tpinġija
biss il-numri erbgħa, wieħed, tlieta,

1223
00:57:33,820 --> 00:57:39,490
tnejn fuq il-bord, il-kompjuter se
verament ikollhom dan il setup fil-memorja.

1224
00:57:39,490 --> 00:57:43,347
>> U dak li jkun ħdejn il-
tnejn fil-memorja tal-kompjuter?

1225
00:57:43,347 --> 00:57:44,680
Ukoll, hemm ebda risposta għal din.

1226
00:57:44,680 --> 00:57:45,770
Aħna ma verament jafu.

1227
00:57:45,770 --> 00:57:48,200
U sakemm l-
kompjuter ma bżonnha,

1228
00:57:48,200 --> 00:57:51,440
ma jkollhiex kura dak li huwa li jmiss
għan-numri li tagħmel ħsieb dwar.

1229
00:57:51,440 --> 00:57:55,130
U meta għidt qabel li l-kompjuter
tista 'tħares biss lejn indirizz wieħed fi żmien,

1230
00:57:55,130 --> 00:57:56,170
dan huwa tip ta 'għaliex.

1231
00:57:56,170 --> 00:57:59,490
>> Mhux b'differenza rekord
player u ras qari

1232
00:57:59,490 --> 00:58:03,030
biss tkun tista 'tħares lejn ċertu
kanal fi rekord fiżika qodma l-iskola

1233
00:58:03,030 --> 00:58:06,500
fi żmien, bl-istess mod
jista 'kompjuter grazzi

1234
00:58:06,500 --> 00:58:09,810
biex CPU tiegħu u tagħha
Intel sett istruzzjoni,

1235
00:58:09,810 --> 00:58:12,480
fost li istruzzjoni
jinqara mill-memorja

1236
00:58:12,480 --> 00:58:15,590
jew ħlief għal memory-- għal
kompjuter tista 'biss tfittex

1237
00:58:15,590 --> 00:58:19,210
fil-post wieħed kull time--
kultant kombinazzjoni ta 'dawn,

1238
00:58:19,210 --> 00:58:21,770
imma verament waħda biss post kull darba.

1239
00:58:21,770 --> 00:58:24,770
Allura meta aħna kienu qed jagħmlu
dawn id-diversi algoritmi,

1240
00:58:24,770 --> 00:58:28,110
Jien mhux biss bil-miktub fi
vacuum-- erba, wieħed, tlieta, tnejn.

1241
00:58:28,110 --> 00:58:30,849
Dawk in-numri fil-fatt jappartjenu
x'imkien fiżika fil-memorja.

1242
00:58:30,849 --> 00:58:32,890
Allura hemm ftit żgħira
transisters jew xi tip

1243
00:58:32,890 --> 00:58:35,840
tal-elettronika taħtha l
barnuża ħażna dawn il-valuri.

1244
00:58:35,840 --> 00:58:40,460
>> U f'totali, kemm bits huma
involut dritt issa, biss biex tkun ċara?

1245
00:58:40,460 --> 00:58:45,580
Allura dan huwa erba 'bytes, jew
issa huwa 32 bits totali.

1246
00:58:45,580 --> 00:58:49,280
Allura hemm attwalment 32 żerijiet u
Dawk li jikkomponu dawn l-erba 'affarijiet.

1247
00:58:49,280 --> 00:58:52,070
Hemm saħansitra aktar hawn, iżda
darb'oħra aħna ma jimpurtahom dwar dan.

1248
00:58:52,070 --> 00:58:55,120
>> Allura issa ejja jistaqsu ieħor
kwistjoni bl-użu tal-memorja,

1249
00:58:55,120 --> 00:58:57,519
minħabba li fl-aħħar
tal-ġurnata hija fil varjanza.

1250
00:58:57,519 --> 00:59:00,310
Ma jimpurtax dak li nistgħu nagħmlu mal
il-kompjuter, fl-aħħar tal-ġurnata

1251
00:59:00,310 --> 00:59:02,560
il-hardware għadu l-
istess taħt il-barnuża.

1252
00:59:02,560 --> 00:59:04,670
Kif inkun taħżen kelma fil hawn?

1253
00:59:04,670 --> 00:59:09,710
Ukoll, kelma fil-kompjuter bħal
"Ħej!" se tkun maħżuna biss bħal din.

1254
00:59:09,710 --> 00:59:12,300
U jekk inti riedu itwal
kelma, inti tista 'sempliċement

1255
00:59:12,300 --> 00:59:19,120
jissostitwixxu dak u jgħidu xi ħaġa
bħal "bonjour" u maħżen li hawn.

1256
00:59:19,120 --> 00:59:23,930
>> U hekk hawn, wisq, dan contiguousness
huwa attwalment ta 'vantaġġ,

1257
00:59:23,930 --> 00:59:26,530
minħabba kompjuter tista 'sempliċement
aqra mill-lemin għax-xellug.

1258
00:59:26,530 --> 00:59:28,680
Iżda hawn l-mistoqsija.

1259
00:59:28,680 --> 00:59:33,480
Fil-kuntest ta 'din il-kelma,
h e-l-l-o, punt exclamation,

1260
00:59:33,480 --> 00:59:38,740
kif tista 'l-kompjuter taf fejn il-
kelma jibda u fejn jintemm il-kelma?

1261
00:59:38,740 --> 00:59:41,690

1262
00:59:41,690 --> 00:59:43,800
Fil-kuntest ta 'numri,
kif ma 'l-kompjuter

1263
00:59:43,800 --> 00:59:48,396
taf kemm żmien il-sekwenza ta '
numri huwa jew fejn jibda?

1264
00:59:48,396 --> 00:59:50,270
Ukoll, jirriżulta out--
u aħna mhux se jmorru wisq

1265
00:59:50,270 --> 00:59:54,970
fis dan il-livell ta 'detail--
Kompjuters jimxu Jittieħed madwar fil-memorja

1266
00:59:54,970 --> 00:59:57,800
litteralment permezz ta 'dawn l-indirizzi.

1267
00:59:57,800 --> 01:00:02,080
Allura fil-kompjuter, jekk int
miktub kodiċi li jaħżnu l-affarijiet

1268
01:00:02,080 --> 01:00:05,800
bħal kliem, dak li int
verament tagħmel huwa ittajpjar

1269
01:00:05,800 --> 01:00:11,320
espressjonijiet li tiftakar meta fil
memorja tal-kompjuter dawn il-kliem huma.

1270
01:00:11,320 --> 01:00:14,370
So let me do ħafna,
Eżempju sempliċi ħafna.

1271
01:00:14,370 --> 01:00:18,260
>> Jien ser jimxi 'l quddiem u
jiftħu program test sempliċi,

1272
01:00:18,260 --> 01:00:20,330
u jien ser joħolqu
fajl imsejjaħ hello.c.

1273
01:00:20,330 --> 01:00:22,849
Ħafna minn din l-informazzjoni aħna
mhux se tidħol fis f'dettall kbir,

1274
01:00:22,849 --> 01:00:25,140
imma jien ser jiktbu
programm f'dik il-lingwa,

1275
01:00:25,140 --> 01:00:31,140
C. Dan huwa ferm aktar intimidanti,
Nixtieq jargumentaw, minn Scratch,

1276
01:00:31,140 --> 01:00:32,490
imma hija simili ħafna fl-ispirtu.

1277
01:00:32,490 --> 01:00:34,364
Fil-fatt, dawn kaboċċi
braces-- inti tista tip ta

1278
01:00:34,364 --> 01:00:37,820
think ta 'dak I biss ma dan.

1279
01:00:37,820 --> 01:00:39,240
>> Ejja nagħmlu dan, fil-fatt.

1280
01:00:39,240 --> 01:00:45,100
Meta bandiera aħdar għafast,
tagħmel dan li ġej.

1281
01:00:45,100 --> 01:00:50,210
Irrid li jistampa "bonjour."

1282
01:00:50,210 --> 01:00:51,500
Allura issa din hija pseudocode.

1283
01:00:51,500 --> 01:00:53,000
Jien tip ta 'ċajpir-linji.

1284
01:00:53,000 --> 01:00:56,750
Fl Ċ, din il-lingwa jien jitkellem
dwar, dan l-istampar linja bonjour

1285
01:00:56,750 --> 01:01:01,940
fil-fatt isir "printf" ma
xi parentesi u semi-colon.

1286
01:01:01,940 --> 01:01:03,480
>> Imma hija l-istess idea eżatt.

1287
01:01:03,480 --> 01:01:06,730
U dan ħafna faċli għall-utent
"Meta flag aħdar għafast" isir

1288
01:01:06,730 --> 01:01:10,182
l ferm aktar arcane "nulli prinċipali int."

1289
01:01:10,182 --> 01:01:12,890
U dan verament għandha l-ebda immappjar,
hekk jien biss se jinjora dan.

1290
01:01:12,890 --> 01:01:17,210
Iżda l-braces kaboċċi huma simili l-
biċċiet puzzle mgħawġa bħal dan.

1291
01:01:17,210 --> 01:01:18,700
>> Allura inti tista 'tip ta' raden.

1292
01:01:18,700 --> 01:01:22,357
Anke jekk inti stajt qatt programmati qabel,
dak ma dan il-programm probabbilment jagħmlu?

1293
01:01:22,357 --> 01:01:25,560

1294
01:01:25,560 --> 01:01:28,000
Probabbilment prints bonjour
ma 'punt exclamation.

1295
01:01:28,000 --> 01:01:29,150
>> Mela ejja jippruvaw dan.

1296
01:01:29,150 --> 01:01:30,800
Jien ser tiffranka.

1297
01:01:30,800 --> 01:01:34,000
U dan huwa, għal darb'oħra, ħafna
ambjent tal-iskola antika.

1298
01:01:34,000 --> 01:01:35,420
I ma tista 'tikklikkja, I ma tista' ttawwal.

1299
01:01:35,420 --> 01:01:36,910
Għandi biex jikkmanda tip.

1300
01:01:36,910 --> 01:01:41,320
So I tixtieq li run program tiegħi, so
I tista 'tagħmel dan, bħall hello.c.

1301
01:01:41,320 --> 01:01:42,292
Dik hija l-inkartament I dam.

1302
01:01:42,292 --> 01:01:43,500
Imma stenna, jien nieqsa pass.

1303
01:01:43,500 --> 01:01:46,470
What did ngħidu huwa neċessarju
pass għal lingwa bħal C?

1304
01:01:46,470 --> 01:01:49,470
Stajt biss sors miktub
kodiċi, imma dak li għandi bżonn?

1305
01:01:49,470 --> 01:01:50,670
Yeah, I bżonn kompilatur.

1306
01:01:50,670 --> 01:01:57,670
Allura fuq Mac tiegħi hawn, għandi
programm imsejjaħ GCC, GNU Ċ kompilatur,

1307
01:01:57,670 --> 01:02:03,990
li tippermetti lili biex tagħmel this-- dawran
sors tiegħi kodiċi fis, aħna ser sejħa hija,

1308
01:02:03,990 --> 01:02:04,930
kodiċi tal-magna.

1309
01:02:04,930 --> 01:02:10,180
>> UI jista 'jara li,
darb'oħra, kif ġej, dawn

1310
01:02:10,180 --> 01:02:14,090
huma żerijiet u dawk I biss
maħluqa mill-kodiċi sors tiegħi,

1311
01:02:14,090 --> 01:02:15,730
kollha ta 'l-żerijiet u dawk.

1312
01:02:15,730 --> 01:02:17,770
U jekk jien tixtieq li run
tiegħi program-- dan jiġri

1313
01:02:17,770 --> 01:02:23,010
li għandu jissejjaħ a.out għall
reasons-- storiku "bonjour."

1314
01:02:23,010 --> 01:02:24,070
I tista 'taħdem mill-ġdid.

1315
01:02:24,070 --> 01:02:25,690
Hello, bonjour, bonjour.

1316
01:02:25,690 --> 01:02:27,430
U jidher li tkun qed taħdem.

1317
01:02:27,430 --> 01:02:31,000
>> Iżda dan ifisser x'imkien fil tiegħi
memorja tal-kompjuter huma l-kliem

1318
01:02:31,000 --> 01:02:35,279
h e-l--l o, punt exclamation.

1319
01:02:35,279 --> 01:02:38,070
U jirriżulta li, hekk bħala twarrib,
dak kompjuter kieku tipikament

1320
01:02:38,070 --> 01:02:40,550
jagħmlu b'tali mod li jaf fejn
affarijiet jibdew u end-- huwa

1321
01:02:40,550 --> 01:02:42,460
se timplimenta simbolu speċjali hawn.

1322
01:02:42,460 --> 01:02:46,064
U l-konvenzjoni huwa li tpoġġi l-
Numru żero fl-aħħar ta 'kelma

1323
01:02:46,064 --> 01:02:48,230
sabiex tkun taf fejn
fil-fatt jintemm, sabiex inti

1324
01:02:48,230 --> 01:02:52,750
ma jżommux istampar aktar u aktar
karattri mill inti fil-fatt il-ħsieb.

1325
01:02:52,750 --> 01:02:55,400
>> Iżda l-takeaway hawn, anke
għalkemm dan huwa pjuttost arcane,

1326
01:02:55,400 --> 01:02:58,140
hija li huwa finalment
relattivament sempliċi.

1327
01:02:58,140 --> 01:03:04,550
Inti ġew mogħtija tip ta 'tejp, vojt
spazju fuqha tista 'tikteb ittri.

1328
01:03:04,550 --> 01:03:07,150
Inti sempliċiment għandek jkollhom
simbolu speċjali, bħal b'mod arbitrarju

1329
01:03:07,150 --> 01:03:10,316
in-numru żero, li tqiegħed fi tmiem l-
kliem tiegħek hekk li l-kompjuter jaf,

1330
01:03:10,316 --> 01:03:13,410
oh, I għandu jieqaf istampar wara
Nara l-punt exclamation.

1331
01:03:13,410 --> 01:03:16,090
Minħabba li l-ħaġa li jmiss hemmhekk
hija valur ASCII ta 'żero,

1332
01:03:16,090 --> 01:03:19,125
jew il-karattru nulli bħala
xi ħadd kieku ssejjaħ dan.

1333
01:03:19,125 --> 01:03:21,500
Iżda hemm tip ta 'problema
hawn, u ejja jerġa 'lura

1334
01:03:21,500 --> 01:03:23,320
għal numri għal mument.

1335
01:03:23,320 --> 01:03:28,720
Ejja ngħidu li nagħmel, fil-fatt,
għandhom firxa ta 'numri,

1336
01:03:28,720 --> 01:03:30,730
u jissoponi li l
programm jien bil-miktub huwa

1337
01:03:30,730 --> 01:03:34,680
bħal ktieb grad ta 'għalliem
u għalliema klassi.

1338
01:03:34,680 --> 01:03:38,720
U dan il-programm jippermetti lilu jew lilha
it-tip fil-punteġġi istudenti tagħhom

1339
01:03:38,720 --> 01:03:39,960
fuq kwizzijiet.

1340
01:03:39,960 --> 01:03:43,750
U jissoponi li l-istudent gets
100 fuq ewwel kwizz tagħhom, forsi

1341
01:03:43,750 --> 01:03:49,920
bħal 80 fuq dak li jmiss, allura
75, imbagħad 90 dwar ir-raba kwizz.

1342
01:03:49,920 --> 01:03:54,150
>> Allura f'dan il-punt fl-istorja,
il-firxa hija ta 'daqs erbgħa.

1343
01:03:54,150 --> 01:03:58,470
Hemm memorja assolutament aktar fil-
kompjuter, iżda l-firxa, biex ngħidu hekk,

1344
01:03:58,470 --> 01:04:00,350
hija ta 'daqs erbgħa.

1345
01:04:00,350 --> 01:04:06,060
Ejja ngħidu issa li l-għalliem irid
li tassenja wieħed minn ħamsa kwizz għall-klassi.

1346
01:04:06,060 --> 01:04:08,510
Ukoll, waħda mill-affarijiet li
jew hi se jkollhom jagħmlu

1347
01:04:08,510 --> 01:04:10,650
huwa issa jaħżnu valur addizzjonali hawn.

1348
01:04:10,650 --> 01:04:15,490
Iżda jekk il-firxa tal-għalliem għandu
maħluqa f'dan il-programm huwa ta 'daqs għall-

1349
01:04:15,490 --> 01:04:22,440
wieħed mill-problema ma 'firxa hija li
inti tista 'mhux biss ikompli jżid mal-memorja.

1350
01:04:22,440 --> 01:04:26,470
Minħabba dak li jekk f'parti oħra tad-
programm għandu l-kelma "ħej" hemm dritt?

1351
01:04:26,470 --> 01:04:29,650
>> Fi kliem ieħor, memorja tiegħi jista 'jkun
użat għal kwalunkwe ħaġa fi programm.

1352
01:04:29,650 --> 01:04:33,250
U jekk qabel I ittajpjat fil, ħej,
Irrid li l-input erba punteġġi kwizz,

1353
01:04:33,250 --> 01:04:34,784
dawn jistgħu jmorru hawn u hawn.

1354
01:04:34,784 --> 01:04:37,700
U jekk f'daqqa waħda tbiddel moħħok
wara, u jgħidu Irrid wieħed minn ħamsa kwizz

1355
01:04:37,700 --> 01:04:40,872
punteġġ, inti ma tistax sempliċement
poġġih fejn inti tixtieq,

1356
01:04:40,872 --> 01:04:42,580
għaliex dak jekk dan
Memorja qed tintuża

1357
01:04:42,580 --> 01:04:45,990
għal xi ħaġa else-- xi programm ieħor
jew xi karatteristika oħra tal-programm

1358
01:04:45,990 --> 01:04:46,910
li int taħdem?

1359
01:04:46,910 --> 01:04:50,650
Allura inti għandek taħseb minn qabel
kif inti tixtieq li jaħżen id-data tiegħek,

1360
01:04:50,650 --> 01:04:54,480
għaliex issa inti stajt miżbugħa
lilek innifsek fis-kantuniera diġitali.

1361
01:04:54,480 --> 01:04:57,280
>> Allura għalliem jista minflok
jgħidu meta kitba ta 'programm

1362
01:04:57,280 --> 01:04:59,360
taħżen tiegħu jew tagħha
gradi, inti taf liema?

1363
01:04:59,360 --> 01:05:04,180
I am ser jitolbu,
meta tikteb programm tiegħi,

1364
01:05:04,180 --> 01:05:12,070
li nixtieq żero, wieħed, tnejn, tlieta,
erba, ħames, sitt, tmien gradi total.

1365
01:05:12,070 --> 01:05:15,320
Allura wieħed, tnejn, tlieta, erba,
ħames, sitt, seba ', tmien.

1366
01:05:15,320 --> 01:05:18,612
L-għalliem jista 'ftit aktar minn jallokaw
Memorja meta tikteb programm tiegħu jew tagħha

1367
01:05:18,612 --> 01:05:19,570
u jgħidu, inti taf liema?

1368
01:05:19,570 --> 01:05:22,236
Jien qatt ma ser tassenja aktar
minn tmien kwizzijiet fi semestru.

1369
01:05:22,236 --> 01:05:23,130
Li jinsab biss crazy.

1370
01:05:23,130 --> 01:05:24,470
Jien qatt ma ser jalloka dik.

1371
01:05:24,470 --> 01:05:28,270
Allura li dan il-mod hu jew hi għandu l-
flessibilità biex punteġġi taħżen istudenti,

1372
01:05:28,270 --> 01:05:33,010
bħall 75, 90, u forsi waħda żejda fejn
l-istudent ltqajna kreditu żejda, 105.

1373
01:05:33,010 --> 01:05:36,130
>> Imma jekk l-għalliem qatt
tuża dawn it-tliet spazji,

1374
01:05:36,130 --> 01:05:38,860
hemm takeaway intuwittivi hawn.

1375
01:05:38,860 --> 01:05:41,410
Hu jew hi huwa biss ħela ispazju.

1376
01:05:41,410 --> 01:05:44,790
Allura fi kliem ieħor, hemm dan
tradeoff komuni fil-programmazzjoni

1377
01:05:44,790 --> 01:05:48,241
fejn inti tista 'jew talloka
eżattament kemm memorja kif trid,

1378
01:05:48,241 --> 01:05:51,490
il rasu tagħha huwa li int super
efficient-- int ma tkun ħela

1379
01:05:51,490 --> 01:05:54,640
fil all-- iżda l-tnaqqis tagħhom
huwa dak li jekk inti tbiddel moħħok meta

1380
01:05:54,640 --> 01:05:58,780
użu tal-programm li inti tixtieq li taħżen
dejta aktar milli suppost oriġinarjament maħsub.

1381
01:05:58,780 --> 01:06:03,030
>> Allura forsi l-soluzzjoni hija, imbagħad,
jiktbu programmi tiegħek b'tali mod

1382
01:06:03,030 --> 01:06:05,605
li huma jużaw memorja aktar
milli huma attwalment ħtieġa.

1383
01:06:05,605 --> 01:06:07,730
Dan il-mod int mhux ser
li jinżel fit din il-problema,

1384
01:06:07,730 --> 01:06:09,730
imma int qed ħela.

1385
01:06:09,730 --> 01:06:12,960
U l-memorja aktar programm tiegħek juża,
kif iddiskutejna bieraħ, l-inqas

1386
01:06:12,960 --> 01:06:15,410
memorja li ikunu disponibbli
għal programmi oħra,

1387
01:06:15,410 --> 01:06:18,790
l-ewwel kompjuter tiegħek jista 'jnaqqas
minħabba r memorja virtwali.

1388
01:06:18,790 --> 01:06:22,670
U hekk is-soluzzjoni ideali tista 'tkun liema?

1389
01:06:22,670 --> 01:06:24,610
>> Nuqqas ta 'jiġu allokati jidher ħażin.

1390
01:06:24,610 --> 01:06:27,030
Over-jiġu allokati jidher ħażin.

1391
01:06:27,030 --> 01:06:31,120
Allura dak li jista 'jkun soluzzjoni aħjar?

1392
01:06:31,120 --> 01:06:32,390
Allokazzjoni mill-ġdid.

1393
01:06:32,390 --> 01:06:33,590
Tkun aktar dinamiku.

1394
01:06:33,590 --> 01:06:37,520
Ma seħħ lilek innifsek biex jagħżlu
priori, fil-bidu, dak li trid.

1395
01:06:37,520 --> 01:06:41,370
U ċertament ma over-jalloka,
lest inti tkun ħela.

1396
01:06:41,370 --> 01:06:45,770
>> U dan biex jintlaħaq dak l-għan, aħna
bżonn li tarmi din l-istruttura tad-data,

1397
01:06:45,770 --> 01:06:48,100
biex ngħidu hekk, 'il bogħod.

1398
01:06:48,100 --> 01:06:51,080
U iva, liema programmer
tipikament se jużaw

1399
01:06:51,080 --> 01:06:55,940
huwa xi ħaġa imsejħa mhijiex
firxa iżda lista marbuta.

1400
01:06:55,940 --> 01:07:00,860
Fi kliem ieħor, hu jew hi se
jibdew jaħsbu memorja tagħhom

1401
01:07:00,860 --> 01:07:05,280
bħala tip ta 'forma li huma
jista 'jiġbed fil-mod li ġej.

1402
01:07:05,280 --> 01:07:08,520
Jekk irrid li jaħżen numru wieħed fil
a program-- hekk huwa f'Settembru,

1403
01:07:08,520 --> 01:07:12,600
Stajt mogħtija istudenti tiegħi kwizz; Irrid
li jaħżen ewwel kwizz l-istudenti,

1404
01:07:12,600 --> 01:07:16,220
u dawn ltqajna 100 fuq it-- I
vais jistaqsu kompjuter tiegħi,

1405
01:07:16,220 --> 01:07:19,540
permezz tal-programm stajt
miktub, għal blokki wieħed ta 'memorja.

1406
01:07:19,540 --> 01:07:22,570
U jien ser taħżen l-
Numru 100 fiha, u li hu.

1407
01:07:22,570 --> 01:07:24,820
>> Imbagħad ftit ġimgħat wara
meta nasal tieni kwizz tiegħi,

1408
01:07:24,820 --> 01:07:27,890
u wasal iż-żmien għat-tip
f'dak 90%, jiena ser

1409
01:07:27,890 --> 01:07:32,129
li jitlob lill-kompjuter, ħej, kompjuter,
nista 'jkollhom blokki ieħor ta' memorja?

1410
01:07:32,129 --> 01:07:34,170
Huwa ser tagħti me dan il
blokki vojta ta 'memorja.

1411
01:07:34,170 --> 01:07:39,370
Jien ser jitqiegħdu fil-numru 90,
iżda fil-programm tiegħi b'xi jew other--

1412
01:07:39,370 --> 01:07:42,100
u aħna mhux se joqogħdu jinkwetaw dwar
il sintassi għall this-- I bżonn

1413
01:07:42,100 --> 01:07:44,430
li b'xi mod katina dawn l-affarijiet flimkien.

1414
01:07:44,430 --> 01:07:47,430
U jien ser katina flimkien ma '
dak qisu vleġġa hawn.

1415
01:07:47,430 --> 01:07:50,050
>> It-tielet kwizz li jitla ',
Jien se ngħid, ħej, kompjuter,

1416
01:07:50,050 --> 01:07:51,680
agħtini blokki ieħor ta 'memorja.

1417
01:07:51,680 --> 01:07:54,660
U jien ser jħott
kwalunkwe kien, bħal 75,

1418
01:07:54,660 --> 01:07:56,920
u I għandhom katina din il
flimkien issa b'xi.

1419
01:07:56,920 --> 01:08:00,290
Ir-Raba 'kwizz tidħol flimkien, u forsi
dak l lejn it-tmiem tas-semestru.

1420
01:08:00,290 --> 01:08:03,140
U minn dak il-punt il-programm tiegħi
jista 'jkun bl-użu tal-memorja

1421
01:08:03,140 --> 01:08:05,540
kollha fuq il-post, madwar fiżikament.

1422
01:08:05,540 --> 01:08:08,170
U hekk biss għall kicks, jien
ser tiġbed lura

1423
01:08:08,170 --> 01:08:11,260
quiz-- ninsa dak li kien; I
think forsi 80 jew something--

1424
01:08:11,260 --> 01:08:12,500
mod minn hawn.

1425
01:08:12,500 --> 01:08:15,920
>> Imma li l-multa, għaliex pictorially
Jien ser tiġbed il-linja.

1426
01:08:15,920 --> 01:08:19,063
Fi kliem ieħor, fir-realtà,
fil-hardware tal-kompjuter tiegħek,

1427
01:08:19,063 --> 01:08:20,979
l-ewwel punteġġ tista
tispiċċa hawnhekk għaliex dan huwa

1428
01:08:20,979 --> 01:08:22,529
dritt fil-bidu tas-semestru.

1429
01:08:22,529 --> 01:08:25,810
Il-wieħed li jmiss tista 'tispiċċa hawn
minħabba ftit ta 'żmien ikun għadda

1430
01:08:25,810 --> 01:08:27,210
u l-programm jżomm taħdem.

1431
01:08:27,210 --> 01:08:30,060
Il-punteġġ jmiss, li kienet
75, jista 'jkun aktar hawn.

1432
01:08:30,060 --> 01:08:33,420
U l-aħħar punteġġ tista 'tkun
80, li huwa fuq hawn.

1433
01:08:33,420 --> 01:08:38,729
>> Allura fir-realtà, fiżikament, dan jista 'jkun
liema memorja tal-kompjuter tiegħek Dehra.

1434
01:08:38,729 --> 01:08:41,569
Iżda din mhix mentali utli
paradigma għal programmer kompjuter.

1435
01:08:41,569 --> 01:08:44,649
Għaliex għandek kura fejn il-
Heck data tiegħek huwa jispiċċaw?

1436
01:08:44,649 --> 01:08:46,200
Inti biss tixtieq li taħżen id-data.

1437
01:08:46,200 --> 01:08:49,390
>> Dan huwa tip simili diskussjoni tagħna
aktar kmieni tal tinġibed l-kubu.

1438
01:08:49,390 --> 01:08:52,200
Għaliex inti kura dak
l-angolu huwa tal-kubu

1439
01:08:52,200 --> 01:08:53,740
u kif għandek li jduru għal tiġbed?

1440
01:08:53,740 --> 01:08:54,950
Inti biss jixtiequ kubu.

1441
01:08:54,950 --> 01:08:57,359
Bl-istess mod hawn, inti
biss jixtiequ ktieb grad.

1442
01:08:57,359 --> 01:08:59,559
Inti biss tixtieq li jaħsbu ta '
dan bħala lista ta 'numri.

1443
01:08:59,559 --> 01:09:01,350
Quién kif huwa
implimentat fil-hardware?

1444
01:09:01,350 --> 01:09:05,180
>> Allura l-estrazzjoni issa
hija din l-istampa hawn.

1445
01:09:05,180 --> 01:09:07,580
Din hija lista marbuta, kif
programmer kieku ssejjaħ dan,

1446
01:09:07,580 --> 01:09:10,640
sakemm ikollok
lista, ovvjament ta 'numri.

1447
01:09:10,640 --> 01:09:14,990
Iżda huwa marbut pictorially
permezz ta 'dawn vleġeġ,

1448
01:09:14,990 --> 01:09:18,510
u dawn vleġeġ kollha are-- taħt
il-barnuża, jekk int kurjuż,

1449
01:09:18,510 --> 01:09:23,210
ifakkar li hardware fiżiċi tagħna
indirizzi żero, wieħed, tnejn, tlieta, erba '.

1450
01:09:23,210 --> 01:09:28,465
Kollha dawn vleġeġ huma huwa bħal mappa
jew direzzjonijiet, fejn jekk 90 is-- issa

1451
01:09:28,465 --> 01:09:29,090
Sibt biex jingħaddu.

1452
01:09:29,090 --> 01:09:31,750
>> Żero, wieħed, tnejn, tlieta,
erba ', ħames, sitt, seba'.

1453
01:09:31,750 --> 01:09:35,640
Jidher qisu l-90 huwa fil
Memorja Numru indirizz sebgħa.

1454
01:09:35,640 --> 01:09:38,460
Kollha dawn vleġeġ huma hu
bħal ruttam ftit ta 'karta

1455
01:09:38,460 --> 01:09:42,439
li jagħti lill direzzjonijiet għall-
programm li tgħid jsegwu din il-mappa

1456
01:09:42,439 --> 01:09:43,880
biex jiksbu l-post sebgħa.

1457
01:09:43,880 --> 01:09:46,680
U hemm inti ser issib l-
tieni punteġġ kwizz istudent.

1458
01:09:46,680 --> 01:09:52,100
Sadanittant, il-75-- jekk jien tkompli dan,
dan huwa seba ', tmien, disa', 10, 11, 12,

1459
01:09:52,100 --> 01:09:54,240
13, 14, 15.

1460
01:09:54,240 --> 01:09:59,080
>> Din il-vleġġa oħra biss tirrappreżenta
mappa biex post memorja 15.

1461
01:09:59,080 --> 01:10:02,550
Iżda għal darb'oħra, l-programmer ġeneralment ma
ma jimpurtahom dwar dan il-livell ta 'dettall.

1462
01:10:02,550 --> 01:10:05,530
U fil aktar minn darba kull ipprogrammar
lingwa llum, l-programmer

1463
01:10:05,530 --> 01:10:10,490
mhux se anki taf fejn fil-memorja
dawn in-numri fil-fatt huma.

1464
01:10:10,490 --> 01:10:14,830
Kollha hu jew hi għandu kura dwar huwa
li b'xi mod huma marbuta flimkien

1465
01:10:14,830 --> 01:10:18,390
fi struttura tad-data bħal dan.

1466
01:10:18,390 --> 01:10:21,580
>> Iżda jirriżulta mhux
biex tikseb wisq tekniċi.

1467
01:10:21,580 --> 01:10:27,430
Iżda sempliċiment minħabba nistgħu forsi
jaffordjaw li jkollhom din id-diskussjoni hawn,

1468
01:10:27,430 --> 01:10:33,630
jissoponi li aħna tirrevedi
din il-kwistjoni hawnhekk ta 'firxa.

1469
01:10:33,630 --> 01:10:35,780
Ejja naraw jekk aħna dispjaċir tmur hawn.

1470
01:10:35,780 --> 01:10:42,950
Dan huwa 100, 90, 75, u 80.

1471
01:10:42,950 --> 01:10:44,980
>> Let me qosor tagħmel din it-talba.

1472
01:10:44,980 --> 01:10:48,980
Dan huwa firxa, u għal darb'oħra, il-
karatteristika saljenti ta 'firxa

1473
01:10:48,980 --> 01:10:52,400
hija li kollha tad-data tiegħek huwa lura għall
lura lura fil memory-- litteralment

1474
01:10:52,400 --> 01:10:56,830
wieħed byte jew forsi erba 'bytes,
xi numru fiss ta 'bytes bogħod.

1475
01:10:56,830 --> 01:11:00,710
F'lista marbuta, li nistgħu jiġbed
bħal dan, minn taħt il-barnuża li

1476
01:11:00,710 --> 01:11:02,000
jaf fejn dan il-għalf huwa?

1477
01:11:02,000 --> 01:11:03,630
Hija lanqas ma jeħtieġ għall-fluss bħal dan.

1478
01:11:03,630 --> 01:11:06,050
Parti mid-dejta tista 'tkun
lura lejn ix-xellug up hemm.

1479
01:11:06,050 --> 01:11:07,530
Inti lanqas biss jafu.

1480
01:11:07,530 --> 01:11:15,430
>> U hekk ma 'firxa, inti għandek
Karatteristika magħrufa bħala t'aċċess bl-addoċċ.

1481
01:11:15,430 --> 01:11:20,570
U x'mezzi b'aċċess każwali huwa
li l-kompjuter tista 'tiżdied istantanjament

1482
01:11:20,570 --> 01:11:22,730
għal kull lokazzjoni fil-firxa.

1483
01:11:22,730 --> 01:11:23,580
Għaliex?

1484
01:11:23,580 --> 01:11:26,000
Minħabba li l-kompjuter ikun jaf
li l-ewwel post huwa

1485
01:11:26,000 --> 01:11:29,540
żero, wieħed, tnejn, u tlieta.

1486
01:11:29,540 --> 01:11:33,890
>> U hekk jekk inti tixtieq li tmur minn
dan l-element li l-element li jmiss,

1487
01:11:33,890 --> 01:11:36,099
inti litteralment, fil-
moħħ tal-kompjuter, żid ftit wieħed.

1488
01:11:36,099 --> 01:11:39,140
Jekk inti tixtieq li tmur għall-tielet element,
żid ftit one-- element li jkun imiss, kemm

1489
01:11:39,140 --> 01:11:40,290
żid waħda.

1490
01:11:40,290 --> 01:11:42,980
Madankollu, f'dan il-verżjoni
tal-istorja, jissoponi

1491
01:11:42,980 --> 01:11:46,080
il-kompjuter bħalissa qed tfittex
fi jew li jittrattaw man-numru 100.

1492
01:11:46,080 --> 01:11:49,770
Kif tista 'tikseb għall-ieħor
grad fil-ktieb grad?

1493
01:11:49,770 --> 01:11:52,560
>> Int għandek tieħu seba
passi, li huwa arbitrarja.

1494
01:11:52,560 --> 01:11:58,120
Biex tikseb għal dak li jmiss, inti għandek
jieħdu ieħor tmien passi biex tikseb sa 15.

1495
01:11:58,120 --> 01:12:02,250
Fi kliem ieħor, mhuwiex ta '
distakk kontinwu bejn in-numri,

1496
01:12:02,250 --> 01:12:04,857
u għalhekk hija biss tieħu l-
kompjuter aktar żmien huwa l-punt.

1497
01:12:04,857 --> 01:12:06,940
Il-kompjuter trid tfittex
permezz memorja sabiex

1498
01:12:06,940 --> 01:12:08,990
biex issib dak li qed tfittex.

1499
01:12:08,990 --> 01:12:14,260
>> Allura billi firxa tendenza li tkun
veloċi tad-data structure-- għaliex inti

1500
01:12:14,260 --> 01:12:17,610
jistgħu litteralment biss tagħmel aritmetika sempliċi
u tikseb fejn inti tixtieq billi żżid waħda,

1501
01:12:17,610 --> 01:12:21,300
għal instance-- lista marbuta,
inti sagrifiċċju dik il-karatteristika.

1502
01:12:21,300 --> 01:12:24,020
Inti ma tistax biss jmorru mill-ewwel
li t-tieni li terz lejn raba.

1503
01:12:24,020 --> 01:12:25,240
Int għandek issegwi l-mappa.

1504
01:12:25,240 --> 01:12:28,160
Int għandek tieħu aktar passi
biex jiksbu l dawk il-valuri, li

1505
01:12:28,160 --> 01:12:30,230
jidher li jkun żżid spiża.

1506
01:12:30,230 --> 01:12:35,910
Allura aħna qed tħallas prezz, imma dak kien
il-karatteristika li Dan kienet qed tfittex hawn?

1507
01:12:35,910 --> 01:12:38,110
Xi jfisser lista marbuta
apparentament inessu tagħmel,

1508
01:12:38,110 --> 01:12:40,240
li kienet l-oriġini ta '
din l-istorja partikolari?

1509
01:12:40,240 --> 01:12:43,250

1510
01:12:43,250 --> 01:12:43,830
>> Eżattament.

1511
01:12:43,830 --> 01:12:46,220
Daqs dinamika għalih.

1512
01:12:46,220 --> 01:12:48,040
Aħna tista 'żżid mal-lista.

1513
01:12:48,040 --> 01:12:51,430
Nistgħu anke tiċkien il-lista, hekk
li aħna qed biss jużaw memorja kemm

1514
01:12:51,430 --> 01:12:55,560
kif aħna fil-fatt tixtieq u l-bqija
aħna qed qatt jiġu allokati fuq.

1515
01:12:55,560 --> 01:12:58,470
>> Issa biss sabiex ikunu verament nit-picky,
hemm spiża moħbija.

1516
01:12:58,470 --> 01:13:01,980
Allura inti m'għandekx biss let me jikkonvinċu
inti li dan huwa tradeoff konvinċenti.

1517
01:13:01,980 --> 01:13:04,190
Hemm spiża oħra moħbija hawn.

1518
01:13:04,190 --> 01:13:06,550
Il-benefiċċju, li tkun ċara,
hija li nagħmlu dinamiżmu.

1519
01:13:06,550 --> 01:13:10,359
Jekk irrid element ieħor, I tista 'sempliċement
tiġbed u tpoġġi numru fil hemmhekk.

1520
01:13:10,359 --> 01:13:12,150
U mbagħad I tista 'rabta li
bi stampa hawn,

1521
01:13:12,150 --> 01:13:14,970
billi aktar minn hawnhekk, għal darb'oħra, jekk stajt
miżbugħa myself fil-kantuniera,

1522
01:13:14,970 --> 01:13:19,410
jekk xi ħaġa oħra huwa diġà jużaw
il-memorja hawnhekk, jien minn xortih.

1523
01:13:19,410 --> 01:13:21,700
Stajt miżbugħa myself fil-kantuniera.

1524
01:13:21,700 --> 01:13:24,390
>> Imma x'inhu l-moħbija
ispiża fil din l-istampa?

1525
01:13:24,390 --> 01:13:27,690
Huwa mhux biss l-ammont
ta 'żmien li dan jieħu

1526
01:13:27,690 --> 01:13:29,870
li jmorru minn hawn hawn,
li huwa ta 'seba passi, allura

1527
01:13:29,870 --> 01:13:32,820
tmien passi, li hija aktar minn waħda.

1528
01:13:32,820 --> 01:13:34,830
X'hemm ispiża ieħor moħbija?

1529
01:13:34,830 --> 01:13:35,440
Mhux biss darba.

1530
01:13:35,440 --> 01:13:44,790

1531
01:13:44,790 --> 01:13:49,940
Informazzjoni addizzjonali hija
meħtieġ biex jinkiseb dan l-istampa.

1532
01:13:49,940 --> 01:13:53,210
>> Yeah, li mappa, dawk ruttam ftit tal
karta, kif I iżommu jiddeskrivu lilhom bħala.

1533
01:13:53,210 --> 01:13:55,650
Dawn arrows-- dawn mhumiex ħielsa.

1534
01:13:55,650 --> 01:13:57,660
A computer-- tafu
dak kompjuter għandu.

1535
01:13:57,660 --> 01:13:58,790
Hija għandha żerijiet u dawk.

1536
01:13:58,790 --> 01:14:03,170
Jekk inti tixtieq li jirrappreżentaw vleġġa jew
mappa jew numru, għandek bżonn xi memorja.

1537
01:14:03,170 --> 01:14:05,950
Allura l-prezz oħra li
jħallsu għal lista marbuta,

1538
01:14:05,950 --> 01:14:09,070
xjenza tal-kompjuter komuni
tar-riżorsi, huwa wkoll l-ispazju.

1539
01:14:09,070 --> 01:14:11,710
>> U fil-fatt hekk, hekk komuni,
fost il-kompromessi

1540
01:14:11,710 --> 01:14:15,580
fit-tfassil inġinerija tas-softwer
sistemi huwa żmien u space--

1541
01:14:15,580 --> 01:14:18,596
huma tnejn mill-ingredjenti tiegħek, tnejn
ta 'ingredjenti l-aktar għaljin tiegħek.

1542
01:14:18,596 --> 01:14:21,220
Dan huwa jiswew me aktar ħin
minħabba I għandhom isegwu din il-mappa,

1543
01:14:21,220 --> 01:14:25,730
imma hija wkoll jiswew me aktar spazju
minħabba I għandhom iżommu din il-mappa madwar.

1544
01:14:25,730 --> 01:14:28,730
Allura l-tama, kif konna tip ta '
diskussi matul bieraħ u llum,

1545
01:14:28,730 --> 01:14:31,720
huwa li l-benefiċċji
se jegħlbu l-ispejjeż.

1546
01:14:31,720 --> 01:14:33,870
>> Iżda hemm ebda soluzzjoni ovvja hawn.

1547
01:14:33,870 --> 01:14:35,870
Forsi huwa better--
malajr la u maħmuġin,

1548
01:14:35,870 --> 01:14:38,660
kif Kareem propost earlier--
li tarmi memorja lejn il-problema.

1549
01:14:38,660 --> 01:14:42,520
Biss jixtru memorja aktar, think inqas
diffiċli dwar soluzzjoni tal-problema,

1550
01:14:42,520 --> 01:14:44,595
u ssolvi din b'mod aktar faċli.

1551
01:14:44,595 --> 01:14:46,720
U fil-fatt qabel, meta
tkellimna dwar kompromessi,

1552
01:14:46,720 --> 01:14:49,190
ma kienx spazju fil
l-kompjuter u l-ħin.

1553
01:14:49,190 --> 01:14:51,810
Kien żmien iżviluppatur, li
huwa pass ieħor riżorsa.

1554
01:14:51,810 --> 01:14:54,829
>> Għalhekk għal darb'oħra, huwa dan l-att ta 'bilanċ
jippruvaw li jiddeċiedi liema minn dawk l-affarijiet

1555
01:14:54,829 --> 01:14:55,870
huma inti lest li jonfqu?

1556
01:14:55,870 --> 01:14:57,380
Liema hija l-inqas għalja?

1557
01:14:57,380 --> 01:15:01,040
Li jagħti l-aħjar riżultati?

1558
01:15:01,040 --> 01:15:01,540
Yeah?

1559
01:15:01,540 --> 01:15:11,310

1560
01:15:11,310 --> 01:15:12,580
>> Tabilħaqq.

1561
01:15:12,580 --> 01:15:15,970
F'dan il-każ, jekk int
li jirrappreżenta numri fil-maps--

1562
01:15:15,970 --> 01:15:18,820
dawn huma msejħa f'ħafna lingwi
"pointers" jew "l-indirizzi" -

1563
01:15:18,820 --> 01:15:20,390
huwa doppju tal-ispazju.

1564
01:15:20,390 --> 01:15:24,390
Dak m'għandhomx għalfejn ikunu ħażin daqs doppju jekk
dritt issa aħna qed biss ħażna numri.

1565
01:15:24,390 --> 01:15:27,410
Ejja ngħidu li konna ħażna
rekords tal-pazjenti fil-hospital--

1566
01:15:27,410 --> 01:15:30,870
hekk ismijiet Pierson tal, numri tat-telefon,
numri tas-sigurtà soċjali, it-tabib

1567
01:15:30,870 --> 01:15:31,540
istorja.

1568
01:15:31,540 --> 01:15:34,160
Din il-kaxxa tista 'tkun ferm,
ħafna akbar, f'liema każ

1569
01:15:34,160 --> 01:15:38,000
pointer ftit żgħira, l-indirizz tal
li jmiss element-- mhuwiex big deal.

1570
01:15:38,000 --> 01:15:40,620
Huwa tali marġinali
ispiża ma jimpurtax.

1571
01:15:40,620 --> 01:15:43,210
Iżda f'dan il-każ, yeah, huwa l-irduppjar.

1572
01:15:43,210 --> 01:15:45,290
Good kwistjoni.

1573
01:15:45,290 --> 01:15:47,900
>> Ejja nitkellmu dwar ħin ta '
ftit aktar konkret.

1574
01:15:47,900 --> 01:15:50,380
X'hemm-running time
ta 'tiftix din il-lista?

1575
01:15:50,380 --> 01:15:53,640
Ejja ngħidu jien ridt li tfittxija
permezz gradi kollha tal-istudenti,

1576
01:15:53,640 --> 01:15:55,980
u hemm gradi n
f'din l-istruttura tad-data.

1577
01:15:55,980 --> 01:15:58,830
Hawnhekk, ukoll, nistgħu tissellef
l-vokabularju ta 'qabel.

1578
01:15:58,830 --> 01:16:00,890
Din hija struttura tad-data lineari.

1579
01:16:00,890 --> 01:16:04,570
>> O Big n huwa dak li meħtieġ sabiex tikseb
sa l-aħħar ta 'din l-istruttura tad-data,

1580
01:16:04,570 --> 01:16:08,410
whereas-- u ma rajniex
dan il before-- firxa jagħtik

1581
01:16:08,410 --> 01:16:13,555
dak li sejjaħ ħin kostanti, li jfisser
pass wieħed inkella tnejn jew 10 steps--

1582
01:16:13,555 --> 01:16:14,180
ma jimpurtax.

1583
01:16:14,180 --> 01:16:15,440
Huwa numru fiss.

1584
01:16:15,440 --> 01:16:17,440
Hija għandha x'taqsam xejn mal-
-daqs tal-array.

1585
01:16:17,440 --> 01:16:20,130
U r-raġuni għal dan,
darb'oħra, huwa t'aċċess bl-addoċċ.

1586
01:16:20,130 --> 01:16:23,180
Il-kompjuter tista 'sempliċement immedjatament
jaqbżu post għall-ieħor,

1587
01:16:23,180 --> 01:16:27,770
għaliex dawn qed kollha l-istess
distanza mill kull ħaġa oħra.

1588
01:16:27,770 --> 01:16:29,112
M'hemm l-ebda ħsieb involut.

1589
01:16:29,112 --> 01:16:31,900

1590
01:16:31,900 --> 01:16:32,400
Kull dritt.

1591
01:16:32,400 --> 01:16:39,230
Mela jekk nista ', let me jippruvaw
żebgħa żewġ stampi finali.

1592
01:16:39,230 --> 01:16:42,830
A waħda komuni ħafna magħruf bħala mejda hash.

1593
01:16:42,830 --> 01:16:51,120
Allura biex jimmotivaw din id-diskussjoni,
let me jaħsbu dwar kif għandek tagħmel dan.

1594
01:16:51,120 --> 01:16:52,610
>> Allura kif dwar dan?

1595
01:16:52,610 --> 01:16:55,160
Ejja ngħidu li l-problema
irridu li ssolvi issa

1596
01:16:55,160 --> 01:16:58,360
qed timplimenta b'mod dictionary--
hekk mazz sħiħ ta 'kliem Ingliż

1597
01:16:58,360 --> 01:16:59,330
jew ikun x'ikun.

1598
01:16:59,330 --> 01:17:02,724
U l-għan huwa li tkun kapaċi twieġeb
kwistjonijiet tal-formola huwa dan kelma?

1599
01:17:02,724 --> 01:17:04,640
Allura inti tixtieq li jimplimentaw
jespliċitaw kontrollur, biss

1600
01:17:04,640 --> 01:17:07,220
bħal dizzjunarju fiżika
li inti tista 'tfittex affarijiet up fil.

1601
01:17:07,220 --> 01:17:10,490
Suppose I kellhom jagħmlu dan ma 'firxa.

1602
01:17:10,490 --> 01:17:12,590
I jistgħu jagħmlu dan.

1603
01:17:12,590 --> 01:17:20,756
>> U jissoponi il-kliem huma tuffieħ
u banana u cantaloupe.

1604
01:17:20,756 --> 01:17:23,330

1605
01:17:23,330 --> 01:17:26,465
U ma nistax think ta 'frott
li tibda bil d, hekk aħna qed biss

1606
01:17:26,465 --> 01:17:27,590
ser ikollhom tliet frottiet.

1607
01:17:27,590 --> 01:17:31,510
Allura dan huwa firxa, u aħna qed
ħażna kollha ta 'dawn il-kliem

1608
01:17:31,510 --> 01:17:34,200
f'dan il-dizzjunarju bħala firxa.

1609
01:17:34,200 --> 01:17:39,350
Il-kwistjoni, allura, huwa kif inkella
jista int taħżen din l-informazzjoni?

1610
01:17:39,350 --> 01:17:43,160
>> Well, jien tip ta 'qerq hawn, għaliex
kull wieħed minn dawn l-ittri fil-kelma

1611
01:17:43,160 --> 01:17:44,490
huwa verament byte individwali.

1612
01:17:44,490 --> 01:17:46,740
Mela jekk jien verament riedu li jkun
nit-picky, I għandhom verament

1613
01:17:46,740 --> 01:17:49,600
jkun diviż dan up fis ħafna
biċċiet iżgħar ta 'memorja,

1614
01:17:49,600 --> 01:17:51,289
u nistgħu nagħmlu eżattament dan.

1615
01:17:51,289 --> 01:17:53,580
Iżda aħna qed tmur biex jibda fis
l-istess problema bħal qabel.

1616
01:17:53,580 --> 01:17:56,674
X'jiġri jekk, kif Merriam-Webster jew Oxford
ma kull year-- huma jżidu kliem

1617
01:17:56,674 --> 01:17:59,340
għall-dictionary-- aħna ma
neċessarjament jixtiequ li żebgħa lilna nfusna

1618
01:17:59,340 --> 01:18:00,780
fil-kantuniera ma 'firxa?

1619
01:18:00,780 --> 01:18:05,710
>> Allura minflok, forsi approċċ aktar intelliġenti
huwa li l-tuffieħ fil-node jew kaxxa tiegħu stess,

1620
01:18:05,710 --> 01:18:11,190
kif aħna ngħid, banana, u
allura hawnhekk għandna cantaloupe.

1621
01:18:11,190 --> 01:18:14,990

1622
01:18:14,990 --> 01:18:16,790
U aħna string dawn l-affarijiet flimkien.

1623
01:18:16,790 --> 01:18:19,980
Allura dan huwa l-firxa, u
dan huwa l-lista marbuta.

1624
01:18:19,980 --> 01:18:23,300
Jekk inti ma tistax pjuttost tara, hija biss
jgħid "matriċi," u dan jgħid "lista."

1625
01:18:23,300 --> 01:18:25,780
>> Allura aħna għandna l-istess
Kwistjonijiet eżatti bħal qabel,

1626
01:18:25,780 --> 01:18:28,600
permezz tagħha issa għandna
dinamiżmu fil-lista marbuta tagħna.

1627
01:18:28,600 --> 01:18:31,090
Imma aħna għandna dizzjunarju pjuttost bil-mod.

1628
01:18:31,090 --> 01:18:32,870
Suppose I tixtieq tfittex up kelma.

1629
01:18:32,870 --> 01:18:35,430
Jista 'jieħu me O kbar ta' n
passi, minħabba li l-kelma tista

1630
01:18:35,430 --> 01:18:37,840
tkun it-triq kollha fl-aħħar tal
-lista, bħall cantaloupe.

1631
01:18:37,840 --> 01:18:40,600
U jirriżulta li
fl-ipprogrammar, sort

1632
01:18:40,600 --> 01:18:42,700
tal-Grail qaddis ta 'data
strutturi, hija xi ħaġa

1633
01:18:42,700 --> 01:18:46,620
li jagħtik kostanti
żmien bħal firxa

1634
01:18:46,620 --> 01:18:50,870
iżda li xorta jagħtik dinamiżmu.

1635
01:18:50,870 --> 01:18:52,940
>> Allura nistgħu jkollhom l-aħjar taż-żewġ dinjiet?

1636
01:18:52,940 --> 01:18:55,570
U fil-fatt, hemm xi ħaġa
imsejjaħ il-mejda hash

1637
01:18:55,570 --> 01:18:59,320
li tippermetti li tagħmel eżattament
li, għalkemm madwar.

1638
01:18:59,320 --> 01:19:03,140
Tabella hash huwa fancier
istruttura tad-data li aħna

1639
01:19:03,140 --> 01:19:06,340
jistgħu jaħsbu bħala l-
kombinazzjoni ta 'array--

1640
01:19:06,340 --> 01:19:12,390
u jien ser tiġbed
bħall this-- u l-listi marbuta

1641
01:19:12,390 --> 01:19:17,310
li jien ser tfassal bħal dan aktar hawn.

1642
01:19:17,310 --> 01:19:19,760
>> U l-mod dan ħaġa
xogħlijiet hija kif ġej.

1643
01:19:19,760 --> 01:19:23,310

1644
01:19:23,310 --> 01:19:29,540
Jekk dan now-- hash table--
huwa struttura tiegħi dejta tielet,

1645
01:19:29,540 --> 01:19:32,590
u jien tixtieq li taħżen
kliem f'dan, jien ma

1646
01:19:32,590 --> 01:19:35,440
jridux biss taħżen kollha ta 'l-
Kliem lura lura lura biex lura.

1647
01:19:35,440 --> 01:19:37,430
Irrid li lieva xi
biċċa informazzjoni

1648
01:19:37,430 --> 01:19:40,330
dwar il-kliem li se let
me ġġibu fejn huwa aktar mgħaġġel.

1649
01:19:40,330 --> 01:19:43,666
>> Allura minħabba l-kliem tat-tuffieħ
u banana u cantaloupe,

1650
01:19:43,666 --> 01:19:45,040
I deliberatament għażlet dawn il-kliem.

1651
01:19:45,040 --> 01:19:45,340
Għaliex?

1652
01:19:45,340 --> 01:19:47,631
X'hemm tip ta fundamentalment
differenti dwar it-tliet?

1653
01:19:47,631 --> 01:19:49,950

1654
01:19:49,950 --> 01:19:51,484
X'hemm-ovvju?

1655
01:19:51,484 --> 01:19:52,900
Huma jibdew bl-ittri differenti.

1656
01:19:52,900 --> 01:19:53,900
>> Allura inti taf liema?

1657
01:19:53,900 --> 01:19:57,120
Pjuttost milli tpoġġi kliem kollha tiegħi fil
l-istess barmil, biex ngħidu hekk,

1658
01:19:57,120 --> 01:20:00,390
bħal fil-lista waħda kbira, għaliex ma
I mill-inqas tipprova l-ottimizzazzjoni

1659
01:20:00,390 --> 01:20:04,180
u jagħmlu listi tiegħi 26/01 sakemm.

1660
01:20:04,180 --> 01:20:07,440
A ottimizzazzjoni konvinċenti
jista 'jkun għaliex ma

1661
01:20:07,440 --> 01:20:10,650
I-- meta ddaħħal kelma
fis din l-istruttura tad-data,

1662
01:20:10,650 --> 01:20:14,300
fil-memorja tal-kompjuter, għaliex
ma nressaq il-"a" kliem hawn,

1663
01:20:14,300 --> 01:20:17,270
kollha l- "b" kliem hawnhekk,
u l-"ċ" kliem hawn?

1664
01:20:17,270 --> 01:20:24,610
Allura dan jispiċċa tqegħid tuffieħa
hawn, banana hawn, cantaloupe hawn,

1665
01:20:24,610 --> 01:20:25,730
u oħrajn.

1666
01:20:25,730 --> 01:20:31,700
>> U jekk I jkollhom addizzjonali
kelma like-- x'hemm ieħor?

1667
01:20:31,700 --> 01:20:36,640
Tuffieħ, banana, lanġas.

1668
01:20:36,640 --> 01:20:39,370
Kulħadd jaħseb ta 'frotta
li jibda bil-, b, jew c?

1669
01:20:39,370 --> 01:20:40,570
perfetta Blueberry--.

1670
01:20:40,570 --> 01:20:43,990
Li ser jispiċċaw hawn.

1671
01:20:43,990 --> 01:20:47,530
U hekk aħna jidhru li jkollhom
marġinalment soluzzjoni aħjar,

1672
01:20:47,530 --> 01:20:50,820
għaliex issa jekk irrid
tiftix għal tuffieħ, I

1673
01:20:50,820 --> 01:20:53,200
first-- I do mhux biss adsa
fl-istruttura tad-data tiegħi.

1674
01:20:53,200 --> 01:20:54,850
Jien ma adsa fil-memorja tal-kompjuter tiegħi.

1675
01:20:54,850 --> 01:20:56,530
I l-ewwel ħarsa lejn l-ewwel ittra.

1676
01:20:56,530 --> 01:20:58,610
>> U dan huwa dak kompjuter
xjentist ngħid.

1677
01:20:58,610 --> 01:21:00,760
Inti hash fl-istruttura tad-data tiegħek.

1678
01:21:00,760 --> 01:21:04,100
Tieħu input tiegħek, li fil
F'dan il-każ hija kelma simili tuffieħ.

1679
01:21:04,100 --> 01:21:07,150
Inti janalizzah, tħares lejn
l-ewwel ittra f'dan il-każ,

1680
01:21:07,150 --> 01:21:08,340
b'hekk hashing dan.

1681
01:21:08,340 --> 01:21:10,950
Hashing huwa biha terminu ġenerali
tieħu xi ħaġa bħala input

1682
01:21:10,950 --> 01:21:12,116
u inti jipproduċi xi output.

1683
01:21:12,116 --> 01:21:15,090
U l-produzzjoni f'dak
każ huwa l-post

1684
01:21:15,090 --> 01:21:18,150
inti trid tfittex, l-ewwel
post, it-tieni post, it-tielet.

1685
01:21:18,150 --> 01:21:22,160
Allura l-input huwa tuffieħ,
l-output huwa l-ewwel.

1686
01:21:22,160 --> 01:21:25,054
L-input huwa banana, l-
output għandu jkun sekonda.

1687
01:21:25,054 --> 01:21:27,220
L-input huwa cantaloupe,
il-produzzjoni għandha tkun terza.

1688
01:21:27,220 --> 01:21:30,320
L-input huwa blueberry, l
output għandu jerġa 'jkun it-tieni.

1689
01:21:30,320 --> 01:21:34,010
U dan huwa dak li jgħinek tieħu
shortcuts permezz memorja tiegħek

1690
01:21:34,010 --> 01:21:39,050
sabiex insir kliem
jew data aktar effettiv.

1691
01:21:39,050 --> 01:21:43,330
>> Issa dan inaqqas l isfel żmienna potenzjalment
billi kemm wieħed minn 26,

1692
01:21:43,330 --> 01:21:45,850
għaliex jekk inti tassumi li int
għandhom bħala ħafna "a" kliem bħala "z"

1693
01:21:45,850 --> 01:21:48,080
Kliem bħal kliem "q", li
mhuwiex verament realistic--

1694
01:21:48,080 --> 01:21:50,830
int se jkollhom skew madwar
ċerti ittri ta 'l-alphabet--

1695
01:21:50,830 --> 01:21:53,204
imma dan ikun inkrimentali
approċċ li ma jippermettu

1696
01:21:53,204 --> 01:21:55,930
li tirċievi kliem ferm aktar malajr.

1697
01:21:55,930 --> 01:21:59,660
U fir-realtà, sofistikati
programm, il-Google tad-dinja,

1698
01:21:59,660 --> 01:22:02,180
il facebooks tal-world--
huma se jużaw tabella hash

1699
01:22:02,180 --> 01:22:03,740
għal ħafna skopijiet differenti.

1700
01:22:03,740 --> 01:22:06,590
Iżda dawn ma jkunux daqshekk naive kif
li biss ħarsa lejn l-ewwel ittra

1701
01:22:06,590 --> 01:22:09,700
fil tuffieħ jew tal-banana jew
lanġas jew cantaloupe,

1702
01:22:09,700 --> 01:22:13,420
għaliex kif inti tista 'tara dawn
listi xorta jistgħu jiksbu twil.

1703
01:22:13,420 --> 01:22:17,130
>> U hekk dan jista 'xorta waħda jkun tip
ta linear-- hekk tip ta 'bil-mod,

1704
01:22:17,130 --> 01:22:19,980
bħal ma 'lO kbar ta' n
li aħna diskussa aktar kmieni.

1705
01:22:19,980 --> 01:22:25,290
Allura dak tabella reali hash tajba se
do-- se jkollhom firxa ħafna akbar.

1706
01:22:25,290 --> 01:22:28,574
U se tuża ħafna aktar
funzjoni hashing sofistikati,

1707
01:22:28,574 --> 01:22:30,240
b'tali mod li ma biss ħarsa lejn il-"a."

1708
01:22:30,240 --> 01:22:35,480
Forsi jidher fil- "a-p-p-l-e" u
b'xi tikkonverti dawn il-ħames ittri

1709
01:22:35,480 --> 01:22:38,400
fil-post fejn
tuffieħ għandhom ikunu maħżuna.

1710
01:22:38,400 --> 01:22:42,660
Aħna biss naively bl-ittra "a"
waħedhom, għaliex dan huwa sbieħ u sempliċi.

1711
01:22:42,660 --> 01:22:44,600
>> Iżda tabella hash, fil
-aħħar, inti tista 'taħseb

1712
01:22:44,600 --> 01:22:47,270
bħala taħlita ta '
firxa, li kull wieħed minnhom

1713
01:22:47,270 --> 01:22:51,700
għandu lista marbuta li idealment
għandu jkun qasir kemm jista 'jkun.

1714
01:22:51,700 --> 01:22:54,364
U dan mhux soluzzjoni ovvja.

1715
01:22:54,364 --> 01:22:57,280
Fil-fatt, ħafna mill-irfinar
li tmur fuq taħt il-barnuża meta

1716
01:22:57,280 --> 01:22:59,654
implimentazzjoni ta dawn it-tipi ta '
strutturi tad-dejta sofistikati

1717
01:22:59,654 --> 01:23:01,640
huwa dak li huwa d-dritt
tul tal-firxa?

1718
01:23:01,640 --> 01:23:03,250
X'inhi l-funzjoni hash dritt?

1719
01:23:03,250 --> 01:23:04,830
Kif inti taħżen l-affarijiet fil-memorja?

1720
01:23:04,830 --> 01:23:07,249
>> Imma tirrealizza kemm malajr
dan it-tip ta 'diskussjoni

1721
01:23:07,249 --> 01:23:10,540
eskalat, jew s'issa li huwa tip
ta fuq ras wieħed f'dan il-punt, li

1722
01:23:10,540 --> 01:23:11,360
huwa multa.

1723
01:23:11,360 --> 01:23:18,820
Iżda bdejna, irtirar, bil tassew
xi ħaġa ta 'livell baxx u elettroniku.

1724
01:23:18,820 --> 01:23:20,819
U għalhekk dan għal darb'oħra huwa dan
tema ta 'estrazzjoni,

1725
01:23:20,819 --> 01:23:23,610
fejn ladarba inti tibda tieħu għall
mogħtija, OK, stajt ltqajna it-- hemm

1726
01:23:23,610 --> 01:23:26,680
memorja fiżika, OK, ltqajna, kull
lokazzjoni fiżika għandha l-indirizz,

1727
01:23:26,680 --> 01:23:29,910
OK, I ltqajna, I tista 'tirrappreżenta
dawk l-indirizzi bħala arrows--

1728
01:23:29,910 --> 01:23:34,650
inti tista 'malajr ħafna jibda jkollu
konversazzjonijiet aktar sofistikati li

1729
01:23:34,650 --> 01:23:38,360
fl-aħħar jidhru li huma jħallina naqtgħu
sabiex isolvu problemi bħal tiftix

1730
01:23:38,360 --> 01:23:41,620
u l-għażla aktar effettiv.

1731
01:23:41,620 --> 01:23:44,190
U mistrieħ assigurat, too--
għaliex naħseb dan il

1732
01:23:44,190 --> 01:23:48,700
huwa l-aktar fonda konna marret fis xi
ta 'dawn is-suġġetti CS proper-- Imxejna

1733
01:23:48,700 --> 01:23:51,880
isir fil-jum u nofs f'dan
punt dak li inti tista tipikament do fuq

1734
01:23:51,880 --> 01:23:55,520
il-kors ta 'tmien ġimgħat fil-semestru.

1735
01:23:55,520 --> 01:23:59,670
>> Kwalunkwe mistoqsijiet dwar dawn?

1736
01:23:59,670 --> 01:24:01,100
Nru?

1737
01:24:01,100 --> 01:24:01,940
Kull dritt.

1738
01:24:01,940 --> 01:24:05,610
Ukoll, għaliex ma we nieqaf hemm,
tibda ikla ftit minuti kmieni,

1739
01:24:05,610 --> 01:24:07,052
jerġgħu jibdew fi ftit madwar siegħa?

1740
01:24:07,052 --> 01:24:08,760
U jien ser linger għal
daqsxejn bil-mistoqsijiet.

1741
01:24:08,760 --> 01:24:11,343
Imbagħad jien ser ikollhom imorru
jieħdu sejħiet koppja jekk dan huwa OK.

1742
01:24:11,343 --> 01:24:15,000
I ser idur fuq xi mużika fil-frattemp,
imma ikla għandu jkun l-kantuniera.

1743
01:24:15,000 --> 01:24:17,862