1
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>> [Ddoqq il-mużika]

2
00:00:15,059 --> 00:00:19,170
>> Dan huwa CS50-- Harvard
introduzzjoni università

3
00:00:19,170 --> 00:00:22,070
għall-intellettwali
intrapriżi ta 'xjenza tal-kompjuter

4
00:00:22,070 --> 00:00:23,800
u l-arti tal-ipprogrammar.

5
00:00:23,800 --> 00:00:27,020
U jien jisimni David Malan, u
I kien biss ħsieb dalgħodu,

6
00:00:27,020 --> 00:00:33,120
huwa kien amazingly 20 sena llum
peress li jien aħħar sib fejn inti guys tagħmel issa.

7
00:00:33,120 --> 00:00:33,840
>> Kien 1996.

8
00:00:33,840 --> 00:00:37,550
I kien sophomore, u jien kien qed
CS50 għall-ewwel darba.

9
00:00:37,550 --> 00:00:40,890
U kelli lanqas gotten l-nerv
li teħodha myself sena freshman,

10
00:00:40,890 --> 00:00:42,500
parzjalment minħabba ż-żmien.

11
00:00:42,500 --> 00:00:44,782
xjenza tal-kompjuter lili
kien tip ta simili, meh.

12
00:00:44,782 --> 00:00:46,990
I kien daqsxejn ta geek li qed tikber
up, imma jien ma verament

13
00:00:46,990 --> 00:00:49,180
xi intelletwali
interess fil dak li deher

14
00:00:49,180 --> 00:00:51,920
li jkun biss mazz sħiħ ta '
nies programmazzjoni il-ħin kollu.

15
00:00:51,920 --> 00:00:53,904
>> UI kien jibża li tkun onest.

16
00:00:53,904 --> 00:00:56,820
Il-kors u l-kompjuter xjenza aktar
ġeneralment kellhom u sa ċertu punt,

17
00:00:56,820 --> 00:01:01,230
għad għandha dan l-reputazzjoni ta 'kamp li
beware, jekk biss minħabba dan ħafna minna

18
00:01:01,230 --> 00:01:04,410
ma jkunux familjari magħha u ċert ta 'dan.

19
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U huwa verament ma kienx qabel I shopped
din il-klassi li sophomore fall--

20
00:01:08,480 --> 00:01:10,880
u anke dakinhar, jien biss iskritta
minħabba li l-professor--

21
00:01:10,880 --> 00:01:13,950
wieħed mill-ewwel konsulenti tiegħi, Brian
Kernighan issa fil Princeton--

22
00:01:13,950 --> 00:01:15,700
permessi me biex jieħdu l-pass klassi jonqsu.

23
00:01:15,700 --> 00:01:18,020
U fil-fatt, hu għalhekk
illum aħna jippermettu u jħeġġu

24
00:01:18,020 --> 00:01:20,030
istudenti biex jieħdu din il-klassi sib / unsat.

25
00:01:20,030 --> 00:01:22,040
>> U biss imbagħad, mill-
aħħar tas-semestru

26
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ma I realizzata simili, Ara naqra, dan il-
ma kienx tali kamp familjari.

27
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Tabilħaqq, dan kien
ħafna setgħa qasam,

28
00:01:26,850 --> 00:01:28,970
u aktar excitingly,
speċjalment aktar tard,

29
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kif I ħa korsijiet fil
Arti drammatici 101 u Latin A

30
00:01:32,809 --> 00:01:34,600
u mbagħad eventwalment
arkeoloġija iskola grad,

31
00:01:34,600 --> 00:01:37,860
ma I verament bidu biex tara d-
intersezzjonijiet ta 'dan il-qasam, kompjuter

32
00:01:37,860 --> 00:01:41,979
xjenza, mal-istudji umanistiċi,
xjenzi naturali, l-arti, mediċina,

33
00:01:41,979 --> 00:01:42,520
u simili.

34
00:01:42,520 --> 00:01:44,420
U hekk dan huwa dak biss hekk
pulita dwar ix-xjenza tal-kompjuter

35
00:01:44,420 --> 00:01:46,930
finalment, kif aħna nittamaw li intom ser
see-- huwa applikabbiltà tagħha

36
00:01:46,930 --> 00:01:50,280
għal dawn l-oqsma l-oħra, u kif tista '
terfa 'ftit mill llum u ta' l-semestru

37
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ideat u l-ħiliet prattiċi
lura għall-dominju tiegħek stess,

38
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u fil-fatt jesploraw dan intersezzjoni
ta 'l-arti liberali u x-xjenzi.

39
00:01:58,200 --> 00:02:02,690
>> Allura 73% tal inti, jekk l-aħħar
sena huwa kwalunkwe indikazzjoni,

40
00:02:02,690 --> 00:02:04,390
qatt ma ħa kors CS qabel.

41
00:02:04,390 --> 00:02:06,389
Mela jekk, bħali, inti
tħossok xi ftit

42
00:02:06,389 --> 00:02:09,190
jibża ', jew franchement int mhux
verament ċert għaliex int anke hawn.

43
00:02:09,190 --> 00:02:11,510
Forsi inti biss segwiti xi
ħbieb fuq biex Sanders dritt issa.

44
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C'est totalment multa.

45
00:02:12,490 --> 00:02:15,059
L-għan hawnhekk huwa li ganċ
inti u biex iserraħ ras inti

46
00:02:15,059 --> 00:02:17,100
li jekk inti tfittex li
ix-xellug u lejn il-lemin,

47
00:02:17,100 --> 00:02:21,480
int ser tara klassi ma
esperjenza ftit jew kemm

48
00:02:21,480 --> 00:02:22,890
li inti stess jista 'jkollok.

49
00:02:22,890 --> 00:02:25,280
U fil-fatt, aħna ser jaqsmu
xi statistiċi aktar tard illum

50
00:02:25,280 --> 00:02:28,120
dwar liema l-demografija ta '
il-klassi tipikament look like.

51
00:02:28,120 --> 00:02:31,440
>> U kif miżjud reassurance-- u dan aħna
do jfisser peress I ħa matul il-kors

52
00:02:31,440 --> 00:02:33,252
xi snin ago-- fil
sillabu tal-kors tal-

53
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huwa this-- li dak li finalment
materji jiġu trattati f'din kors

54
00:02:35,460 --> 00:02:38,040
huwa mhux tant fejn inti tispiċċa
sa relattiva għall-klassi tiegħek,

55
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imma fejn inti fil-ġimgħa 11, l-aħħar tad-
semestru, jispiċċaw relattiva lilek innifsek

56
00:02:43,110 --> 00:02:46,280
fil-ġimgħa 0, li hija
fejn aħna qegħdin hawn illum.

57
00:02:46,280 --> 00:02:48,704
U dan huwa dak I realizzati
dawk is-snin kollha ilu.

58
00:02:48,704 --> 00:02:50,620
U naf ħafna
klassijiet ngħid dan, iżda huwa

59
00:02:50,620 --> 00:02:52,450
veru speċjalment fix-xjenza tal-kompjuter.

60
00:02:52,450 --> 00:02:55,320
Fl-aħħar tal-ġurnata, dan il-qasam
huwa familjari kif kien lili

61
00:02:55,320 --> 00:02:58,590
u jista 'jkun li inti, huwa verament
biss dwar soluzzjoni ta 'problemi.

62
00:02:58,590 --> 00:03:01,324
U bħala tali, hi ma jkollhiex din l
applikabilità biex tikseb oqsma oħra.

63
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U fil-fatt, jekk aħna ppruvaw
li jiddistillaw dak li dan ifisser,

64
00:03:03,490 --> 00:03:06,897
din hija soluzzjoni ta 'problemi
fl-essenza tiegħu, I daresay.

65
00:03:06,897 --> 00:03:09,480
Hemm input-- hekk tkun xi
hija li inti qed jippruvaw isolvu.

66
00:03:09,480 --> 00:03:12,264
Hemm output, li huwa wieħed jittama
is-soluzzjoni għal din il-problema.

67
00:03:12,264 --> 00:03:14,180
U mbagħad, kif aħna kieku
jgħidu fix-xjenza tal-kompjuter,

68
00:03:14,180 --> 00:03:17,310
hemm din il-kaxxa sewda fil-
nofs li inti ma neċessarjament

69
00:03:17,310 --> 00:03:19,450
għandek kura dwar kif taħdem.

70
00:03:19,450 --> 00:03:22,230
Inti stess eventwalment tista
jimplimentaw x'hemm ġewwa dik il-kaxxa.

71
00:03:22,230 --> 00:03:25,194
Imma għal skopijiet lum u aktar
ġeneralment fil-ħajja, inti kollha jimpurtahom

72
00:03:25,194 --> 00:03:26,610
hija li dawn il-problemi nikseb solvuti.

73
00:03:26,610 --> 00:03:29,340
>> U dak li dan il-kors huwa
finalment dwar qed tesplora

74
00:03:29,340 --> 00:03:31,700
l-intersezzjoni ta '
dawn l-inputs u l-outputs,

75
00:03:31,700 --> 00:03:34,410
u dawn l-hekk imsejħa
algoritmi, kif aħna ser dalwaqt ara,

76
00:03:34,410 --> 00:03:37,450
li jimplimenta dak li huwa
taħt hemmhekk, il-barnuża.

77
00:03:37,450 --> 00:03:40,487
Iżda dawn l-inputs u dawn outputs--
dak li ma attwalment jfisser?

78
00:03:40,487 --> 00:03:43,570
Ukoll, fl-aħħar tal-ġurnata, għandna bżonn
xi mod ta jirrappreżentaw informazzjoni.

79
00:03:43,570 --> 00:03:46,660
Dan hu veru speċjalment fil-kompjuter,
li bħala fancy u kumplessi kif

80
00:03:46,660 --> 00:03:48,160
jista 'jidher, huwa mezz pjuttost mutu.

81
00:03:48,160 --> 00:03:52,240
Huwa jieħu electricity-- kemm jekk minn
kejbil jew batterija kif input--

82
00:03:52,240 --> 00:03:55,820
u mbagħad hija tipproduċi xi
tweġibiet preprogramed fuq l-iskrin.

83
00:03:55,820 --> 00:03:57,970
>> Imma kif nistgħu tikseb minn
bidu sat-tmiem hemmhekk?

84
00:03:57,970 --> 00:03:59,470
Ukoll, dak li problema li għandha tiġi solvuta?

85
00:03:59,470 --> 00:04:01,050
Well, forsi aħna jistgħu, fi
-bidu ta 'kull semestru,

86
00:04:01,050 --> 00:04:02,841
jippruvaw jieħdu attendenza
fil-kamra bħal dan.

87
00:04:02,841 --> 00:04:04,750
So I tista 'tagħmel bħal wieħed, tnejn, tlieta.

88
00:04:04,750 --> 00:04:07,060
Jew forsi, jekk I ma kien
li tip ta 'iżżomm kont

89
00:04:07,060 --> 00:04:10,560
ta myself-- li jżommu rekord ta things--
I tista 'malajr jispiċċaw ta' swaba.

90
00:04:10,560 --> 00:04:14,650
So I tista 'biss tagħmel hash waħda marks--
persuna, tnejn, tlieta, erba ', ħames, sitt,

91
00:04:14,650 --> 00:04:15,431
seba ', tmien.

92
00:04:15,431 --> 00:04:17,930
U lkoll għandna probabbilment
għamlu dan, kemm jekk fuq idejk

93
00:04:17,930 --> 00:04:19,680
jew fuq biċċa karta.

94
00:04:19,680 --> 00:04:22,140
U dan huwa attwalment biss
xi ħaġa imsejħa notation-- unary

95
00:04:22,140 --> 00:04:26,130
fejn jekk inti biss għandek ittra waħda
fil alfabett tiegħek, hash wieħed jew

96
00:04:26,130 --> 00:04:29,440
marka f'dan il-każ, għal kull
kontribut inti tixtieq li jgħoddu,

97
00:04:29,440 --> 00:04:32,330
għandek bżonn li jħott waħda minn dawn
letters-- waħda minn dawn il-marki.

98
00:04:32,330 --> 00:04:32,510
>> Kull dritt.

99
00:04:32,510 --> 00:04:34,790
Li kollox multa u tajba u
mhux kollha li ikkumplikata.

100
00:04:34,790 --> 00:04:37,800
Iżda kompjuters mhumiex kollha
li ħafna aktar ikkumplikat.

101
00:04:37,800 --> 00:04:40,770
Tabilħaqq, ħafna mill inti probabilment
taf anki jekk inti stajt ma verament

102
00:04:40,770 --> 00:04:44,080
meqjus dak li dan ifisser, li
Kompjuters jifhmu biss żerijiet

103
00:04:44,080 --> 00:04:45,870
u ones-- l-hekk imsejħa sistema binarja.

104
00:04:45,870 --> 00:04:49,390
Aħna bnedmin, għall-kuntrarju, huma tant
ħafna aktar sofistikata safejn

105
00:04:49,390 --> 00:04:51,770
kif nifhmu żerijiet permezz nines.

106
00:04:51,770 --> 00:04:55,740
>> Iżda anke jekk binarju huwa, fl-ewwel
daqqa t'għajn, mhux kollha li familjari,

107
00:04:55,740 --> 00:05:00,330
jirriżulta huwa bħad-sistemi
u l-ideat li aħna diġà jafu.

108
00:05:00,330 --> 00:05:02,420
Allura per eżempju, jikkunsidraw dan.

109
00:05:02,420 --> 00:05:03,896
Dan huwa biss sekwenza ta 'simboli.

110
00:05:03,896 --> 00:05:05,770
U lilkom kollha, meta
glancing lejn dan, probabbilment

111
00:05:05,770 --> 00:05:09,380
think 123-- xejn
tassew interessanti hemmhekk.

112
00:05:09,380 --> 00:05:11,940
Iżda għaliex hi dan in-numru, 123?

113
00:05:11,940 --> 00:05:14,440
Dawn huma biss glyphs fuq
il screen-- biss mudelli

114
00:05:14,440 --> 00:05:16,387
li xi ħadd jista 'fasslu jew ittajpjat.

115
00:05:16,387 --> 00:05:18,970
Imma jekk int simili me, inti
probabbilment tiftakar mill-iskola grad

116
00:05:18,970 --> 00:05:21,610
li hemm it-tip ta '
kolonni jew postijiet hawn.

117
00:05:21,610 --> 00:05:25,340
Hemm post u l- l-wieħed
-post għaxar u l-post tal-mitt s.

118
00:05:25,340 --> 00:05:29,820
U r-raġuni li dan huwa 123 u
mhux biss mudell ta 'tliet simboli

119
00:05:29,820 --> 00:05:33,090
għaliex, naturalment, jekk irridu
jkollhom wieħed fil-post mijiet,

120
00:05:33,090 --> 00:05:36,610
inti tagħmel l-matematika ta '100 darba waħda,
u mbagħad tnejn fil-post tal-għaxra ta.

121
00:05:36,610 --> 00:05:41,390
Allura dak 10 darbiet 2, u mbagħad tlieta fil
post l-waħda u li għamilhom 1 ħinijiet 3.

122
00:05:41,390 --> 00:05:45,670
U meta inti żid kollha ta 'dawk manifatturati, ta'
kors, ikollok 100 miżjud b'20 miżjuda bi 3.

123
00:05:45,670 --> 00:05:48,220
>> Allura bdejna biss bi mudell
ta symbols-- 'l alphabet--

124
00:05:48,220 --> 00:05:51,670
iżda mbagħad aħna mapping tifsira fuq
dan permezz ta 'dawn il-kolonni.

125
00:05:51,670 --> 00:05:54,450
Ukoll, jirriżulta li
kompjuters huma verament mhux

126
00:05:54,450 --> 00:05:56,300
dak kollu li differenti minn int u jien.

127
00:05:56,300 --> 00:06:01,840
Iżda minflok li jużaw poteri ta '10,
hekk li speak-- 1, 10, 100, 1000,

128
00:06:01,840 --> 00:06:04,330
10000 post u l-bqija
forth-- huma attwalment

129
00:06:04,330 --> 00:06:08,930
biss tuża l-poteri ta '2--
hekk wieħed, 2, 4, u mbagħad

130
00:06:08,930 --> 00:06:12,810
jekk npoġġux aktar ċifri, 8, 16,
32, 64, 128, u oħrajn.

131
00:06:12,810 --> 00:06:16,050
U għalhekk dan huwa kif kompjuter
tirrappreżenta n-numru 0,

132
00:06:16,050 --> 00:06:17,300
bħad aħna bnedmin.

133
00:06:17,300 --> 00:06:21,660
>> 0, 0, 0-- u inti tista 'probabbilment raden
liema mudell ta 'żerijiet u dawk,

134
00:06:21,660 --> 00:06:24,610
jekk il-kompjuter jista 'biss
jitkellmu 0 jew 1-- liema

135
00:06:24,610 --> 00:06:29,110
mudell se jirrappreżenta
in-numru aħna bnedmin magħrufa bħala 1?

136
00:06:29,110 --> 00:06:30,590
Yeah-- 0, 0, 1.

137
00:06:30,590 --> 00:06:31,090
Kull dritt.

138
00:06:31,090 --> 00:06:35,900
Allura 0, 0, 1 hija kif aħna nirrappreżentaw
1, sabiex inti tista 'tkun inklinata mbagħad

139
00:06:35,900 --> 00:06:39,510
biex jirrappreżentaw in-numru 2, jekk għandek
post tal-erba 'u l-post l-żewġ li

140
00:06:39,510 --> 00:06:48,290
bħala l-post wieħed, inti jista 'jgħid, ukoll,
jekk kellna 1 minflok il-wieħed,

141
00:06:48,290 --> 00:06:50,430
u issa rridu
joqgħod sa 2, inti tista

142
00:06:50,430 --> 00:06:53,310
tagħmel dan u jħallu din tkun żero.

143
00:06:53,310 --> 00:06:56,397
Iżda naturalment dan mhux kif
is-sistema deċimali taħdem jew.

144
00:06:56,397 --> 00:06:58,230
Jekk inti tpoġġi ċifri fil
dawn iż-żewġ kolonni,

145
00:06:58,230 --> 00:06:59,563
inti stajt ltqajna biex jagħmlu l-aritmetika.

146
00:06:59,563 --> 00:07:01,930
Allura liema numru ma I
aċċidentalment biss jirrappreżenta?

147
00:07:01,930 --> 00:07:06,710
>> Allura huwa 3, għaliex 2 darbiet 1 flimkien ma '1
żminijiet 1, naturalment, jagħtina tlieta.

148
00:07:06,710 --> 00:07:08,340
Għalhekk dan ikun tnejn.

149
00:07:08,340 --> 00:07:12,730
-Bit-tip ta Flips, biex ngħidu hekk, kif 0
isir wieħed, ħafna bħal 9 rwoli aktar

150
00:07:12,730 --> 00:07:14,840
u ssir 0 meta inti twettaq l-1.

151
00:07:14,840 --> 00:07:16,510
Dan imbagħad ikun tlieta tal-kors.

152
00:07:16,510 --> 00:07:20,170
Four-- ħaġa oħra interessanti
jiġri, meta dawk qlib

153
00:07:20,170 --> 00:07:21,750
u inti twettaq l-1, biex ngħidu hekk.

154
00:07:21,750 --> 00:07:23,320
Allura dan, naturalment, huwa ta '4.

155
00:07:23,320 --> 00:07:25,160
>> Imma jekk inti fast quddiem issa,
x'inhu l-akbar numru għaddej

156
00:07:25,160 --> 00:07:26,660
biex tkun li l-kompjuter jista 'jirrappreżenta?

157
00:07:26,660 --> 00:07:30,420

158
00:07:30,420 --> 00:07:32,380
Allura huwa biss sebgħa f'dan il-każ, id-dritt?

159
00:07:32,380 --> 00:07:35,570
Għax għandek wieħed fil-erbgħa,
waħda fil-tnejn, waħda fil-wieħed.

160
00:07:35,570 --> 00:07:36,900
Allura li għamilhom 4 flimkien ma '2 flimkien ma' 1.

161
00:07:36,900 --> 00:07:37,972
Allura li jagħtik sebgħa.

162
00:07:37,972 --> 00:07:39,680
U fil-fatt, dan iwassal
jidher fl-ewwel daqqa t'għajn

163
00:07:39,680 --> 00:07:43,750
li l-kompjuters jista 'joqgħod
mhux ogħla minn hekk.

164
00:07:43,750 --> 00:07:45,210
>> Iżda dan il-kors mhux veru.

165
00:07:45,210 --> 00:07:48,243
What do aħna bnedmin jagħmlu meta rridu
li jgħoddu ogħla milli simili 999?

166
00:07:48,243 --> 00:07:51,000

167
00:07:51,000 --> 00:07:53,900
Kompli l-waħda u biss
żid raba 'ċifra lejn ix-xellug.

168
00:07:53,900 --> 00:07:55,070
U hekk tabilħaqq nistgħu.

169
00:07:55,070 --> 00:07:57,900
Aħna jista 'jkollhom tmint tal
post u post ta '16 s,

170
00:07:57,900 --> 00:08:02,000
u l-post ta '32 s, 64, 128-- u int
jistgħu biss iżommu għaddejjin sa infinit.

171
00:08:02,000 --> 00:08:04,640
Allura dawn żerijiet u ones--
l-hekk imsejħa system-- binarja

172
00:08:04,640 --> 00:08:10,290
huma dak xjenzat kompjuter kieku
ġeneralment sejħa daqsxejn, jew ċifri binarja.

173
00:08:10,290 --> 00:08:13,590
>> Imma issa, kif do we jiksbu mill-
kunċett jew il-grafika ta 'dawn l-affarijiet

174
00:08:13,590 --> 00:08:14,620
għal kompjuter attwali?

175
00:08:14,620 --> 00:08:17,170
Aħna jidhru li taqbeż pass hawn.

176
00:08:17,170 --> 00:08:20,210
Ukoll, l-unika input fl-aħħar
tal-ġurnata, għall-laptop tiegħi hawn

177
00:08:20,210 --> 00:08:22,060
huwa dan il-fluss ta 'l-elettriku.

178
00:08:22,060 --> 00:08:24,560
Anki jekk huwa kien twil
ħin peress li inti ħsibt dwar

179
00:08:24,560 --> 00:08:26,580
jew qatt ħsibt dwar
kif taħdem l-elettriku,

180
00:08:26,580 --> 00:08:30,909
hemm elettroni li jirriżultaw fi jew
barra, u li tip tiegħi ta 'input.

181
00:08:30,909 --> 00:08:34,659
>> Mela jekk dan huwa dak kollu li aħna qed
jkollna bħala input hawn,

182
00:08:34,659 --> 00:08:36,830
x'nistgħu nagħmlu ma 'dik l-informazzjoni?

183
00:08:36,830 --> 00:08:40,040
Ukoll, nistgħu naħsbu ta 'żero bħala
biss nuqqas ta 'l-elettriku.

184
00:08:40,040 --> 00:08:42,540
Xejn huwa flowinw, xejn huwa
jiċċaqilqu, xejn qed jiġri.

185
00:08:42,540 --> 00:08:44,690
Li jinsab biss l-inadempjenza state-- żero.

186
00:08:44,690 --> 00:08:48,200
Iżda jekk ikun hemm l-elettriku li jirriżultaw, għaliex
ma we biss b'mod arbitrarju, imma globalment

187
00:08:48,200 --> 00:08:50,250
b'mod konsistenti, sejħa li wieħed.

188
00:08:50,250 --> 00:08:54,760
>> Allura sempliċiment billi li ma jkollux enerġija,
għandna żero, iva enerġija,

189
00:08:54,760 --> 00:08:57,520
għandna one-- ebda setgħa, iva enerġija.

190
00:08:57,520 --> 00:09:01,520
U b'dan il-mod, bl-użu xi ħaġa
aktar fiżiku jew elettroniku

191
00:09:01,520 --> 00:09:05,340
nibdew biex jimplimentaw dan il-kunċett ta '
xi ħaġa jew li tkun waħda jew żero.

192
00:09:05,340 --> 00:09:07,230
Tabilħaqq, nistgħu biss tagħmel dan hawn fuq.

193
00:09:07,230 --> 00:09:10,590
So here, I ma tliet xhur iżda
tmien bozoz tad-dawl, li kull wieħed minnhom

194
00:09:10,590 --> 00:09:11,810
għandha swiċċ tiegħu stess.

195
00:09:11,810 --> 00:09:15,760
>> U hekk jekk jien ridt li tirrappreżenta
in-numru sebgħa hawn,

196
00:09:15,760 --> 00:09:18,510
I jistgħu jduru fuq dawn it-tliet bozoz tad-dawl.

197
00:09:18,510 --> 00:09:21,470
U fil-fatt, ġewwa ta '
kompjuter tiegħi huwa miljuni,

198
00:09:21,470 --> 00:09:25,650
biljuni ta 'affarijiet li huma biss
iżgħar minn dak, imsejħa transisters,

199
00:09:25,650 --> 00:09:27,330
swiċċijiet, li inti sempliċiment dawwar fuq u off.

200
00:09:27,330 --> 00:09:30,420
Allura dawn huma big-- relattivament
swiċċijiet big-- ġewwa laptop-- tiegħi

201
00:09:30,420 --> 00:09:32,150
huma ħafna, ħafna, ħafna,
ħafna swiċċijiet aktar.

202
00:09:32,150 --> 00:09:35,160
Imma kull ma tagħmel huwa eżattament that--
dawran xi ħaġa fuq, dawwar xi ħaġa off.

203
00:09:35,160 --> 00:09:38,076
U bħala tali, kompjuter jista 'jirrappreżenta,
ma 'dawk miljuni jew biljuni

204
00:09:38,076 --> 00:09:40,480
ta transisters, lottijiet u
lottijiet ta 'żero u dawk.

205
00:09:40,480 --> 00:09:43,160
U hemm hardware ieħor għadu dak
ihallik jaħżen informazzjoni fit-tul,

206
00:09:43,160 --> 00:09:45,243
b'tali mod li meta inti iġbed il-
plug, inti ma titilfu.

207
00:09:45,243 --> 00:09:46,900
Imma dak li storja għal jum ieħor.

208
00:09:46,900 --> 00:09:51,170
>> Allura x'nistgħu nagħmlu ma 'dawn bits?

209
00:09:51,170 --> 00:09:54,309
Jista aħna biss jieħdu
il-pressjoni off ta 'me--

210
00:09:54,309 --> 00:09:56,600
tista 'xi ħadd tixtieq li ġejjin
up hawn u joffru up demo?

211
00:09:56,600 --> 00:09:57,516
Rajt dan il-idejn ewwel.

212
00:09:57,516 --> 00:09:58,709
X'hemm isem tiegħek?

213
00:09:58,709 --> 00:09:59,250
MADAY: MADAY.

214
00:09:59,250 --> 00:10:00,542
DAVID Malan: MADAY, come fuq up.

215
00:10:00,542 --> 00:10:01,250
Għandi pjaċir.

216
00:10:01,250 --> 00:10:02,390
MADAY: Nizza biex jissodisfaw inti.

217
00:10:02,390 --> 00:10:02,930
>> DAVID Malan: Come b'dan il-mod.

218
00:10:02,930 --> 00:10:04,182
I mhux se jkollhom lip inti up.

219
00:10:04,182 --> 00:10:04,682
Kull dritt.

220
00:10:04,682 --> 00:10:11,090
Allura hawnhekk, aħna għandna, notice-- waħda, two--
aħna ser jeditjaw dak out-- wieħed, tnejn, erba,

221
00:10:11,090 --> 00:10:13,350
tmienja, 16, 32, 64, 128.

222
00:10:13,350 --> 00:10:14,220
Dan huwa intenzjonat.

223
00:10:14,220 --> 00:10:17,370
Hemm tmien bits here--
żero digits-- u dawk binarja.

224
00:10:17,370 --> 00:10:21,460
U daqsxejn hija unità utli ta measure--
mhux bħala utli unità ta 'miżura

225
00:10:21,460 --> 00:10:21,999
fuq innifsu.

226
00:10:21,999 --> 00:10:24,290
Normalment inti tixtieq mill-inqas
tmienja minn dawn l-affarijiet, a.k.a.

227
00:10:24,290 --> 00:10:24,790
byte.

228
00:10:24,790 --> 00:10:26,230
Allura aħna għandna byte ta 'bits hawn.

229
00:10:26,230 --> 00:10:31,130
>> Mela jekk ridna li jikkontesta inti ma,
per eżempju, ortografija, b'mod binarju,

230
00:10:31,130 --> 00:10:33,230
dan il-valur here-- 42.

231
00:10:33,230 --> 00:10:35,140
Trid tieħu stab f'dak?

232
00:10:35,140 --> 00:10:36,034
>> MADAY: [inaudible].

233
00:10:36,034 --> 00:10:38,700
DAVID Malan: Yeah, biss imbotta l-
swiċċijiet ftit abjad fuq quddiem.

234
00:10:38,700 --> 00:10:41,290
U inti tixtieq li jespliċitaw
barra 42, u x'jintrebħu

235
00:10:41,290 --> 00:10:44,061
huwa dan l-istress CS50
ballun jekk ikollok dan.

236
00:10:44,061 --> 00:10:44,560
Kull dritt.

237
00:10:44,560 --> 00:10:46,420
Allura inti għandek 32.

238
00:10:46,420 --> 00:10:48,430
Aħna ser jeħtieġu 42.

239
00:10:48,430 --> 00:10:51,410
Allura dak ta 'tmien, b'tali mod li 40.

240
00:10:51,410 --> 00:10:54,160
U excellent-- ħafna nicely jsir.

241
00:10:54,160 --> 00:10:55,186
Grazzi.

242
00:10:55,186 --> 00:10:58,790
>> [Applause]

243
00:10:58,790 --> 00:10:59,290
Kull dritt.

244
00:10:59,290 --> 00:11:00,623
Allura aħna għandna waħda aktar ballun istress.

245
00:11:00,623 --> 00:11:03,595
Ejja nagħmlu dan darba aktar jekk irridu jistgħu.

246
00:11:03,595 --> 00:11:05,368
Wieħed voluntier ieħor?

247
00:11:05,368 --> 00:11:07,970
Stress ħielsa ball, ballun stress ħielsa.

248
00:11:07,970 --> 00:11:08,470
KOLLOX SEW.

249
00:11:08,470 --> 00:11:11,640
Minn hawn fin-nofs,
do inti tixtieq li tinżel?

250
00:11:11,640 --> 00:11:14,100
Kull dritt.

251
00:11:14,100 --> 00:11:15,552
Naf.

252
00:11:15,552 --> 00:11:16,360
Hemm immorru.

253
00:11:16,360 --> 00:11:20,818
>> Allura n-numri here-- jaqgħu fuq l isfel.

254
00:11:20,818 --> 00:11:21,567
X'inhu l-isem tiegħek?

255
00:11:21,567 --> 00:11:21,984
>> DAVEY: Davey.

256
00:11:21,984 --> 00:11:22,820
>> DAVID Malan: Davey.

257
00:11:22,820 --> 00:11:23,320
KOLLOX SEW.

258
00:11:23,320 --> 00:11:24,810
Come fuq up, Davey.

259
00:11:24,810 --> 00:11:25,890
Għandi pjaċir.

260
00:11:25,890 --> 00:11:28,639
U dak li aħna qed tmur biex ikollhom inti
spell-- jekk inti tista 'linger hemm

261
00:11:28,639 --> 00:11:32,810
għal waħda biss moment-- huwa n-numru 50.

262
00:11:32,810 --> 00:11:36,293
Iżda, imma, imma imma, imma, dawn huma
kalamiti Iskola ta 'grad għal raġuni.

263
00:11:36,293 --> 00:11:39,370

264
00:11:39,370 --> 00:11:43,327
Biss ltqajna ftit diffiċli, id-dritt?

265
00:11:43,327 --> 00:11:44,160
Hemm għadu tmienja.

266
00:11:44,160 --> 00:11:46,820

267
00:11:46,820 --> 00:11:47,320
Kull dritt.

268
00:11:47,320 --> 00:11:48,486
Allura dak li għandna fuq hemmhekk?

269
00:11:48,486 --> 00:11:51,356
Għandna 32.

270
00:11:51,356 --> 00:11:54,344
Nizza.

271
00:11:54,344 --> 00:11:58,610
32 flimkien ma '16 jagħtina 48-- tant qrib.

272
00:11:58,610 --> 00:12:00,390
U wunderbare.

273
00:12:00,390 --> 00:12:02,831
Prosit lil Davey kif ukoll.

274
00:12:02,831 --> 00:12:05,720
>> [Applause]

275
00:12:05,720 --> 00:12:06,516
>> Kull dritt.

276
00:12:06,516 --> 00:12:09,390
Allura nistgħu nagħmlu din il-ġurnata kollha, u
ma jiksbu kollha li ħafna aktar

277
00:12:09,390 --> 00:12:10,800
interessanti u aktar ta 'sfida.

278
00:12:10,800 --> 00:12:13,250
Imma dak li verament il-point--
huwa kif relattivament sempliċi

279
00:12:13,250 --> 00:12:16,930
huwa, fl-aħħar tal-ġurnata, liema
kompjuter ma biex jaħżnu l-informazzjoni,

280
00:12:16,930 --> 00:12:21,740
biex jaħżnu inputs u finalment
jaħżen jew jirrappreżentaw dawk outputs.

281
00:12:21,740 --> 00:12:23,750
Iżda n-numri waħedhom mhumiex
dak kollu li interessanti.

282
00:12:23,750 --> 00:12:26,069
>> Allura bnedmin, xi snin ilu,
iddeċieda, inti taf liema?

283
00:12:26,069 --> 00:12:27,860
Ikun sbieħ jekk
kompjuters ma kinux biss

284
00:12:27,860 --> 00:12:31,030
kalkolaturi għall aritmetika
operazzjonijiet, imma attwalment tista

285
00:12:31,030 --> 00:12:35,209
do affarijiet simili word-processing, jew
email, jew incarnations aktar moderni

286
00:12:35,209 --> 00:12:36,500
ta 'dawn it-tipi ta' teknoloġiji.

287
00:12:36,500 --> 00:12:40,680
U għalhekk il-dinja iddeċieda
arbitrarju, iżda universalment,

288
00:12:40,680 --> 00:12:44,380
li jekk inti tixtieq li taħżen il-kapital
ittra A fil-kompjuter, inti taf liema?

289
00:12:44,380 --> 00:12:47,730
Ejja biss kollha jaqblu li jaħżen
xi mudell ta 'żerijiet u ones--

290
00:12:47,730 --> 00:12:52,422
bits-- li finalment
jirrappreżenta n-numru deċimali 65..

291
00:12:52,422 --> 00:12:53,630
Aħna ser biss kollha jaqblu fuq dan.

292
00:12:53,630 --> 00:12:56,620
>> 66 tkun tirrappreżenta B,
67 tkun tirrappreżenta Ċ,

293
00:12:56,620 --> 00:13:00,210
u hemm għenieqed ta 'mudelli oħrajn ta'
żerijiet u dawk, jew numri bażiċi,

294
00:13:00,210 --> 00:13:02,224
li jirrappreżenta
ittri l-oħra għadhom.

295
00:13:02,224 --> 00:13:04,390
Mela jekk inti tip ta mentalment
jassorbi dan għal mument,

296
00:13:04,390 --> 00:13:10,900
I deliberatament imqiegħed A sa
I, fejn H 72 u I huwa 73.

297
00:13:10,900 --> 00:13:15,830
Jekk kompjuter imbagħad, fil-kuntest ta '
programm ta 'pproċessar kelma jew e-mail,

298
00:13:15,830 --> 00:13:19,620
żvelat taħt il-barnuża li jkollhom
dawn it-tendenzi ta 'mudell bits--

299
00:13:19,620 --> 00:13:22,500
ta 'bits li jirrappreżentaw
72, imbagħad 73, allura 33--

300
00:13:22,500 --> 00:13:26,640
x'jista 'din il-jespliċitaw f'dak il-programm?

301
00:13:26,640 --> 00:13:28,150
>> Allura hi, u mbagħad xi ħaġa.

302
00:13:28,150 --> 00:13:31,460
Aħna ma neċessarjament jaf, imma tassew
33-- mhux fuq il-karta earlier--

303
00:13:31,460 --> 00:13:33,170
kien sempliċement punt exclamation.

304
00:13:33,170 --> 00:13:38,870
Allura 72 kien H, 73 huwa jien, 33 jiġri
li tkun punt exclamation xorta.

305
00:13:38,870 --> 00:13:41,719
Imma li kollox multa u tajba,
u fil-fatt illum, aktar milli

306
00:13:41,719 --> 00:13:43,760
biss tuża seba 'jew tmien
bits, grazzi għal xi ħaġa

307
00:13:43,760 --> 00:13:46,530
sejjaħ Unicode kuntrarju
li ASCII lura fil-ġurnata,

308
00:13:46,530 --> 00:13:50,010
aħna fil-fatt jista 'jirrappreżenta saħansitra aktar
karattri interessanti milli sempliċement

309
00:13:50,010 --> 00:13:52,980
dawn oriġinali bl-Ingliż ittri preġudikata.

310
00:13:52,980 --> 00:13:56,030
Iżda nistgħu wkoll jirrapreżenta anki
affarijiet neater simili kuluri.

311
00:13:56,030 --> 00:13:59,750
>> Jekk inti stajt qatt semgħu l-akronimu
RGB, aħmar, aħdar, blu, li

312
00:13:59,750 --> 00:14:03,510
ifisser biss li l-kompjuter
tipikament juża tliet settijiet ta 'bits--

313
00:14:03,510 --> 00:14:06,760
xi numru ta 'bits li jirrappreżentaw
numru ta 'kemm aħmar trid,

314
00:14:06,760 --> 00:14:08,940
sett ieħor ta 'bits għal
kemm ħadra trid,

315
00:14:08,940 --> 00:14:11,430
u numru ieħor stabbilit għal
kemm blu trid.

316
00:14:11,430 --> 00:14:14,457
Allura numru kbir jfisser lottijiet ta '
aħmar, numru żgħir tfisser l-ebda aħmar.

317
00:14:14,457 --> 00:14:16,290
U hekk dawn huma tip
ta 'valuri nofs hawn.

318
00:14:16,290 --> 00:14:20,180
>> Allura tagħti me xi aħmar, Nirċievi
aħdar, u tagħti me xi ftit ta 'blu.

319
00:14:20,180 --> 00:14:24,260
U jekk inti taħlita dawn it-tliet sfumaturi
ta 'kulur flimkien, f'dan il-każ,

320
00:14:24,260 --> 00:14:26,850
ikollok dan dell murky
isfar jew kannella.

321
00:14:26,850 --> 00:14:32,330
Iżda dak il-mudell ta 'tmien flimkien
tmienja plus eight-- hekk 24 bits--

322
00:14:32,330 --> 00:14:36,550
xellug għal-lemin, huwa kif kompjuter
tirrappreżenta dak il-kulur partikolari.

323
00:14:36,550 --> 00:14:38,090
Issa din hija biss tikka fuq skrin.

324
00:14:38,090 --> 00:14:42,230
Jekk inti tħares verament qrib lejn TV tiegħek tiegħek
kompjuter, tkun taf tara tikek jew pixels.

325
00:14:42,230 --> 00:14:45,420
U jekk ikollok grilja sħiħa ta
pixel, orizzontalment u vertikalment,

326
00:14:45,420 --> 00:14:46,630
għandek immaġini.

327
00:14:46,630 --> 00:14:49,029
U mbagħad jekk inti tieħu
immaġni u mbagħad aħsel

328
00:14:49,029 --> 00:14:52,070
juru lilek innifsek ieħor immaġini, ieħor
immaġni, immaġni ieħor, ieħor immaġini,

329
00:14:52,070 --> 00:14:54,760
verament mgħaġġel, inti naturalment għandek films.

330
00:14:54,760 --> 00:14:56,109
>> U hekk Avviż fejn bdejna.

331
00:14:56,109 --> 00:14:57,650
Bdejna ma 'dawn żerijiet u dawk.

332
00:14:57,650 --> 00:15:00,570
Ħdimna minn hemm sa deċimali
numri, kif aħna jirrappreżentawhom.

333
00:15:00,570 --> 00:15:02,070
Issa għandna l-ittri tal-alfabett.

334
00:15:02,070 --> 00:15:05,664
Iżda f'kuntesti oħra stenna, nistgħu nużaw
a aktar bits u jirrappreżentaw kuluri ftit.

335
00:15:05,664 --> 00:15:07,830
Hekk kif inti għandek l-
abbiltà li jirrappreżentaw kuluri,

336
00:15:07,830 --> 00:15:11,200
inti għandek il-ħila biex jirrappreżentaw
ritratti u gifs animati

337
00:15:11,200 --> 00:15:13,780
u l-karattri oħra bħal dawn fuq l-iskrin.

338
00:15:13,780 --> 00:15:17,160
U meta jkollok mazz sħiħ ta '
immaġini li jtajru l-bniedem fil-darba,

339
00:15:17,160 --> 00:15:21,480
jidher qisu stampi mozzjoni,
u għalhekk inti tikseb videos ukoll.

340
00:15:21,480 --> 00:15:23,460
>> Allura jużaw dawn ħafna
primitives sempliċi do we

341
00:15:23,460 --> 00:15:28,070
għandhom il-mod ta jirrappreżentaw
finalment kollha ta 'dawn il-forom ta' midja.

342
00:15:28,070 --> 00:15:30,450
U konna estratt mill-ġdid
u għal darb'oħra u għal darb'oħra, sakemm aħna

343
00:15:30,450 --> 00:15:33,467
jiksbu mill-aktar livell baxx
għal dan l-ogħla livell.

344
00:15:33,467 --> 00:15:35,550
Allura li jagħtina din il
idea ġenerali ta 'estrazzjoni.

345
00:15:35,550 --> 00:15:36,990
Iżda bdejna hawn.

346
00:15:36,990 --> 00:15:38,790
>> Hawnhekk issa, nistgħu
jirrappreżentaw fil-kompjuter

347
00:15:38,790 --> 00:15:41,920
inputs tagħna ma żerijiet u dawk,
riżultati tagħna fl żerijiet u dawk,

348
00:15:41,920 --> 00:15:43,640
imma dak li jmur ġewwa l-kaxxa?

349
00:15:43,640 --> 00:15:46,080
Li meta kompjuter
xjenza gets interessanti.

350
00:15:46,080 --> 00:15:49,770
Li meta inti fil-fatt iġġib tiegħek
imħuħ tagħhom biex iġorru sabiex isolvu problemi.

351
00:15:49,770 --> 00:15:52,590
Aħna issa jistgħu jistipulaw, għall-
bqija tas-semestru, iva.

352
00:15:52,590 --> 00:15:53,870
Naf xogħlijiet kif binarja.

353
00:15:53,870 --> 00:15:57,942
Niftakar kif ASCII jew Unicode--
l-immappjar li letters-- xogħlijiet.

354
00:15:57,942 --> 00:15:59,650
U ċertament inhi
għal raġuni li aħna

355
00:15:59,650 --> 00:16:03,470
jista 'jirrappreżenta aħmar u aħdar u
blu, u jirrappreżentaw multimedjali kif ukoll.

356
00:16:03,470 --> 00:16:05,390
Iżda din hija l-għalf interessanti.

357
00:16:05,390 --> 00:16:09,790
Dan huwa dak li jagħmel xi ħadd
kapaċi li ssolvi problemi.

358
00:16:09,790 --> 00:16:11,980
>> U problema waħda tali
aħna nixtiequ li tagħmel, fil-fatt,

359
00:16:11,980 --> 00:16:15,345
qed tieħu attendenza, jew
tagħmel dan algorithmically.

360
00:16:15,345 --> 00:16:16,470
U għal darb'oħra, I jista 'tagħmel dan.

361
00:16:16,470 --> 00:16:19,580
I tista 'tagħmel wieħed, tnejn, tlieta, erba
ħames, sitt, seba ', tmien disa.

362
00:16:19,580 --> 00:16:21,520
UI tista 'tikteb it
l isfel li jżommu rekord ta 'dan.

363
00:16:21,520 --> 00:16:23,769
Imma dak li kemm nixtieq
jirrappreżentaw l-informazzjoni.

364
00:16:23,769 --> 00:16:27,550
Jew I jistgħu jagħmlu dan faster-- tnejn, erba,
sitta, tmienja, għaxra, 12, 14, 16, 18, 20,

365
00:16:27,550 --> 00:16:30,380
22-- jħoss simili darbtejn
malajr iżda huwa għadu

366
00:16:30,380 --> 00:16:32,050
ser jieħdu lott kollu ta 'żmien.

367
00:16:32,050 --> 00:16:35,990
>> Iżda jirriżulta, jekk aħna lieva għadu
ieħor kompjuters resource-- u tabilħaqq

368
00:16:35,990 --> 00:16:38,940
dawn il-jiem għandhom CPUs multipli jew imħuħ.

369
00:16:38,940 --> 00:16:41,970
Jirriżulta kompjuters jistgħu
jagħmlu lottijiet ta 'affarijiet f'daqqa,

370
00:16:41,970 --> 00:16:44,460
u tabilħaqq aħna, f'din il-kamra,
jafu jirrappreżentaw eżattament din il.

371
00:16:44,460 --> 00:16:47,130
>> Allura huwa ftit soċjalment
skomdi, imma jekk inti Humer lili

372
00:16:47,130 --> 00:16:51,550
għal ftit proċess ta 'tliet stadji, let
me nitolbok kulħadd fil-post hemm biss

373
00:16:51,550 --> 00:16:54,640
biex stand up għal mument.

374
00:16:54,640 --> 00:16:57,380
Qum bilwieqfa.

375
00:16:57,380 --> 00:17:01,580
Allura taħseb li inti stess, in-numru
one-- sabiex kulħadd f'din il-kamra,

376
00:17:01,580 --> 00:17:05,010
ħlief il-persuni li ma kinux
jobbligaw, taħseb numru wieħed.

377
00:17:05,010 --> 00:17:06,510
Allura li huwa numru tiegħek dritt issa.

378
00:17:06,510 --> 00:17:09,399
Dan huwa l-ewwel pass, jew bħala
kompjuter xjenzat jew programmer

379
00:17:09,399 --> 00:17:11,827
tipikament do, aħna qed tmur
biex jibdew jingħaddu fuq iż-żero.

380
00:17:11,827 --> 00:17:14,410
Jekk l-iżgħar numru nistgħu
jirrappreżentaw dawk bozoz tad-dawl

381
00:17:14,410 --> 00:17:17,410
huwa żero, bi ftit filwaqt li jħallihom
kollha off, I jistgħu wkoll biss

382
00:17:17,410 --> 00:17:19,271
jibdew jingħaddu mid
żero hija minflok waħda.

383
00:17:19,271 --> 00:17:21,020
U hekk dan huwa dak
xjenzjati tal-kompjuter do.

384
00:17:21,020 --> 00:17:23,750
Allura pass żero, stand up u
think tan-numru wieħed.

385
00:17:23,750 --> 00:17:26,339
Il-pass li jmiss huwa this-- par
off ma wieqfa xi ħadd

386
00:17:26,339 --> 00:17:27,660
u żid in-numri tiegħek flimkien.

387
00:17:27,660 --> 00:17:30,660

388
00:17:30,660 --> 00:17:32,850
Wonderful.

389
00:17:32,850 --> 00:17:37,640
>> Allura f'dan il-mument fiż-żmien,
litteralment kulħadd jipparteċipa

390
00:17:37,640 --> 00:17:41,930
huwa ħsieb tan-numru 2, ħlief
għal persuna waħda fard jekk ikollna

391
00:17:41,930 --> 00:17:43,450
numru fard ta 'nies fil-kamra.

392
00:17:43,450 --> 00:17:50,640
U issa l-tielet pass hawnhekk se
ikunu this-- wieħed minnkom għandu joqogħdu bilqegħda.

393
00:17:50,640 --> 00:17:54,490
Wieħed minnkom għandu joqogħdu bilqegħda,
u jekk int xorta bil-wieqfa,

394
00:17:54,490 --> 00:17:56,590
mur lura għall-pass wieħed.

395
00:17:56,590 --> 00:18:44,799

396
00:18:44,799 --> 00:18:45,790
Kull dritt.

397
00:18:45,790 --> 00:19:00,760

398
00:19:00,760 --> 00:19:01,650
Kull dritt.

399
00:19:01,650 --> 00:19:03,880
Allura aktar u aktar nies
għandhom jiġu bilqiegħda.

400
00:19:03,880 --> 00:19:08,280
Avviż li dan indotta
a loop-- xi tip ta 'ċiklu.

401
00:19:08,280 --> 00:19:11,983
Xi wħud minnkom għandu jkun awkwardly staġnati,
jmorru quddiem u lura bejn pass wieħed

402
00:19:11,983 --> 00:19:14,180
u tnejn, wieħed u tnejn, wieħed u tnejn.

403
00:19:14,180 --> 00:19:21,190

404
00:19:21,190 --> 00:19:21,810
Kollox sew.

405
00:19:21,810 --> 00:19:22,630
ewwel bug tagħna.

406
00:19:22,630 --> 00:19:24,740
Aħna ser tittratta dik.

407
00:19:24,740 --> 00:19:25,320
Kull dritt.

408
00:19:25,320 --> 00:19:27,370
Let me jippruvaw biex jixprunaw affarijiet flimkien.

409
00:19:27,370 --> 00:19:31,454
>> Fit-teorija, persuna waħda biss hija wieqfa
kif kulħadd qed tkompli par off.

410
00:19:31,454 --> 00:19:33,870
Imma ħalluni tħaffef affarijiet up
mal-poplu għadha wieqfa.

411
00:19:33,870 --> 00:19:35,480
Liema numru huma inti taħseb?

412
00:19:35,480 --> 00:19:36,070
46..

413
00:19:36,070 --> 00:19:36,570
KOLLOX SEW.

414
00:19:36,570 --> 00:19:37,820
Jimxi 'l quddiem u joqogħdu bilqegħda.

415
00:19:37,820 --> 00:19:39,190
You guys għadhom wieqfa.

416
00:19:39,190 --> 00:19:42,130
Min hu għadha wieqfa?

417
00:19:42,130 --> 00:19:45,240
Liema numru huma inti taħseb?

418
00:19:45,240 --> 00:19:46,160
KOLLOX SEW.

419
00:19:46,160 --> 00:19:47,900
>> Allura aħna ser terga 'lura lilek.

420
00:19:47,900 --> 00:19:49,630
Fid-dahar?

421
00:19:49,630 --> 00:19:50,790
X'inhu li?

422
00:19:50,790 --> 00:19:53,100
22.

423
00:19:53,100 --> 00:19:56,540
OK xi ħadd ieħor sa top-- yeah?

424
00:19:56,540 --> 00:19:57,720
34..

425
00:19:57,720 --> 00:19:58,300
KOLLOX SEW.

426
00:19:58,300 --> 00:20:02,780
Minn hawn fuq right-- tiegħi up here?

427
00:20:02,780 --> 00:20:06,820
132, sbieħ ħafna.

428
00:20:06,820 --> 00:20:08,380
22?

429
00:20:08,380 --> 00:20:08,990
>> KOLLOX SEW.

430
00:20:08,990 --> 00:20:10,031
U li għadu wieqaf?

431
00:20:10,031 --> 00:20:11,000
Hawnhekk?

432
00:20:11,000 --> 00:20:14,520
46, sbieħ ħafna.

433
00:20:14,520 --> 00:20:16,890
72..

434
00:20:16,890 --> 00:20:18,220
I ma jistgħux stall ħafna itwal.

435
00:20:18,220 --> 00:20:20,520
Yeah?

436
00:20:20,520 --> 00:20:22,490
30, sbieħ.

437
00:20:22,490 --> 00:20:24,120
Hawnhekk?

438
00:20:24,120 --> 00:20:26,200
23?

439
00:20:26,200 --> 00:20:27,270
23.

440
00:20:27,270 --> 00:20:30,920
>> U naħseb li kulħadd
ħlief inti guys, ebda pressjoni.

441
00:20:30,920 --> 00:20:32,860
Oh, stenna.

442
00:20:32,860 --> 00:20:33,360
28?

443
00:20:33,360 --> 00:20:37,500

444
00:20:37,500 --> 00:20:38,281
Biss tmienja.

445
00:20:38,281 --> 00:20:38,780
KOLLOX SEW.

446
00:20:38,780 --> 00:20:41,030
Biss tmienja.

447
00:20:41,030 --> 00:20:42,580
Down hawn?

448
00:20:42,580 --> 00:20:44,570
30.

449
00:20:44,570 --> 00:20:47,344
23.

450
00:20:47,344 --> 00:20:47,843
24.

451
00:20:47,843 --> 00:20:50,810

452
00:20:50,810 --> 00:20:52,310
18.

453
00:20:52,310 --> 00:20:54,690
Dan huwa l-agħar implimentazzjoni
ta 'dan algoritmu qatt.

454
00:20:54,690 --> 00:20:55,190
KOLLOX SEW.

455
00:20:55,190 --> 00:20:59,760
Allura xi ħadd ieħor?

456
00:20:59,760 --> 00:21:00,421
Ħaddieħor?

457
00:21:00,421 --> 00:21:00,920
KOLLOX SEW.

458
00:21:00,920 --> 00:21:03,300
Wieħed aktar.

459
00:21:03,300 --> 00:21:04,400
16?

460
00:21:04,400 --> 00:21:04,900
KOLLOX SEW.

461
00:21:04,900 --> 00:21:05,510
16.

462
00:21:05,510 --> 00:21:06,010
Kull dritt.

463
00:21:06,010 --> 00:21:09,070
Mela jekk jien ma qbiżt xi ħadd fil
l-dija hawn, meta I hit Ikteb,

464
00:21:09,070 --> 00:21:13,091
se naraw, algorithmically, il
Numru totali ta 'persuni fl Sanders.

465
00:21:13,091 --> 00:21:16,340
Minħabba darb'oħra, huwa bħallikieku kulħadd
kif inti sib stabbiliti, għadda numru tiegħek off

466
00:21:16,340 --> 00:21:19,215
lil xi ħadd ieħor, lil xi ħadd ieħor,
lil xi ħadd ieħor, b'tali mod li fit-teorija,

467
00:21:19,215 --> 00:21:22,304
fl-aħħar, wieħed biss skomdi
persuna għandha titħalla wieqfa.

468
00:21:22,304 --> 00:21:22,970
Imma li l-multa.

469
00:21:22,970 --> 00:21:24,290
Aħna titħaffef affarijiet up manwalment.

470
00:21:24,290 --> 00:21:27,590
Huwa speċjalment diffiċli li wieħed jara
f'dan l-ispazju partikolari.

471
00:21:27,590 --> 00:21:34,200
>> U n-numru totali ta 'nies
naħsbu qegħdin hemm hawnhekk huwa 546.

472
00:21:34,200 --> 00:21:37,330
In-numru totali ta kelli f'idha
mill-fellows tagħlim,

473
00:21:37,330 --> 00:21:40,660
li ma kien il-qadim
iskola mod bil-mod, kien 820.

474
00:21:40,660 --> 00:21:43,660
>> [Laughing]

475
00:21:43,660 --> 00:21:47,170
>> [Applause]

476
00:21:47,170 --> 00:21:48,670
>> Kollox sew.

477
00:21:48,670 --> 00:21:50,740
Allura żgur allura, hemm dawn bugs.

478
00:21:50,740 --> 00:21:51,460
U li l-multa.

479
00:21:51,460 --> 00:21:53,810
U hekk naħseb lura fuq din
l-ewwel ħaġa darba

480
00:21:53,810 --> 00:21:55,420
tikteb ma neċessarjament xogħol.

481
00:21:55,420 --> 00:21:57,620
Dan ġara lili hawnhekk ukoll.

482
00:21:57,620 --> 00:22:00,844
Imma ejja issa jikkunsidraw kif nistgħu
japplikaw din l-istess idea li xi ħaġa

483
00:22:00,844 --> 00:22:03,760
inti tista raw qabel, li
huwa dan here-- qodma teknoloġija iskola

484
00:22:03,760 --> 00:22:05,130
ktieb tat-telefon verament kbir.

485
00:22:05,130 --> 00:22:09,380
U jissoponi li dan il-ktieb tat-telefon
għandha 1,000 paġni u 1,000 ismijiet

486
00:22:09,380 --> 00:22:11,360
u n-numri alfabetikament ġewwa ta 'dan.

487
00:22:11,360 --> 00:22:14,860
>> Ukoll, nistgħu tip ta 'japplika simili
idea li din il-problema ħafna fiżika,

488
00:22:14,860 --> 00:22:16,270
biss bl-użu lili.

489
00:22:16,270 --> 00:22:18,810
I biss tip ta 'misruqin
billi jwieżen lilkom kollha

490
00:22:18,810 --> 00:22:23,240
ma 'lottijiet u lottijiet ta' CPUs differenti
jew imħuħ jsiru xi algoritmu.

491
00:22:23,240 --> 00:22:25,440
Imma jekk huwa biss ftit
qodma me, I xorta tista

492
00:22:25,440 --> 00:22:29,630
lieva dik l-istess essenza ta 'idea
li jikkonsisti f'li u conquering din il-problema

493
00:22:29,630 --> 00:22:32,970
għal darb'oħra u għal darb'oħra, li biha nofs tal inti,
nofs tal inti, nofs tal inti, nofs tal inti,

494
00:22:32,970 --> 00:22:35,830
teoretikament miżmuma bilqiegħda,
sakemm konna xellug, teoretikament,

495
00:22:35,830 --> 00:22:36,990
mal biss persuna waħda.

496
00:22:36,990 --> 00:22:39,810
>> Allura f'din l-iskola antika
technology-- aħna ma

497
00:22:39,810 --> 00:22:43,030
bżonn dan map-- din il
teknoloġija iskola antika,

498
00:22:43,030 --> 00:22:47,300
nistgħu tibda 'tfittex għal xi ħadd
bħall Mike Smith, paġna waħda fi żmien.

499
00:22:47,300 --> 00:22:49,410
U nara li l-ebda, Mike mhix hawn.

500
00:22:49,410 --> 00:22:51,110
Jien xorta fit-taqsima A.

501
00:22:51,110 --> 00:22:53,900
Eventwalment, I find
ruħi fit-taqsima B.

502
00:22:53,900 --> 00:22:56,910
U dan huwa algorithm--
pass pass istruzzjoni.

503
00:22:56,910 --> 00:22:59,890
Tibda fil-bidu u waħda paġna
fi żmien, tfittex Mike Smith.

504
00:22:59,890 --> 00:23:03,410
Huwa dan correct-- din il
algoritmu jew strateġija?

505
00:23:03,410 --> 00:23:04,550
>> Yeah, huwa korrett.

506
00:23:04,550 --> 00:23:06,840
Jekk Mike hawnhekk, eventwalment
I ser tingħata lilu.

507
00:23:06,840 --> 00:23:08,139
Imma din mhix effiċjenti.

508
00:23:08,139 --> 00:23:09,180
Huwa ovvjament bil-mod ħafna.

509
00:23:09,180 --> 00:23:11,340
So I tista 'lieva tal-
istess twosies approċċ.

510
00:23:11,340 --> 00:23:15,350
I tista 'tagħmel tip ta' tnejn,
erba ', sitt, tmien, 10, 12.

511
00:23:15,350 --> 00:23:16,330
Huwa darbtejn aktar malajr.

512
00:23:16,330 --> 00:23:18,290
Jien ser tikseb sa Mike
aktar malajr jekk hu hemmhekk.

513
00:23:18,290 --> 00:23:20,770
Huwa korrett?

514
00:23:20,770 --> 00:23:22,320
Iva, imma smajt ebda little--.

515
00:23:22,320 --> 00:23:24,200
Issa Smajt ebda.

516
00:23:24,200 --> 00:23:24,700
Yeah.

517
00:23:24,700 --> 00:23:26,190
Hemm bug potenzjalment.

518
00:23:26,190 --> 00:23:29,374
Forsi Mike biss aċċidentalment gets
imfattra bejn żewġ paġni,

519
00:23:29,374 --> 00:23:31,290
għaliex jien jtajru permezz
dan il tnejn fi żmien.

520
00:23:31,290 --> 00:23:33,580
Dan bl-inqas għandna bżonn xi
tip ta 'jiffissaw kondizzjonali.

521
00:23:33,580 --> 00:23:35,330
I ħtieġa li jgħidu, ħej,
jekk I hit xi ħadd li

522
00:23:35,330 --> 00:23:39,190
isem jibda 'T minflok ta' S,
I aħjar doppju lura paġna mill-inqas wieħed.

523
00:23:39,190 --> 00:23:40,767
Allura Buggy fl-ewwel, iżda fixable.

524
00:23:40,767 --> 00:23:43,850
Iżda ħadd minna tmur biex tfittex
Mike Smith permezz ta 'telefon 1000 paġna

525
00:23:43,850 --> 00:23:45,290
ktieb paġna waħda fi żmien.

526
00:23:45,290 --> 00:23:48,486
X'hemm persuna normali se jagħmlu?

527
00:23:48,486 --> 00:23:50,860
Inti qed tmur biex tmur fil-S, il
jekk inti kienu jafu fejn il-s S.

528
00:23:50,860 --> 00:23:54,230
Inti tista 'tmur madwar in-nofs
jew ftit distorti lejn tmiem.

529
00:23:54,230 --> 00:23:56,850
U jien tfittex l isfel hawn u
Jien fis-sezzjoni M.

530
00:23:56,850 --> 00:23:58,952
Imma dak do you know
dwar din il-problema issa,

531
00:23:58,952 --> 00:24:02,160
li aħna ma neċessarjament taf qabel
ma 'kull wieħed minna biss kif jingħaddu nfusna

532
00:24:02,160 --> 00:24:03,030
ekwivalenti?

533
00:24:03,030 --> 00:24:06,010
Ukoll, Mike huwa kjarament tmur
li jkun Din it-taqsima tal-ktieb

534
00:24:06,010 --> 00:24:07,920
jekk hu hawnhekk fil-livelli kollha, għaliex dan huwa magħżul.

535
00:24:07,920 --> 00:24:10,160
>> U għalhekk inti tista ħafna dramatically--

536
00:24:10,160 --> 00:24:11,250
>> [Gasping]

537
00:24:11,250 --> 00:24:12,300
>> Naf.

538
00:24:12,300 --> 00:24:16,940
>> [Applause]

539
00:24:16,940 --> 00:24:19,450
>> Huwa fil-fatt tassew faċli jekk
inti tagħmel l-isfel l-ispina hemmhekk.

540
00:24:19,450 --> 00:24:22,070
Iżda int tista 'mbagħad tarmi
nofs il-problema bogħod.

541
00:24:22,070 --> 00:24:25,950
Issa, jien xellug ma 'l-istess problem--
isibu Mike Smith fil-telefon book--

542
00:24:25,950 --> 00:24:29,610
iżda issa l-ktieb tat-telefon jibda fil M
u tmur sa Z, imma hija nofs bħala kbar.

543
00:24:29,610 --> 00:24:30,890
>> Imma dan huwa dak i impressjonanti.

544
00:24:30,890 --> 00:24:34,170
Eżatt bħal fit-teorija, inti guys, meta
inti kollha sib stabbiliti biss nofs fi żmien,

545
00:24:34,170 --> 00:24:37,150
il-problema ltqajna nofs bħala kbar,
nofs bħala kbar, u għal darb'oħra.

546
00:24:37,150 --> 00:24:40,260
Allura jkun din il-problema saret l-
istess problema iżda nofs bħala kbar.

547
00:24:40,260 --> 00:24:42,670
Issa huwa problema 250 paġna.

548
00:24:42,670 --> 00:24:45,340
Hekk kif I realizzata, oh, jien
fit-taqsima T aċċidentalment.

549
00:24:45,340 --> 00:24:46,590
Stajt marret wisq.

550
00:24:46,590 --> 00:24:48,500
I tista tarmi li nofs
tal-ktieb tat-telefon bogħod.

551
00:24:48,500 --> 00:24:50,410
Issa, jien isfel għal
kwart tal-problema.

552
00:24:50,410 --> 00:24:53,910
>> U inti tista 'tirrepeti, irrepeti,
irrepeti sakemm, fit-teorija, int

553
00:24:53,910 --> 00:24:55,460
xellug ma biss paġna waħda.

554
00:24:55,460 --> 00:24:59,010
U jekk Mike huwa fuq dik il-paġna,
I issa jistgħu issolvi din il-problema.

555
00:24:59,010 --> 00:25:00,810
Imma kif malajr ma I issolviha?

556
00:25:00,810 --> 00:25:05,420
Fl-ewwel każ, hija ħadet me simili
forsi 1,000 passi biex isibu Mike Smith.

557
00:25:05,420 --> 00:25:09,260
Jista ħadu me--
I telgħet il-ktieb tat-telefon

558
00:25:09,260 --> 00:25:11,440
u bdejt tfittex
paġna waħda fi żmien,

559
00:25:11,440 --> 00:25:13,480
u Mike jista 'jkun 1,000 paġni aktar tard.

560
00:25:13,480 --> 00:25:16,020
>> It-tieni approċċ forsi
tieħu me 500 passi,

561
00:25:16,020 --> 00:25:17,960
għaliex jien jtajru
permezz tnejn fi żmien.

562
00:25:17,960 --> 00:25:21,082
U t-tielet metodu għalkemm,
huwa speċjalment qawwija.

563
00:25:21,082 --> 00:25:23,790
Imma ejja jikkunsidraw dak li aħna attwalment
kien mal din it-tielet approċċ.

564
00:25:23,790 --> 00:25:27,590
I ser ikollhom dak I ser sejħa biss dawn
dikjarazzjonijiet hawn, wieħed fi żmien.

565
00:25:27,590 --> 00:25:28,560
Aqbad ktieb tat-telefon.

566
00:25:28,560 --> 00:25:30,130
Iftaħ għall-nofs tal-ktieb tat-telefon.

567
00:25:30,130 --> 00:25:31,419
Ħares lejn l-ismijiet.

568
00:25:31,419 --> 00:25:33,960
U mbagħad affarijiet jiksbu ftit
aktar intellettwalment interessanti,

569
00:25:33,960 --> 00:25:35,170
jekk għadhom sempliċi.

570
00:25:35,170 --> 00:25:38,350
Jekk Smith huwa fost l-
ismijiet fuq dik il-paġna kurrenti,

571
00:25:38,350 --> 00:25:40,170
imbagħad tagħmel xi ħaġa kundizzjonali.

572
00:25:40,170 --> 00:25:41,840
Huwa simili furketta fit-triq.

573
00:25:41,840 --> 00:25:42,660
Sejħa Mike.

574
00:25:42,660 --> 00:25:44,930
Jekk Mike hija fost l-ismijiet
fuq dik il-paġna, imsejħa Mike.

575
00:25:44,930 --> 00:25:49,720
Iżda biss tagħmel linja erbgħa jekk linja
siġra, jekk inti se, huwa veru.

576
00:25:49,720 --> 00:25:51,590
It-tweġiba għal din id-domanda hija iva.

577
00:25:51,590 --> 00:25:55,520
>> Else jekk Smith huwa aktar kmieni fil-book--
fi kliem ieħor, jekk jien fit-taqsima M

578
00:25:55,520 --> 00:25:58,540
u jien infittxu xi ħadd biex
ix-xellug, imbagħad dak I għandhom jagħmlu

579
00:25:58,540 --> 00:26:00,300
hija xi ħaġa simili ħafna.

580
00:26:00,300 --> 00:26:03,440
Imbagħad I għandha tiftaħ għan-nofs
ta 'nofs tax-xellug tal-ktieb.

581
00:26:03,440 --> 00:26:07,930
Allura jmorru xellug, u mbagħad
mur lura għall-pass tnejn.

582
00:26:07,930 --> 00:26:09,290
Ħares lejn l-ismijiet hemmhekk.

583
00:26:09,290 --> 00:26:12,779
>> Allura fi kliem ieħor, jagħmlu l-istess ħaġa,
iżda fuq problema li kien bin-nofs.

584
00:26:12,779 --> 00:26:13,570
Inti taf x'iktar?

585
00:26:13,570 --> 00:26:16,470
Jekk Smith huwa aktar tard fil-ktieb
ibbażata fuq il-paġna jien tħares lejn,

586
00:26:16,470 --> 00:26:18,790
miftuħa għall-nofs tal-
nofs tal-lemin tal-ktieb

587
00:26:18,790 --> 00:26:22,050
u mbagħad mur lura
li pass tnejn, else--

588
00:26:22,050 --> 00:26:24,000
hemm ir-raba possibbiltà hawn.

589
00:26:24,000 --> 00:26:28,830
Mike kemm hawn jew lejn ix-xellug
jew lejn il-lemin jew le hemmhekk.

590
00:26:28,830 --> 00:26:30,570
U hawn aħna nikkunsidraw aħjar dan.

591
00:26:30,570 --> 00:26:33,360
U fil-fatt, jekk inti stajt qatt kellu
kompjuter tiegħek biss crash fuqek,

592
00:26:33,360 --> 00:26:36,822
jiġifieri kultant, iżda mhux dejjem, il
riżultat ta 'ftit programmer bniedem ma

593
00:26:36,822 --> 00:26:39,280
realizzazzjoni, oh rimja, hemm
attwalment din ir-raba ix-xenarju.

594
00:26:39,280 --> 00:26:41,650
U jekk inti ma jiktbu kodiċi
biex jimmaniġġaw dan ix-xenarju,

595
00:26:41,650 --> 00:26:43,220
xi kultant ma tkunx taf
dak il-kompjuter tista 'tagħmel.

596
00:26:43,220 --> 00:26:44,770
U tabilħaqq programm jista crash.

597
00:26:44,770 --> 00:26:47,550
>> Iżda f'dan il-każ, ħsibt
dwar dan, u I said, inkella nieqaf,

598
00:26:47,550 --> 00:26:49,850
minħabba li l-raba '
xenarju loġiku possibbli.

599
00:26:49,850 --> 00:26:51,950
Issa, ejja żid ftit
xi vokabularju hekk aħna

600
00:26:51,950 --> 00:26:55,320
jistgħu jibdew toss madwar termini li
huma altrimenti pjuttost intuwittivi.

601
00:26:55,320 --> 00:26:57,870
Kollha ta 'l-affarijiet stajt biss
enfasizzat bl-isfar hawn,

602
00:26:57,870 --> 00:27:00,140
Jien biss ser-
funzjonijiet jew proċeduri.

603
00:27:00,140 --> 00:27:01,590
Huma qed biss tip ta 'azzjonijiet.

604
00:27:01,590 --> 00:27:04,900
Allura aqbad, miftuħa għall-ħarsa
fil, sejħa, miftuħa, miftuħa,

605
00:27:04,900 --> 00:27:09,170
quit-- dawn huma biss azzjonijiet, jew aħna ser
jsejħulhom b'mod aktar formali, il-funzjonijiet.

606
00:27:09,170 --> 00:27:11,410
>> Sadanittant, issa fl-isfar,
Stajt enfasizzat affarijiet

607
00:27:11,410 --> 00:27:14,084
that-- ejja biss tibda sejħa
lilhom kondizzjonijiet jew fergħat.

608
00:27:14,084 --> 00:27:16,750
Dawn huma punti ta 'deċiżjoni fejn
inti tista 'tmur b'dan il-mod, dan il-mod,

609
00:27:16,750 --> 00:27:18,100
jew xi direzzjoni oħra għadhom.

610
00:27:18,100 --> 00:27:19,430
Allura dawn se jkunu kondizzjonijiet.

611
00:27:19,430 --> 00:27:20,930
U issa dan wieħed l-ftit fancier.

612
00:27:20,930 --> 00:27:24,600
Ejja sejħa dawn il-mistoqsijiet
espressjonijiet Boolean,

613
00:27:24,600 --> 00:27:26,530
wara xi ħadd bl-isem l-aħħar BOOL.

614
00:27:26,530 --> 00:27:28,340
>> U espressjoni Boolean
huwa biss xi ħaġa

615
00:27:28,340 --> 00:27:30,290
dan huwa jew vera jew falza, iva jew le.

616
00:27:30,290 --> 00:27:35,870
Allura huwa l-mistoqsija li tweġiba li inti
kura dwar, sabiex f'kundizzjoni

617
00:27:35,870 --> 00:27:39,210
tagħmel decision-- tikseb lura risposta,
u mbagħad mur xellug jew il-lemin, jew xi ħaġa

618
00:27:39,210 --> 00:27:40,450
oħra għal kollox.

619
00:27:40,450 --> 00:27:42,860
>> U mbagħad fl-aħħar nett, dawn
Linji here-- mur lura

620
00:27:42,860 --> 00:27:44,737
li pass tnejn, jmorru lura
li pass two-- nistgħu

621
00:27:44,737 --> 00:27:46,320
jimplimentaw din l-idea b'modi differenti.

622
00:27:46,320 --> 00:27:49,028
U allura dawk tal inti ma
esperjenza ta 'programmazzjoni jista' jsir

623
00:27:49,028 --> 00:27:50,670
jew jista 'jimmaġina tagħmel dan b'mod differenti.

624
00:27:50,670 --> 00:27:53,170
Imma għal skopijiet tal-lum, huwa
biss l-idea li l-kwistjonijiet.

625
00:27:53,170 --> 00:27:55,400
Dan huwa jinduċu dak
aħna ser ġeneralment sejħa

626
00:27:55,400 --> 00:28:00,110
a loop-- xi tip ta 'ċiklu, għaliex
huwa tagħmel me jagħmlu xi ħaġa mill-ġdid.

627
00:28:00,110 --> 00:28:03,340
>> Allura issa, ejja biss tikkunsidra
kif tajba din il algoritmu huwa.

628
00:28:03,340 --> 00:28:03,899
Huwa korrett.

629
00:28:03,899 --> 00:28:06,940
Jekk Mike fil-ktieb, huwa wieħed mill
dawk erba scenarios-- ġdid u għal darb'oħra

630
00:28:06,940 --> 00:28:08,023
u għal darb'oħra, aħna ser issib lilu.

631
00:28:08,023 --> 00:28:08,890
Imma kif tajba huwa?

632
00:28:08,890 --> 00:28:10,150
Ukoll, aħna ma jkollhomx
li jkunu wisq formali hawn.

633
00:28:10,150 --> 00:28:12,066
Imma ejja biss plot
xi ħaġa, X u Y, biex tikseb

634
00:28:12,066 --> 00:28:14,470
sens tal-forma ta 'din il-problema.

635
00:28:14,470 --> 00:28:17,160
>> Fuq l-assi x hawnhekk huwa
id-daqs tal-problema tiegħi.

636
00:28:17,160 --> 00:28:20,256
U huma y-axis hawn
se jkun il-ħin biex issolvi.

637
00:28:20,256 --> 00:28:21,630
Allura forsi dan huwa numru ta 'paġni.

638
00:28:21,630 --> 00:28:24,400
Forsi dan huwa sekonda jew
paġna turns-- ikun x'ikun.

639
00:28:24,400 --> 00:28:27,290
Madankollu inti tixtieq li jgħodd huwa
dak li din l-istampa se jirrappreżenta.

640
00:28:27,290 --> 00:28:30,630
U li l-ewwel algoritmu, jien ser
biex jiddeskrivu bħala biss linja dritta.

641
00:28:30,630 --> 00:28:33,120
Jekk hemm n paġni fil
-ktieb tat-telefon, allura

642
00:28:33,120 --> 00:28:36,010
tista 'tieħu me kif ħafna
passi n biex isibu Mike.

643
00:28:36,010 --> 00:28:38,930
Jekk Verizon jew il-kumpanija tat-telefon
iżid paġna waħda aktar sena d-dieħla,

644
00:28:38,930 --> 00:28:42,170
jista 'jieħu me waħda aktar step--
waħda aktar unità ta 'ħin biex isibu Mike.

645
00:28:42,170 --> 00:28:44,230
Allura hemm biss dan wieħed għal proporzjon wieħed.

646
00:28:44,230 --> 00:28:45,970
Huwa linja inklinazzjoni dritta.

647
00:28:45,970 --> 00:28:49,110
>> Sadanittant, dan it-tieni
algorithm-- jekk jien

648
00:28:49,110 --> 00:28:51,570
jmorru tnejn fi tnejn time--,
erba ', sitt, tmien, jew double--

649
00:28:51,570 --> 00:28:54,550
għaddejjin mill-paġni darbtejn
fi żmien, tnejn fi żmien,

650
00:28:54,550 --> 00:28:55,710
huwa għadu linja dritta.

651
00:28:55,710 --> 00:28:58,720
Hemm issa 01:59
proporzjon, iżda bi ftit.

652
00:28:58,720 --> 00:29:02,240
Mela jekk hemm dan ħafna paġni
fuq il-karta hawn isfar,

653
00:29:02,240 --> 00:29:04,800
li jista 'jieħu me dan il
bosta passi jew f'sekondi,

654
00:29:04,800 --> 00:29:07,980
inkella li għaddej biex jieħdu me
darbtejn kif ħafna fuq il-linja ħamra.

655
00:29:07,980 --> 00:29:10,190
>> Iżda l-linja ħadra hija l-takeaway reali.

656
00:29:10,190 --> 00:29:12,290
Dan huwa dak li aħna ġeneralment
sejħa log logorithm--

657
00:29:12,290 --> 00:29:13,840
ta 'n, fejn n huwa n-numru ta' paġni.

658
00:29:13,840 --> 00:29:16,450
Imma hija l-forma li l-kwistjonijiet
illum, għaliex aħna ma jkollhomx

659
00:29:16,450 --> 00:29:17,950
li anke taħseb dwar plotting punti.

660
00:29:17,950 --> 00:29:19,830
>> Aħseb dwar xenarju estrem.

661
00:29:19,830 --> 00:29:23,070
Ejja ngħidu Verizon għada jirdoppja l
Numru ta 'paġni dak il-ktieb tat-telefon,

662
00:29:23,070 --> 00:29:24,900
minn 1,000 sa 2,000.

663
00:29:24,900 --> 00:29:28,440
Fl-ewwel algoritmu, jien
jista iskart extra 1000

664
00:29:28,440 --> 00:29:32,080
passi tfittex Mike, sempliċement minħabba
Verizon rdoppja-daqs tal-ktieb.

665
00:29:32,080 --> 00:29:34,740
It-tieni algorithm-- dan jista 'jkun
jieħdu me extra 500 passi.

666
00:29:34,740 --> 00:29:38,370
1,000 paġni aktar, mmur tnejn fi
time-- 500 passi aktar biex isibu Mike.

667
00:29:38,370 --> 00:29:41,020
>> Iżda dan it-tielet algoritmu
huwa tip ta maġika.

668
00:29:41,020 --> 00:29:44,270
Verizon jirdoppja n-numru
ta 'paġni minn 1,000 sa 2,000,

669
00:29:44,270 --> 00:29:47,730
Imma kemm passi aktar ma
hija tieħu me biex tfittex Mike?

670
00:29:47,730 --> 00:29:51,220
Huwa biss wieħed, minħabba I tista 'sempliċement
tiċrita l-ktieb tat-telefon wieħed aktar ħin

671
00:29:51,220 --> 00:29:55,280
minn problema 2000 paġna lil
1000 problema paġna, u voila.

672
00:29:55,280 --> 00:29:57,030
Stajt meħuda gidma massiv barra minnha.

673
00:29:57,030 --> 00:29:59,405
>> U jekk inti tmur verament estrema,
jissoponi li l-ktieb tat-telefon

674
00:29:59,405 --> 00:30:03,600
Kumpanija kienet xi ħaġa crazy bħal
telefon ktieb 4000000000 paġna.

675
00:30:03,600 --> 00:30:07,020
Ukoll kemm passi tista tieħu
biex isibu Mike Smith fil 4000000000

676
00:30:07,020 --> 00:30:09,990
paġna telefon ktieb?

677
00:30:09,990 --> 00:30:16,450
Huwa numru kbir, iżda biss 4 biljuni għal
2000000000-1000000000 biex 500 miljun,

678
00:30:16,450 --> 00:30:18,720
250 million-- xorta
ħsejjes simili numri kbar,

679
00:30:18,720 --> 00:30:20,980
imma jien malajr ħafna
jkollna għall-valuri iżgħar.

680
00:30:20,980 --> 00:30:24,790
>> U fil-fatt, jekk I jagħmlu l-matematika
dritt, nista 'biss jaqsmu 4000000000

681
00:30:24,790 --> 00:30:28,750
billi madwar 32 darbiet qabel
I nikseb l isfel sa wieħed biss.

682
00:30:28,750 --> 00:30:31,640
Mela jekk dak il-ktieb tat-telefon kienu 4
biljun paġni fit-tul, no big deal.

683
00:30:31,640 --> 00:30:35,270
Fi ftit sekondi, forsi 32
sekondi, I jistgħu jaqsmu min-nofs

684
00:30:35,270 --> 00:30:39,560
u eventwalment isibu Mike jew
jikkonkludi li hu ma jkunx hemm.

685
00:30:39,560 --> 00:30:42,219
U dan huwa l-essenza ta '
algorithm-- algoritmu tajba.

686
00:30:42,219 --> 00:30:44,260
U dan huwa wieħed mill-
għanijiet ta 'klassi bħal din,

687
00:30:44,260 --> 00:30:47,350
qed tipprova figura kif nista
issolvi l-problema mhux biss korrett,

688
00:30:47,350 --> 00:30:52,360
bħal I dejjem kienu jafu kif jagħmlu dan wieħed
paġna fi time-- iżda b'mod korrett u tajjeb.

689
00:30:52,360 --> 00:30:55,034
Kif nista disinn tajba
soluzzjonijiet għall-problemi?

690
00:30:55,034 --> 00:30:57,200
Mela ejja tieħu mument hawn
u jagħtik sens issa

691
00:30:57,200 --> 00:31:00,260
tal CS50-kors itself-- jintroduċu
membri tal-persunal ta 'kors ftit tal.

692
00:31:00,260 --> 00:31:02,010
Eżatt qabel 02:00, aħna ser
jieħu pawża qasira

693
00:31:02,010 --> 00:31:03,520
sabiex dawk minnkom
li shopping jistgħu

694
00:31:03,520 --> 00:31:05,130
papra out u jieħdu
tħares lejn xi klassi oħra

695
00:31:05,130 --> 00:31:06,580
u tara l-bqija ta 'dan fuq l-internet.

696
00:31:06,580 --> 00:31:09,250
Iżda għal issa, let me jintroduċu
CS50, il-klassi innifsu,

697
00:31:09,250 --> 00:31:11,330
u b'mod partikolari dak li hu ġdid.

698
00:31:11,330 --> 00:31:13,960
>> Allura l-rebbiegħa passat, aħna
qattgħu pjuttost ftit ta time--

699
00:31:13,960 --> 00:31:17,911
persunal tal-kors u I-- ħsieb
dwar dak li tkun rridu CS50 li tkun,

700
00:31:17,911 --> 00:31:19,910
u li jmorru lura għall-ewwel
prinċipji, biex ngħidu hekk,

701
00:31:19,910 --> 00:31:22,760
biex tikkunsidra dak li hu li rridu
dan il-kors lill-dehra u jkun

702
00:31:22,760 --> 00:31:23,740
bħal għall-istudenti tagħha.

703
00:31:23,740 --> 00:31:26,480
U hekk tkun taf tara fil-problema
sett żero kif ukoll, stedina

704
00:31:26,480 --> 00:31:28,780
biex tagħti ħarsa lejn dak
URL li tiġbor fil-qosor

705
00:31:28,780 --> 00:31:33,270
xi wħud mill-motivazzjonijiet wara l-
segwenti karatteristiċi tal-waqgħa 2016.

706
00:31:33,270 --> 00:31:35,570
>> Allura kif jista 'jkollok miġbura
mill-TL: volantin DR

707
00:31:35,570 --> 00:31:39,060
sillabu illum kif ukoll minn
-katalogu kors, din is-sena fil CS50,

708
00:31:39,060 --> 00:31:42,540
int biss mistennija li jattendu
today-- hekk impjieg tajjeb done--

709
00:31:42,540 --> 00:31:45,960
u l-aħħar taħdita dwar 21 Nov.

710
00:31:45,960 --> 00:31:49,150
U inti qed jilqgħu iżda mhux mistenni li
jattendu dawk lectures fin-nofs,

711
00:31:49,150 --> 00:31:51,180
għaliex dak li aħna qed tagħmel
din is-sena, huwa isparar

712
00:31:51,180 --> 00:31:52,661
fil-ħin reali materjali tal-kors tal.

713
00:31:52,661 --> 00:31:54,660
Allura kollox se jibqgħu
kurrenti u inkorporati

714
00:31:54,660 --> 00:31:57,410
bħala l-aħjar aħna can-- ġrajjiet kurrenti
u konversazzjonijiet li folks tista

715
00:31:57,410 --> 00:32:00,400
jkun li jkollhom fl-industrija fil-
dinja, iżda t-teħid dak il-materjal

716
00:32:00,400 --> 00:32:03,892
disponibbli, bħala riżultat, anki earlier--
kompluta bil traskrizzjonijiet test sħiħ

717
00:32:03,892 --> 00:32:05,850
u tiftix u
links għal riżorsi oħra.

718
00:32:05,850 --> 00:32:07,930
>> U fil-fatt, aħna kont qed
titlob għal xi żmien

719
00:32:07,930 --> 00:32:10,830
u aħna issa nemmen li din,
li nistgħu noħolqu, diġitalment,

720
00:32:10,830 --> 00:32:15,170
aktar immersive, aktar konvinċenti
esperjenza edukattiva, għall-kuntrarju

721
00:32:15,170 --> 00:32:19,110
li jinġabru hawn madwar 23 darbiet
fil-persuna, smigħ xi ħadd bħali

722
00:32:19,110 --> 00:32:22,925
sempliċiment jitkellmu dwar ix-xjenza tal-kompjuter,
għall-kuntrarju involviment aktar attiv.

723
00:32:22,925 --> 00:32:25,800
Allura inti taf tara fil sillabu tal-kors tal-
skeċċ tas-semestru hawn,

724
00:32:25,800 --> 00:32:27,840
flimkien ma 'meta lekċers se
tkun iffilmjati, li int

725
00:32:27,840 --> 00:32:29,710
merħba iżda mhux mistenni,
u meta se

726
00:32:29,710 --> 00:32:31,640
ikunu rilaxxati fuq il-websajt tal-kors tal.

727
00:32:31,640 --> 00:32:34,300
>> U dak li aħna ser nagħmlu hawnhekk fuq
Erbgħa jibdew ġimgħa d-dieħla,

728
00:32:34,300 --> 00:32:37,362
huwa ħafna aktar mill-qrib, bil biss
dawk folks li jixtiequ jieħdu sehem,

729
00:32:37,362 --> 00:32:39,820
huwa hekk imsejjaħ walk-through,
fejn I u kapijiet tal-kors tal-

730
00:32:39,820 --> 00:32:41,730
fil-fatt se tagħmel affarijiet
ftit aktar intimi

731
00:32:41,730 --> 00:32:44,313
stabbiliti hawn fil-orkestra
taqsima, għad għandhom xi teknoloġija

732
00:32:44,313 --> 00:32:46,365
u jimxu permezz tal-
Sett problema ġimgħa kurrenti,

733
00:32:46,365 --> 00:32:50,020
u joffrilek particularly-- jekk fost
dawk inqas comfortable-- l-aktar

734
00:32:50,020 --> 00:32:52,790
gwida li inti tista 'tixtieq jew
ħtieġa għall-isfida tal-ġimgħa.

735
00:32:52,790 --> 00:32:55,820
U l-istess, għal dawk li ma jistgħux
jattendu dawk personalment, no big deal.

736
00:32:55,820 --> 00:32:58,486
Se jkun hemm bl-istess mod immexxi minn
wieħed mill-persunal anzjan tal-kors, l

737
00:32:58,486 --> 00:33:02,650
Zamalya, l-istess opportunità integrati
fil-problema settijiet infushom.

738
00:33:02,650 --> 00:33:04,960
>> Problema settijiet din is-sena
se jkunu rilaxxati nhar ta 'Ġimgħa

739
00:33:04,960 --> 00:33:08,080
u li m'għadhomx jagħmlu sebat ijiem wara,
iżda 10 ijiem later-- deliberatament

740
00:33:08,080 --> 00:33:10,910
overlapping ma 'kull problema
stabbiliti, sabiex jakkomodaw aħjar,

741
00:33:10,910 --> 00:33:13,050
nittamaw, ebb u l-fluss
fl-iskedi istudenti,

742
00:33:13,050 --> 00:33:16,550
speċjalment meta midterms jew atletika
jew akkademiċi jew extracurriculars

743
00:33:16,550 --> 00:33:18,465
tendenza li jidħlu jew joħorġu
speċjalment nofs l-semestru.

744
00:33:18,465 --> 00:33:21,340
Dan għandu jtik aktar ftit
diskrezzjoni dwar jekk inti quddiem

745
00:33:21,340 --> 00:33:25,690
tagħbija ġimgħa tiegħek ma CS50 jew tagħbija oħra lura
fuq il-weekend ta 'wara minflok.

746
00:33:25,690 --> 00:33:28,817
Sabiex tfittex għall sillabu tal-kors tal-
hawn għall-iskeda tagħha.

747
00:33:28,817 --> 00:33:30,900
U inti taf Avviż wisq fost
il-bidliet din is-sena,

748
00:33:30,900 --> 00:33:34,082
għal dawk aktar familjari mal
programmazzjoni fil-passat,

749
00:33:34,082 --> 00:33:36,290
aħna ser tibda l-semestru bħala
aħna se illum fil Scratch,

750
00:33:36,290 --> 00:33:39,730
jiffokaw speċjalment fuq il-lingwa
imsejħa Ċ, u mbagħad tranżizzjoni mhux

751
00:33:39,730 --> 00:33:43,430
li PHP, iżda għal lingwa msejħa
Python lejn l-aħħar tas-semestru

752
00:33:43,430 --> 00:33:46,565
fil-kuntest tal-ipprogrammar tal-web,
flimkien ma 'SQL u JavaScript,

753
00:33:46,565 --> 00:33:48,930
HTML, CSS, u għadhom aktar.

754
00:33:48,930 --> 00:33:51,790
>> U bi tweġiba għal FAQ,
huwa tabilħaqq il-każ

755
00:33:51,790 --> 00:33:55,520
li KEFA mhix kif scary kif I ladarba
ħsibt li kien, iżda huwa kemm ix-xogħol

756
00:33:55,520 --> 00:33:57,280
kif I kien sema li jista 'jkun.

757
00:33:57,280 --> 00:34:03,210
Iżda dan huwa l-jgħidu li hawn huma xi wħud
istatistika mill-waqgħa 2015 ġisem istudenti,

758
00:34:03,210 --> 00:34:06,460
fejn il-linji blu orizzontali
jirrappreżentaw in-numru medju ta 'sigħat

759
00:34:06,460 --> 00:34:06,960
rrappurtati.

760
00:34:06,960 --> 00:34:10,570
U tkun taf tara medja ta '
sitta sa 10 sa 12-- forsi 16

761
00:34:10,570 --> 00:34:14,580
jew hekk u ibqa 'sejjer hekk, imma ma
varjanza għolja li tkun ċara.

762
00:34:14,580 --> 00:34:18,570
U hekk tirrealizza li hemm mhux biss
studenti aktar komdu u inqas

763
00:34:18,570 --> 00:34:22,150
komdu fil-kors,
iżda appoġġ korrispondenti

764
00:34:22,150 --> 00:34:25,699
struttura biex tikseb dawk l-istudenti
permezz tal-semestru b'suċċess.

765
00:34:25,699 --> 00:34:29,409
>> Tabilħaqq, b'risposta għal FAQ, jekk
inti tieħu CS50 bħala l-ewwel sena?

766
00:34:29,409 --> 00:34:30,139
Assolutament.

767
00:34:30,139 --> 00:34:32,690
U fil-fatt, I do jiddispjaċina
li ma sabet mod tiegħi

768
00:34:32,690 --> 00:34:35,170
jew misjuba qasam ġdid
l-ewwel sena kif ukoll.

769
00:34:35,170 --> 00:34:39,149
U għandek tieħu CS50 ma
korsijiet oħra, ċertament bħala well--

770
00:34:39,149 --> 00:34:41,940
u l-pariri ġenerali nistgħu
jagħtu lill-istudenti, li CS50 probabbilment

771
00:34:41,940 --> 00:34:44,929
mhux it-tip ta 'klassi jew klassi intro
li għandek tieħu bi tliet

772
00:34:44,929 --> 00:34:47,199
oħra jew erba 'klassijiet oħra set-p.

773
00:34:47,199 --> 00:34:50,583
Imma jekk inti qed tieħu tnejn l-oħra p set
klassijiet, xi ħaġa oħra, u CS50,

774
00:34:50,583 --> 00:34:51,499
assolutament maniġġabbli.

775
00:34:51,499 --> 00:34:54,900
I kellna ħafna studenti fil-
passat għamlu hekk pjuttost b'suċċess.

776
00:34:54,900 --> 00:34:57,490
>> U biex ikollok lejn dak
finitura linja b'suċċess,

777
00:34:57,490 --> 00:35:00,260
ma l-kors jkollhom sections--
binarji differenti għall-istudenti

778
00:35:00,260 --> 00:35:03,100
inqas komdi, aktar komda,
u x'imkien bejniethom,

779
00:35:03,100 --> 00:35:04,850
li permezz tagħha fil--kors tal
ewwel sett problema,

780
00:35:04,850 --> 00:35:06,360
inti ser tintalab biex tiddeskrivi lilek innifsek.

781
00:35:06,360 --> 00:35:09,151
U jekk inti fost dawk inqas
komdu, huwa t-tip ta 'ħaġa

782
00:35:09,151 --> 00:35:10,420
li inti biss pjuttost taf.

783
00:35:10,420 --> 00:35:13,010
U fil-fatt, li kien l-
jikber demografika fl CS50

784
00:35:13,010 --> 00:35:14,090
għal pjuttost ftit snin.

785
00:35:14,090 --> 00:35:17,680
>> Bħala ta 'l-aħħar jaqgħu għall
Pereżempju, 58% tal-klassi

786
00:35:17,680 --> 00:35:20,560
deskritta lilhom infushom bħala
fost dawk inqas komdi,

787
00:35:20,560 --> 00:35:23,210
b'9% fost dawk aktar
komdu, u mbagħad

788
00:35:23,210 --> 00:35:25,900
l-istudenti l-oħra hemmhekk fis
aħmar jiddeskrivu lilhom infushom

789
00:35:25,900 --> 00:35:27,890
kif x'imkien bejniethom.

790
00:35:27,890 --> 00:35:31,980
U tkun taf tara hawn is-suġġetti ġenerali
u l-iskeda ta 'sezzjonijiet, li kollha

791
00:35:31,980 --> 00:35:34,820
huma offruti fil-persuna, b'mod
ħin reali, bl--kors tal

792
00:35:34,820 --> 00:35:38,320
persunal aqwa ta 'fellows tagħlim
u l-assistenti kors, li wħud minnhom

793
00:35:38,320 --> 00:35:39,660
inti ser jiltaqgħu fi ftit mument.

794
00:35:39,660 --> 00:35:42,993
>> Taqsimiet infushom, kif tkun taf tara, se
jkun Tnejn u Tlieta u l-Erbgħa,

795
00:35:42,993 --> 00:35:45,910
sabiex jippermettu li inti adsa
għal ġewwa wara involviment, jekk hekk

796
00:35:45,910 --> 00:35:48,110
jagħżlu, fil-s kors
lecture qabel dik il-ġimgħa.

797
00:35:48,110 --> 00:35:51,420
U mbagħad ħinijiet tal-uffiċċju, li
ċertament, ma 'kull sena li tgħaddi,

798
00:35:51,420 --> 00:35:54,110
kienu mhux inqas minn
isfida għall-kors.

799
00:35:54,110 --> 00:35:57,040
U din is-sena, aħna qed tippjana mhux
biss mill-kariga hours-- wieħed

800
00:35:57,040 --> 00:36:00,300
fuq naħa waħda opportunitajiet għal għajnuna għall-
studenti nhar ta 'Erbgħa ta' Ħamis

801
00:36:00,300 --> 00:36:03,790
u Ħdud, l-aħħar ta 'dawk
jkunu fil-wara nofsinhar permezz tad-disinn

802
00:36:03,790 --> 00:36:06,910
biex tnaqqas xi wħud mill-istress li
dejjem tqum bil-lejl tard

803
00:36:06,910 --> 00:36:10,180
p-settting bi skadenza looming--
iżda ħinijiet tal-uffiċċju se jiġu offruti wkoll

804
00:36:10,180 --> 00:36:14,920
nhar ta 'Tnejn u t-Tlieta u
Erbgħa, u Ġimgħa u s-Sibt,

805
00:36:14,920 --> 00:36:17,080
grazzi lill-ħbieb tagħna fil HSA.

806
00:36:17,080 --> 00:36:20,330
>> CS50 issa għandha spazju tagħha stess
għall-istudenti u l-persunal CS50,

807
00:36:20,330 --> 00:36:23,070
atop 67 Mount Auburn Street,
hemm dritt fil-Harvard Square.

808
00:36:23,070 --> 00:36:26,340
Il-viżjoni li għaliha hija li CS50 s
TFS u CAs matul il-ġimgħa,

809
00:36:26,340 --> 00:36:29,052
pretty ħafna matul parti kbira
ġranet, se jkun hemm għall-appoġġ.

810
00:36:29,052 --> 00:36:30,760
Mela jekk inti ħadthom ltqajna xi
mistoqsija dwar p set

811
00:36:30,760 --> 00:36:33,093
jew int tħossok ftit
imblukkata jew ftit konfuż,

812
00:36:33,093 --> 00:36:35,640
u Heck, inti stajt ltqajna siegħa jew
nofs siegħa bejn il-klassijiet,

813
00:36:35,640 --> 00:36:38,920
speċjalment fil-square-- tista
pop u jkollhom din il-kwistjoni wieġeb

814
00:36:38,920 --> 00:36:41,720
ta jkollhom dik konfużjoni clarified--
ħafna fl-ispirtu,

815
00:36:41,720 --> 00:36:45,490
int familjari, tal-matematika
dipartiment stess mistoqsijiet matematika ċentru,

816
00:36:45,490 --> 00:36:49,300
imma pjuttost ħafna madwar l-arloġġ għal kull
[? GCAL?] Li aħna se jpoġġu onlajn.

817
00:36:49,300 --> 00:36:52,400
>> Tutoring hija wkoll disponibbli għal dawk
studenti, liberament mill-l-kors

818
00:36:52,400 --> 00:36:54,750
persunal stess jekk inti tixtieq
aktar intimi waħda fuq waħda,

819
00:36:54,750 --> 00:36:58,940
jew tnejn jew tlieta klassi biss, li jaħdmu
ma 'wieħed mill-membri tal-persunal tal-kors tal.

820
00:36:58,940 --> 00:37:02,320
U fil-fatt, dawn hawn huma biss
uħud mill-membri tal-persunal tal-kors, il-

821
00:37:02,320 --> 00:37:04,120
ftit minnhom tkun taf
jiltaqgħu fi ftit mument.

822
00:37:04,120 --> 00:37:07,440
Fil-fatt, CS50 stess
ras sħabi tagħlim,

823
00:37:07,440 --> 00:37:09,790
u kors ras
assistent, u preceptor,

824
00:37:09,790 --> 00:37:12,998
tista 'toħroġ fuq up, jippermettu
biex jgħidu bonjour.

825
00:37:12,998 --> 00:37:22,498
>> [Applause]

826
00:37:22,498 --> 00:37:23,456
Speaker 1: [inaudible].

827
00:37:23,456 --> 00:37:51,842

828
00:37:51,842 --> 00:37:57,856
>> [Applause]

829
00:37:57,856 --> 00:37:58,814
Speaker 2: [inaudible].

830
00:37:58,814 --> 00:38:17,240

831
00:38:17,240 --> 00:38:27,238
>> [Applause]

832
00:38:27,238 --> 00:38:28,196
Speaker 3: [inaudible].

833
00:38:28,196 --> 00:38:58,951

834
00:38:58,951 --> 00:39:03,120
>> [Applause]

835
00:39:03,120 --> 00:39:06,740
>> DAVID Malan: U inessu
iġibu abbord tnejn mill CS50-aktar

836
00:39:06,740 --> 00:39:09,730
persunal anzjan, Rob u Zamayla kif ukoll.

837
00:39:09,730 --> 00:39:15,120
>> [Applause]

838
00:39:15,120 --> 00:39:17,226
>> Tabilħaqq, kemm Rob u
Zamayla kienu magħna

839
00:39:17,226 --> 00:39:19,940
għal sakemm, I kienet f'pożizzjoni
li jmorru fis-arkivji CS50 s

840
00:39:19,940 --> 00:39:22,470
u ssib dan SD ħafna
filmati minnhom jieħdu sehem

841
00:39:22,470 --> 00:39:25,402
fuq il-palk infushom xi snin ilu.

842
00:39:25,402 --> 00:39:26,110
ROB: [inaudible].

843
00:39:26,110 --> 00:39:53,660

844
00:39:53,660 --> 00:39:59,247
>> [Applause]

845
00:39:59,247 --> 00:40:00,080
ZAMAYLA: [inaudible]

846
00:40:00,080 --> 00:40:50,888

847
00:40:50,888 --> 00:40:52,467
>> [Applause]

848
00:40:52,467 --> 00:40:53,425
DAVID Malan: Grazzi.

849
00:40:53,425 --> 00:40:56,160

850
00:40:56,160 --> 00:40:58,030
Għalhekk fl Minbarra dawn
membri tat-tim hawn,

851
00:40:58,030 --> 00:41:01,662
CS50 għandu tim ta 'kważi 100
membri tal-persunal, li lkoll

852
00:41:01,662 --> 00:41:04,370
se jkunu disponibbli għas-sezzjonijiet
u ħinijiet tal-uffiċċju u għalhekk ħafna aktar.

853
00:41:04,370 --> 00:41:06,920
U kif Rob jgħid wisq, dan huwa
l reviżjoni aktar sinifikanti

854
00:41:06,920 --> 00:41:09,534
tal CS50 fl-10 snin li
Stajt ġew fil [inaudible].

855
00:41:09,534 --> 00:41:12,200
[Inaudible] ffukat partikolarment
biex jipprovdu struttura ta 'appoġġ,

856
00:41:12,200 --> 00:41:14,050
tirqim bogħod ħafna
biċċa l-kbira li kien

857
00:41:14,050 --> 00:41:16,870
akkumulat fl-10 snin
iżviluppi tal iterattiv

858
00:41:16,870 --> 00:41:18,120
fuq settijiet problema tal-kors tal.

859
00:41:18,120 --> 00:41:21,470
>> Allura din is-sena, mhux biss fil-klassi iżda li
anki fil-forma ta 'problema tal-kors tal-

860
00:41:21,470 --> 00:41:24,800
settijiet, għandek issib affarijiet li
ikunu aktar simplifikat, trimmer, ħafna

861
00:41:24,800 --> 00:41:26,700
aktar maniġġabbli minn
fl-aħħar snin, kif aħna

862
00:41:26,700 --> 00:41:31,330
shed xi wħud mill-bagalji li l-
żviluppati min-natura tas-sena tevolvi

863
00:41:31,330 --> 00:41:32,970
wara sena u mtennija.

864
00:41:32,970 --> 00:41:35,110
Allura l-ġodda u mtejba jibda llum.

865
00:41:35,110 --> 00:41:37,860
>> Int ser ikollok jilħqu ftit aktar mill-
persunal fl-kors fil-[inaudible]

866
00:41:37,860 --> 00:41:40,186
fil 02:30, fejn naqdu,
bħala tradizzjoni, kejk.

867
00:41:40,186 --> 00:41:42,060
Hemm kejk daqsxejn aktar
minn dan, imma int ser

868
00:41:42,060 --> 00:41:44,690
jissodisfaw Erin u Tobias u oħrajn għadhom.

869
00:41:44,690 --> 00:41:46,470
U let me jagħtuk
tour qabel nisimgħu

870
00:41:46,470 --> 00:41:49,600
minn uħud mill-membri l-oħra tal-persunal
fil-klassi, ta 'dak li jistenna kif ukoll.

871
00:41:49,600 --> 00:41:52,730
Fil-fatt, aħna dejjem tibda CS50 s
semestru din ġejjin Sibt,

872
00:41:52,730 --> 00:41:54,330
ma 'dak li sejjaħ CS50 Puzzle Jum.

873
00:41:54,330 --> 00:41:56,710
>> Hija għandha x'taqsam xejn mal-
xjenza tal-kompjuter fih innifsu,

874
00:41:56,710 --> 00:41:58,669
iżda b'madwar problema
jissolvew b'mod aktar ġenerali.

875
00:41:58,669 --> 00:42:01,210
U jekk hekk jagħżlu li jieħdu sehem,
kull wħud mill-inviti,

876
00:42:01,210 --> 00:42:03,460
inti tista raw bieb
mwaqqa 'jew fuq il-palk hawn,

877
00:42:03,460 --> 00:42:05,830
huwa opportunità f'timijiet
ta 'tnejn jew tlieta jew erbgħa,

878
00:42:05,830 --> 00:42:10,680
li jipparteċipaw għall puzzles u pizza
u l-premjijiet u more-- din is-Sibt,

879
00:42:10,680 --> 00:42:12,560
waqfa sintonizzat għal aktar.

880
00:42:12,560 --> 00:42:15,082
>> Inti ser issib ukoll li kull
Ġimgħa, fuq nar u Silġ,

881
00:42:15,082 --> 00:42:16,790
ma CS50 ġġib
mazz sħiħ ta 'studenti

882
00:42:16,790 --> 00:42:19,100
lunch, biex tagħmel kbir
klassi iħossuhom aktar intimi,

883
00:42:19,100 --> 00:42:21,820
u ġeneralment iġibu flimkien
alumni u ħbieb minn industrija

884
00:42:21,820 --> 00:42:24,710
biex jitkellmu dwar dak li stajt
kien sa peress li jiggradwaw.

885
00:42:24,710 --> 00:42:27,820
Bl-istess mod, din is-sena, se aħna
jinawgura l-ewwel CS50 50

886
00:42:27,820 --> 00:42:31,390
kodifikazzjoni contest-- ta 'nofs it-semestru
opportunità li jippermetti lil kulħadd

887
00:42:31,390 --> 00:42:35,430
fuq opt fil-bażi, li jkollhom
isfida tal wits kontra klassi,

888
00:42:35,430 --> 00:42:39,250
għal darb'oħra fi gruppi ta 'tnejn jew tlieta jew
erbgħa, bl-użu biss li l-ipprogrammar

889
00:42:39,250 --> 00:42:41,920
sofistikati li inti mbagħad ikollhom taħt
ċinturin tiegħek wara biss sitt jew seba

890
00:42:41,920 --> 00:42:44,710
ġimgħat tal-klassi, u jieħdu sehem
f'dan it-tip ta 'kompetizzjoni

891
00:42:44,710 --> 00:42:50,261
online-- jekk inti tixtieq li hone tiegħek stess
ħiliet l-aktar f'dak sfida.

892
00:42:50,261 --> 00:42:52,760
Fit-tmiem tas-semestru huwa
l-hekk imsejħa CS50 Hackathon--

893
00:42:52,760 --> 00:42:56,970
opportunità li jibda fi 7:00
PM jintemm 07:00, u matul it-triq

894
00:42:56,970 --> 00:43:01,900
huma 12-il siegħa filgħaxija li fihom adsa
fil project-- finali tal-kors tal-

895
00:43:01,900 --> 00:43:04,820
opportunità li disinn u
jimplimentaw aktar ħaġa ta 'interess

896
00:43:04,820 --> 00:43:06,980
lilek bit-tagħlim tiegħek
gwida sħabi s.

897
00:43:06,980 --> 00:43:09,600
Madwar 09:00 għandna tipikament
jservu pizza, 01:00,

898
00:43:09,600 --> 00:43:13,210
Philippe, u l-ftit minna
li għadhom imqajjem fil 05:00,

899
00:43:13,210 --> 00:43:16,310
huma shuttle bussed l-
triq biex IHOP għall-kolazzjon.

900
00:43:16,310 --> 00:43:19,340
>> U mbagħad ftit jiem wara
hija l-CS50 hekk imsejħa fare--

901
00:43:19,340 --> 00:43:23,450
tmiem ta 'wirja semestru
ċelebrazzjoni ta 'ftit kemm tant

902
00:43:23,450 --> 00:43:28,200
ta CS50 studenti jkunu ġejjin minn
ġimgħa żero it-triq kollha lejn il-ġimgħa,

903
00:43:28,200 --> 00:43:32,610
u jżomm f'moħħu li 73% ta 'dawk
klassi u tiegħek din is-sena jkollu

904
00:43:32,610 --> 00:43:34,840
qatt ħadet klassi CS qabel.

905
00:43:34,840 --> 00:43:39,226
Fil-fatt, sabiex reemphasize kemm, hawnhekk
hija ftit aktar tiffaċċja minn persunal CS50 s.

906
00:43:39,226 --> 00:43:40,184
Speaker 4: [inaudible].

907
00:43:40,184 --> 00:43:45,909

908
00:43:45,909 --> 00:43:46,867
Speaker 5: [inaudible].

909
00:43:46,867 --> 00:43:51,332

910
00:43:51,332 --> 00:43:52,290
Speaker 6: [inaudible].

911
00:43:52,290 --> 00:43:55,276

912
00:43:55,276 --> 00:43:56,234
Speaker 7: [inaudible].

913
00:43:56,234 --> 00:44:01,727

914
00:44:01,727 --> 00:44:02,643
Speaker 8: [inaudible]

915
00:44:02,643 --> 00:44:10,066

916
00:44:10,066 --> 00:44:11,024
Speaker 9: [inaudible].

917
00:44:11,024 --> 00:44:14,475

918
00:44:14,475 --> 00:44:15,461
>> Speaker 4: [inaudible].

919
00:44:15,461 --> 00:44:16,461
>> Speaker 10: [inaudible].

920
00:44:16,461 --> 00:44:21,456

921
00:44:21,456 --> 00:44:23,438
Speaker 11: [inaudible].

922
00:44:23,438 --> 00:44:24,438
Speaker 12: [inaudible].

923
00:44:24,438 --> 00:44:30,438

924
00:44:30,438 --> 00:44:31,396
Speaker 13: [inaudible]

925
00:44:31,396 --> 00:44:37,360

926
00:44:37,360 --> 00:44:40,342
>> Speaker 14: [inaudible].

927
00:44:40,342 --> 00:44:42,863
>> Speaker 13: [inaudible].

928
00:44:42,863 --> 00:44:43,821
Speaker 15: [inaudible]

929
00:44:43,821 --> 00:44:48,785

930
00:44:48,785 --> 00:44:49,785
Speaker 16: [inaudible].

931
00:44:49,785 --> 00:44:53,761

932
00:44:53,761 --> 00:44:55,252
>> Speaker 11: [inaudible]

933
00:44:55,252 --> 00:44:57,773

934
00:44:57,773 --> 00:44:58,731
Speaker 5: [inaudible].

935
00:44:58,731 --> 00:45:11,250

936
00:45:11,250 --> 00:45:15,130
DAVID Malan: Uħud mit-tim
huma nfushom shopping klassijiet.

937
00:45:15,130 --> 00:45:17,760
Imma jekk dawk il-membri
tal-persunal CS50 hawn,

938
00:45:17,760 --> 00:45:19,230
jistgħu jidħlu fuq up għal ftit mument.

939
00:45:19,230 --> 00:45:23,450
CS50 s TFS u AKs u [? persunal?]
membri here-- dawn huma biss ftit

940
00:45:23,450 --> 00:45:28,880
tal-faces-- waħda minnhom tkun għadek
raw, u ftit other-- u fi ftit oħrajn

941
00:45:28,880 --> 00:45:30,020
xorta.

942
00:45:30,020 --> 00:45:33,242
Għaliex ma we jimxi 'l quddiem u jippermettu
inti guys pawża ta 'ħames minuti.

943
00:45:33,242 --> 00:45:35,450
Jekk għandek bżonn biex papra lil
klassijiet shop, li l-multa.

944
00:45:35,450 --> 00:45:38,900
U f'ħames minuti, aħna ser jerġa,
tieħu ħarsa lejn Scratch---ewwel

945
00:45:38,900 --> 00:45:42,420
tal-lingwa ta 'programmar tagħna, jiltaqa
persunal tal-kors hawn ftit aktar,

946
00:45:42,420 --> 00:45:45,020
u tiffoka finalment
dwar il-problema sett żero.

947
00:45:45,020 --> 00:45:46,710
Allura aħna ser jiġu lura f'ħames minuti.

1
00:45:46,864 --> 00:45:47,370
>> Kull dritt.

2
00:45:47,370 --> 00:45:48,590
Allura aħna lura.

3
00:45:48,590 --> 00:45:51,330
U fil fadal tagħna
ħin tal-lum, l-għan

4
00:45:51,330 --> 00:45:54,320
huwa li jkun hemm kundizzjonijiet ugwali
f'termini ta 'xi wħud terminoloġija,

5
00:45:54,320 --> 00:45:55,297
f'termini ta 'xi ideat.

6
00:45:55,297 --> 00:45:57,380
Minħabba fil-fatt, skond
xi wħud mill-mapep ta 'qabel,

7
00:45:57,380 --> 00:46:00,130
hemm se tkun sensiela ta '
livelli ta 'esperjenza fil-klassi,

8
00:46:00,130 --> 00:46:03,210
xi wħud li l-istudenti jkollhom
ħadu xi programmazzjoni qabel,

9
00:46:03,210 --> 00:46:04,200
li wħud minnhom m'għamlux dan.

10
00:46:04,200 --> 00:46:07,430
U hekk ma dan l-ewwel il-problema
stabbiliti u ma 'dan l-ewwel lingwa

11
00:46:07,430 --> 00:46:10,830
għandna l-opportunità li jibdew
li jieħdu għal mogħtija wara lum

12
00:46:10,830 --> 00:46:12,960
xi vokabularju komuni u l-idea.

13
00:46:12,960 --> 00:46:15,590
>> U aħna ser nagħmlu dan permezz ta '
ewwel languages---kors tal

14
00:46:15,590 --> 00:46:21,070
flimkien ma 'C u Python u
JavaScript u SQL u HTML u CSS,

15
00:46:21,070 --> 00:46:24,450
aħna ser jkun qed jiffoka inizjalment
u biss għall-problema sett żero

16
00:46:24,450 --> 00:46:28,160
fuq din il-lingwa grafika, imsejħa
Scratch, żviluppata mill-MIT'S Media Lab

17
00:46:28,160 --> 00:46:30,880
fl-triq, biex tgħin
studenti u tfal speċjalment

18
00:46:30,880 --> 00:46:35,070
jesprimu ruħhom algorithmically--
b'mod aktar konsistenti ma 'dak li

19
00:46:35,070 --> 00:46:37,300
nistgħu sejħa ħsieb komputazzjoni.

20
00:46:37,300 --> 00:46:40,985
>> U huwa lingwa utli għaliex
malajr ħafna ġimgħa d-dieħla fi żmien ġimgħa,

21
00:46:40,985 --> 00:46:44,360
do we transizzjoni għal aktar
lingwa tradizzjonali u arcane imsejħa

22
00:46:44,360 --> 00:46:46,370
Ċ, li hija purament testwali.

23
00:46:46,370 --> 00:46:48,930
Inti biss użu tastiera tiegħek fil
Sabiex jiktbu istruzzjonijiet

24
00:46:48,930 --> 00:46:50,230
bħall dawn fuq l-iskrin.

25
00:46:50,230 --> 00:46:52,840
Iżda anke jekk inti stajt qatt dehru
lingwa ta 'programmar qabel,

26
00:46:52,840 --> 00:46:55,170
fi ftit glancing fil
dan, kull kemm jekk tkun cryptic,

27
00:46:55,170 --> 00:47:00,010
inti tista 'probabbilment raden li
probabbilment stampi Hello Dinja.

28
00:47:00,010 --> 00:47:02,050
Iżda hemm ħafna ta '
overhead sintattika hemmhekk.

29
00:47:02,050 --> 00:47:05,770
Hemm il-hash stramb
simbolu jew hash tikketta top up.

30
00:47:05,770 --> 00:47:08,900
Hemm il-parentesi angolu, xi
parentesi, ċingi kaboċċi, semi-colon--

31
00:47:08,900 --> 00:47:11,880
hemm biss tant viżwali
sintassi li gets fil-mod.

32
00:47:11,880 --> 00:47:13,940
Nibdew l-kors bi
Scratch sabiex tikseb

33
00:47:13,940 --> 00:47:17,600
passat kollha ta 'dawk intellettwalment
distrazzjonijiet uninteresting,

34
00:47:17,600 --> 00:47:20,290
u minflok tiffoka fuq l-ideat.

35
00:47:20,290 --> 00:47:22,540
>> Fil-fatt, dan jista 'jkun qabel.

36
00:47:22,540 --> 00:47:24,830
Dan, għal dan, ġimgħa għandha tkun wara.

37
00:47:24,830 --> 00:47:26,760
Dan, f'dan il-grafika
Scratch lingwa,

38
00:47:26,760 --> 00:47:29,870
huwa kif inti jimplimentaw l-istess
program-- programm li meta jiddekorri,

39
00:47:29,870 --> 00:47:31,340
sempliċiment jgħid bonjour dinja.

40
00:47:31,340 --> 00:47:34,740
U x'hemm sbieħ dwar Scratch huwa
li huwa din il-programmazzjoni grafika

41
00:47:34,740 --> 00:47:38,780
ambjent li tuża biċċiet puzzle jew
blokki, li jorbtu ma 'xulxin biss flimkien

42
00:47:38,780 --> 00:47:40,440
jekk jagħmel sens loġiku li jagħmlu dan.

43
00:47:40,440 --> 00:47:43,810
U ma scratch tista 'tiżviluppa
animazzjonijiet u logħob interattiv

44
00:47:43,810 --> 00:47:47,270
u l-arti, u kull numru ta 'affarijiet li
inti tista 'timmaġina f'moħħu tiegħek stess,

45
00:47:47,270 --> 00:47:51,200
u timplimentahom sempliċiment billi
jittrattienu u twaqqa biċċiet puzzle.

46
00:47:51,200 --> 00:47:54,265
>> U fil-fatt, aħna ser ikollhom l-abbiltà
biex jesprimu xi wħud mill-istess ideat

47
00:47:54,265 --> 00:47:56,890
li I biss imsemmija mument
ilu fil-kuntest ta 'Mike Smith

48
00:47:56,890 --> 00:48:00,670
u tiftix telefon book-- affarijiet
bħall-funzjonijiet, biss azzjonijiet,

49
00:48:00,670 --> 00:48:03,070
affarijiet simili linji li jagħmlu
affarijiet darb'oħra u għal darb'oħra,

50
00:48:03,070 --> 00:48:05,170
varjabbli, li hija
xi ħaġa aħna ser jintroduċu,

51
00:48:05,170 --> 00:48:08,086
imma hija familjari forsi minn
algebra-- biss xi tip ta 'placeholder

52
00:48:08,086 --> 00:48:10,840
li jaħżen xi valur inti tista
bżonn espressjonijiet Boolean later--,

53
00:48:10,840 --> 00:48:13,720
fejn dawk iva le jew vera
mistoqsijiet falza minn qabel.

54
00:48:13,720 --> 00:48:17,117
Kundizzjonijiet huma dawk frieket fl-
road-- dawn il-friegħi biex ngħidu hekk.

55
00:48:17,117 --> 00:48:19,700
U allura hemm xi fancier
Karatteristiċi aħna ser tara anke llum,

56
00:48:19,700 --> 00:48:22,850
imsejħa arrays u ħjut u
avvenimenti, li aħna ser mbagħad tirrevedi fuq

57
00:48:22,850 --> 00:48:24,460
ħin f'lingwi differenti.

58
00:48:24,460 --> 00:48:26,790
Iżda Scratch jippermetti
biex jesploraw dawn kollha.

59
00:48:26,790 --> 00:48:30,779
Allura hawn fil Scratch, dan vjola
blokk huwa dak funzjoni huwa tipikament

60
00:48:30,779 --> 00:48:31,570
ser look like.

61
00:48:31,570 --> 00:48:35,620
Din il-biċċa puzzle vjola li għandha xi
kelma simili ngħidu aħna, li hija l-azzjoni,

62
00:48:35,620 --> 00:48:38,490
u allura jista 'jkollu
argument jew parameter-- b'xi mod

63
00:48:38,490 --> 00:48:41,140
tax-xorta ta customizing
dak li blokka ma

64
00:48:41,140 --> 00:48:45,182
b'tali mod li mhuwiex predeterminat mill
MIT liema dan il-blokk vjola jgħid.

65
00:48:45,182 --> 00:48:47,390
Fil-fatt, tkun taf tara fil-
mument li jien tista 'tip

66
00:48:47,390 --> 00:48:49,931
il-kliem bħal dinja bonjour, jew
bonjour David, jew bonjour Zamayla,

67
00:48:49,931 --> 00:48:53,750
jew kwalunkwe Irrid, fil--argument
għal dak puzzle piece---kaxxa bajda

68
00:48:53,750 --> 00:48:54,251
hemmhekk.

69
00:48:54,251 --> 00:48:57,166
Sadanittant, jekk irrid loop, aħna ser
tara li hemm biċċiet puzzle li

70
00:48:57,166 --> 00:48:58,640
ħarsa oranġjo ftit bħal dan.

71
00:48:58,640 --> 00:49:01,690
U l-għamla tagħhom tip ta tissuġġerixxi li
xi ħaġa jiġri mill-ġdid u għal darb'oħra

72
00:49:01,690 --> 00:49:02,680
f'ċiklu.

73
00:49:02,680 --> 00:49:06,800
>> Mela jekk jien nagħlaq jgħidu bonjour blokk dinja
bi dejjem blokk fil Scratch,

74
00:49:06,800 --> 00:49:10,307
huwa biss se żżomm qal bonjour
dinja dejjem, pjuttost litteralment.

75
00:49:10,307 --> 00:49:12,390
Sadanittant, hemm ieħor
tip ta loop fil scratch

76
00:49:12,390 --> 00:49:14,348
li aħna ser see-- repetizzjoni
block-- fejn, jekk inti

77
00:49:14,348 --> 00:49:17,940
jaf minn qabel kif ħafna drabi
trid li l-linja li tesegwixxi

78
00:49:17,940 --> 00:49:21,850
numru finit ta 'drabi fil fact-- inti
tista 'tispeċifika li billi jittajpja f'numru

79
00:49:21,850 --> 00:49:25,380
jew saħansitra fejn jitwaħħal b'mod varjabbli,
bħal x jew y kif Ser naraw.

80
00:49:25,380 --> 00:49:27,690
>> Fil-fatt, il-varjabbli bħall
i f'dan il-każ, li

81
00:49:27,690 --> 00:49:30,109
huwa isem komuni għal
varjabbli numru sħiħ li

82
00:49:30,109 --> 00:49:31,900
biss ħwienet number--
integer jista 'jkun,

83
00:49:31,900 --> 00:49:35,470
biex jużaw dan il-blokk oranġjo hawn biex
tistabbilixxi varjabbli bħal I għal żero.

84
00:49:35,470 --> 00:49:38,900
Hawn eżempju fl-aħdar ta '
espressjoni Boolean fl scratch.

85
00:49:38,900 --> 00:49:43,700
Anke jekk dan qisu matematika
formula, inugwaljanzi matematika bħal dan

86
00:49:43,700 --> 00:49:45,320
verament huma espressjonijiet Boolean.

87
00:49:45,320 --> 00:49:46,570
Dan huwa la vera jew falza.

88
00:49:46,570 --> 00:49:48,300
I hija inqas minn 50.

89
00:49:48,300 --> 00:49:51,815
Huwa jew iva jew le risposta
jew tweġiba vera jew falza.

90
00:49:51,815 --> 00:49:53,940
U aħna ser ġeneralment sejħa
dawn l-espressjonijiet Boolean.

91
00:49:53,940 --> 00:49:55,148
U ma għandhom ikunu 50.

92
00:49:55,148 --> 00:49:57,970
Jista 'jkun x inqas minn y,
akbar minn y, ugwali għal y--

93
00:49:57,970 --> 00:50:00,020
kwalunkwe numru ta ohra
mistoqsijiet jistgħu jiġu mistoqsija.

94
00:50:00,020 --> 00:50:03,250
>> Issa, fl-ewwel daqqa t'għajn, dan jista 'tfittex
f'daqqa waħda pjuttost kuraġġużi hawn, u huwa.

95
00:50:03,250 --> 00:50:06,540
Iżda kunċett għaqli, huwa
pretty familjari minn qabel.

96
00:50:06,540 --> 00:50:09,370
Jekk x hija inqas minn y, minn say kemm.

97
00:50:09,370 --> 00:50:12,230
Else jekk x huwa akbar
minn y, allura jgħidu kemm.

98
00:50:12,230 --> 00:50:14,260
Else jgħidu x hija ugwali għal y.

99
00:50:14,260 --> 00:50:17,220
Allura aħna għandna eżempju
hemm ta 'tielet scenario--

100
00:50:17,220 --> 00:50:20,600
l-unika tielet possibility-- x huwa jew
akbar minn, inqas minn, jew ugwali għal.

101
00:50:20,600 --> 00:50:22,420
Allura aħna għandna tliet mod furketta ta 'fit-triq.

102
00:50:22,420 --> 00:50:26,290
>> U avviż x'hemm jibred Scratch here--,
jidher, għandha wieħed biss puzzle

103
00:50:26,290 --> 00:50:28,840
biċċa, f'dan il-każ, fil jekk blokk ieħor.

104
00:50:28,840 --> 00:50:32,090
U għadhom li tidher li timplika inti tista
biss ikollhom żewġ mod furketta fit-triq.

105
00:50:32,090 --> 00:50:34,631
Inti tista 'tmur lemin jew xellug imma
dak dwar din it-tielet xenarju?

106
00:50:34,631 --> 00:50:35,760
X'jiġri jekk x huwa daqs y?

107
00:50:35,760 --> 00:50:36,500
No big deal.

108
00:50:36,500 --> 00:50:39,640
Ħu biċċa puzzle wieħed, poġġi
ieħor ġewwa waħda ta 'dan

109
00:50:39,640 --> 00:50:45,759
biex joħolqu l-ekwivalenti semantiku
ta jekk, inkella jekk, else-- u issa int

110
00:50:45,759 --> 00:50:47,300
tliet mod furketta tiegħek fit-triq.

111
00:50:47,300 --> 00:50:49,091
U kif aħna ser tara, il-
biċċiet puzzle Scratch

112
00:50:49,091 --> 00:50:51,820
jista 'jiġi miġbud u jikbru, sabiex
kif CRAM Jittieħed aktar fihom.

113
00:50:51,820 --> 00:50:54,420
Inti ma għandekx li tajbin
kollox fid-daqs kontumaċja tagħha.

114
00:50:54,420 --> 00:50:56,690
>> Din hija xi ħaġa li aħna ser
Hekk ara jissejjaħ firxa.

115
00:50:56,690 --> 00:51:00,880
Huwa simili list-- xi mod
ħażna biċċiet multipli ta 'informazzjoni

116
00:51:00,880 --> 00:51:02,886
fi varjabbli, mhux biss numru.

117
00:51:02,886 --> 00:51:05,760
Dawn Ser naraw rappreżentant tal
xi ħaġa imsejħa multi-kamini.

118
00:51:05,760 --> 00:51:08,280
Fil-fatt, kollha ta 'tiegħek
MACs u PCs dawn il-jiem

119
00:51:08,280 --> 00:51:10,810
jappoġġja multi-kamini,
li jfisser li inti tista litteralment

120
00:51:10,810 --> 00:51:12,390
tagħmel affarijiet multipli fi żmien.

121
00:51:12,390 --> 00:51:15,390
Inti jista 'jkollhom Microsoft Word fil-
tagħrif miksub, li jaħdmu fuq xi essay.

122
00:51:15,390 --> 00:51:17,160
Inti jista 'jkollhom browser
fil-ftuħ isfond

123
00:51:17,160 --> 00:51:18,720
G-mail jew Facebook jew bħalhom.

124
00:51:18,720 --> 00:51:22,730
Kompjuter tiegħek tista 'tagħmel affarijiet multipli
illum għaliex hija multi-kamin,

125
00:51:22,730 --> 00:51:26,390
u programmi li qed fl fil
partikolari huma wkoll multi-kamin.

126
00:51:26,390 --> 00:51:28,970
>> Hemm affarijiet imsejħa avvenimenti bħall
sew fid-dinja tal-scratch,

127
00:51:28,970 --> 00:51:32,640
u allura hemm mod wisq, biex jagħmlu
biċċiet tagħna stess puzzle dwana jekk l-affarijiet

128
00:51:32,640 --> 00:51:34,810
ma jeżistu attwalment bil-quddiem.

129
00:51:34,810 --> 00:51:38,260
Mela ejja jimmotivaw din l kif ġej.

130
00:51:38,260 --> 00:51:40,580
Xi snin ilu, meta I
ewwel skoperti Scratch,

131
00:51:40,580 --> 00:51:43,530
meta I kien effettivament
Student grad fil-MIT, aħna

132
00:51:43,530 --> 00:51:45,640
irwieħna kienu kompitu li jagħmel dar.

133
00:51:45,640 --> 00:51:47,614
U jien implemented--
li, retrospettivament,

134
00:51:47,614 --> 00:51:50,780
kienet deċiżjoni ħażina ħafna għaliex dan huwa
l-kanzunetta aktar infuriating fid-dinja

135
00:51:50,780 --> 00:51:53,321
li tisma 'għal tmien sigħat
filwaqt li jaħdmu fuq homework-- tiegħek

136
00:51:53,321 --> 00:51:57,180
imma xi ħaġa I kien talab Oscar Ħin,
li hija forsi kanzunetta familjari.

137
00:51:57,180 --> 00:51:59,820
>> CS50s stess Ġordan Hayashi, wieħed mill
membri tagħna aktar persunal anzjan,

138
00:51:59,820 --> 00:52:03,920
tejbet dan għall-2015 u
Issa 2016, peress lura fil-ġurnata,

139
00:52:03,920 --> 00:52:06,610
Kelli kollox biss se
fis Oscar Trash jista.

140
00:52:06,610 --> 00:52:09,320
Issa aħna appoġġ riċiklaġġ u kompostaġġ.

141
00:52:09,320 --> 00:52:12,050
>> Iżda biex żebgħa l-istampa
ta 'dak li nistgħu nagħmlu hawnhekk

142
00:52:12,050 --> 00:52:14,130
u biex jimmotivaw xi wħud
l-eżempji livell aktar baxx,

143
00:52:14,130 --> 00:52:16,400
nistgħu tikseb wieħed ieħor
voluntier għal ftit toħroġ fuq up

144
00:52:16,400 --> 00:52:18,331
u play tiegħi ewwel
assenjazzjoni huiswerk qatt?

145
00:52:18,331 --> 00:52:18,830
Come fuq up.

146
00:52:18,830 --> 00:52:19,250
X'hemm isem tiegħek?

147
00:52:19,250 --> 00:52:20,030
>> HENRY: Henry.

148
00:52:20,030 --> 00:52:22,660
>> DAVID Malan: Henry, come fuq up.

149
00:52:22,660 --> 00:52:24,190
Come fuq up.

150
00:52:24,190 --> 00:52:27,070
Ras jew mod, u
tkun taf tara fil-mument,

151
00:52:27,070 --> 00:52:29,870
Jien ser jimxi 'l quddiem u laqat il-
bandiera aħdar fil-lemin ta 'fuq

152
00:52:29,870 --> 00:52:31,100
kantuniera, li jfisser go.

153
00:52:31,100 --> 00:52:33,320
Is-sinjal ikona ftit waqfien
se ngħid waqfien,

154
00:52:33,320 --> 00:52:35,490
u li meta tibda
u twaqqaf il-programm.

155
00:52:35,490 --> 00:52:36,450
Għandi pjaċir.

156
00:52:36,450 --> 00:52:36,950
Kull dritt.

157
00:52:36,950 --> 00:52:39,100
Allura aħna qed tmur biex tara l-istruzzjonijiet
fuq l-iskrin fi ftit mument.

158
00:52:39,100 --> 00:52:41,450
U biss billi jilagħbu din il-logħba
għal ftit seconds-- trust me,

159
00:52:41,450 --> 00:52:43,670
aħna ma tkunx qed tmur jridu jilagħbu
it-triq kollha lejn il-end-- inti se

160
00:52:43,670 --> 00:52:45,470
jiksbu sens ta 'dak il-programm ma.

161
00:52:45,470 --> 00:52:49,170
U aktar milli sempliċement jiffukaw fuq Henry
tkun tajba jew ħżiena fuq din il-logħba, tiffoka

162
00:52:49,170 --> 00:52:52,600
u kif ma kien implimentat permezz lili
oriġinarjament u mbagħad mill-Ġordan.

163
00:52:52,600 --> 00:52:54,640
Fi kliem ieħor, fejn huma l-varjabbli?

164
00:52:54,640 --> 00:52:55,520
Fejn huma l-linji?

165
00:52:55,520 --> 00:52:56,520
Fejn huma l-funzjonijiet?

166
00:52:56,520 --> 00:53:00,700
U aħna ser tara jekk aħna ma tara
dawk taħt il-barnuża.

167
00:53:00,700 --> 00:53:03,660
>> Agħfas u drag Trash
għall-bin xierqa.

168
00:53:03,660 --> 00:54:02,100
>> [Ddoqq il-mużika]

169
00:54:02,100 --> 00:54:02,600
Kull dritt.

170
00:54:02,600 --> 00:54:03,160
Li tajjeb ħafna.

171
00:54:03,160 --> 00:54:04,286
Għaliex ma we stop hemmhekk.

172
00:54:04,286 --> 00:54:04,786
Grazzi.

173
00:54:04,786 --> 00:54:05,830
Prosit lil Henry.

174
00:54:05,830 --> 00:54:07,002
Grazzi.

175
00:54:07,002 --> 00:54:10,690
>> [Applause]

176
00:54:10,690 --> 00:54:12,450
>> Immaġina debugging dak il-programm.

177
00:54:12,450 --> 00:54:15,880
Jekk hemm problema tnejn
Fil-song-- imma hekk minuti

178
00:54:15,880 --> 00:54:17,430
x'inhu għaddej hawn tassew?

179
00:54:17,430 --> 00:54:20,900
Bħala kkumplikati kif jista
tibda jidhru li nikseb matul iż-żmien,

180
00:54:20,900 --> 00:54:22,910
tabilħaqq aktar u aktar
Jittieħed beda jonqos,

181
00:54:22,910 --> 00:54:25,370
x'hemm interessanti dwar
dan it-tip ta example--

182
00:54:25,370 --> 00:54:27,270
u aħna ser tara xi ftit
others-- hija li jekk inti

183
00:54:27,270 --> 00:54:30,416
tfittex passat l-kumplessità jew
l-sofistikazzjoni tal-logħba,

184
00:54:30,416 --> 00:54:33,040
hemm bini sempliċi ħafna
blokki li play-- kollha,

185
00:54:33,040 --> 00:54:35,840
jekk inti jiddistillaw minnhom lil dawk
blokki tal-bini, huma aċċessibbli ħafna

186
00:54:35,840 --> 00:54:37,401
u implimentabbli unto infushom.

187
00:54:37,401 --> 00:54:39,150
Per eżempju, huwa
Kien xi żmien, imma jien

188
00:54:39,150 --> 00:54:42,900
pretty żgur dak li inizjalment għamlet meta
jagħmlu din il-logħba għall-ewwel darba

189
00:54:42,900 --> 00:54:44,787
kien I kompletament simili procrastinated.

190
00:54:44,787 --> 00:54:47,120
I ma tiffoka xejn fuq il
loġika jew il-biċċiet puzzle,

191
00:54:47,120 --> 00:54:50,810
I iffukat fuq il-grafika u sejba
-post toroq u l-Trash jista

192
00:54:50,810 --> 00:54:51,540
u kollha ta 'dak.

193
00:54:51,540 --> 00:54:53,456
Iżda dawn kienu meħtieġa
ingredjenti fl-ewwel.

194
00:54:53,456 --> 00:54:57,220
U ladarba I lest procrastinating u
li jippreskrivi l-qafas ġenerali,

195
00:54:57,220 --> 00:55:00,337
I iddeċieda, let me biss tagħmel waħda
biċċa Trash jaqgħu mis-sema.

196
00:55:00,337 --> 00:55:02,170
U aħna ser tara Scratch
jappoġġja l-affarijiet imsejħa

197
00:55:02,170 --> 00:55:06,386
karattri sprites-- li jistgħu
għandhom kostumi differenti fuq hekk dawn

198
00:55:06,386 --> 00:55:07,010
tfittex differenti.

199
00:55:07,010 --> 00:55:09,660
>> U hekk nressaq Trash
kostum fuq wieħed Sprite tali.

200
00:55:09,660 --> 00:55:12,007
U jien biss bżonnha
li jaqgħu mis-sema.

201
00:55:12,007 --> 00:55:14,590
U hekk jirriżulta, Scratch,
bħall lingwi ta 'programmar aktar,

202
00:55:14,590 --> 00:55:18,099
jappoġġja każwali numri jew
każwali numri teknikament pseudocode,

203
00:55:18,099 --> 00:55:20,390
hekk li billi jittrattienu u
twaqqa ċerti biċċiet puzzle,

204
00:55:20,390 --> 00:55:22,890
I kien kapaċi li jkollhom l-Trash
ġejjin minn fuq ix-xellug fl-ewwel.

205
00:55:22,890 --> 00:55:25,580
U allura l-ħin li jmiss li niżel, mill-
dritt u mbagħad mill-nofs.

206
00:55:25,580 --> 00:55:28,060
U l-logħba ma kinitx biss
jkollhom Trash jaqgħu mis-sema.

207
00:55:28,060 --> 00:55:29,770
Inti ma jista 'punt lejn din jew ikklikkja fuqha.

208
00:55:29,770 --> 00:55:31,103
Inti ma tista 'tiftaħ il-Trash jista.

209
00:55:31,103 --> 00:55:32,160
Inti ma tistax tagħmel xejn.

210
00:55:32,160 --> 00:55:34,450
Iżda dan kien pass tarbija
lejn viżjoni aħħari tiegħi.

211
00:55:34,450 --> 00:55:36,720
>> U wara dan, I attwalment
implimentati xi tip

212
00:55:36,720 --> 00:55:41,230
ta sensing b'tali mod li jekk inti ma tikklikkja
u drag fuq il-biċċa ta 'trash

213
00:55:41,230 --> 00:55:44,350
fuq il-Trash jista, Oscar
għatu se tinfetaħ u tingħalaq.

214
00:55:44,350 --> 00:55:47,650
Xejn jiġri lill-Trash, iżda
mill-inqas l-għatu se tinfetaħ u tingħalaq.

215
00:55:47,650 --> 00:55:49,642
Allura mbagħad tiċċekkja, pass tnejn minn tnejn.

216
00:55:49,642 --> 00:55:52,100
U dan huwa dak li għaddej biex tkun
ewlieni fiż-żewġ problema zero

217
00:55:52,100 --> 00:55:55,970
u fl-ipprogrammar aktar ġenerali, huwa li
jieħdu dawn il-passi tarbija intenzjonat ħafna.

218
00:55:55,970 --> 00:55:59,390
Minħabba li mhux biss ma jippermetti li inti
jħossu onestament akkomplit ħafna aktar

219
00:55:59,390 --> 00:56:01,250
quickly-- huwa l-
-agħar ħaġa fid-dinja

220
00:56:01,250 --> 00:56:06,149
biex tipprova timplimenta kollha Oscar Ħin,
imbagħad siegħa wara laqat il-bandiera aħdar,

221
00:56:06,149 --> 00:56:08,440
u xejn xogħlijiet kif mistenni
għaliex fejn do you anke

222
00:56:08,440 --> 00:56:11,150
jibdew debug jew
troubleshoot dak il-programm?

223
00:56:11,150 --> 00:56:12,470
Huwa biss kbira.

224
00:56:12,470 --> 00:56:16,792
>> U hekk tassew tħaddan din l-idea
li jittieħdu passi tarbija steps-- darb'oħra

225
00:56:16,792 --> 00:56:19,000
u again-- tibni
xi ħaġa li, fl-aħħar,

226
00:56:19,000 --> 00:56:23,672
verament impressjonanti u kumplessi, iżda
fl-ewwel, mhuwiex kważi bħala hu hekk.

227
00:56:23,672 --> 00:56:24,630
Fil-fatt, ejja tagħmel dan.

228
00:56:24,630 --> 00:56:28,989
Let me imorru quddiem and-- Scratch innifsu
teżisti fuq il-web fuq Scratch.MIT.edu,

229
00:56:28,989 --> 00:56:30,780
u tkun taf tkun told kif
ħafna mill-ġdid fl problema

230
00:56:30,780 --> 00:56:34,200
sett żero, l-ispeċifikazzjoni għall-
li diġà qiegħda fuq il-websajt CS50 s.

231
00:56:34,200 --> 00:56:35,725
>> Imma dan huwa dak Scratch nnifisha hija.

232
00:56:35,725 --> 00:56:38,210
U hemm verament ftit
tliet oqsma primarji.

233
00:56:38,210 --> 00:56:40,980
Fil-quċċata xellug hemm
huwa l-istadju hekk imsejħa.

234
00:56:40,980 --> 00:56:41,810
Dan huwa scratch.

235
00:56:41,810 --> 00:56:43,710
Il-kostumi default qattus.

236
00:56:43,710 --> 00:56:46,950
U dan huwa l-dinja rettangolari
li inti tista move-- up, down, xellug,

237
00:56:46,950 --> 00:56:48,130
dritt u xi għalf ieħor.

238
00:56:48,130 --> 00:56:51,839
Fin-nofs hawn huma kategoriji tagħna
jew paletti tagħna ta 'biċċiet puzzle,

239
00:56:51,839 --> 00:56:53,630
u kuluri differenti
tfisser affarijiet differenti.

240
00:56:53,630 --> 00:56:56,520
U jekk inti poke madwar, tkun taf tara
affarijiet simili loops u kundizzjonijiet

241
00:56:56,520 --> 00:56:58,160
u l-varjabbli u ingredjenti oħra.

242
00:56:58,160 --> 00:57:00,060
>> U allura hawn hija ż-żona skripts.

243
00:57:00,060 --> 00:57:03,020
Dan huwa fejn I tista 'ttawwal u qatra
dawk il-biċċiet puzzle biex tagħmel affarijiet.

244
00:57:03,020 --> 00:57:04,690
Mela ejja do tali ħaġa waħda.

245
00:57:04,690 --> 00:57:06,630
Let me imorru quddiem and--
u naf fejn hu.

246
00:57:06,630 --> 00:57:10,110
Hekk jien ser immedjatament ikklikkja fuq
fejn naf affarijiet huma lesti li jkunu,

247
00:57:10,110 --> 00:57:13,140
iżda tipponta u tikklikkja u
poking madwar huma inevitabbli.

248
00:57:13,140 --> 00:57:15,320
Allura meta bandiera aħdar għafast,
dak li nixtieq do?

249
00:57:15,320 --> 00:57:17,100
Jien ser tagħmel dan.

250
00:57:17,100 --> 00:57:20,699
Jien ser jkaxkru dan puzzle vjola
biċċa, jgħidu bonjour għal żewġ sekondi,

251
00:57:20,699 --> 00:57:21,490
u let me zoom in.

252
00:57:21,490 --> 00:57:23,865
>> U jien ser tbiddel dan
li jkun dak li nixtieq li be--

253
00:57:23,865 --> 00:57:26,471
bonjour dinja għal żewġ sekondi huwa multa.

254
00:57:26,471 --> 00:57:28,970
Issa, jien ser ikklikkja l-
bandiera aħdar, jew jekk I verament irridu,

255
00:57:28,970 --> 00:57:31,820
I jistgħu full screen u mbagħad jiġu lura.

256
00:57:31,820 --> 00:57:34,060
Hija se biss iżommu
kollox fi tieqa waħda.

257
00:57:34,060 --> 00:57:36,141
Aħdar dinja bonjour flag--.

258
00:57:36,141 --> 00:57:36,640
Kull dritt.

259
00:57:36,640 --> 00:57:38,789
Mhux kollha li interessanti.

260
00:57:38,789 --> 00:57:40,080
So let me go quddiem u tagħmel dan.

261
00:57:40,080 --> 00:57:41,038
Let me pprova ieħor.

262
00:57:41,038 --> 00:57:44,740
Meta bandiera aħdar clicked-- ejja
jagħmel xi ħaġa bħal soda.

263
00:57:44,740 --> 00:57:46,880
U tinnota li minn
-kaxxa b'xejn ikollok

264
00:57:46,880 --> 00:57:49,910
ħoss qattus, kif inhu l-Sprite default.

265
00:57:49,910 --> 00:57:52,380
Allura issa let me imorru quddiem u
laqat il-bandiera aħdar issa.

266
00:57:52,380 --> 00:57:53,224
>> [Meowing]

267
00:57:53,224 --> 00:57:54,490
>> Aw.

268
00:57:54,490 --> 00:57:55,370
Li adorable.

269
00:57:55,370 --> 00:57:57,040
Jien programmazzjoni.

270
00:57:57,040 --> 00:57:58,550
Allura dak li jiena jsir?

271
00:57:58,550 --> 00:58:00,430
Dan huwa l-ekwivalenti ta 'programm.

272
00:58:00,430 --> 00:58:01,600
Huwa ovvjament super sempliċi.

273
00:58:01,600 --> 00:58:05,300
Hija ma verament jieħu kollha li ħafna
sforzi u MIT ma ħafna mix-xogħol,

274
00:58:05,300 --> 00:58:07,890
imma jien imsejħa funzjoni.

275
00:58:07,890 --> 00:58:08,940
I użaw funzjoni.

276
00:58:08,940 --> 00:58:12,480
Stajt għamel xi azzjoni, bl-użu biss
li wieħed biċċa puzzle vjola.

277
00:58:12,480 --> 00:58:15,960
>> Ukoll, jekk nixtieq do
tliet meows fir-ringiela?

278
00:58:15,960 --> 00:58:18,570
Let me imorru quddiem u jagħmlu tnejn u tlieta.

279
00:58:18,570 --> 00:58:20,910
U avviż li meta inti
imbagħad jerġgħu qrib biċċa puzzle,

280
00:58:20,910 --> 00:58:22,970
linja bajda ftit jidher
tip ta 'manjetikament,

281
00:58:22,970 --> 00:58:25,190
u se snap
flimkien meta inti let go.

282
00:58:25,190 --> 00:58:26,600
Ejja naraw x'jiġri hawn.

283
00:58:26,600 --> 00:58:27,920
>> [Meowing]

284
00:58:27,920 --> 00:58:32,390

285
00:58:32,390 --> 00:58:34,510
>> Hemm bug.

286
00:58:34,510 --> 00:58:35,650
I biss tisma meow wieħed.

287
00:58:35,650 --> 00:58:37,440
Għaliex jista 'jkun?

288
00:58:37,440 --> 00:58:39,001
Yeah?

289
00:58:39,001 --> 00:58:39,500
Yeah.

290
00:58:39,500 --> 00:58:41,650
Aħna ma verament tismagħha,
iżda li intwizzjoni tajba.

291
00:58:41,650 --> 00:58:43,400
Huma qed kollha jilagħbu fl-istess ħin.

292
00:58:43,400 --> 00:58:44,000
Għaliex?

293
00:58:44,000 --> 00:58:46,587
Ukoll, il-kompjuter huwa biss se
li tagħmel dak li għid li tagħmel.

294
00:58:46,587 --> 00:58:48,670
Mela jekk inti tgħidli, il-logħba ħoss,
play ħoss, play ħoss,

295
00:58:48,670 --> 00:58:52,887
imma inti ma jgħidux li jkollha sakemm
inti qed isir, play sakemm inti qed isir,

296
00:58:52,887 --> 00:58:54,970
li għaddej biex blow permezz
il-programm verament mgħaġġel

297
00:58:54,970 --> 00:58:56,830
u ma biss dak li inti tgħid li tagħmel.

298
00:58:56,830 --> 00:58:59,040
>> So I attwalment bżonn biex jiffissaw
dan fi ftit ta 'modi.

299
00:58:59,040 --> 00:59:00,623
I jistgħu biss jagħmlu dan, jeħles ta 'dan.

300
00:59:00,623 --> 00:59:04,180
Let me tipprova dan puzzle ieħor
piece-- play meow ħoss sal isir,

301
00:59:04,180 --> 00:59:07,072
u mbagħad drag tlieta
dawn u Play kklikkja.

302
00:59:07,072 --> 00:59:09,430
>> [Meowing]

303
00:59:09,430 --> 00:59:13,350
>> Mhuwiex verament very--
nirringrazzja you-- ħafna naturali.

304
00:59:13,350 --> 00:59:16,590
Allura għaliex ma I-- let
me go għall-kontroll hawn.

305
00:59:16,590 --> 00:59:17,090
Nizza.

306
00:59:17,090 --> 00:59:22,230
Stenna tieni wieħed, u issa let me jmorru lura
ħsejjes, u jilagħbu ħoss sal isir,

307
00:59:22,230 --> 00:59:24,620
u mbagħad let me nikseb stenna sekonda waħda.

308
00:59:24,620 --> 00:59:28,692
U allura let me go u tikseb wieħed
aktar soda, u here we go.

309
00:59:28,692 --> 00:59:31,350
>> [Meowing]

310
00:59:31,350 --> 00:59:35,930
>> A ftit aktar naturali, iżda
dan mhux effiċjenti ħafna.

311
00:59:35,930 --> 00:59:39,830
Bħal I kien jkollna bored, kollha jkunu
fil-qosor, tikklikkja quddiem u lura

312
00:59:39,830 --> 00:59:42,724
u verament jidduplikaw work-- tiegħi
pretty ħafna ikkupjar u pasta.

313
00:59:42,724 --> 00:59:44,640
Tabilħaqq, jekk I Kontroll
għafast jew dritt għafast,

314
00:59:44,640 --> 00:59:46,500
I setgħet biss kkupjati u pasted.

315
00:59:46,500 --> 00:59:49,870
Dak li jkun aħjar tibni għall-użu?

316
00:59:49,870 --> 00:59:51,090
Liema idea mill qabel?

317
00:59:51,090 --> 00:59:51,990
>> Yeah, hekk loop.

318
00:59:51,990 --> 00:59:54,580
U fil-fatt, jekk aħna poked madwar,
nistgħu jsibu eżattament dan.

319
00:59:54,580 --> 00:59:57,730
Let me mur Avvenimenti jew pjuttost Kontroll.

320
00:59:57,730 --> 00:59:59,650
So repeat-- I do not
jixtiequ li din tkun ta '10 darbiet.

321
00:59:59,650 --> 01:00:01,370
Li għaddej biex tikseb annoying malajr.

322
01:00:01,370 --> 01:00:03,380
Imma jien se jirrepeti tliet darbiet.

323
01:00:03,380 --> 01:00:06,355
Let me jmorru lura għall-ħoss u
jilagħbu l-ħoss sakemm dan isir.

324
01:00:06,355 --> 01:00:08,480
Let me jmorru lura għall-Kontroll tal-
u biss stenna sekonda waħda.

325
01:00:08,480 --> 01:00:10,271
U avviż, inti tista
naħseb li ma jinstallax,

326
01:00:10,271 --> 01:00:13,520
iżda għal darb'oħra jekk manjetikament inti tħallih
snap fil-post, ser tikber biex timla.

327
01:00:13,520 --> 01:00:14,971
X'hemm dan play issa?

328
01:00:14,971 --> 01:00:18,500
>> [Meowing]

329
01:00:18,500 --> 01:00:19,000
KOLLOX SEW.

330
01:00:19,000 --> 01:00:19,660
Nizza.

331
01:00:19,660 --> 01:00:22,540
U dan huwa dak li se jiġi mistieden
programm li wkoll korretta.

332
01:00:22,540 --> 01:00:27,590
Hija meowed tliet darbiet pjuttost
naturalment, iżda huwa ddisinjat aħjar.

333
01:00:27,590 --> 01:00:29,580
Jien jużaw inqas sensja.

334
01:00:29,580 --> 01:00:30,970
I ma kopja u paste xejn.

335
01:00:30,970 --> 01:00:32,470
I biss użati idea aħjar.

336
01:00:32,470 --> 01:00:35,340
>> Issa, dan għadu mhux kollha li
interessanti ma Scratch ma nagħmilx

337
01:00:35,340 --> 01:00:35,930
xejn.

338
01:00:35,930 --> 01:00:37,388
Mela ejja nagħmlu xi ħaġa oħra minflok.

339
01:00:37,388 --> 01:00:38,670
Ejja nagħmlu xi ħaġa għal dejjem.

340
01:00:38,670 --> 01:00:39,420
U inti taf liema?

341
01:00:39,420 --> 01:00:40,470
Mozzjoni jidher interessanti.

342
01:00:40,470 --> 01:00:45,760
Ejja jkollhom lilu jimxu 10
passi u hit play issa.

343
01:00:45,760 --> 01:00:46,570
>> KOLLOX SEW.

344
01:00:46,570 --> 01:00:49,300
Well nistgħu tip ta 'tkarkir
lura lilu, u hu għadu

345
01:00:49,300 --> 01:00:51,250
running għaliex hu qed jagħmel dan il dejjem.

346
01:00:51,250 --> 01:00:53,150
Allura l-linja qed tagħmel
dak li kien qal li tagħmel,

347
01:00:53,150 --> 01:00:54,650
iżda dan mhux kollox li interessanti.

348
01:00:54,650 --> 01:00:55,310
Ejja nagħmlu dan.

349
01:00:55,310 --> 01:00:59,870
Let me żid blokk ta 'kontroll, u l-użu wieħed
ta 'dawk il-kondizzjonijiet għall-ewwel darba.

350
01:00:59,870 --> 01:01:03,119
>> Allura li għaddej biex tmexxi 10 steps--
10 tikek, 10 pixels fuq l-screen--

351
01:01:03,119 --> 01:01:04,660
allura huwa għaddej biex jistaqsu din il-kwistjoni.

352
01:01:04,660 --> 01:01:09,340
Jekk xi ħaġa huwa veru, mela
xi ħaġa ġewwa dan il-blokk.

353
01:01:09,340 --> 01:01:13,060
Għalhekk jirriżulta li sensing għandu sħiħa
mazz ta expressions-- Boolean

354
01:01:13,060 --> 01:01:16,580
kwistjonijiet ta 'l-iva le jew vera
falza form-- let me jagħmlu dan.

355
01:01:16,580 --> 01:01:19,260
>> Jekk touching-- u allura hemm
din il-waqgħa ftit down menu.

356
01:01:19,260 --> 01:01:20,410
I jistgħu parameterize dan.

357
01:01:20,410 --> 01:01:23,010
Jekk tmiss il edge-- ejja
tagħmel xi ħaġa bħal dik.

358
01:01:23,010 --> 01:01:27,310
Mela jekk jmissu edge--
let me jmorru lura għall-mozzjoni.

359
01:01:27,310 --> 01:01:32,281
U għaliex ma we biss
jdur 180 gradi?

360
01:01:32,281 --> 01:01:32,780
Kull dritt.

361
01:01:32,780 --> 01:01:35,070
Allura dejjem, jimxu 10 passi.

362
01:01:35,070 --> 01:01:37,670
Jekk inti qed tmiss il-
tarf, dawran 180 grad.

363
01:01:37,670 --> 01:01:39,720
U li mhux it-tmiem tal-programm
għaliex int fil-dejjem blokk,

364
01:01:39,720 --> 01:01:42,053
hekk huwa għaddej biex tmur għal darb'oħra u
ġdid u għal darb'oħra u għal darb'oħra.

365
01:01:42,053 --> 01:01:43,980
Mela ejja ara dak li jiġri.

366
01:01:43,980 --> 01:01:44,785
KOLLOX SEW.

367
01:01:44,785 --> 01:01:48,270
A ftit Buggy, iżda tip ta 'kessaħ.

368
01:01:48,270 --> 01:01:51,710
>> U nistgħu jżidu ma 'dan xi affarijiet iblah
li mhumiex kollha li intellettwalment

369
01:01:51,710 --> 01:01:52,270
interessanti.

370
01:01:52,270 --> 01:01:57,210
Imma jekk aħna hit din il ftit
mikrofonu button-- Ouch.

371
01:01:57,210 --> 01:01:58,480
Let me tnaddaf dan up.

372
01:01:58,480 --> 01:02:01,540
Let me jsaħħu dan bħala
huma jgħidu fuq it-TV.

373
01:02:01,540 --> 01:02:05,400
Naddaf li sa, Save, u
issa jitla 'sa skripts.

374
01:02:05,400 --> 01:02:07,500
>> U issa, let me go għall-ħoss.

375
01:02:07,500 --> 01:02:09,002
Let me tagħtiha isem.

376
01:02:09,002 --> 01:02:12,440
I ser sejħa dan Ouch.

377
01:02:12,440 --> 01:02:13,840
U issa jilagħbu Ouch ħoss.

378
01:02:13,840 --> 01:02:16,520
Avviż jidher fil-
ftit drop down menu.

379
01:02:16,520 --> 01:02:17,612
Ejja naraw.

380
01:02:17,612 --> 01:02:20,444
>> [Ouch]

381
01:02:20,444 --> 01:02:24,377
>> [Laughing]

382
01:02:24,377 --> 01:02:25,835
Iżda nistgħu nbiddlu t tieghu fuq il-fly.

383
01:02:25,835 --> 01:02:28,106
Nistgħu nkunu darbtejn bħala tedjanti.

384
01:02:28,106 --> 01:02:31,760
>> [Ouch]

385
01:02:31,760 --> 01:02:35,332
>> Jew jekk nagħmlu dan bħal
1,000 passi fi time--

386
01:02:35,332 --> 01:02:39,900

387
01:02:39,900 --> 01:02:40,670
>> KOLLOX SEW.

388
01:02:40,670 --> 01:02:42,295
Allura aħna qed tmur biex jitilqu li wieħed waħdu.

389
01:02:42,295 --> 01:02:45,290
Għalhekk għal darb'oħra, bini I blocks--
beda ma 'xi ħaġa sempliċi super,

390
01:02:45,290 --> 01:02:47,930
u mbagħad I miżjuda karatteristika,
miżjud karatteristika, miżjuda karatteristika.

391
01:02:47,930 --> 01:02:50,721
U jien m'għadhomx bżonn ninkwetaw dwar
kif l-ewwel wieħed minn dawn il-karatteristiċi

392
01:02:50,721 --> 01:02:53,690
ġie implimentat kif I tkompli
saff affarijiet fuq nett.

393
01:02:53,690 --> 01:02:55,430
Allura fil-fatt, let me do wieħed ieħor hawnhekk.

394
01:02:55,430 --> 01:03:00,580
Let me imorru quddiem u tiftaħ fajl li
I miġjuba bil-quddiem, imsejħa Nagħaġ.

395
01:03:00,580 --> 01:03:03,970
>> Għalhekk għandu kemmxejn differenti
karattru li tidher bħal dan.

396
01:03:03,970 --> 01:03:07,370
U let me ara jekk ma nistax
jagħmel xi ħaġa permezz ta 'kontro

397
01:03:07,370 --> 01:03:09,310
f'dan il case---hekk imsejħa varjabbli.

398
01:03:09,310 --> 01:03:15,540
Jien ser jimxi 'l quddiem u taħt Events--
let me nikseb bandiera aħdar għafast.

399
01:03:15,540 --> 01:03:19,030
Imbagħad let me go għad-Data, li naf
minn ftit playing madwar qabel,

400
01:03:19,030 --> 01:03:20,214
huwa fejn varjabbli.

401
01:03:20,214 --> 01:03:21,880
U jien ser jimxi 'l quddiem u drag din l.

402
01:03:21,880 --> 01:03:25,144
>> Allura varjabbli msejħa kontro, u
Jien ser initialize fuq żero.

403
01:03:25,144 --> 01:03:27,560
I tista 'sejħa hija anything-- x jew
y jew z-- iżda fl-ipprogrammar,

404
01:03:27,560 --> 01:03:30,410
jitlob xi ħaġa fil-semantikament
Mod utli, bħall-bank,

405
01:03:30,410 --> 01:03:34,540
li jiddeskrivi dak li hi, huwa
ħafna aktar faċli biex jinqara kodiċi tiegħek aktar tard.

406
01:03:34,540 --> 01:03:37,460
Let me imorru quddiem u jiksbu
a dejjem blokk hawn.

407
01:03:37,460 --> 01:03:41,289
U let me go għall-jistenna
-paġna u do a blokk Say.

408
01:03:41,289 --> 01:03:44,330
Imma x'hemm jibred dwar varjabbli hija I
ma jkollhom biss it-tip fil xi ħaġa

409
01:03:44,330 --> 01:03:47,850
bħall bonjour dinja, li aħna ħadthom diġà
jsir, I tista 'minflok tmur għall-Data

410
01:03:47,850 --> 01:03:50,690
u drag varjabbli tiegħi, u anki
għalkemm il-forma ma pjuttost

411
01:03:50,690 --> 01:03:53,000
look like dan għandu jitwaħħal,
se jikber biex jimlew.

412
01:03:53,000 --> 01:03:58,396
U jien ser biss jgħidu l-kontro għal wieħed
spoiler-- second-- hu għaddej biex jingħaddu.

413
01:03:58,396 --> 01:04:00,380
Aħna ser jgħidu li għat-tieni waħda.

414
01:04:00,380 --> 01:04:02,840
Imbagħad jien ser imorru u
jkollhom lilu jistennew għat-tieni waħda,

415
01:04:02,840 --> 01:04:04,650
għalhekk ma tgħoddx up wisq malajr.

416
01:04:04,650 --> 01:04:08,430
U mbagħad fl-aħħar, bidla kontro
billi one-- fi kliem ieħor,

417
01:04:08,430 --> 01:04:13,520
inkrement-counter minn waħda
valur addizzjonali u jagħmlu dan għal dejjem.

418
01:04:13,520 --> 01:04:16,129
>> Allura l-nagħaġ wisq, bħal
programmer, għadd minn 0.

419
01:04:16,129 --> 01:04:20,350

420
01:04:20,350 --> 01:04:23,740
U jekk aħna nistennew twil biżżejjed,
hu se jagħmel dan għal dejjem.

421
01:04:23,740 --> 01:04:27,740
Imma dak li mhux eżattament veru, għaliex
fil-fatt, kif aħna ser tiskopri fil gimgha,

422
01:04:27,740 --> 01:04:31,871
interi u kompjuters b'mod aktar ġenerali,
teknikament għandhom biss finite-- sew,

423
01:04:31,871 --> 01:04:33,829
pjuttost kompjuters, meta
huma jirrappreżentaw interi,

424
01:04:33,829 --> 01:04:35,670
biss għandhom numru finit ta 'bits.

425
01:04:35,670 --> 01:04:37,860
Dawk bozoz tad-dawl hemmhekk
jistgħu jitqiesu biss tant għoli

426
01:04:37,860 --> 01:04:39,239
qabel int minn bozoz tad-dawl.

427
01:04:39,239 --> 01:04:41,590
U kompjuter wisq,
għandha biss memorja tant,

428
01:04:41,590 --> 01:04:44,640
biss tant transisters,
u għalhekk jistgħu jitqiesu biss tant għoli.

429
01:04:44,640 --> 01:04:47,409
>> Għalhekk jirriżulta li l-nagħaġ,
I think, jista 'joqgħod sa 2000000000

430
01:04:47,409 --> 01:04:48,409
jew xi ħaġa pretty big.

431
01:04:48,409 --> 01:04:50,325
Allura aħna mhux qed tmur biex
stenna sabiex dan iseħħ.

432
01:04:50,325 --> 01:04:54,850
Iżda eventwalment xi bug se jiġri
li jista 'jkollhom xi dinja reali ħafna

433
01:04:54,850 --> 01:04:55,970
ramifikazzjonijiet.

434
01:04:55,970 --> 01:04:58,861
Iżda lil hinn mill-nagħaġ, li
biss tintroduċi varjabbli.

435
01:04:58,861 --> 01:05:01,110
Ejja imorru quddiem u tiftaħ
xi ħaġa I magħmula bil-quddiem

436
01:05:01,110 --> 01:05:07,430
hawn imsejjaħ Pet l Cat--
Pet l-Kat hawn fuq.

437
01:05:07,430 --> 01:05:10,420
U avviż hawn huwa ftit
blokki, iżda meta bandiera aħdar

438
01:05:10,420 --> 01:05:12,474
għafast, dejjem tagħmel dan li ġej.

439
01:05:12,474 --> 01:05:15,265
Jekk inti qed tmiss il-mouse
Pointer hekk il-cursor fuq l-iskrin,

440
01:05:15,265 --> 01:05:18,529
il arrow-- play meow ħoss
u mbagħad stenna żewġ sekondi.

441
01:05:18,529 --> 01:05:19,570
U biss tagħmel dan għal dejjem.

442
01:05:19,570 --> 01:05:22,619
Just kontinwament stenna
biex tara jekk il-Pointer

443
01:05:22,619 --> 01:05:24,710
jekk il-qattus qed imiss il-pointer.

444
01:05:24,710 --> 01:05:26,060
>> So I hit play.

445
01:05:26,060 --> 01:05:26,920
Xejn jiġri.

446
01:05:26,920 --> 01:05:28,980
Imma kif jien tmexxi l-cursor fuq il-qtates,

447
01:05:28,980 --> 01:05:31,960
>> [Meowing]

448
01:05:31,960 --> 01:05:34,750
>> U jekk jien jġorrhom bogħod, ma
petting-qattus aktar.

449
01:05:34,750 --> 01:05:38,090
Allura xi loġika kondizzjonali
nested ġewwa ta 'linja.

450
01:05:38,090 --> 01:05:43,070
Kif dwar dan l-eżempju, deliberatament
imsejjaħ Ma Pet l-Kat?

451
01:05:43,070 --> 01:05:45,253
X'hemm dan se jagħmlu?

452
01:05:45,253 --> 01:05:47,880
>> [Meowing]

453
01:05:47,880 --> 01:05:50,215
>> Għaliex inti ma pet-qattus?

454
01:05:50,215 --> 01:05:59,440
>> [Meowing]

455
01:05:59,440 --> 01:06:00,699
>> KOLLOX SEW.

456
01:06:00,699 --> 01:06:03,880
Allura dan huwa eżempju ta 'jekk inkella.

457
01:06:03,880 --> 01:06:06,482
Huwa punt deċiżjoni u
għaliex dan huwa seduta fil-linja,

458
01:06:06,482 --> 01:06:07,690
dawn qed kemm jkollna ċċekkjati.

459
01:06:07,690 --> 01:06:08,280
Huwa dan veru?

460
01:06:08,280 --> 01:06:08,760
Huwa dan veru?

461
01:06:08,760 --> 01:06:09,250
Huwa dan veru?

462
01:06:09,250 --> 01:06:09,791
Huwa dan veru?

463
01:06:09,791 --> 01:06:11,880
U eventwalment, wieħed mill
dawk li jkun ser japplikaw

464
01:06:11,880 --> 01:06:16,480
u għalhekk inti tisma 'jew l meow jew
il-kanuni tal-iljun f'dak il-każ.

465
01:06:16,480 --> 01:06:21,400
>> Ukoll, ejja do wieħed ftit aktar fancy
li għamilt qabel too-- ħjut.

466
01:06:21,400 --> 01:06:25,210
Allura ħajt hija biss waħda
ħaġa li l-kompjuter tista 'tagħmel.

467
01:06:25,210 --> 01:06:29,349
Allura programm multi-kamin huwa programm
li tista 'tagħmel affarijiet multipli fuq darba.

468
01:06:29,349 --> 01:06:31,140
U kollha ta 'dawn l-eżempji
s'issa kellhom

469
01:06:31,140 --> 01:06:35,980
waħda biss iskrittura, hekk li speak--
programm wieħed bħal dan up hawn.

470
01:06:35,980 --> 01:06:38,810
Iżda Avviż dan il-programm għandu l
żewġ sprites, żewġ karattri.

471
01:06:38,810 --> 01:06:40,020
Wieħed huwa għasfur.

472
01:06:40,020 --> 01:06:40,870
Wieħed huwa qattus.

473
01:06:40,870 --> 01:06:45,080
>> U Avviż meta I ikklikkja fuq dawn l isfel
xellug, t-tnejn għandhom skripts tagħhom stess

474
01:06:45,080 --> 01:06:47,120
jew programmi assoċjati magħhom.

475
01:06:47,120 --> 01:06:49,420
U kemm dawk
programmi, avviż, bidu

476
01:06:49,420 --> 01:06:52,600
bil clicked-- bandiera meta jkun aħdar
ejja nħarsu lejn il-cat--

477
01:06:52,600 --> 01:06:54,030
meta bandiera aħdar għafast.

478
01:06:54,030 --> 01:06:58,220
U hekk fil-fatt, meta I hit play issa,
żewġ affarijiet se jiġri f'daqqa.

479
01:06:58,220 --> 01:07:01,750
Il-qattus u l-għasafar huma t-tnejn
ser jaħdmu b'mod separat

480
01:07:01,750 --> 01:07:03,815
biex joħolqu dan l-effett.

481
01:07:03,815 --> 01:07:05,440
U inti tista 'timmaġina dak li qed jiġri.

482
01:07:05,440 --> 01:07:08,340
Hemm linja u l-għasafar
u l-qattus huma fil-linja.

483
01:07:08,340 --> 01:07:11,270
L-għasafar huwa biss bouncing bħal
I kien qabel meta għidt Ouch.

484
01:07:11,270 --> 01:07:13,040
Iżda l-qattus b'mod ċar għandha vantaġġ.

485
01:07:13,040 --> 01:07:16,040
Hemm ieħor blokk sensing
li jindika l-qattus deliberatament

486
01:07:16,040 --> 01:07:19,836
għall-għasafar f'dan il-każ hawnhekk.

487
01:07:19,836 --> 01:07:22,960
Allura nistgħu tease apparti, billi tħares
permezz ta 'dawk blokki, dak li qed jiġri.

488
01:07:22,960 --> 01:07:25,460
Iżda l-ingredjent ewlieni hawnhekk huwa wieħed.

489
01:07:25,460 --> 01:07:28,520
L-għasafar, b'tali mod li din il-logħba ma tkunx
kompletament boring-- jew ta 'dan animation--

490
01:07:28,520 --> 01:07:30,060
jibda fil direzzjoni każwali.

491
01:07:30,060 --> 01:07:32,890
U l-kompjuter qed jiżdied
numru bejn 90 u 180

492
01:07:32,890 --> 01:07:36,110
essenzjalment, b'tali mod li huwa kemmxejn
animazzjoni differenti kull darba.

493
01:07:36,110 --> 01:07:39,480
>> U mbagħad avviż hawn, jekk il
qattus huwa jmissu l-għasafar, allura

494
01:07:39,480 --> 01:07:42,030
jilagħbu l-iljun erba sound-- l kanuni.

495
01:07:42,030 --> 01:07:46,330
Iżda sadanittant fil-s għasfur
paletta, aħna għandna dan il.

496
01:07:46,330 --> 01:07:49,229
Forever, jekk ma jmissux il-qattus,
biss iżommu miexja tliet passi.

497
01:07:49,229 --> 01:07:50,770
U allura hawnhekk ieħor biċċa puzzle.

498
01:07:50,770 --> 01:07:52,030
Jekk int fuq it-tarf, bounce.

499
01:07:52,030 --> 01:07:54,840
Allura l-għasafar hija biss tip ta '
minding n-negozju tiegħu stess,

500
01:07:54,840 --> 01:07:57,330
biss jtajru madwar u
bouncing, u huwa verament

501
01:07:57,330 --> 01:08:01,780
il-qattus li kellha l-loġika kondizzjonali
biex jiġi stabbilit jekk kien qabad l-għasafar.

502
01:08:01,780 --> 01:08:02,280
Kull dritt.

503
01:08:02,280 --> 01:08:08,800
Mela ejja jagħmlu waħda oħra hawnhekk,
dan wieħed qed jissejjaħ Hi Hi Hi.

504
01:08:08,800 --> 01:08:15,100
U dan wieħed hawn biss ma
dan fi dejjem loop.

505
01:08:15,100 --> 01:08:18,925
Imma notice-- kif nistgħu stop
dan il-programm ħafna annoying?

506
01:08:18,925 --> 01:08:21,600

507
01:08:21,600 --> 01:08:22,640
Hit-ispazju bar.

508
01:08:22,640 --> 01:08:27,990
Minħabba li jekk nagħmel dan,
il program-- naħa tax-xellug

509
01:08:27,990 --> 01:08:31,550
avviż huwa kontinwament listening--
huwa l-istampa ispazju ċavetta.

510
01:08:31,550 --> 01:08:34,090
Jekk l-ispazju bar ippressat,
u jekk iva, liema ma tagħmel?

511
01:08:34,090 --> 01:08:35,980
Hija ma 'teknika komuni ħafna.

512
01:08:35,980 --> 01:08:38,590
Hija tistabbilixxi varjabbli ugwali għal xi valur.

513
01:08:38,590 --> 01:08:39,741
Iżda huwa toggles dak il-valur.

514
01:08:39,741 --> 01:08:41,490
[? Allura dehra?]
ibbażata fuq il-I shape--

515
01:08:41,490 --> 01:08:43,160
ikollhom varjabbli li I
kiteb bil-quddiem imsejħa

516
01:08:43,160 --> 01:08:44,770
Siekta, li biss jgħid iva jew le.

517
01:08:44,770 --> 01:08:45,880
Huwa l-ħoss siekta jew le?

518
01:08:45,880 --> 01:08:46,990
Veru jew falz?

519
01:08:46,990 --> 01:08:51,580
U avviż, jien qal this-- jekk
siekta huwa żero, mbagħad bidla għal waħda,

520
01:08:51,580 --> 01:08:53,840
inkella sett mutu fuq żero.

521
01:08:53,840 --> 01:08:55,540
Hekk biss flip-valur minn żero għal wieħed.

522
01:08:55,540 --> 01:08:58,320
I jista 'jkollhom done-- bidla
minn sentejn għal tliet u 01:57

523
01:08:58,320 --> 01:09:00,162
jew 4-5 jew 4-6.

524
01:09:00,162 --> 01:09:01,870
Iżda dan ma jimpurtax
dak in-numri nuża,

525
01:09:01,870 --> 01:09:04,090
sakemm I iżommu
jinbidlu l-oppost.

526
01:09:04,090 --> 01:09:07,290
>> U l-aktar kwalunkwe programmer kieku biss
jagħżlu żero u one-- foloz u vera,

527
01:09:07,290 --> 01:09:09,510
darba u on-- biex jirrappreżentaw din l.

528
01:09:09,510 --> 01:09:10,930
U dan ikun għadu għaddej.

529
01:09:10,930 --> 01:09:12,190
Jekk I hit l-ispazju bar għal darb'oħra

530
01:09:12,190 --> 01:09:13,590
>> [SIĠILL Ħsejjes]

531
01:09:13,590 --> 01:09:15,440
>> Il-programm għadu għaddej.

532
01:09:15,440 --> 01:09:18,400
Għaliex hemm din l-iskrittura oħra
li tgħid, dejjem jagħmel dan li ġej.

533
01:09:18,400 --> 01:09:21,390

534
01:09:21,390 --> 01:09:24,770
Jekk il-varjabbli siekta huwa daqs
zero-- hekk jekk int mhux siekta

535
01:09:24,770 --> 01:09:29,609
huwa l-logic-- jekk huwa falz
jew le, allura jilagħbu l-ħoss,

536
01:09:29,609 --> 01:09:30,650
għaliex int ma siekta.

537
01:09:30,650 --> 01:09:33,358
Għandek jilagħbu l-ħoss u mbagħad
think hi hi hi għal żewġ sekondi

538
01:09:33,358 --> 01:09:35,790
u mbagħad stenna, u jagħmlu dan
ġdid u għal darb'oħra u għal darb'oħra.

539
01:09:35,790 --> 01:09:40,760
>> U għalhekk b'dan il-mod għandna mod għall
nies to-- għal programmi li jinteraġixxu.

540
01:09:40,760 --> 01:09:43,120
U dawn ma jkollhomx biex
ikunu kif datata bħala oħrajn.

541
01:09:43,120 --> 01:09:46,280
Fil-fatt, poking around--
no pun intended--

542
01:09:46,280 --> 01:09:49,250
xi ħadd qattgħu ammont kbir ta '
ħin fuq l-internet ta 'implimentazzjoni

543
01:09:49,250 --> 01:09:51,580
PokemonGo fil scratch.

544
01:09:51,580 --> 01:09:55,440
Huwa anki geolocates int fl
Cambridge jew ALLSTON hawn.

545
01:09:55,440 --> 01:10:03,120
Mela jekk inti tixtieq li tara wisq liema nies
tista 'tagħmel huwa this-- menu fancy ħafna.

546
01:10:03,120 --> 01:10:04,780
Ikklikkja fuq hawn.

547
01:10:04,780 --> 01:10:07,430
>> Dan huwa me ma arrow ċwievet tiegħi issa.

548
01:10:07,430 --> 01:10:09,446
Jien se jmorru wara dan il.

549
01:10:09,446 --> 01:10:09,946
Ikklikkja.

550
01:10:09,946 --> 01:10:12,949

551
01:10:12,949 --> 01:10:14,240
U issa inti ikklikkja l-PokeBall.

552
01:10:14,240 --> 01:10:17,130

553
01:10:17,130 --> 01:10:20,260
I mean, I think int
suppost li ikklikkja l-PokeBall.

554
01:10:20,260 --> 01:10:20,760
Kull dritt.

555
01:10:20,760 --> 01:10:22,680
So I ma dak.

556
01:10:22,680 --> 01:10:23,950
I tista 'tmur fuq hawn.

557
01:10:23,950 --> 01:10:27,790
U din il-persuna implimentat ftit aktar
Pokeballs aktar here-- tliet pokeballs.

558
01:10:27,790 --> 01:10:29,950
>> Aħna ser post link għal dan l-
online sabiex inti tista 'tilgħab.

559
01:10:29,950 --> 01:10:32,364
Iżda avviż hemm biss
xi moduli bażiċi.

560
01:10:32,364 --> 01:10:33,780
Huwa jistenna ħafna fancier, u huwa.

561
01:10:33,780 --> 01:10:35,905
Dan huwa impressjonanti u aktar
milli nixtiequ tipikament

562
01:10:35,905 --> 01:10:37,740
jistennew, ċertament għall-problema stabbilita żero.

563
01:10:37,740 --> 01:10:40,809
Għandi l-ebda idea kemm żmien
din il-persuna jintefqu fuq l-internet.

564
01:10:40,809 --> 01:10:41,850
Imma dan kollu biss loop.

565
01:10:41,850 --> 01:10:43,180
Hemm logħob tajba.

566
01:10:43,180 --> 01:10:44,850
Hemm xi tip ta 'linja
jisimgħu għall jekk jien

567
01:10:44,850 --> 01:10:47,558
laqtu l-vleġġa up jew l-isfel
vleġġa jew ix-xellug u l-lemin,

568
01:10:47,558 --> 01:10:49,834
u mbagħad jekk iva, huwa li jiċċaqalqu
hija xi numru ta 'pixels.

569
01:10:49,834 --> 01:10:51,750
U mbagħad jekk jien ikklikkja fuq
Sprite ieħor, hemm

570
01:10:51,750 --> 01:10:53,390
xi tip ta 'jekk il-kundizzjoni hemmhekk.

571
01:10:53,390 --> 01:10:54,806
Yeah, dan huwa jkollna wisq intensi.

572
01:10:54,806 --> 01:10:56,100
Aħna qed tmur biex tieqaf.

573
01:10:56,100 --> 01:10:57,750
Huwa dawk kollha moduli bażiċi.

574
01:10:57,750 --> 01:11:01,530
M'hemm l-ebda ingredjent ieħor oħra
minn dawk konna ħares lejn diġà.

575
01:11:01,530 --> 01:11:04,670
>> And yet hawn, let me do
finali sett wieħed ta 'eżempji

576
01:11:04,670 --> 01:11:06,960
li żebgħa stampa wisq
ta 'dak li inti tista' tagħmel hawn.

577
01:11:06,960 --> 01:11:10,481
Hawn program sempliċi ħafna li
biss ma this-- sogħla, sogħla, sogħla.

578
01:11:10,481 --> 01:11:12,480
U bbażati biss fuq dak
konna ħares lejn s'issa,

579
01:11:12,480 --> 01:11:14,570
fejn hija l-ovvju
opportunità għal titjib.

580
01:11:14,570 --> 01:11:15,570
Dan il-programm hija korretta.

581
01:11:15,570 --> 01:11:17,980
Hija sogħla tliet darbiet,
li huwa dak I maħsub.

582
01:11:17,980 --> 01:11:19,650
Iżda huwa ħażin implimentati.

583
01:11:19,650 --> 01:11:20,600
Huwa ħażin mfassla.

584
01:11:20,600 --> 01:11:22,000
Għaliex?

585
01:11:22,000 --> 01:11:22,500
Yeah.

586
01:11:22,500 --> 01:11:23,230
Mhuwiex loop.

587
01:11:23,230 --> 01:11:24,610
U huwa mhux tant
li mhuwiex linja,

588
01:11:24,610 --> 01:11:26,400
huwa li hemm ħafna ta 'sensja.

589
01:11:26,400 --> 01:11:28,830
Hemm hija kkupjata u
kodiċi pasted, biex ngħidu hekk.

590
01:11:28,830 --> 01:11:31,830
U s-soluzzjoni probabbilment
huwa tabilħaqq linja.

591
01:11:31,830 --> 01:11:34,350
So let me go quddiem
u jtejbu fuq dak.

592
01:11:34,350 --> 01:11:36,250
U jien ser jkaxkru dawn fuq hawn.

593
01:11:36,250 --> 01:11:39,986
Let me imorru quddiem u jiksbu ripetuta
blokk, bidla dan għal tlieta.

594
01:11:39,986 --> 01:11:41,860
Jien ser armih
xi wħud minn dawk il-blokki.

595
01:11:41,860 --> 01:11:43,150
>> U tkun taf Avviż huwa pjuttost intuwittivi.

596
01:11:43,150 --> 01:11:45,691
Inti drag u qatra u affarijiet
jidhru u jisparixxu eventwalment.

597
01:11:45,691 --> 01:11:49,170
U nista 'biss drag dan fil hawn, u
issa għandi verżjoni aktar nadifa xorta.

598
01:11:49,170 --> 01:11:50,730
Imma inti taf liema?

599
01:11:50,730 --> 01:11:52,940
Hemm din l-opportunità
issa għall abstraction--

600
01:11:52,940 --> 01:11:56,350
biex tibda biex tiddefinixxi vokabularju ġdida
li MIT ma kinitx tantiċipa.

601
01:11:56,350 --> 01:11:59,110
Hemm stenna u rrepeti
u dejjem u jekk,

602
01:11:59,110 --> 01:12:02,590
imma dak jekk nixtieq li jintroduċu
il sogħla kelma bħala blokk?

603
01:12:02,590 --> 01:12:06,230
X'jiġri jekk irrid biċċa puzzle
iskop tagħhom fil-ħajja huwa li sogħla?

604
01:12:06,230 --> 01:12:10,720
>> Ukoll, ejja nħarsu lejn din il-verżjoni
hawn, li I magħmula kif ġej.

605
01:12:10,720 --> 01:12:13,579
Magically, I ħolqu
din il-biċċa puzzle hawn,

606
01:12:13,579 --> 01:12:14,870
li Scratch tippermetti li inti tagħmel.

607
01:12:14,870 --> 01:12:16,787
U tabilħaqq C u Python
u JavaScript huma

608
01:12:16,787 --> 01:12:18,370
ser jippermettu li tagħmel dan ukoll.

609
01:12:18,370 --> 01:12:21,830
Tista 'toħloq custom tiegħek stess
biċċiet li inti sejħa dak li trid.

610
01:12:21,830 --> 01:12:24,890
F'dan il-każ, sogħla iħoss
bħal definizzjoni raġjonevoli.

611
01:12:24,890 --> 01:12:27,880
U mbagħad ma 'dawn il-biċċiet isfel
hawn inti tista tiddefinixxi xi tfisser.

612
01:12:27,880 --> 01:12:30,290
>> I mkaxkra u niżel minn
dan il paletta here-- aktar

613
01:12:30,290 --> 01:12:33,500
blocks-- din il big vjola
blokk, fejn I ittajpjat fil-sogħla

614
01:12:33,500 --> 01:12:35,290
bħala l-isem tal-biċċa tiegħi puzzle ġdida.

615
01:12:35,290 --> 01:12:39,920
U mbagħad jien qal kwalunkwe ħin l-utent
jitlob din il-biċċa ġdida puzzle sogħla,

616
01:12:39,920 --> 01:12:41,770
do sehem u stenna.

617
01:12:41,770 --> 01:12:46,160
U hekk hawn fil blokk irrepeti tiegħi,
I tista 'biss sogħla tliet darbiet.

618
01:12:46,160 --> 01:12:49,972
>> U jien se jargumentaw, speċjalment
jekk issa inti jaħbu dan id-dettall.

619
01:12:49,972 --> 01:12:51,430
Who cares kif sogħla hija implimentata?

620
01:12:51,430 --> 01:12:54,390
All I jimpurtahom bħala
programmer li nista 'sogħla.

621
01:12:54,390 --> 01:12:56,280
I do not care kif jgħidu hija implimentata.

622
01:12:56,280 --> 01:12:58,620
I biss kura li l-
qattus tista 'tgħid xi ħaġa.

623
01:12:58,620 --> 01:13:02,720
Nista 'astratt bogħod li dettall u
biss jiffoka fuq x'hemm fuq l-iskrin hawn.

624
01:13:02,720 --> 01:13:04,400
Imma I tista 'tieħu dan il-pass wieħed ulterjuri.

625
01:13:04,400 --> 01:13:08,070
>> Avviż li hawn, għandi
implimentat il-linja tlett darbiet.

626
01:13:08,070 --> 01:13:11,560
Imma x'jiġri jekk minflok jien grab din il-verżjoni?

627
01:13:11,560 --> 01:13:14,640
U jekk dak minflok
f'dan il-verżjoni hawn,

628
01:13:14,640 --> 01:13:18,730
I biss bidla biċċa puzzle tiegħi biex jieħdu
argument u l-input unto innifsu?

629
01:13:18,730 --> 01:13:21,100
U li l-input jista 'jkun
numru simili tlieta.

630
01:13:21,100 --> 01:13:24,580
Allura issa, jekk I am miktub program
u nixtieq il-qattus sogħla,

631
01:13:24,580 --> 01:13:28,270
I jistgħu attwalment tell-puzzle
biċċa kif ħafna drabi sogħla,

632
01:13:28,270 --> 01:13:31,990
għaliex fil-qiegħ hawn, a fancier
verżjoni ta 'dawn il-biċċiet puzzle dwana

633
01:13:31,990 --> 01:13:34,500
tikri me jispeċifikaw li
sogħla effettivament jieħu

634
01:13:34,500 --> 01:13:36,951
l input-- jieħu argument bħal dan.

635
01:13:36,951 --> 01:13:37,700
U inti taf liema?

636
01:13:37,700 --> 01:13:38,890
Maybe I realizzata, stenna minuta.

637
01:13:38,890 --> 01:13:40,680
Sogħla hija l same--
huwa fundamentalment

638
01:13:40,680 --> 01:13:42,120
l-istess idea bħal għatis.

639
01:13:42,120 --> 01:13:44,040
Huwa biss differenti
kelma fuq l-iskrin.

640
01:13:44,040 --> 01:13:46,550
Nista astratt bogħod
aktar u jimplimentaw

641
01:13:46,550 --> 01:13:48,750
din il-verżjoni finali ta '
sogħla, li ewwel daqqa t'għajn

642
01:13:48,750 --> 01:13:50,660
huwa mod aktar kumplessa tfittex.

643
01:13:50,660 --> 01:13:52,140
Imma Avviż dak li ghamilt.

644
01:13:52,140 --> 01:13:55,930
Għandi issa generalized-- genericized
really-- din il-biċċa puzzle

645
01:13:55,930 --> 01:13:59,900
li għandu jissejjaħ ngħid kelma n darbiet.

646
01:13:59,900 --> 01:14:04,410
>> U issa għandi żewġ biċċiet puzzle ġodda
stabbiliti hawn jiddefinixxu sogħla n darbiet.

647
01:14:04,410 --> 01:14:06,790
U dak ma l-funzjoni sogħla do?

648
01:14:06,790 --> 01:14:08,420
X'jagħmel tiegħi drawwa biċċa puzzle do?

649
01:14:08,420 --> 01:14:11,996
Huwa biss jappella il-blokk jiġifieri,
tgħaddi fil-kelma Irrid ngħid,

650
01:14:11,996 --> 01:14:13,870
tgħaddi fin-numru
ta 'drabi Irrid ngħid.

651
01:14:13,870 --> 01:14:18,210
Għaliex issa I tista 'timplimenta
tgħatas billi sempliċiment qal achoo,

652
01:14:18,210 --> 01:14:20,320
f'dan il-każ, xi għadd ta 'drabi.

653
01:14:20,320 --> 01:14:22,360
>> U hekk jien saffi u saffi.

654
01:14:22,360 --> 01:14:25,690
U għal darb'oħra, il-muftieħ hawnhekk mhix
kif I implimentata, iżda l-fatt

655
01:14:25,690 --> 01:14:28,070
li jekk I biss litteralment
jċaqalqu dawn barra l-iskrin,

656
01:14:28,070 --> 01:14:31,280
ħarsa kemm sempliċi jekk le
pretty programm tiegħi issa jistenna.

657
01:14:31,280 --> 01:14:33,930
Minħabba li ma dak li
jgħid, stajt estratt

658
01:14:33,930 --> 01:14:37,640
bogħod minn dak li hu ġewwa l-kaxxa sewda.
dan jiġri jkun kaxxa vjola hawn,

659
01:14:37,640 --> 01:14:41,430
imma stajt ostakolat lil hinn x'hemm ġewwa
minħabba I do not care kif taħdem.

660
01:14:41,430 --> 01:14:43,650
I biss care issa li taħdem.

661
01:14:43,650 --> 01:14:46,375
>> U fil-fatt, fil-problema
sett żero, dan huwa eżattament

662
01:14:46,375 --> 01:14:49,250
-tip ta saffi ta 'ideat inti ser
jkollhom l-opportunità biex jesploraw.

663
01:14:49,250 --> 01:14:53,510
Huwa eżattament l-opportunità li
japplikaw tekniki soluzzjoni ta 'problemi,

664
01:14:53,510 --> 01:14:55,550
għal dak li probabbilment xi
ambjent mhux familjari.

665
01:14:55,550 --> 01:14:57,890
U jekk inti stajt ma jkunux ipprogrammati
qabel jew programmati qabel,

666
01:14:57,890 --> 01:14:59,500
inti ser issib li hemm
ftit xi ħaġa

667
01:14:59,500 --> 01:15:00,874
f'dan l-ambjent għal kulħadd.

668
01:15:00,874 --> 01:15:02,770
U mal-problema stabbilita
wieħed fi żmien ta 'ġimgħa,

669
01:15:02,770 --> 01:15:06,630
aħna ser tkun transitioned għal iffukar
fuq lingwa f'livell ogħla imsejjaħ

670
01:15:06,630 --> 01:15:09,290
C-- jew pjuttost aktar baxx
lingwa livell imsejħa

671
01:15:09,290 --> 01:15:11,347
C-- li saħansitra aktar
qawwija, anki jekk huwa

672
01:15:11,347 --> 01:15:12,930
ftit aktar cryptic ewwel daqqa t'għajn.

673
01:15:12,930 --> 01:15:16,740
>> U inti ser tirrealizza kull TL lum: DR
li din il-problema stabbilita għandha iqsar

674
01:15:16,740 --> 01:15:19,880
tieqa ta 'żmien milli dawk tal-ġejjieni, sempliċement
għaliex inti għandek issib lilha pjuttost

675
01:15:19,880 --> 01:15:20,420
aċċessibbli.

676
01:15:20,420 --> 01:15:22,211
U biex ma tinkwetax jekk
inti żid il-klassi tard.

677
01:15:22,211 --> 01:15:23,920
Aħna ser tindirizza dak qabel twil.

678
01:15:23,920 --> 01:15:28,480
U qabel we tiddifferixxi għal kejk, ejja
finitura biss ħarsa żewġ minuti

679
01:15:28,480 --> 01:15:30,500
fuq dak li jistenna inti hawn fil CS50.

680
01:15:30,500 --> 01:15:40,950

681
01:15:40,950 --> 01:17:20,803
[Ddoqq il-mużika]

682
01:17:20,803 --> 01:17:21,302
Kull dritt.

683
01:17:21,302 --> 01:17:22,690
Li lilha għall CS50.

684
01:17:22,690 --> 01:17:23,650
Aħna se tara inti hekk.

685
01:17:23,650 --> 01:17:25,526
Kejk issa hija servuta.

686
01:17:25,526 --> 01:17:28,998

687
01:17:28,998 --> 01:18:14,267
[Ddoqq il-mużika]

688
01:18:14,267 --> 01:18:16,350
Speaker 17: Smajtu
ta 'leave, Kap?

689
01:18:16,350 --> 01:18:29,490

690
01:18:29,490 --> 01:18:31,920
Speaker 18: Forsi hemm
aktar taħt il-barnuża.

691
01:18:31,920 --> 01:18:38,279