1
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>> [Ddoqq il-mużika]

2
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3
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>> [Ddoqq il-mużika]

4
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5
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DAVID Malan: Kull dritt.

6
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Dan huwa CS50.

7
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[Daqq tal-mużika Tritonal, Cash Cash,
 "Untouchable"]

8
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9
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[Ddoqq il-mużika]

10
00:01:41,844 --> 00:01:45,337
Speaker 1: jien ser
Franza, u int ser, wisq.

11
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[Ddoqq il-mużika]

12
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13
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DAVID Malan: Dan huwa CS50,
introduzzjoni ta 'Harvard University

14
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għall-intellettwali
intrapriżi ta 'xjenza tal-kompjuter

15
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u l-arti tal-program-- u
għall-ewwel darba fl-istorja,

16
00:02:47,940 --> 00:02:49,800
Yale University kif ukoll.

17
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Tabilħaqq, kemm jekk int hawn fil-Cambridge
jew fi New Haven jew Miami jew St Louis

18
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jew Amsterdam jew fi kwalunkwe post
madwar id-dinja

19
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filwaqt CS50, kompjuter
xjenza E50, CS50X, CS50 AP,

20
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aħna lkoll wieħed u l-istess.

21
00:03:02,090 --> 00:03:04,490
Merħba għall CS50.

22
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>> Dak li have--

23
00:03:05,380 --> 00:03:06,348
>> [Applause]

24
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>> [Laughs]

25
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>> [Applause]

26
00:03:10,220 --> 00:03:13,610

27
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>> So I għamel żball myself xi
żmien ilu meta I bdew kulleġġ.

28
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U sirt kulleġġ, u I iddeċieda li
franchement, stick fiż-żona kumdità tiegħi.

29
00:03:21,580 --> 00:03:24,475
I ended up li tiddikjara konċentrazzjoni,
jew maġġuri, tal-gvern.

30
00:03:24,475 --> 00:03:27,880
Ant li kien l-aktar funzjoni ta 'lili
qed pretty familjari mal-gvern

31
00:03:27,880 --> 00:03:31,270
jew għall-inqas l-istorja jew I really gustado
liġi kostituzzjonali fl-iskola għolja.

32
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U hekk meta sirt hawn, I tip
ta gravitated lejn l-affarijiet

33
00:03:34,150 --> 00:03:35,800
li magħha jien diġà kien familjari.

34
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Dritt?

35
00:03:36,300 --> 00:03:38,167
Alla jipprojbixxu nagħmel ħażin fil-klassi.

36
00:03:38,167 --> 00:03:40,250
I ċertament ridt li tissospendi
fiż-żona kumdità tiegħi,

37
00:03:40,250 --> 00:03:43,010
u kien biss
sena sophomore li I finalment

38
00:03:43,010 --> 00:03:46,820
ltqajna l-nerv li pass marda
fil-klassi msejħa CS50.

39
00:03:46,820 --> 00:03:51,150
U f'dak il-punt, ma I finalment realizzata
li, Alla tiegħi, huiswerk tista 'attwalment

40
00:03:51,150 --> 00:03:51,910
jkun pjaċevoli.

41
00:03:51,910 --> 00:03:54,410
>> Tabilħaqq, I kien wieħed minn dawk gidjien
li fuq Ġimgħa filgħaxija meta

42
00:03:54,410 --> 00:03:57,640
il P-SETTIJIET se jiġu rilaxxati, jiena
imur lura għall-kamra tiegħi u adsa

43
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Fil-lejl ta 'P-SETTIJIET.

44
00:03:58,790 --> 00:04:01,606
U għalija, li kien sinjal
li dan kien il-qasam għalija.

45
00:04:01,606 --> 00:04:04,480
Imma dak kien aktar importanti kien l-
fatt li I ma jiksbu up dan nerv

46
00:04:04,480 --> 00:04:08,000
biex jesploraw ilmijiet familjari lili
u tmur lilhinn mill żona tiegħi kumdità stess

47
00:04:08,000 --> 00:04:12,320
u franchement, jien biss kienet f'pożizzjoni li tagħmel dan
sena sophomore billi din il-klassi

48
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suċċess / falliment.

49
00:04:13,050 --> 00:04:16,470
>> Tabilħaqq, kien l-aħħar jum li
I finalment qalbu u finalment

50
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iddikjarati KEFA kif konċentrazzjoni tiegħi,
tqegħid gov f'dak il-punt lura lili.

51
00:04:19,707 --> 00:04:22,290
U hekk aħna mhux qed jistabbilixxu fid-
dan il-kors li jduru kollu inti

52
00:04:22,290 --> 00:04:25,780
fis kumpanniji prinċipali CS jew Konċentraturi, iżda
pjuttost li jagħtik l-opportunità

53
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li nisperaw jmorru lil hinn mill-dinja
li magħhom int bħalissa familjari

54
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u jġib lura minn din id-dinja
ħiliet u l-għarfien u sofistikati

55
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li inti tista 'tapplika għall tiegħek
dinja stess, jekk din

56
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fl-istudji umanistiċi, ix-xjenzi soċjali,
xjenzi naturali, jew lil hinn.

57
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>> Tabilħaqq, jekk int
tħossok ftit Intrepid

58
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dwar jiġu f'din il-kamra
aħseb u ara f'din il-klassi,

59
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jirrealizzaw li jekk l-istorja hija
kwalunkwe indikazzjoni, 72% tal inti

60
00:04:47,560 --> 00:04:49,802
qatt ma ħa kors CS qabel.

61
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Għalhekk huwa bil-mezzi kollha mhux il-każ
li l-istudent seduta lejn ix-xellug

62
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jew lejn il-lemin jew quddiem jew
lura int taf ħafna aktar dwar KEFA

63
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jew l-ipprogrammar b'mod partikolari milli suppost.

64
00:04:58,820 --> 00:05:00,432
Li mhux fil-fatt il-każ.

65
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U fil-fatt, ħafna mill
l-istruttura ta 'appoġġ

66
00:05:02,140 --> 00:05:04,600
li konna stabbiliti f'dan
Naturalment matul l-aħħar bosta snin

67
00:05:04,600 --> 00:05:08,840
kien għal eżattament dak reason-- li
nipprovdu dan is rampa li għad ħruġ

68
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daqstant rigoruż u
daqstant għoli daqs ever--

69
00:05:11,640 --> 00:05:14,860
iżda l-inklinazzjoni tiegħu jippermetti lill-istudenti
inqas komdi u aktar komdi

70
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bl-istess mod biex jirnexxu irrispettivament
tal-isfond qabel tiegħu jew tagħha.

71
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>> Tabilħaqq, dak li finalment
kwistjonijiet f'din il-klassi mhuwiex

72
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tant fejn inti tispiċċa
relattiva għall-klassi tiegħek

73
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imma fejn inti fil-ġimgħa 12
jispiċċaw relattiv lilek innifsek

74
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fil-ġimgħa żero, li hija
fejn aħna qegħdin hawn illum.

75
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>> Tabilħaqq, u dan jista 'tajjeb ħafna
u probabbilment ma look like Grieg

76
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li ħafna minnkom.

77
00:05:32,940 --> 00:05:35,200
Iżda mistrieħ assigurat, li
dan u għalhekk ħafna aktar

78
00:05:35,200 --> 00:05:38,990
se tkun kompletament fil tiegħek
jaħtfu fi ftit ftit ta 'żmien.

79
00:05:38,990 --> 00:05:41,410
>> Imma llum, aħna niffukaw fuq xi
mill-ideat ta 'livell ogħla

80
00:05:41,410 --> 00:05:43,822
li jtik togħma ta '
CS50 u kompjuter xjenza

81
00:05:43,822 --> 00:05:45,530
fis sens ta 'dak
int rreġistrar għal.

82
00:05:45,530 --> 00:05:48,000
U fil-fatt, ix-xjenza tal-kompjuter
jista 'jiġi distillat aktar

83
00:05:48,000 --> 00:05:51,209
sempliċement bħala thinking-- komputazzjoni
ħsieb bħal kompjuter, jekk inti se.

84
00:05:51,209 --> 00:05:54,000
U hemm affarijiet differenti ħafna
ingredjenti li jmorru fis dan,

85
00:05:54,000 --> 00:05:56,240
imma ejja jipproponu biss tlieta għal-lum.

86
00:05:56,240 --> 00:05:59,420
Jekk l-għan tal-klassi fl-aħħar
mhux biex jgħallmu lilek programmazzjoni,

87
00:05:59,420 --> 00:06:03,022
mhux biex jgħallmu lilek C jew PHP jew
SQL jew kwalunkwe numru ta 'kliem

88
00:06:03,022 --> 00:06:04,730
u akronimi fil-
Deskrizzjoni kors, l

89
00:06:04,730 --> 00:06:07,850
iżda pjuttost li jgħallmu li
isolvu problemi b'mod aktar effettiv

90
00:06:07,850 --> 00:06:11,670
u biex jaħsbu b'mod aktar metodiku u
aktar algorithmically, biex ngħidu hekk.

91
00:06:11,670 --> 00:06:13,610
Ejja naraw dak li eżattament dan ifisser.

92
00:06:13,610 --> 00:06:17,000
>> Hekk nixtieq nipproponi li l-ħsieb
computationally jeħodna

93
00:06:17,000 --> 00:06:17,834
li soluzzjoni ta 'problemi.

94
00:06:17,834 --> 00:06:19,333
What do għandek bżonn biex isolvu problema?

95
00:06:19,333 --> 00:06:21,470
Ikollok bżonn li input-- simili
l-input għall-problem--

96
00:06:21,470 --> 00:06:23,636
għandek bżonn output, li
huwa wieħed jittama s-soluzzjoni,

97
00:06:23,636 --> 00:06:26,720
u imbagħad inti għandek bżonn proċess li permezz
li biex isolvu din il-problema, li

98
00:06:26,720 --> 00:06:30,030
aħna ser sejħa ta 'algorithm-- sett ta'
istruzzjonijiet għas-soluzzjoni xi problema.

99
00:06:30,030 --> 00:06:33,340
>> Iżda l-ewwel, ejja tiffoka fuq l-ewwel u
l-aħħar ta 'dawn l-inputs u l-outputs.

100
00:06:33,340 --> 00:06:38,070
Kompjuters wara kollox, apparentement
biss jifhem żerijiet u dawk.

101
00:06:38,070 --> 00:06:39,299
Imma kif jista 'dan possibbilment tkun?

102
00:06:39,299 --> 00:06:42,090
Anke jekk int ma jkunux familjari fil-livelli kollha
ma 'dak l taħtha il-barnuża,

103
00:06:42,090 --> 00:06:44,980
inti probabilment mill-inqas sema 'li
Kompjuters jifhmu binary--

104
00:06:44,980 --> 00:06:48,050
biss żerijiet u ones-- imma kif tista
inti tista 'possibilment tagħmel xejn interessanti?

105
00:06:48,050 --> 00:06:49,960
>> Ukoll, waħda mit-temi
tal-klassi li qed jiġri

106
00:06:49,960 --> 00:06:53,293
li jkun dan layering-- fejn illum, aħna ser
tieħu t'għajn malajr fil-livell l-aktar baxx

107
00:06:53,293 --> 00:06:55,620
dettalji, iżda ma 'kull
ġurnata li tgħaddi, fejn aħna saff

108
00:06:55,620 --> 00:06:59,420
jew astratt fuq quċċata ta 'dawk id-dettalji
li attwalment isolvu livell ogħla

109
00:06:59,420 --> 00:07:01,080
problemi ta 'interess għalina.

110
00:07:01,080 --> 00:07:04,730
>> Allura hawnhekk huwa dak li aħna tista 'sejħa binary--
mal biss alfabett ta '0 u 1.

111
00:07:04,730 --> 00:07:06,960
Iżda aħna bnedmin huma l-aktar
familjari ma 'deċimali.

112
00:07:06,960 --> 00:07:08,130
Diċembru tifsira 10.

113
00:07:08,130 --> 00:07:09,070
Bi tifsira tnejn.

114
00:07:09,070 --> 00:07:12,100
U hekk fil-deċimali
sistema, għandna 10 numri

115
00:07:12,100 --> 00:07:14,099
fil disposal-- tagħna ta '
Naturalment, żero permezz disgħa.

116
00:07:14,099 --> 00:07:16,140
Mela jekk inti tħares lejn numru
bħal dan, ħafna minnkom

117
00:07:16,140 --> 00:07:19,016
intuwittivament biss jaħtfu din hija 123.

118
00:07:19,016 --> 00:07:20,640
M'hemm xejn verament diffiċli dwar dan.

119
00:07:20,640 --> 00:07:22,452
Iżda għaliex hi 123?

120
00:07:22,452 --> 00:07:24,660
Ukoll, jekk inti taħseb lura għal
school-- grad jew għall-inqas

121
00:07:24,660 --> 00:07:26,410
il-mod I tgħallimt dan il
tip ta 'world-- inti

122
00:07:26,410 --> 00:07:29,640
jista tfakkar li aħna trattati dawn
affarijiet fil-kolonni, jew postijiet.

123
00:07:29,640 --> 00:07:31,412
>> Allura aħna għandna l-post dawk fuq il-lemin.

124
00:07:31,412 --> 00:07:32,620
Il għexieren poġġi fin-nofs.

125
00:07:32,620 --> 00:07:34,240
-Mijiet poġġi fuq ix-xellug.

126
00:07:34,240 --> 00:07:36,980
U allura kif se nilħqu
minn dan il-mudell symbols--

127
00:07:36,980 --> 00:07:41,771
1 2 3-- għal dan il-livell ogħla
idea li nafu bħala 123?

128
00:07:41,771 --> 00:07:43,461
Ukoll, huwa biss xi aritmetika sempliċi.

129
00:07:43,461 --> 00:07:43,960
Dritt?

130
00:07:43,960 --> 00:07:48,960
>> Il-waħda hemm essenzjalment ifisser
agħtina 100 darba 1 plus 10 darbiet

131
00:07:48,960 --> 00:07:50,410
2 flimkien ma '1 darbiet 3.

132
00:07:50,410 --> 00:07:53,430
U ovvjament jekk nagħmlu l-
matematika hemmhekk, huwa 100 flimkien ma '20

133
00:07:53,430 --> 00:07:56,480
flimkien 3-- inkella magħruf bħala 123.

134
00:07:56,480 --> 00:07:58,820
>> Mela jekk int fuq il-
paġna istess dak id-dritt

135
00:07:58,820 --> 00:08:02,320
issa u huma komdi mal-
hekk imsejħa sistema deċimali bhala bniedem,

136
00:08:02,320 --> 00:08:05,750
huwa attwalment ukoll fi ħdan
ambitu tiegħek ta 'kumdità

137
00:08:05,750 --> 00:08:07,220
biex tikkunsidra issa s-sistema binarja.

138
00:08:07,220 --> 00:08:10,110
Ħu selvaġġi guess-- dan jirrappreżenta,
fid-dinja tal-kompjuters

139
00:08:10,110 --> 00:08:12,001
fil binary-- liema numru?

140
00:08:12,001 --> 00:08:12,500
Żero.

141
00:08:12,500 --> 00:08:13,580
>> Iżda għaliex huwa li?

142
00:08:13,580 --> 00:08:17,460
Ukoll, jirriżulta li l-kolonni jew
postijiet here-- dawn mhux qed poteri ta '10.

143
00:08:17,460 --> 00:08:19,670
1, 10, 100, 1,000, u oħrajn.

144
00:08:19,670 --> 00:08:21,890
Huma qed minflok, pjuttost
sempliċi, poteri ta '2.

145
00:08:21,890 --> 00:08:25,400
Allura, 1, 2, 4, 8, 16, 32, u l-bqija.

146
00:08:25,400 --> 00:08:29,630
U hekk issa aħna naturalment nikseb għal 0
hawnhekk sempliċement għaliex għandna 4 darbiet

147
00:08:29,630 --> 00:08:34,510
0 plus 2 darbiet 0 plus 1 darbiet
0, li naturalment tagħtina 0.

148
00:08:34,510 --> 00:08:37,399
>> Imma kif nista tmur dwar
tirrappreżenta n-numru 1?

149
00:08:37,399 --> 00:08:39,440
X'hemm l-mudell ta '
żero u dawk li jirrappreżentaw

150
00:08:39,440 --> 00:08:42,720
in-numru aħna bnedmin magħrufa bħala 1?

151
00:08:42,720 --> 00:08:44,280
001.

152
00:08:44,280 --> 00:08:46,370
U 2?

153
00:08:46,370 --> 00:08:47,480
010.

154
00:08:47,480 --> 00:08:49,760
>> U issa l-mudell jibda jirrepeti.

155
00:08:49,760 --> 00:08:50,890
Issa huwa 011.

156
00:08:50,890 --> 00:08:54,310
U għal darb'oħra, 0 fours, wieħed 2, wieħed 1.

157
00:08:54,310 --> 00:08:55,180
Allura 2 flimkien ma '1.

158
00:08:55,180 --> 00:08:56,140
Li 3.

159
00:08:56,140 --> 00:08:59,069
>> U issa li jirrappreżentaw 4, aħna
ma biss bidla li għamilhom 0 għal 1.

160
00:08:59,069 --> 00:09:01,360
Inti tip ta jkollha twettaq,
biex ngħidu hekk, u n-numri

161
00:09:01,360 --> 00:09:03,700
bidu flipping madwar biss
bħall fid-dinja deċimali.

162
00:09:03,700 --> 00:09:04,670
>> Allura dan huwa 4.

163
00:09:04,670 --> 00:09:05,410
Dan huwa 5.

164
00:09:05,410 --> 00:09:06,330
Dan huwa 6.

165
00:09:06,330 --> 00:09:07,580
Dan huwa 7.

166
00:09:07,580 --> 00:09:09,720
U hekk aħna ve magħduda għoli daqs 7.

167
00:09:09,720 --> 00:09:12,400
>> Issa kollha għandna biss bżonn huwa aktar
bits-- aktar żero u s wieħed.

168
00:09:12,400 --> 00:09:15,700
U fil-fatt "bits", jekk inti stajt
smajt dan ċifri binarju term--.

169
00:09:15,700 --> 00:09:17,470
Bit huwa fejn li tiġi minn.

170
00:09:17,470 --> 00:09:20,190
U hekk jekk irridu li jirrappreżentaw
numri akbar, neħtieġu aktar bits.

171
00:09:20,190 --> 00:09:24,360
Imma ejja jimxu 'l bogħod mill slides issa
għal xi ħaġa ftit aktar reali.

172
00:09:24,360 --> 00:09:27,540
Ejja ngħidu li aħna rridu li
attwalment jirrappreżentaw dan il-ħaġa.

173
00:09:27,540 --> 00:09:31,790
>> Well ejja tagħti ħarsa issa
fi dimostrazzjoni ftit.

174
00:09:31,790 --> 00:09:35,270
Allura dan huwa applikazzjoni web ibbażat
li wieħed mill CS50 stess, Michael G,

175
00:09:35,270 --> 00:09:38,160
tpoġġi flimkien dan is-sajf biex jgħinu
us jispjegaw eżattament din l-idea.

176
00:09:38,160 --> 00:09:40,420
U kieku xi ħadd bħal
li venture up fuq il-palk

177
00:09:40,420 --> 00:09:42,915
quddiem klassi kollha tiegħu jew tagħha?

178
00:09:42,915 --> 00:09:43,790
Hemm dritt quddiem.

179
00:09:43,790 --> 00:09:45,660
Come fuq up.

180
00:09:45,660 --> 00:09:48,350
>> Int għandek tkun komda
fuq camera u l-internet.

181
00:09:48,350 --> 00:09:50,930

182
00:09:50,930 --> 00:09:52,450
Oh, dritt hawn.

183
00:09:52,450 --> 00:09:52,950
KOLLOX SEW.

184
00:09:52,950 --> 00:09:53,740
Aħna OK.

185
00:09:53,740 --> 00:09:54,240
Kull dritt.

186
00:09:54,240 --> 00:09:54,740
Come fuq up.

187
00:09:54,740 --> 00:09:56,150
X'hemm isem tiegħek?

188
00:09:56,150 --> 00:09:58,550
Emily come fuq up.

189
00:09:58,550 --> 00:09:59,410
Allura dan huwa Emily.

190
00:09:59,410 --> 00:10:00,840
Liema sena int?

191
00:10:00,840 --> 00:10:01,660
>> Freshman.

192
00:10:01,660 --> 00:10:02,810
>> Emily, sbieħ li jissodisfaw inti.

193
00:10:02,810 --> 00:10:03,310
David.

194
00:10:03,310 --> 00:10:03,810
>> Kull dritt.

195
00:10:03,810 --> 00:10:06,120
Allura fuq l-iskrin hawn,
Għandna din touch screen

196
00:10:06,120 --> 00:10:08,425
li se jippermettilna naslu biex
attwalment jinteraġixxu ma 'dan il-programm,

197
00:10:08,425 --> 00:10:09,265
u huwa biss browser.

198
00:10:09,265 --> 00:10:11,390
Huwa Chrome sħiħ skrinjati
fil-mument, imma hija

199
00:10:11,390 --> 00:10:14,030
ġew ipprogrammati minn Michael lil
jirrispondu b'mod li jippermetti

200
00:10:14,030 --> 00:10:15,970
ahna play madwar numri binarja.

201
00:10:15,970 --> 00:10:20,220
>> Allura per eżempju, hawn aħna ma
tliet iżda tmien żero bits-- u dawk.

202
00:10:20,220 --> 00:10:22,000
Dritt issa, aħna qed
tħares lejn in-numru 0.

203
00:10:22,000 --> 00:10:25,150
U tabilħaqq, kollha tmien żerijiet
fil deċimali mezzi żero.

204
00:10:25,150 --> 00:10:26,900
Allura li kollox dan huwa
qed hi aċċennata hawn.

205
00:10:26,900 --> 00:10:29,395
>> Mela jekk int riedu
jirrappreżentaw in-numru 8,

206
00:10:29,395 --> 00:10:31,520
x'inhu l-mudell ta 'żerijiet
u dawk li inti tixtieq?

207
00:10:31,520 --> 00:10:35,160
Inti tista 'sempliċement vit jew' l isfel
jew in-numri nfushom.

208
00:10:35,160 --> 00:10:35,660
Kull dritt.

209
00:10:35,660 --> 00:10:37,659
Allura li naturalment huwa 8,
kif tistgħu taraw up hemm.

210
00:10:37,659 --> 00:10:41,260
U jekk ridna li
do 16, dak li nagħmlu?

211
00:10:41,260 --> 00:10:42,701
>> Yep, biss tmiss mill-ġdid.

212
00:10:42,701 --> 00:10:43,200
16.

213
00:10:43,200 --> 00:10:43,870
Kull dritt.

214
00:10:43,870 --> 00:10:46,522
Allura din hija kollha multa u tajjeb,
huwa għadu f'livell baxx ħafna.

215
00:10:46,522 --> 00:10:48,230
Għandna bżonn mod fil-
dinja reali għall Emily

216
00:10:48,230 --> 00:10:50,550
li attwalment jirrappreżenta dawn l-affarijiet.

217
00:10:50,550 --> 00:10:54,230
U hekk jissoponi li ngħaddu dawn
żerijiet u dawk, li huwa ferm

218
00:10:54,230 --> 00:10:55,980
kunċettwali, fis bozoz tad-dawl attwali.

219
00:10:55,980 --> 00:10:56,480
Dritt?

220
00:10:56,480 --> 00:10:59,540
>> A kompjuter huwa fiżiku,
mekkaniċi, apparat elettriku.

221
00:10:59,540 --> 00:11:02,220
U input-- tiegħu għall-inqas jekk
inti plagg fil jew ħlas it--

222
00:11:02,220 --> 00:11:05,090
huwa li jkun hemm enerġija tal-batterija u
elettroni li jirriżultaw fi u barra.

223
00:11:05,090 --> 00:11:08,150
>> Allura issa, għaliex ma we stop ħsieb
dwar bits bħala żerijiet u dawk,

224
00:11:08,150 --> 00:11:10,470
imma xi ħaġa aktar fiżika
bħal bozoz tad-dawl hawn.

225
00:11:10,470 --> 00:11:13,815
U jekk Dan Armendáriz tista 'tingħaqad
me għal ftit moment-- come fuq up--

226
00:11:13,815 --> 00:11:15,440
aħna qed tmur biex kju applikazzjoni.

227
00:11:15,440 --> 00:11:15,940
>> Come fuq matul, Emily.

228
00:11:15,940 --> 00:11:18,270
Jiddispjacini dan huwa l-aktar
demo skomdi ghalik qatt.

229
00:11:18,270 --> 00:11:20,330
Come fuq matul hawn.

230
00:11:20,330 --> 00:11:22,080
Aħna qed tmur biex kju
up ma grazzi għall Dan

231
00:11:22,080 --> 00:11:25,300
Armendáriz, membru ieħor tal-persunal tagħna,
applikazzjoni magħrufa bħala bozza binarja.

232
00:11:25,300 --> 00:11:28,070
>> Allura dak li għandna hawnhekk
hija applikazzjoni iPad

233
00:11:28,070 --> 00:11:31,970
li għandha l-utent li ġejja
interface fuq l-iskrin għal Emily.

234
00:11:31,970 --> 00:11:35,400
Huwa biss ltqajna l-istess IU eżatt
essenzjalment li l-hemmhekk.

235
00:11:35,400 --> 00:11:39,220
U jekk inti issa tixtieq li
jirrappreżentaw in-numru, jgħidu 8,

236
00:11:39,220 --> 00:11:42,094
kif tista 'tmur dwar kif isir
dan il Jinnota fil-lemin,

237
00:11:42,094 --> 00:11:43,510
-bozoz tad-dawl li għandna hawn?

238
00:11:43,510 --> 00:11:46,576

239
00:11:46,576 --> 00:11:47,620
Ah-ha.

240
00:11:47,620 --> 00:11:48,290
Maġika.

241
00:11:48,290 --> 00:11:51,830
Mela jekk irridu issa jibdlu din fi
xi ħaġa ftit aktar ta 'sfida,

242
00:11:51,830 --> 00:11:58,100
u ejja imorru quddiem u pick każwali
Numru bħan-numru 50 hawn.

243
00:11:58,100 --> 00:11:59,015
Input dan il.

244
00:11:59,015 --> 00:12:01,640
U jekk inti tista 'issa tiġi sfidata
biex toħroġ man-numru 50,

245
00:12:01,640 --> 00:12:04,268
aħna ser ikollhom premju fabulous għalik.

246
00:12:04,268 --> 00:12:06,144
>> EMILY: OK.

247
00:12:06,144 --> 00:12:08,692
Oh my God.

248
00:12:08,692 --> 00:12:10,650
DAVID Malan: Aritmetika
huwa tabilħaqq iebsa quddiem

249
00:12:10,650 --> 00:12:12,860
ta 'mijiet ta' klassi tiegħek.

250
00:12:12,860 --> 00:12:16,260
Iżda 50 kien ir-risposta hawn.

251
00:12:16,260 --> 00:12:18,132
>> [Applause]

252
00:12:18,132 --> 00:12:21,875
>> U għalhekk issa, din maħsuba li
jkun dimostrattiva għall Emily.

253
00:12:21,875 --> 00:12:24,315
Allura, fil hawn, huwa xi dawl
basal pjuttost bħal dawn,

254
00:12:24,315 --> 00:12:26,190
iżda huwa attwalment l-
strixxi manjetiċi ftit.

255
00:12:26,190 --> 00:12:28,570
U x'hemm jibred dwar dawn u
-raġuni aħna jużawhom fil CS50

256
00:12:28,570 --> 00:12:31,640
huwa li dawn jappoġġjaw xi ħaġa imsejħa
l API-- l-ipprogrammar applikazzjoni

257
00:12:31,640 --> 00:12:34,681
interface, li huwa biss mod fancy
ta 'tgħid li dak li wieħed mill-istaff tagħna

258
00:12:34,681 --> 00:12:37,284
ma tul is-sajf kien joħloq
applikazzjoni iPad hawn

259
00:12:37,284 --> 00:12:39,700
li taħdidiet fuq l-internet
għall-bozoz tad-dawl fuq hawn,

260
00:12:39,700 --> 00:12:41,810
li huma wirelessly
mqabbad ma 'mezz ieħor.

261
00:12:41,810 --> 00:12:43,912
Imma issa din hija għażla
għall-proġetti finali.

262
00:12:43,912 --> 00:12:46,370
U għalhekk Emily, jekk inti hekk
simili, fl-aħħar tat-terminu,

263
00:12:46,370 --> 00:12:48,703
inti tista adorn kamra dorm tiegħek
fil-frattemp ma 'dawk.

264
00:12:48,703 --> 00:12:50,376
Grazzi għal Emily kif ukoll.

265
00:12:50,376 --> 00:12:53,244
>> [Applause]

266
00:12:53,244 --> 00:12:56,590

267
00:12:56,590 --> 00:13:00,055
>> Imma issa, ejja dawwar
attenzjoni tagħna għal dak li

268
00:13:00,055 --> 00:13:03,180
dak il-messaġġ jista 'jkollhom dehru qishom,
u huwa ftit xi ħaġa bħal din.

269
00:13:03,180 --> 00:13:05,320
Fil-fatt, dan huwa
Eżempju daqstant teaser

270
00:13:05,320 --> 00:13:08,400
ta dak li ġejjin ta 'x'hemm
imsejħa talba API.

271
00:13:08,400 --> 00:13:11,409
U hekk dak li għandna hawnhekk huwa sempliċement
eżattament it-tipi ta 'messaġġ

272
00:13:11,409 --> 00:13:13,200
li wara ftit ġimgħat
żmien fil CS50, inti ser

273
00:13:13,200 --> 00:13:16,590
tkun tista 'tibgħat xi ħaġa pjuttost
familjari bħal dik li attwalment

274
00:13:16,590 --> 00:13:18,100
jdawruhom u jintfew.

275
00:13:18,100 --> 00:13:19,350
Iżda din hija kollha multa u tajba.

276
00:13:19,350 --> 00:13:19,850
Dritt?

277
00:13:19,850 --> 00:13:22,710
Għandna l-mudell mentali nisperaw
biex jirrappreżentaw numri ma

278
00:13:22,710 --> 00:13:23,660
s żero u s wieħed.

279
00:13:23,660 --> 00:13:26,290
U minn żero u dawk, nistgħu
jiksbu numri ogħla bħall 50,

280
00:13:26,290 --> 00:13:29,460
kif Emily biss għamlet, jew aħna
jista nħaffu minn dik.

281
00:13:29,460 --> 00:13:32,160
U jien jsostnu li nistgħu jirrappreżentaw
affarijiet simili ittri kif ukoll.

282
00:13:32,160 --> 00:13:32,660
Dritt?

283
00:13:32,660 --> 00:13:35,360
>> Kompjuters li huma ferm aktar
interessanti minn sempliċiment numri.

284
00:13:35,360 --> 00:13:37,340
U allura kif do you go
dwar kliem li jirrappreżentaw

285
00:13:37,340 --> 00:13:39,420
fuq l-iskrin jew emails
jew esejs jew bħalhom?

286
00:13:39,420 --> 00:13:43,170
Ukoll, jirriżulta li l-kompjuters sempliċiment
astratta fuq quċċata ta 'dawn f'livell baxx

287
00:13:43,170 --> 00:13:47,380
Dettalji, u l-bnedmin ftit taż-żmien ilu, daħal
up ma 'arbitrarja, iżda konsistenti,

288
00:13:47,380 --> 00:13:51,710
immappjar ta 'numri li letters-- hekk
li kwalunkwe ħin li inti tara ittra kapitali

289
00:13:51,710 --> 00:13:54,170
A fuq il-kompjuter tiegħek
iskrin, odds huma x'hemm

290
00:13:54,170 --> 00:13:57,370
taħt il-barnuża hija
mudell ta 'żero u dawk

291
00:13:57,370 --> 00:14:00,650
li jirrappreżentaw in-numru,
kull din it-tabella, 65.

292
00:14:00,650 --> 00:14:02,830
>> U aktar fiżikament
ġewwa tal-kompjuter tiegħek,

293
00:14:02,830 --> 00:14:06,450
miljuni ta 'affarijiet imsejħa
transistors-- dawn days-- li

294
00:14:06,450 --> 00:14:10,190
huma biss swiċċijiet jekk inti se, affarijiet
li tista 'tmur fuq u barra u għalhekk jimmaġina.

295
00:14:10,190 --> 00:14:14,130
Mhux tmienja minn dawn bozoz tad-dawl kbar
imma miljuni ta 'dawn dawl ftit żgħira

296
00:14:14,130 --> 00:14:17,490
basal, jew swiċċijiet jew transisters,
li jistgħu jixgħel u jitfi

297
00:14:17,490 --> 00:14:19,170
bbażata fuq kif inti program minnhom.

298
00:14:19,170 --> 00:14:22,120
U hekk issa għandna mod ta '
li jirrappreżentaw ittri kif ukoll.

299
00:14:22,120 --> 00:14:25,300
>> Fil-fatt, jekk I kellhom jużaw dan
mapping hawn u jippruvaw attwalment

300
00:14:25,300 --> 00:14:28,731
tispjega xi ħaġa, nistgħu nħarsu
fuq dan il-mudell ta 'numri deċimali

301
00:14:28,731 --> 00:14:29,230
dritt issa.

302
00:14:29,230 --> 00:14:31,354
Allura aħna mhux qed tmur biex saħansitra
tiffoka fuq binarju aktar.

303
00:14:31,354 --> 00:14:35,910
Ejja biss tikkunsidra dawn bħala
numru deċimali 72, 73, 33.

304
00:14:35,910 --> 00:14:38,044
Imma dak li jista din il jirrappreżenta?

305
00:14:38,044 --> 00:14:39,960
Kull min ikollu biżżejjed
memorja fotografiku

306
00:14:39,960 --> 00:14:43,060
li tkun taf x'inhu spelt
fuq l-iskrin hawn?

307
00:14:43,060 --> 00:14:43,560
Yeah ftit.

308
00:14:43,560 --> 00:14:44,190
Allura hi.

309
00:14:44,190 --> 00:14:48,330
H-I u mbagħad punt exclamation,
li ma kienx fil-fatt fuq l-iskrin.

310
00:14:48,330 --> 00:14:51,060
Iżda fil-fatt hemm immappjar
għal kull ittra li kull numru

311
00:14:51,060 --> 00:14:53,340
li inti tista 'tixtieq li
tip fuq it-tastiera tiegħek.

312
00:14:53,340 --> 00:14:55,430
>> Imma numri ma għandekx
jirrappreżentaw biss l-ittri.

313
00:14:55,430 --> 00:14:55,930
Dritt?

314
00:14:55,930 --> 00:14:59,570
Lkoll jafu dwar stampi
u ritratti u fajls awdjo

315
00:14:59,570 --> 00:15:00,870
u video files u simili.

316
00:15:00,870 --> 00:15:03,580
Allura ċar nistgħu jirrappreżentaw
livell affarijiet ogħla għadhom.

317
00:15:03,580 --> 00:15:06,920
U iva, liema kompjuter
ma hija sempliċement tagħżel

318
00:15:06,920 --> 00:15:11,240
li tinterpreta xejriet ta 'żero dawk
b'mod differenti bbażat fuq l-kuntest.

319
00:15:11,240 --> 00:15:13,130
>> Jekk inti double ikklikkja
Microsoft Word ikona,

320
00:15:13,130 --> 00:15:15,900
tara kliem fuq l-iskrin
minflok kuluri u stampi

321
00:15:15,900 --> 00:15:18,850
għax kelma jaf li dan huwa
esej li inti stajt attwalment ittajpjat.

322
00:15:18,850 --> 00:15:21,510
Jekk inti minflok ikklikkja darbtejn
fuq JPEG jew GIF jew PNG,

323
00:15:21,510 --> 00:15:27,070
it jiftaħ u hija immaġni minħabba li l-
Png jew il docx jew ikun x'ikun l-fajl

324
00:15:27,070 --> 00:15:30,450
estensjoni hija u tkun xi tkun is-software
inti qed tuża jaf li tinterpreta

325
00:15:30,450 --> 00:15:34,420
mudell ta 'żerijiet u dawk differenti
ibbażati fuq dak l-iskop tiegħu fil-ħajja huwa.

326
00:15:34,420 --> 00:15:37,330
>> Allura per eżempju, dan
istess sekwenza ta 'numri

327
00:15:37,330 --> 00:15:41,250
jafu jirrappreżentaw kemm aħmar kemm taħseb
trid, kemm ħadra kemm tridu,

328
00:15:41,250 --> 00:15:42,810
u kemm blu kemm tridu.

329
00:15:42,810 --> 00:15:47,490
U fil-fatt, jekk inti stajt qatt semgħu
RGB-- blu aħdar hekk biss ħamra.

330
00:15:47,490 --> 00:15:51,380
U hekk jekk nara numri simili, din l
tagħti me 72 ħamra, agħti lili 73 ħadra,

331
00:15:51,380 --> 00:15:56,910
u 33 blu, dan huwa kif
kompjuter bl-użu tliet bytes-- fejn

332
00:15:56,910 --> 00:16:01,470
byte huwa tmien bits jew 24 bits--
tirrappreżenta dell pretty diżgustanti

333
00:16:01,470 --> 00:16:03,660
tal kannella jew isfar hawn.

334
00:16:03,660 --> 00:16:07,500
U f'kuntesti differenti, tista dawk
istess xejriet eżatt fl żerijiet u dawk

335
00:16:07,500 --> 00:16:10,780
tfisser xi ħaġa kompletament
differenti kif ukoll.

336
00:16:10,780 --> 00:16:13,899
>> Allura aħna għandna issa mod ta 'tirrappreżenta
żero information-- u dawk.

337
00:16:13,899 --> 00:16:15,190
Barra minn dan, irridu jiksbu l-ittri.

338
00:16:15,190 --> 00:16:16,860
Barra minn dan, nistgħu jiksbu kuluri.

339
00:16:16,860 --> 00:16:19,730
U ejja nassumu għal-lum
li nistgħu nibdew awdjo u vidjo

340
00:16:19,730 --> 00:16:22,590
u l-affarijiet tant aktar
sofistikata minn dik.

341
00:16:22,590 --> 00:16:25,370
>> Imma issa ejja jikkunsidraw
kif nużaw dawk l-inputs

342
00:16:25,370 --> 00:16:27,390
u jipproduċu dawk
outputs issa li għandna

343
00:16:27,390 --> 00:16:29,830
mod ta jirrappreżentaw dik l-informazzjoni.

344
00:16:29,830 --> 00:16:31,820
Ukoll, għandna bżonn xi ħaġa
imsejħa algoritmu.

345
00:16:31,820 --> 00:16:34,320
Għal darb'oħra, sett ta 'struzzjonijiet
sabiex isolvi xi problema

346
00:16:34,320 --> 00:16:37,580
pass step-- u l-
aktar preċiżi, l-aħjar.

347
00:16:37,580 --> 00:16:42,090
>> U hekk eżempju magħhom bnedmin huma
ċertament inqas familjari f'dawn il-jiem,

348
00:16:42,090 --> 00:16:44,300
iżda madankollu hija għadha
magħna fis-software,

349
00:16:44,300 --> 00:16:47,490
huwa l-proċess ta tfittex
up xi ħadd fil-ktieb tat-telefon.

350
00:16:47,490 --> 00:16:51,690
>> Issa, anqas u anqas nies jafu lil
sena liema dan relikwa fil-fatt hu hawnhekk.

351
00:16:51,690 --> 00:16:53,470
Iżda lura fil-jum tiegħi,
dan kien ktieb tat-telefon

352
00:16:53,470 --> 00:16:57,266
ma 'eluf ta' paġni u numri
u l-ismijiet tan-nies mill A permezz Z.

353
00:16:57,266 --> 00:17:00,390
U anki jekk aħna qed tip ta 'qerq
a bit-- dan huwa l-aktar yellow pages.

354
00:17:00,390 --> 00:17:01,920
Kien hemm ukoll bojod
paġni fil-ħin, li

355
00:17:01,920 --> 00:17:04,720
kienu kollha ta 'dawk l-ismijiet u
numri ta 'bnedmin attwali.

356
00:17:04,720 --> 00:17:07,970
>> U jekk jien ridt li tfittex xi ħadd up fil-
ktieb tat-telefon bħal dan illum, naturalment,

357
00:17:07,970 --> 00:17:11,010
I biss tip fl-ewwel ftit
karattri ta 'l-isem tiegħu jew tagħha,

358
00:17:11,010 --> 00:17:13,480
u telefon tiegħi ssib li l-informazzjoni.

359
00:17:13,480 --> 00:17:15,970
Imma l-proċess li permezz tiegħu
iPhone tiegħek jew Android telefon

360
00:17:15,970 --> 00:17:18,730
jew kwalunkwe huwa attwalment konstatazzjoni
xi ħadd fil-lista kuntatti tiegħek

361
00:17:18,730 --> 00:17:22,099
huwa identiku għal dak li aħna bnedmin
probabbilment għamlu għal xi żmien.

362
00:17:22,099 --> 00:17:24,260
>> Now I tista 'tieħu din il-
problema, jekk inti se,

363
00:17:24,260 --> 00:17:26,220
u l-inputs hawn
mhumiex żerijiet u dawk.

364
00:17:26,220 --> 00:17:28,730
Huma qed pages-- simili,
ejja ngħidu 1,000 paġni.

365
00:17:28,730 --> 00:17:32,650
U jekk jien ridt li wieħed ifittex xi ħadd
bħal Mike Smith f'dan il-ktieb tat-telefon,

366
00:17:32,650 --> 00:17:35,570
I tista 'tibda fil-bidu
u tara li jien fit-taqsima A

367
00:17:35,570 --> 00:17:38,300
u imbagħad ixgħel paġna waħda fi
żmien, tfittex u tfittex

368
00:17:38,300 --> 00:17:42,820
kif nagħmel il-B u C u
il D'i u oħrajn għall Mike Smith.

369
00:17:42,820 --> 00:17:46,000
Smith li jibdew bi S, I ser
nisperaw eventwalment issib lilu.

370
00:17:46,000 --> 00:17:50,090
>> Huwa dan algorithm--
li process-- korretta?

371
00:17:50,090 --> 00:17:50,590
Yeah.

372
00:17:50,590 --> 00:17:51,610
Huwa korrett.

373
00:17:51,610 --> 00:17:57,040
Jien ser issib Mike jekk hu fil hawn, iżda
x'inhu l-twiddiba li inti tista 'toffri.

374
00:17:57,040 --> 00:17:57,541
Huwa bil-mod.

375
00:17:57,541 --> 00:17:58,040
Dritt?

376
00:17:58,040 --> 00:18:00,975
Naf Mike S huwa tip ta 'lejn
-aħħar nofs tal-ktieb tat-telefon.

377
00:18:00,975 --> 00:18:02,766
Għaliex l-Heck am I
li jibda fil-bidu

378
00:18:02,766 --> 00:18:04,349
u li jmorru paġna mill paġna mill paġna.

379
00:18:04,349 --> 00:18:06,890
Allura naturalment, I jistgħu flip
madwar u tibda mid-dahar,

380
00:18:06,890 --> 00:18:08,973
iżda li għaddej biex tikseb
lili hemm bl-istess rata,

381
00:18:08,973 --> 00:18:10,930
jekk inti willl-- paġna
wara paġna wara.

382
00:18:10,930 --> 00:18:14,190
U mhuwiex sejjer jaħdem jekk irrid
ta 'tiftix għal xi ħadd ieħor li

383
00:18:14,190 --> 00:18:15,880
isem ġej qabel fl-alfabett.

384
00:18:15,880 --> 00:18:17,240
>> Allura dak li jekk nagħmel dak I
mgħallma fl-iskola grad,

385
00:18:17,240 --> 00:18:19,205
għal darb'oħra, jagħmlu affarijiet mhux
billi dawk iżda minn twos.

386
00:18:19,205 --> 00:18:23,060
Allura 2, 4, 6, 8, 10, 12, u oħrajn.

387
00:18:23,060 --> 00:18:23,740
Huwa li korretta?

388
00:18:23,740 --> 00:18:27,030

389
00:18:27,030 --> 00:18:27,560
No

390
00:18:27,560 --> 00:18:28,830
Huwa tip ta 'korretta.

391
00:18:28,830 --> 00:18:33,210
Iżda xi wħud minnkom li murmured le,
fejn hija l-problema, jew il-bug,

392
00:18:33,210 --> 00:18:34,240
l-iżball biex ngħidu hekk.

393
00:18:34,240 --> 00:18:34,580
Yeah.

394
00:18:34,580 --> 00:18:36,570
>> STUDENT: Inti tista skip
fuq id-dħul lemin.

395
00:18:36,570 --> 00:18:37,320
>> DAVID Malan: Yeah.

396
00:18:37,320 --> 00:18:40,340
I jista 'skip fuq Mike Smith huwa
għaliex stajt ħadet żewġ paġni f'daqqa

397
00:18:40,340 --> 00:18:43,190
u hu biss jiġri li jkun
imfattra bejn dawn iż-żewġ paġni.

398
00:18:43,190 --> 00:18:46,500
I jista jirrealizzaw li
Jien fuq il-taqsima T

399
00:18:46,500 --> 00:18:48,690
li ma sabet Mike Smith s'issa.

400
00:18:48,690 --> 00:18:50,820
>> U għalhekk dak li jista fiss hemmhekk tkun?

401
00:18:50,820 --> 00:18:52,709
Ukoll, jekk I do laqat il-
Ts fil-ktieb tat-telefon,

402
00:18:52,709 --> 00:18:54,500
I jista 'jkollhom bżonn li doppju
lura paġna waħda jew hekk.

403
00:18:54,500 --> 00:18:56,830
Allura huwa fixable, iżda
mhuwiex daqshekk sempliċi

404
00:18:56,830 --> 00:18:59,170
kif biss jmorru bi tnejn biex
iħaffu l-prestazzjoni tiegħi.

405
00:18:59,170 --> 00:18:59,680
Imma liema?

406
00:18:59,680 --> 00:19:00,180
Ejja.

407
00:19:00,180 --> 00:19:03,530
X'inhu huwa dak li ħafna nies huma għaddejjin
li tagħmel ma 'dan it-tip ta' ktieb tat-telefon?

408
00:19:03,530 --> 00:19:04,696
Int tingħata l-ktieb tat-telefon.

409
00:19:04,696 --> 00:19:06,280
What do you do?

410
00:19:06,280 --> 00:19:06,922
>> Dak X'inhu?

411
00:19:06,922 --> 00:19:07,630
Mur fil-nofs.

412
00:19:07,630 --> 00:19:10,620
So I smajt jmorru għall-nofs, u jien
find myself bejn wieħed u ieħor fis-sezzjoni M,

413
00:19:10,620 --> 00:19:11,120
biex ngħidu hekk.

414
00:19:11,120 --> 00:19:12,670
U issa liema do I trid tagħmel?

415
00:19:12,670 --> 00:19:14,077
Xogħol tajjeb.

416
00:19:14,077 --> 00:19:14,785
X'hemm isem tiegħek?

417
00:19:14,785 --> 00:19:15,350
>> JAMES: James.

418
00:19:15,350 --> 00:19:15,890
>> DAVID Malan: James, id-dritt.

419
00:19:15,890 --> 00:19:16,829
What do I do jmiss?

420
00:19:16,829 --> 00:19:18,620
JAMES: Inti tmur fil-
nofs li għandha l s S.

421
00:19:18,620 --> 00:19:18,740
DAVID Malan: Kull dritt.

422
00:19:18,740 --> 00:19:20,910
Jien ser jmorru fil-nofs dik
għandha l-s S fiha minħabba li, għal darb'oħra,

423
00:19:20,910 --> 00:19:22,920
stipulazzjoni hawn kien
li din il-ħaġa tkun riżolta.

424
00:19:22,920 --> 00:19:25,461
Huwa pretty inutli 1000
paġni jekk Verizon fatt ma

425
00:19:25,461 --> 00:19:27,339
sort dawn l-affarijiet għalina A permezz Z.

426
00:19:27,339 --> 00:19:30,130
Mela jekk I know Mike huwa probabbilment fl
-aħħar nofs tal-ktieb tat-telefon,

427
00:19:30,130 --> 00:19:31,536
Nista 'issa.

428
00:19:31,536 --> 00:19:33,388
>> [Laughs]

429
00:19:33,388 --> 00:19:35,240

430
00:19:35,240 --> 00:19:37,391
>> Tiċrita l-problema min-nofs.

431
00:19:37,391 --> 00:19:38,615
>> [Applause]

432
00:19:38,615 --> 00:19:39,115

433
00:19:39,115 --> 00:19:40,300
Grazzi.

434
00:19:40,300 --> 00:19:42,510
Tiċrita l-problema min-nofs.

435
00:19:42,510 --> 00:19:44,440
Dan kien fil-fatt real-- dik ġlieda.

436
00:19:44,440 --> 00:19:47,050
Allura tiċrita-ktieb tat-telefon
fil nofs, li jħallu lili nnifsi

437
00:19:47,050 --> 00:19:48,580
bl fundamentalment l-istess problema.

438
00:19:48,580 --> 00:19:50,060
Iżda naturalment, nofs kbar.

439
00:19:50,060 --> 00:19:52,550
U jekk nimxi James
pariri darb'oħra, u mmur hawn.

440
00:19:52,550 --> 00:19:54,400
I say, oh issa jien fit-taqsima T.

441
00:19:54,400 --> 00:19:56,460
>> U għalhekk naturalment, I
jistgħu tiċrita l-ktieb tat-telefon

442
00:19:56,460 --> 00:19:59,660
fil nofs waħda aktar ħin, tħalli
me ma 'problema li l-

443
00:19:59,660 --> 00:20:00,810
issa kwart tad-daqs.

444
00:20:00,810 --> 00:20:05,335
Allura stajt marret minn 1,000 sa 500
biex 250-125 u oħrajn.

445
00:20:05,335 --> 00:20:07,350
Hija tħoss bħal jien
filwaqt gdim akbar minn

446
00:20:07,350 --> 00:20:10,615
ta 'din il-problema ma' kull
iterazzjoni, jew kull pass fiha.

447
00:20:10,615 --> 00:20:15,580
>> U fil-fatt, il-ħin jien ser jonfqu
konstatazzjoni Mike Smith f'dan l-eżempju

448
00:20:15,580 --> 00:20:18,970
tant inqas minħabba li eventwalment jien
ser Whittle dan il-ktieb pone isfel

449
00:20:18,970 --> 00:20:20,192
li wieħed biss paġna isolati.

450
00:20:20,192 --> 00:20:23,010
U jekk Mike huwa fuq dik il-paġna, jien
se jimxi 'l quddiem u jagħtih

451
00:20:23,010 --> 00:20:24,670
sejħa li sabuh.

452
00:20:24,670 --> 00:20:27,030
>> Imma kemm kemm aħjar
hija li algorithm--

453
00:20:27,030 --> 00:20:29,690
li DARE jgħidu intuwittivi
algorithm-- minn dawk we

454
00:20:29,690 --> 00:20:34,920
beda magħhom aħna qed ħafna linear--
xellug biex right-- b'pass ta '1 jew 2x?

455
00:20:34,920 --> 00:20:36,100
>> Ukoll, ejja plot din il.

456
00:20:36,100 --> 00:20:39,380
Aħna ma jkollhom għalfejn tinkwieta wisq dwar
matematika jew numri f'dan il-każ hawnhekk.

457
00:20:39,380 --> 00:20:40,550
Aħna biss ħarsa lejn plot.

458
00:20:40,550 --> 00:20:43,600
Allura fuq il x, jew assi orizzontali,
huwa d-daqs tal-problem--

459
00:20:43,600 --> 00:20:44,700
kemm paġni huma hemmhekk.

460
00:20:44,700 --> 00:20:46,760
Fuq il-y, jew il-vertikali
assi, huwa kemm ħin

461
00:20:46,760 --> 00:20:48,218
huwa se jieħdu me biex issolviha.

462
00:20:48,218 --> 00:20:50,760
U forsi li kemm
dawriet paġna, kemm sekondi,

463
00:20:50,760 --> 00:20:52,370
kif many-- f'xi unità ta 'miżuri.

464
00:20:52,370 --> 00:20:57,810
>> U stajt mfassla linji dritti ħomor
hawnhekk għaliex jekk kull paġna addizzjonali

465
00:20:57,810 --> 00:21:01,740
tal-ktieb tat-telefon, I jeħtieġu
biex jagħmlu pass addizzjonali wieħed.

466
00:21:01,740 --> 00:21:03,680
Mela jekk Verizon iżid wieħed
aktar paġna sena d-dieħla,

467
00:21:03,680 --> 00:21:06,970
I jista 'jkollhom biex flip paġna waħda aktar
li ssib xi ħadd bħal Mike Smith.

468
00:21:06,970 --> 00:21:11,340
>> Sadanittant, it-tieni algoritmu, li
I marru permezz twos, huwa l-istess forma.

469
00:21:11,340 --> 00:21:15,220
Huwa għadu ferm lineari, ħafna xellug biex
dritt, filwaqt bytes ugwali kull darba,

470
00:21:15,220 --> 00:21:16,900
iżda l-inklinazzjoni hija ftit aktar baxxa.

471
00:21:16,900 --> 00:21:23,590
>> Per eżempju, jekk id-daqs ta '
il-problema kienu bejn wieħed u ieħor hawn

472
00:21:23,590 --> 00:21:25,990
u I użati l-ewwel algoritmu tiegħi,
I tista 'tispiċċa-triq kollha

473
00:21:25,990 --> 00:21:27,480
fil-quċċata ta dik il-linja ħamra.

474
00:21:27,480 --> 00:21:29,390
Imma jekk jien minflok jużaw
li l-approċċ twosies,

475
00:21:29,390 --> 00:21:31,480
-linja isfar jissuġġerixxi
għaliex dan huwa aktar baxx,

476
00:21:31,480 --> 00:21:33,790
li huwa għaddej biex tieħu
me inqas ħin l ssolvi.

477
00:21:33,790 --> 00:21:37,400
>> Imma x'inhu l-forma tal-
tielet algorithm-- darb'oħra, forsi

478
00:21:37,400 --> 00:21:38,707
l-algoritmu aktar intuwittivi?

479
00:21:38,707 --> 00:21:40,540
Ukoll, jidher ftit
xi ħaġa bħal din.

480
00:21:40,540 --> 00:21:43,480
Huwa mgħawġa, jew logaritmika, fil-forma.

481
00:21:43,480 --> 00:21:46,510
U anki jekk qatt ma
tip ta flattens out,

482
00:21:46,510 --> 00:21:50,770
it asymptotically pulzieri up u
up u sa iżda terriblement bil-mod

483
00:21:50,770 --> 00:21:52,129
kontra kull ħaġa oħra.

484
00:21:52,129 --> 00:21:53,170
U x'inhu l-take away?

485
00:21:53,170 --> 00:21:54,215
Ukoll, nagħmlu sejħa hija log n.

486
00:21:54,215 --> 00:21:55,820
Imma dak li ma attwalment jfisser?

487
00:21:55,820 --> 00:21:58,580
Ukoll jekk Verizon rdoppja l
Numru ta 'paġni fil-ktieb tat-telefon

488
00:21:58,580 --> 00:22:00,810
sena d-dieħla mill-1000 sa 2000.

489
00:22:00,810 --> 00:22:04,600
Kemm aktar passi huwa tiegħi
ewwel algoritmu se jieħu?

490
00:22:04,600 --> 00:22:05,440
>> ewwel algoritmu tiegħi.

491
00:22:05,440 --> 00:22:06,399
Forsi 1,000 passi aktar.

492
00:22:06,399 --> 00:22:08,106
Jekk dawn rdoppja l
ktieb tat-telefon, jien ser

493
00:22:08,106 --> 00:22:10,590
li jkollhom flip permezz ieħor
1,000 paġni li ssib Mike.

494
00:22:10,590 --> 00:22:13,240
Naturalment, jekk it-tieni
algoritmu, forsi 500 għaliex jien

495
00:22:13,240 --> 00:22:14,610
tmur darbtejn aktar malajr.

496
00:22:14,610 --> 00:22:18,380
>> Imma jekk Verizon jirdoppja n-numru
ta 'paġni bejn din is-sena u d-dieħla,

497
00:22:18,380 --> 00:22:21,650
bil tielet tiegħi algorithm---firda
u conquer li James proposta,

498
00:22:21,650 --> 00:22:24,450
għaddejjin fil nofs u nofs u
half-- passi kemm aktar se

499
00:22:24,450 --> 00:22:29,030
hija tieħu me sena d-dieħla li jkollhom
ktieb tat-telefon ta 'daqs 2000?

500
00:22:29,030 --> 00:22:29,670
Just wieħed.

501
00:22:29,670 --> 00:22:34,110
Minħabba li ma gidma waħda, I tista 'tieħu,
barra minn din il-problema, nofs il-paġni

502
00:22:34,110 --> 00:22:34,694
bogħod.

503
00:22:34,694 --> 00:22:37,860
U jekk taħseb dwar dan ftit
crazily now-- jekk il-ktieb tat-telefon ma

504
00:22:37,860 --> 00:22:41,810
ikollhom 1,000 jew 2,000 paġna, iżda
ejja ngħidu 4000000000 pages--

505
00:22:41,810 --> 00:22:45,282
huwa ta 'telefon kbir book-- kif
bosta drabi jew kif ħafna passi

506
00:22:45,282 --> 00:22:47,740
huwa se jieħdu me biex isibu
Mike Smith fil-ktieb tat-telefon

507
00:22:47,740 --> 00:22:50,489
ma '4 biljun paġni.

508
00:22:50,489 --> 00:22:52,030
Tista 'tip ta' jibdew jagħmlu l-matematika.

509
00:22:52,030 --> 00:22:52,200
Kull dritt.

510
00:22:52,200 --> 00:22:53,175
4 biljun diviż bi 2.

511
00:22:53,175 --> 00:22:54,550
Allura dak 2000000000 diviż bil 1.

512
00:22:54,550 --> 00:22:55,510
C'est 1 biljun.

513
00:22:55,510 --> 00:22:56,410
Imbagħad nofs biljun.

514
00:22:56,410 --> 00:22:59,940
Imbagħad 250-- sabiex inti tista 'tagħmel dan mill-ġdid u
darb'oħra iżda mhux li ħafna drabi qabel

515
00:22:59,940 --> 00:23:01,020
ikollok biex paġna waħda.

516
00:23:01,020 --> 00:23:04,360
>> U fil-fatt, anki jekk il-phone
ktieb huwa ta '4 biljun paġni

517
00:23:04,360 --> 00:23:08,340
jew id-database int tiftix
huwa ta '4 biljun rekords twil,

518
00:23:08,340 --> 00:23:12,720
li għaddej biex tieħu inti tagħti jew jieħu
32 passi biss li jinstabu Mike Smith.

519
00:23:12,720 --> 00:23:15,990
U jekk inti doppju tal-ktieb tat-telefon li jmiss
sena 4000000000-8000000000,

520
00:23:15,990 --> 00:23:19,010
33 passi minflok sempliċiment 32.

521
00:23:19,010 --> 00:23:21,100
>> U dan huwa xhieda
għal waħda mill-ideat

522
00:23:21,100 --> 00:23:24,100
li nistgħu jħaddnu fil-kompjuter
xjenza b'mod aktar ġenerali, li

523
00:23:24,100 --> 00:23:26,760
huwa dan il-ħsieb komputazzjoni
u toqrob problema

524
00:23:26,760 --> 00:23:29,479
franchement permezz ta 'għodod mill
għodda diġà familjari tiegħek

525
00:23:29,479 --> 00:23:31,520
kit-- dinja reali tiegħek ma
li int familjari,

526
00:23:31,520 --> 00:23:34,730
iżda utilizzazzjoni dawk l-ideat
li attwalment isolvu problemi.

527
00:23:34,730 --> 00:23:37,200
>> Iżda għandna bżonn li tifformalizza tagħna
soluzzjonijiet għal dawn il-problemi.

528
00:23:37,200 --> 00:23:40,200
U so let me jintroduċu għal mument
xi ħaġa li aħna tista 'sejħa pseudocode.

529
00:23:40,200 --> 00:23:44,260
Ħafna mill-semestru, aħna ser iqattgħu jużaw
kodiċi attwali fil-lingwi bħall C u PHP

530
00:23:44,260 --> 00:23:46,570
u JavaScript u SQL u simili.

531
00:23:46,570 --> 00:23:49,000
>> Iżda għal issa, ejja biss ħarsa
fuq xi ħaġa pjuttost intuwittivi

532
00:23:49,000 --> 00:23:49,930
bħall-Ingliż.

533
00:23:49,930 --> 00:23:52,490
I jista jiddistillaw li
algoritmu li magħhom

534
00:23:52,490 --> 00:23:54,650
Sibt Mike fi skali bħal dan.

535
00:23:54,650 --> 00:23:55,760
>> Aqbad il-ktieb tat-telefon

536
00:23:55,760 --> 00:23:57,121
>> Miftuħa għal nofs ta 'ktieb tat-telefon

537
00:23:57,121 --> 00:23:57,870
Ħares lejn il--isem

538
00:23:57,870 --> 00:23:59,290
Jekk Mike hija fost l-isem

539
00:23:59,290 --> 00:24:00,450
sejħa Mike

540
00:24:00,450 --> 00:24:02,290
Else jekk Smith huwa aktar kmieni fil-ktieb

541
00:24:02,290 --> 00:24:04,540
Miftuħa għall-nofs ta '
in-nofs xellugi tal-ktieb

542
00:24:04,540 --> 00:24:06,244
Inkella mur għal-linja 3

543
00:24:06,244 --> 00:24:07,660
Else jekk Smith huwa aktar tard fil-ktieb

544
00:24:07,660 --> 00:24:09,330
Miftuħa għall-nofs tal-
nofs tal-lemin tal-ktieb

545
00:24:09,330 --> 00:24:09,996
Mur fil-linja tlieta

546
00:24:09,996 --> 00:24:10,720
Else

547
00:24:10,720 --> 00:24:11,500
jieqfu

548
00:24:11,500 --> 00:24:15,360
U hemm ftit karatteristiċi issa
ta 'dan li huma min isemmi.

549
00:24:15,360 --> 00:24:18,370
Allura wieħed, il-linji kollha
Stajt enfasizzat bl-isfar

550
00:24:18,370 --> 00:24:21,430
aħna qed tmur biex tibda sejħa
dikjarazzjonijiet jew funzjonijiet jew proċeduri.

551
00:24:21,430 --> 00:24:24,160
Huma qed biss azzjonijiet do
dan, u ma jkunx hemm

552
00:24:24,160 --> 00:24:26,400
dak kollu li varjabilità ħafna lilha.

553
00:24:26,400 --> 00:24:30,850
>> Pass li jmiss hawn għalkemm, huma dawn
conditions-- jekk, inkella, inkella jekk, inkella.

554
00:24:30,850 --> 00:24:34,020
U dawn huma kundizzjonijiet msejħa, jew
fergħat, u dawn qed punti ta 'deċiżjoni.

555
00:24:34,020 --> 00:24:36,780
U dawn jippermettu magħna biex jagħmlu
xi ħaġa kondizzjonalment.

556
00:24:36,780 --> 00:24:39,650
>> U fil-fatt, ejja tagħti malajr
tħares lejn forsi face-- familjari

557
00:24:39,650 --> 00:24:43,380
aħna ser jsejjaħħlu Bill-- u
eżattament liema dawn il-kundizzjonijiet,

558
00:24:43,380 --> 00:24:45,670
kif dawn jistgħu jintużaw.

559
00:24:45,670 --> 00:24:48,230
>> Bill Gates: Nies jagħmlu
deċiżjonijiet kuljum.

560
00:24:48,230 --> 00:24:51,800
Per eżempju, qabel ma tmur barra int
tip ta jkollhom jekk id-dikjarazzjoni li tgħid,

561
00:24:51,800 --> 00:24:55,650
jekk huwa ix-xita, imbagħad I
bżonn li tikseb ġakketta tiegħi.

562
00:24:55,650 --> 00:25:00,990
>> U l-kompjuters huma aqwa ladarba inti
tiddeċiedi dawk it-tipi ta 'dikjarazzjonijiet

563
00:25:00,990 --> 00:25:06,450
li huma jistgħu b'mod affidabbli tesegwixxi
dawk l-affarijiet fil-veloċità inkredibbli.

564
00:25:06,450 --> 00:25:12,470
U hekk programm tal-kompjuter verament
huwa xi ftit ta 'matematika u xi

565
00:25:12,470 --> 00:25:16,890
jekk id-dikjarazzjonijiet fejn
-deċiżjoni gets magħmula.

566
00:25:16,890 --> 00:25:19,432
>> DAVID Malan: Allura issa ejja tiffoka
fuq lines-- differenti ftit

567
00:25:19,432 --> 00:25:21,140
dawk stajt enfasizzati
bl-isfar hawn.

568
00:25:21,140 --> 00:25:23,890
U jirriżulta li hemm differenti
modi ta 'tesprimi din l-idea.

569
00:25:23,890 --> 00:25:28,550
Imma intuwittivament dak Linji tagħna 8 u 11
li stajt enfasizzat hawn tghidlek

570
00:25:28,550 --> 00:25:29,100
tagħmel?

571
00:25:29,100 --> 00:25:33,081
Iva, mur għal-linja 3, imma dak
imġieba hija li verament jinduċu?

572
00:25:33,081 --> 00:25:35,580
Huwa xi tip ta 'linja jew ċiklu,
u inti tista 'tip ta jarawha.

573
00:25:35,580 --> 00:25:36,079
Dritt?

574
00:25:36,079 --> 00:25:39,710
Jekk fuq il-linja 8, tmur lura għal-linja
3, u allura inti hit linja 8 darb'oħra,

575
00:25:39,710 --> 00:25:42,700
inti tista 'tmur lura għal-linja 3,
lura għal-linja 3, lura għal-linja 3.

576
00:25:42,700 --> 00:25:44,530
Hemm dan it-tip ta 'rota jew loop.

577
00:25:44,530 --> 00:25:47,177
U fil-fatt, li l-indotta fi
linja 11 potenzjalment ukoll.

578
00:25:47,177 --> 00:25:49,260
U dan huwa bażiku
programmazzjoni jinbena kif ukoll.

579
00:25:49,260 --> 00:25:51,593
>> Inti ma tista 'tixtieq li biss
tagħmel xi ħaġa ma 'dikjarazzjoni

580
00:25:51,593 --> 00:25:54,280
jew tagħmel xi ħaġa kondizzjonalment
bil-kundizzjoni jew il-fergħa.

581
00:25:54,280 --> 00:25:56,644
Inti tista 'tixtieq li tagħmel xi ħaġa
ċiklikament bl-linja.

582
00:25:56,644 --> 00:25:59,810
U aħna ser ikollhom xi ħadd ieħor ma 'min
inti tista 'tkun familiar-- aħna ser jsejjaħħlu

583
00:25:59,810 --> 00:26:02,996
Mark-- jispjegaw dan il-kunċett hawn.

584
00:26:02,996 --> 00:26:04,870
MARKA Zuckerberg: Wieħed
Ħaġa li l-kompjuters huma

585
00:26:04,870 --> 00:26:07,460
verament tajba fil hija tirrepeti jikkmanda.

586
00:26:07,460 --> 00:26:09,510
Bħala persuna, youd tikseb
verament bored jekk inti

587
00:26:09,510 --> 00:26:12,310
kellha tagħmel l-istess ħaġa
lottijiet ta 'drabi fil-filliera,

588
00:26:12,310 --> 00:26:16,230
imma kompjuter tista 'tagħmel l-istess ħaġa
miljuni jew saħansitra biljuni ta 'drabi

589
00:26:16,230 --> 00:26:18,930
u mhux niddejjaq u jkunu kapaċi
biex iwettqu dan l verament tajjeb.

590
00:26:18,930 --> 00:26:21,240
>> Għalhekk, per eżempju, jekk I
jridu jixtiequ kulħadd

591
00:26:21,240 --> 00:26:24,450
fuq Facebook għal għeluq sninha
billi jibgħatilhom email,

592
00:26:24,450 --> 00:26:27,037
jista 'jieħu me aktar minn
seklu li attwalment tikteb

593
00:26:27,037 --> 00:26:28,370
kollha ta 'dawk emails lill kulħadd.

594
00:26:28,370 --> 00:26:33,500
Iżda biss bi ftit linji tal-kodiċi, nista '
ikollhom sistema ibgħat email lil kulħadd

595
00:26:33,500 --> 00:26:35,460
fuq Facebook jixtiequ
minnhom għal għeluq sninha.

596
00:26:35,460 --> 00:26:38,330
>> Allura dak hu li linji huma u għaliex
dawn qed siewja u xi ħaġa

597
00:26:38,330 --> 00:26:40,076
li l-kompjuters tista 'tagħmel tajjeb ħafna.

598
00:26:40,076 --> 00:26:43,109
>> DAVID Malan: Ħafna grazzi lill-ħbieb tagħna
fil code.org għal dawk iż-żewġ films.

599
00:26:43,109 --> 00:26:46,150
U l-aħħar ġimgħa biss, inti jista 'jkollok
jidher li Mark Zuckerberg Facebook

600
00:26:46,150 --> 00:26:47,940
stazzjonati din it-tħabbira,
li huwa li huma biss

601
00:26:47,940 --> 00:26:50,398
ikunu għaddew minn importanti
pass importanti għall-ewwel darba.

602
00:26:50,398 --> 00:26:54,320
1 biljun ruħ użat Facebook fi
ġurnata waħda, it-tnejn speċifikament aħħar.

603
00:26:54,320 --> 00:26:58,650
Wieħed minn kull seba 'bnedmin fid-dinja
apparentement logged in Facebook.

604
00:26:58,650 --> 00:27:03,310
>> Ukoll, dan jidher opportunità tajba
li wieħed iħares lura fuq fejn Facebook beda,

605
00:27:03,310 --> 00:27:06,840
u aħna marru permezz tal CS50 stess
Arkivji għaliex Jirriżulta fl-2005,

606
00:27:06,840 --> 00:27:10,020
Mark taw lecture mistieden fil CS50.

607
00:27:10,020 --> 00:27:13,870
Int ser ikollok tara li l-valuri ta 'produzzjoni
ma kinux pjuttost l-istess lura mbagħad

608
00:27:13,870 --> 00:27:16,110
f'termini tat-teknoloġija
disponibbli, u tkun taf ukoll

609
00:27:16,110 --> 00:27:18,310
tara li l-preżenza
ta 'din lecture mistiedna

610
00:27:18,310 --> 00:27:22,470
ma neċessarjament jqajjmu l-interess
tal-ġisem istudenti, predeċessuri tiegħek,

611
00:27:22,470 --> 00:27:24,910
kemm jista 'jkollhom
biss ftit snin wara.

612
00:27:24,910 --> 00:27:27,902
>> Mela ejja tagħti ħarsa
fil Science Center C.

613
00:27:27,902 --> 00:27:29,389

614
00:27:29,389 --> 00:27:31,014
Speaker 2: Jekk jogħġbok jissieħbu miegħi, u jilqgħu.

615
00:27:31,014 --> 00:27:33,374

616
00:27:33,374 --> 00:27:36,577
[Applause]

617
00:27:36,577 --> 00:27:37,410
MARKA Zuckerberg: Yo.

618
00:27:37,410 --> 00:27:37,900
Kull dritt.

619
00:27:37,900 --> 00:27:40,420
Kessaħ dan huwa l-ewwel darba stajt qatt
kellhom iżommu waħda minn dawn l-affarijiet.

620
00:27:40,420 --> 00:27:42,336
Hekk jien biss ser
iwaħħalha verament malajr.

621
00:27:42,336 --> 00:27:54,354

622
00:27:54,354 --> 00:27:54,854
Kull dritt.

623
00:27:54,854 --> 00:27:57,314
inti tista 'tisma dan?

624
00:27:57,314 --> 00:27:58,298
Huwa dan tajba?

625
00:27:58,298 --> 00:28:00,684
Huwa dan amplifikati fil-livelli kollha?

626
00:28:00,684 --> 00:28:01,184
Kull dritt.

627
00:28:01,184 --> 00:28:02,040
Ħelu.

628
00:28:02,040 --> 00:28:06,860
Allura, dan huwa bħal wieħed mill-ewwel żminijiet
Stajt kien li lecture fil-Harvard,

629
00:28:06,860 --> 00:28:08,660
but--

630
00:28:08,660 --> 00:28:12,510
>> DAVID Malan: Allura eventwalment il Xjenza
Center għamlet zoom fl fuq il-vidjo,

631
00:28:12,510 --> 00:28:15,110
iżda mhux qabel jinqabad dan il
silta fejn jitkellem Mark,

632
00:28:15,110 --> 00:28:18,230
li huwa diskuss tiegħu
roommate, Dustin, li

633
00:28:18,230 --> 00:28:20,885
riedu jagħtu daqqa t'id ma 'dan
sit imsejjaħ il Facebook.com

634
00:28:20,885 --> 00:28:24,540
u induna li Mark waslet biex
isemmu l-ipprogrammar languages--

635
00:28:24,540 --> 00:28:27,290
wieħed imsejjaħ Perl, wieħed
sejjaħ PHP-- kif hu jiddiskuti

636
00:28:27,290 --> 00:28:28,840
l-oriġini tal-kontribuzzjoni Dustin tal.

637
00:28:28,840 --> 00:28:31,499

638
00:28:31,499 --> 00:28:33,290
MARKA Zuckerberg: I
bdiet taħdem is-sit

639
00:28:33,290 --> 00:28:37,770
u nediet dan fil
Harvard fi Frar, 2004.

640
00:28:37,770 --> 00:28:39,540
So I raden kważi sentejn ilu issa.

641
00:28:39,540 --> 00:28:42,322
U fi żmien ftit ġimgħat, a
ftit eluf ta 'nies kienu ffirmaw up,

642
00:28:42,322 --> 00:28:45,280
u bdejna jkollna xi emails
minn nies fil-kulleġġi oħra titlob

643
00:28:45,280 --> 00:28:47,520
għalina biex titnieda fl-iskejjel tagħhom.

644
00:28:47,520 --> 00:28:49,455
>> UI kien qed 161 fil-ħin.

645
00:28:49,455 --> 00:28:52,080
So I do not know jekk inti guys taf
-reputazzjoni ta 'dak il-kors,

646
00:28:52,080 --> 00:28:54,402
iżda kien tip ta tqil.

647
00:28:54,402 --> 00:28:57,110
Kien kors verament gost, imma
hija ma leave me ma 'ħafna ħin

648
00:28:57,110 --> 00:28:59,260
biex tagħmel xi ħaġa oħra ma Facebook.

649
00:28:59,260 --> 00:29:04,309
Allura roommate tiegħi Dustin, li I raden
kien biss lest CS50, kien simili, ħej.

650
00:29:04,309 --> 00:29:05,100
Irrid li jgħinu.

651
00:29:05,100 --> 00:29:08,760
Irrid li tagħmel l-espansjoni u tgħin
inti figura kif jagħmlu l-għalf.

652
00:29:08,760 --> 00:29:10,780
>> So I kien simili, dik pjuttost jibred, raġel.

653
00:29:10,780 --> 00:29:13,130
Imma int ma verament jafu ebda
PHP jew xi ħaġa bħal dik.

654
00:29:13,130 --> 00:29:16,444
Allura li weekend huwa marru dar,
xtara l-ktieb Perl għall-manikini,

655
00:29:16,444 --> 00:29:17,860
daħal lura u kien simili, id-dritt.

656
00:29:17,860 --> 00:29:18,940
Jien lest li tmur.

657
00:29:18,940 --> 00:29:23,010
>> I kien simili, raġel, is-sit-miktub
fil-PHP ma Perl, iżda li jibred.

658
00:29:23,010 --> 00:29:28,530
>> Hekk hu qabad PHP fuq
bħal ftit jiem minħabba I

659
00:29:28,530 --> 00:29:30,790
wegħda li jekk għandek
sfond tajba fis-C,

660
00:29:30,790 --> 00:29:32,970
PHP hija ħaġa sempliċi ħafna li pick up.

661
00:29:32,970 --> 00:29:37,480
U hu biss tip ta 'marru għax-xogħol.

662
00:29:37,480 --> 00:29:40,500
>> Qabel ma aħna tagħti ħarsa issa fil
meta l-kors ikun għaddej,

663
00:29:40,500 --> 00:29:43,047
ippermettuli li jistiednu biss ftit
ta 'mhux aktar persunal SC50 dwar għall-istadju.

664
00:29:43,047 --> 00:29:44,880
Xi wħud minnhom huma shopping
korsijiet tagħhom stess.

665
00:29:44,880 --> 00:29:48,390
Imma jekk dawk TFS u CAs u kors
irjus li huma hawn tista 'toħroġ fuq up

666
00:29:48,390 --> 00:29:50,230
u jingħaqdu miegħi għal bonjour malajr.

667
00:29:50,230 --> 00:29:54,670
>> Ippermettuli li jintroduċu b'mod partikolari,
Hanna, Maria, Daven, u Rob,

668
00:29:54,670 --> 00:29:59,666
kors CS50 s kapijiet hawn fil-Cambridge.

669
00:29:59,666 --> 00:30:02,106
>> [Applause]

670
00:30:02,106 --> 00:30:07,490

671
00:30:07,490 --> 00:30:11,060
>> DAVID Malan: Tabilħaqq, xhieda tal-
istruttura ta 'appoġġ li l-kors għandu

672
00:30:11,060 --> 00:30:15,660
mibnija matul l-aħħar bosta snin,
persunal CS50 numri din is-sena kważi 100,

673
00:30:15,660 --> 00:30:17,170
u li l-hawn fil-Cambridge waħdu.

674
00:30:17,170 --> 00:30:21,240
Sadanittant, fi New Haven, hemm xi
40 TFS u l-CAs u membri tal-persunal hemmhekk

675
00:30:21,240 --> 00:30:22,800
biex imexxu l-kors kif ukoll.

676
00:30:22,800 --> 00:30:26,125
>> Inessu jintroduċu ewwel, Rob Bowden.

677
00:30:26,125 --> 00:30:26,750
ROB Bowden: Hi.

678
00:30:26,750 --> 00:30:27,620
Jien Rob.

679
00:30:27,620 --> 00:30:32,750
Dan huwa sitt sena tiegħi
TFing fil-kors.

680
00:30:32,750 --> 00:30:37,970
Allura, it-triq kollha lura fil tiegħi
sena Freshman, jien ma ħaditx CS50.

681
00:30:37,970 --> 00:30:40,270
Freshman tiegħek fall--
inti tista 'tkun familjari

682
00:30:40,270 --> 00:30:43,270
li inti tista 'biss tieħu erba' korsijiet
u hemm tant korsijiet illum.

683
00:30:43,270 --> 00:30:44,450
Hekk jien simili, eh.

684
00:30:44,450 --> 00:30:48,050
I ħa AP CS sena għolja tiegħi ta '
iskola għolja kien horrible.

685
00:30:48,050 --> 00:30:48,900
Allura, jien simili, eh.

686
00:30:48,900 --> 00:30:50,380
xjenza tal-kompjuter mhuwiex għalija.

687
00:30:50,380 --> 00:30:53,000
>> Mela allura kien fuq il-
kors ta freshman tiegħi

688
00:30:53,000 --> 00:30:58,960
jaqgħu, li kelli xi ħabib fil CS50, u
I think I attendew lecture wieħed magħha.

689
00:30:58,960 --> 00:31:03,760
Huwa simili, oh, dan huwa tip ta 'aħjar
minn dak li kelli fl-iskola għolja.

690
00:31:03,760 --> 00:31:06,990
>> U matul il-kors tal-
sena, kelli settijiet tiegħi problematiċi stess

691
00:31:06,990 --> 00:31:08,750
fil-korsijiet I kien attwalment tieħu.

692
00:31:08,750 --> 00:31:11,870
Imma sibt li kull meta I
riedu li procrastinate fuq dawk,

693
00:31:11,870 --> 00:31:15,111
I imur lura għall-CS50 u
ħarsa lejn uħud li Jittieħed.

694
00:31:15,111 --> 00:31:15,610
Allura, yeah.

695
00:31:15,610 --> 00:31:16,140
Jien jibred.

696
00:31:16,140 --> 00:31:19,350
I procrastination ma kodifikazzjoni.

697
00:31:19,350 --> 00:31:22,910
Mela allura huwa fl-aħħar tal
-waqgħa li I realizzata, ħej,

698
00:31:22,910 --> 00:31:24,410
xjenza tal-kompjuter hija pjuttost jibred.

699
00:31:24,410 --> 00:31:27,730
I jispiċċaw jieħdu CS51.

700
00:31:27,730 --> 00:31:30,430
Fil-semestru li jmiss,
I jispiċċaw jieħdu CS61.

701
00:31:30,430 --> 00:31:32,727
U dan kollu minn hemm,
imbagħad I jispiċċaw tiddikjara

702
00:31:32,727 --> 00:31:35,310
xjenza tal-kompjuter, li kelli
assolutament ebda intenzjoni li jagħmlu

703
00:31:35,310 --> 00:31:36,740
meta Wasalt fis-kulleġġ.

704
00:31:36,740 --> 00:31:39,330
U issa jien hawn.

705
00:31:39,330 --> 00:31:42,230
Allura l-kors huwa dak li inti jagħmlu minnha.

706
00:31:42,230 --> 00:31:43,463
Nispera li tieħdu pjaċir dan.

707
00:31:43,463 --> 00:31:44,066
>> [Applause]

708
00:31:44,066 --> 00:31:45,315
DAVID Malan: Grazzi għall Rob.

709
00:31:45,315 --> 00:31:49,020

710
00:31:49,020 --> 00:31:52,180
>> U issa Maria, tagħna
ras assistent kors.

711
00:31:52,180 --> 00:31:53,140
>> MARIA: Hey guys.

712
00:31:53,140 --> 00:31:53,880
Jisimni Maria.

713
00:31:53,880 --> 00:31:56,930
Jien sophomore fil Cabot
Kamra, li ġejjin mill-Bulgarija,

714
00:31:56,930 --> 00:31:59,880
u jien super eċċitati li tkun
parti mill-istaff din is-sena.

715
00:31:59,880 --> 00:32:03,380
I ħa CS50 bħala freshman
aħħar sena, u jien qatt ma

716
00:32:03,380 --> 00:32:04,750
ħsibt dwar KEFA qabel.

717
00:32:04,750 --> 00:32:08,380
So I assolutament imħabba l-kors, u jien
nittamaw li intom kollha imħabba tiegħu kemm għamilt.

718
00:32:08,380 --> 00:32:09,250
U, yeah.

719
00:32:09,250 --> 00:32:10,868
Merħba għall CS50.

720
00:32:10,868 --> 00:32:12,201
DAVID Malan: Grazzi għall Maria.

721
00:32:12,201 --> 00:32:13,674
[Applause]

722
00:32:13,674 --> 00:32:16,129

723
00:32:16,129 --> 00:32:19,580
Issa Hanna, tagħna sħabi tagħlim ras.

724
00:32:19,580 --> 00:32:20,480
HANNA: Hi, jien Hanna.

725
00:32:20,480 --> 00:32:22,990
I'ma anzjan fil Cabot
jistudjaw ix-xjenza tal-kompjuter.

726
00:32:22,990 --> 00:32:28,120
I ħa CS50 bħala freshman u kellhom
Kien TFing-- dan il taf tkun it-tielet sena tiegħi.

727
00:32:28,120 --> 00:32:31,000
So I se jkunu involuti heureusement
fil CS50 għal erba 'snin kollha,

728
00:32:31,000 --> 00:32:33,569
u jien bil-ħerqa
li jaħdmu miegħek kollha.

729
00:32:33,569 --> 00:32:34,902
DAVID Malan: Grazzi għall Hanna.

730
00:32:34,902 --> 00:32:36,870
[Applause]

731
00:32:36,870 --> 00:32:37,854

732
00:32:37,854 --> 00:32:40,274
U fl-aħħar, Daven, precepter tagħna.

733
00:32:40,274 --> 00:32:40,940
DAVEN: Hey guys.

734
00:32:40,940 --> 00:32:42,390
I'ma preċett fuq fil
xjenza tal-kompjuter hawn.

735
00:32:42,390 --> 00:32:44,010
Din il taf tkun ir-raba 'tagħlim tiegħi sena.

736
00:32:44,010 --> 00:32:45,261
I wkoll tgħin jimmaniġġjaw il-kors.

737
00:32:45,261 --> 00:32:47,801
Hekk jien żgur li int ser tara lili madwar,
speċjalment fil ħinijiet tal-uffiċċju.

738
00:32:47,801 --> 00:32:48,970
Jien dejjem fuq ħinijiet tal-uffiċċju.

739
00:32:48,970 --> 00:32:51,640
Mela jekk tara lili mixi
madwar, jiġu definittivament jgħidu hi.

740
00:32:51,640 --> 00:32:52,681
I imħabba biex jilħqu kulħadd.

741
00:32:52,681 --> 00:32:55,830
Inkella, għandhom gost,
u jien ser tara int madwar.

742
00:32:55,830 --> 00:32:58,210
>> DAVID Malan: Grazzi għall Daven ukoll.

743
00:32:58,210 --> 00:33:01,290
Allura inti ser jissodisfa l-
dawn folks qabel fit-tul.

744
00:33:01,290 --> 00:33:03,040
Iżda mingħajr aktar
dewmien, jekk inti guys se

745
00:33:03,040 --> 00:33:05,840
jixtieq li jerġa 'jibda sedili tiegħek mill-ewwel.

746
00:33:05,840 --> 00:33:10,940
Ippermettuli li jintroduċu minn afar issa
xi wħud mill-ħbieb tagħna minn New Haven,

747
00:33:10,940 --> 00:33:14,690
b'mod partikolari kapijiet tal-kors tal-li ser
jiġu jissorveljaw CS50 there-- Professur

748
00:33:14,690 --> 00:33:19,550
Brian Scassellati, Jason, u Andi,
li just-- hekk li aħna ma tentar destin

749
00:33:19,550 --> 00:33:22,610
ma 'kwalunkwe FaceTime jew il like--
għadek mibgħuta lilna minuti

750
00:33:22,610 --> 00:33:27,380
ilu l-filmat ġejja li fih
huma jgħidu bonjour minn lecture hall

751
00:33:27,380 --> 00:33:31,480
fil-Yale, fejn taħdita
qed jiġi streaming dritt issa.

752
00:33:31,480 --> 00:33:34,052
>> Allura ħbieb tagħna mill-Yale.

753
00:33:34,052 --> 00:33:35,260
BRIAN SCASSELLATI: Hi, David.

754
00:33:35,260 --> 00:33:36,480
Hi, kulħadd fil-Harvard.

755
00:33:36,480 --> 00:33:41,400
Aħna hekk eċċitati li tkun jinġiebu
CS50 għal Yale dan is-semestru.

756
00:33:41,400 --> 00:33:45,250
Jisimni Brian Scassellati,
imma kulħadd biss jappella lili SCAS.

757
00:33:45,250 --> 00:33:50,402
U jien hawn illum biex jintroduċu
lilek il-persunal CS50.

758
00:33:50,402 --> 00:33:52,346
>> [Cheering]

759
00:33:52,346 --> 00:33:55,760

760
00:33:55,760 --> 00:33:59,780
>> U aktar importanti, jien
hawn biex jintroduċu ukoll

761
00:33:59,780 --> 00:34:03,690
kollha ta 'l-istudenti fi
Yale li bħala ta 'dalgħodu

762
00:34:03,690 --> 00:34:09,289
għamlu dan l-aktar popolari
Naturalment fil-Yale l-istudenti CS50.

763
00:34:09,289 --> 00:34:12,090
>> [Cheering]

764
00:34:12,090 --> 00:34:25,850

765
00:34:25,850 --> 00:34:28,310
>> Allura aħna qed eċċitati ħafna
li tkun qed tara inti hawn

766
00:34:28,310 --> 00:34:34,239
nhar il-Ġimgħa u s-Sibt għall
Puzzle Jum u jkollhom lecture kbira.

767
00:34:34,239 --> 00:34:35,440
Bye.

768
00:34:35,440 --> 00:34:37,360
>> [Applause]

769
00:34:37,360 --> 00:34:42,170

770
00:34:42,170 --> 00:34:45,497
>> DAVID Malan: Fuq l-iskrin hawnhekk huwa
l-ismijiet ta 'l-uħud mill 140 persunal

771
00:34:45,497 --> 00:34:48,330
membri li tistenna int fuq il-
Matul l-semester-- xi wħud minnhom

772
00:34:48,330 --> 00:34:50,540
hawn fil-Cambridge, xi
minnhom hawn fi New Haven.

773
00:34:50,540 --> 00:34:52,706
U tabilħaqq inti ser ikollhom
opportunità din is-Sibt,

774
00:34:52,706 --> 00:34:54,530
bħala noti SCAS, li
jattendu CS50 Puzzle Jum.

775
00:34:54,530 --> 00:34:57,780
Inti tista raw biċċiet puzzle ftit
niżel taħt bibien tiegħek reċentement.

776
00:34:57,780 --> 00:35:00,420
Għandna ftit ekstras hawn
aktar tard meta inti jeżistu.

777
00:35:00,420 --> 00:35:04,030
Jekk inti tiġbor l-erba puzzle
biċċiet u l-forzi jingħaqdu ma 'kmamar

778
00:35:04,030 --> 00:35:06,450
tiegħek fil-qrib fil tiegħek
dar jew dorm, dawn ser

779
00:35:06,450 --> 00:35:09,690
jimmuntaw fi code-- QR jew
żewġ dimensjonijiet bar code, li

780
00:35:09,690 --> 00:35:12,970
ladarba immuntati u scanned
mal-telefon ċellulari tiegħek inti se twassal

781
00:35:12,970 --> 00:35:17,060
sa ċertu premju fabulous or-- I jissoponi
inti tista 'biss ritratt dan issa

782
00:35:17,060 --> 00:35:17,560
kif ukoll.

783
00:35:17,560 --> 00:35:22,560
>> Iżda issib dawk il-biċċiet puzzle madankollu
sabiex tirbaħ dan il-premju fabulous.

784
00:35:22,560 --> 00:35:25,900
U fil-fatt wieħed mill-tradizzjonijiet
fil SC50-- ah, bil-mod wisq.

785
00:35:25,900 --> 00:35:29,790
Wieħed mill-tradizzjonijiet fil CS50 huwa li
jservu kejk wara l-ewwel lecture.

786
00:35:29,790 --> 00:35:31,620
>> U għalhekk fil-fatt, fil-
ftit minuti minn issa,

787
00:35:31,620 --> 00:35:36,040
se jkun hemm kejk moqdija barra
kemm hawn u New Haven kif ukoll.

788
00:35:36,040 --> 00:35:39,530
>> Iżda first-- aħna imżejjen minnhom nfusna.

789
00:35:39,530 --> 00:35:43,360
Iżda first-- u nisperaw
se jkun hemm biżżejjed.

790
00:35:43,360 --> 00:35:44,830
>> Iżda l-ewwel, ħarsa.

791
00:35:44,830 --> 00:35:47,880
Allura lekċers hija tabilħaqq se jkun
prodotta aktar hawn fl-Cambridge.

792
00:35:47,880 --> 00:35:51,580
Iżda kull xahar, aħna ser ħops isfel sa Yale
mat-tim tal-produzzjoni CS50 u fluss

793
00:35:51,580 --> 00:35:53,730
il-kors fil-reverse
direzzjoni kif ukoll sabiex

794
00:35:53,730 --> 00:35:56,840
li jġib dawn iż-żewġ kampusijiet
verament għall-ewwel darba fl-istorja

795
00:35:56,840 --> 00:36:00,450
qrib flimkien kemm jista 'jkun
kif wieħed fl-istess kors.

796
00:36:00,450 --> 00:36:04,050
>> F'termini ta 'l-istruttura ta' appoġġ li l-
ġew saqajh hawn fil-Cambridge kif ukoll

797
00:36:04,050 --> 00:36:05,646
kif fi New Haven, huma taqsimiet.

798
00:36:05,646 --> 00:36:08,020
Fil-fatt, kif xi wħud minnkom tista
jafu, aħna għandna binarji differenti

799
00:36:08,020 --> 00:36:10,850
il-partijiet tul għal dawk inqas
komdu, aktar komda,

800
00:36:10,850 --> 00:36:14,610
u x'imkien bejniethom b'tali mod li
irrispettivament mill-isfond qabel tiegħek,

801
00:36:14,610 --> 00:36:17,670
inti tista 'finalment tirnexxi fil-klassi.

802
00:36:17,670 --> 00:36:21,320
>> ħinijiet tal-uffiċċju sadanittant, huma
opportunità nhar ta 'Tnejn u t-Tlieta

803
00:36:21,320 --> 00:36:26,570
u Ħamis filgħaxija ta 'xogħol kemm
hawn u fi New Haven fuq kors ta 'tagħna

804
00:36:26,570 --> 00:36:30,370
problema settijiet ma 'għexieren ta
persunal tal-kors ta ħdejk.

805
00:36:30,370 --> 00:36:35,380
>> Problema settijiet sadanittant, huma
sostnuta minn affarijiet nitolbu

806
00:36:35,380 --> 00:36:39,140
walkthroughs, li huma bbażati vidjo
tutorials li verament twieġeb FAQ

807
00:36:39,140 --> 00:36:41,670
ta 'fejn tibda l-isfida ta' ġimgħa.

808
00:36:41,670 --> 00:36:44,290
U postmortems jimxu miegħek
permezz ta 'soluzzjonijiet possibbli

809
00:36:44,290 --> 00:36:46,490
sabiex it-tarf tal-
problema sett wisq, inti

810
00:36:46,490 --> 00:36:50,820
jafu eżattament dak li għandek seta 'jsir
differenti jew għal kollox mod ieħor.

811
00:36:50,820 --> 00:36:53,895
>> Il-problema settijiet infushom jidħlu
f'żewġ edizzjonijiet, edizzjoni standard

812
00:36:53,895 --> 00:36:57,510
li nistennew u jistiednu aktar ta '
il class-- madwar 90%, kif ukoll lin do--

813
00:36:57,510 --> 00:37:00,520
u l-hekk imsejjaħ edizzjoni Hacker
li fuqha kull paġna huwa emblazoned

814
00:37:00,520 --> 00:37:02,790
Edizzjoni Hacker, Hacker
edizzjoni, edizzjoni Hacker,

815
00:37:02,790 --> 00:37:07,550
sabiex ikollok dak karma
jekk inti se, għall-għadis

816
00:37:07,550 --> 00:37:10,230
fis-verżjonijiet aktar avvanzati
ta 'settijiet problema tal-kors tal-

817
00:37:10,230 --> 00:37:14,970
dik il-kopertura apparentement l-istess materjal
iżda ma 'approċċ aktar sofistikat

818
00:37:14,970 --> 00:37:19,020
u bi sfond addizzjonali
kultant introdotti.

819
00:37:19,020 --> 00:37:22,350
>> Sadanittant, hemm disat ijiem tard li
inti tista 'tapplika għall-problema tal-kors tal-

820
00:37:22,350 --> 00:37:26,160
settijiet kif ukoll l-punteġġ aktar baxx,
li aħna qatra fl-aħħar termini.

821
00:37:26,160 --> 00:37:26,900
>> Imma dak li jistenna?

822
00:37:26,900 --> 00:37:29,300
Ukoll, togħma tal-problema
settijiet fil-idejn fuq il-ġimgħa

823
00:37:29,300 --> 00:37:31,959
u ġimgħa d-dieħla fejn aħna dabble
għal ftit jiem fil xi ħaġa

824
00:37:31,959 --> 00:37:35,000
imsejħa Scratch, programmar grafika
lingwa żviluppati mill-ħbieb tagħna

825
00:37:35,000 --> 00:37:39,290
fil Media Lab MIT li jippermetti li inti
għall-programm jew għall-ewwel darba

826
00:37:39,290 --> 00:37:43,510
jew f'ambjent ġdid għal kollox
bl-użu drag u qatra l-ambjent tat-tip.

827
00:37:43,510 --> 00:37:45,595
Li biha biċċiet puzzle
biss jorbtu ma 'xulxin flimkien

828
00:37:45,595 --> 00:37:48,080
jekk jagħmel sens loġiku li jagħmlu dan.

829
00:37:48,080 --> 00:37:50,440
>> Sadanittant fil-problema stabbilita
tnejn sena li għaddiet per eżempju,

830
00:37:50,440 --> 00:37:53,010
ma aħna nintroduċu l-klassi
għad-dinja ta 'kriptografija,

831
00:37:53,010 --> 00:37:55,370
l-arti tal encrypting jew
scrambling informazzjoni.

832
00:37:55,370 --> 00:37:58,940
Tabilħaqq, dan it-test hawn jekk
decrypted, fil-fatt se

833
00:37:58,940 --> 00:38:01,277
twassal biex inti xi destinazzjoni gost.

834
00:38:01,277 --> 00:38:03,110
U fil-problema stabbiliti,
dak li kellna istudenti

835
00:38:03,110 --> 00:38:06,280
tagħmel hu implimentat eżattament dawk
tipi ta things-- algoritmu,

836
00:38:06,280 --> 00:38:09,530
jew sett ta 'struzzjonijiet għall scrambling
u scrambling informazzjoni.

837
00:38:09,530 --> 00:38:11,850
>> U fl-edizzjoni Hacker
ta 'dik l-istess sett problema,

838
00:38:11,850 --> 00:38:15,800
ma aħna isfida istudenti biex jieħdu
fajl encrypted minn kompjuter tipiku

839
00:38:15,800 --> 00:38:18,840
sistema ma 'lottijiet ta usernames
u l-passwords encrypted

840
00:38:18,840 --> 00:38:21,400
u biex jitwaqqaf dawk passwords--
attwalment figura

841
00:38:21,400 --> 00:38:25,870
dak li kienu bla ma jkunu jafu xejn
a priori dwar dawk passwords attwali.

842
00:38:25,870 --> 00:38:27,620
Sadanittant, nistgħu
transizzjoni fil-problema

843
00:38:27,620 --> 00:38:29,536
settijiet imbagħad tħares lejn
-dinja tal-grafika.

844
00:38:29,536 --> 00:38:32,240
U fil-fatt, inti tista 'timmaġina
issa li dan jista forsi

845
00:38:32,240 --> 00:38:35,200
jkun l-eħfef mod biex jirrappreżentaw
immaġni iswed u abjad.

846
00:38:35,200 --> 00:38:39,570
>> A pixel abjad, jew kwadra,
kif fil-quċċata hemm dritt,

847
00:38:39,570 --> 00:38:41,620
jista 'jiġi rappreżentat bil
ta '1 u kwadru iswed

848
00:38:41,620 --> 00:38:43,490
jista 'jiġi rappreżentat bi 0.

849
00:38:43,490 --> 00:38:47,670
U biss bl-użu aktar bits simili aħna
proposti aktar kmieni bi 72 u 73 u 33,

850
00:38:47,670 --> 00:38:49,882
nistgħu jirrappreżentaw pixels kulur kif ukoll.

851
00:38:49,882 --> 00:38:51,590
U dak li nagħmlu matul
din il-problema sett

852
00:38:51,590 --> 00:38:54,660
ġeneralment tieħu stroll madwar
kampus bil-kamera diġitali,

853
00:38:54,660 --> 00:38:56,730
jieħdu ritratti ta '
nies, postijiet, u affarijiet.

854
00:38:56,730 --> 00:38:59,270
Imbagħad b'xi kull semestru,
aħna jidhru li aċċidentalment

855
00:38:59,270 --> 00:39:02,600
mħassra jew korrotti il-karta tal-memorja
fuqhom kollha ta 'dawk ritratti huma,

856
00:39:02,600 --> 00:39:04,610
u għalhekk inti huma kkontestati
biex imbagħad jiktbu softwer

857
00:39:04,610 --> 00:39:09,650
li biex jirkupraw dawk JPEGs
minn kopja tal-karta tagħna kamera.

858
00:39:09,650 --> 00:39:13,550
>> Sadanittant, nistgħu idejn inti aktar tard fil
it-terminu dizzjunarju ta 'kliem Ingliż

859
00:39:13,550 --> 00:39:16,680
li għandhom 143,000 kelma,
u inti għandek bżonn biex toħroġ

860
00:39:16,680 --> 00:39:19,240
bil-mod intelliġenti ta '
tagħbija tagħhom fil-memorja,

861
00:39:19,240 --> 00:39:22,850
jew muntun biex ngħidu hekk, li tingħata risposta
mistoqsijiet tal-formola: huwa dan kelma,

862
00:39:22,850 --> 00:39:25,910
hija din kelma, li timplimenta l-
mgħaġġla jespliċitaw li inti tista ',

863
00:39:25,910 --> 00:39:28,180
anki pinning yourself
potenzjalment kontra klassi

864
00:39:28,180 --> 00:39:30,460
biex tara liema mill inti tuża
l-inqas ammont ta 'ħin

865
00:39:30,460 --> 00:39:33,440
waqt il-ġiri kodiċi tiegħek u anke
-inqas ammont ta 'memorja.

866
00:39:33,440 --> 00:39:36,060
>> Aktar tard fit-terminu do inti fil-fatt
jimplimentaw web server tiegħek stess.

867
00:39:36,060 --> 00:39:39,470
Allura mhux biss ta 'websajt fil-
lingwa imsejħa HTML u aktar,

868
00:39:39,470 --> 00:39:43,300
imma web server li attwalment
jisma 'talbiet fuq l-internet

869
00:39:43,300 --> 00:39:44,460
u jirrispondi għalihom.

870
00:39:44,460 --> 00:39:47,210
U fil-fatt, dan huwa kif aħna pont
dinja tagħna ta 'C li magħhom inti taf

871
00:39:47,210 --> 00:39:50,550
isiru ġimgħa d-dieħla familjari u
PHP u HTML u JavaScript

872
00:39:50,550 --> 00:39:51,820
u CSS u simili.

873
00:39:51,820 --> 00:39:54,820
>> Għaliex wieħed mill-ewwel web ibbażat
Proġett nagħmlu aktar tard fit-terminu

874
00:39:54,820 --> 00:39:57,516
huwa storikament CS50 Finanzi.

875
00:39:57,516 --> 00:40:02,580
Etrade.com stil websajt li tippermetti
sabiex tixtri u tbiegħ il-ħażniet virtwalment

876
00:40:02,580 --> 00:40:08,240
waqt miktub wkoll kodiċi li tkellem lit-Yahoo
Finanzi jkollna semi-istokk ħin reali

877
00:40:08,240 --> 00:40:11,490
kwotazzjonijiet sabiex tiġi aġġornata
portafoll tiegħek stess.

878
00:40:11,490 --> 00:40:13,370
>> Iżda fl-aħħar nett naturalment,
huwa l-project-- finali

879
00:40:13,370 --> 00:40:16,960
opportunità li tagħmel xejn aktar mill
interess għalik biex issolvi problema hawn

880
00:40:16,960 --> 00:40:20,970
jew lil hinn ta 'interess għall
inti thats b'xi ispirati

881
00:40:20,970 --> 00:40:22,670
billi l-lezzjonijiet mitgħallma fil-klassi.

882
00:40:22,670 --> 00:40:26,140
>> U l-klassi, kif inti tista 'taf,
qofol tagħha fil-hekk imsejħa CS50 Hackathon

883
00:40:26,140 --> 00:40:29,330
u CS50 Ġust u kull numru
ta 'avvenimenti kulturali oħra

884
00:40:29,330 --> 00:40:31,770
matul il-semestru
li jippermettu li inti tidħol

885
00:40:31,770 --> 00:40:33,460
ma 'xulxin u l-persunal tal-kors tal.

886
00:40:33,460 --> 00:40:37,170
>> Per eżempju, fil-nar u Silġ fil Sitar
din is-sena, ukoll, fuq wara nofsinhar il-ġimgħa,

887
00:40:37,170 --> 00:40:39,220
nistiednu xi 50
studenti għall-ikla, min

888
00:40:39,220 --> 00:40:41,190
jixtieq li jingħaqdu magħna,
nnifsi, u l-persunal,

889
00:40:41,190 --> 00:40:44,840
u l-ħbieb tagħna mill-industrija u alumi
li chat dwar il-ħajja fid-dinja reali

890
00:40:44,840 --> 00:40:46,670
u lil hinn filwaqt li tgawdi ikla tajba.

891
00:40:46,670 --> 00:40:49,050
Fil-Hackathon se
tara dawn ix-xbiehat

892
00:40:49,050 --> 00:40:53,740
billi dawn, inkluż ħafna ta candy--
u mill-2014 għall-ewwel time--

893
00:40:53,740 --> 00:40:55,096
ħxejjex.

894
00:40:55,096 --> 00:40:56,960
>> [Applause]

895
00:40:56,960 --> 00:40:58,358

896
00:40:58,358 --> 00:41:02,710
>> Iżda billi 05:00, ma l-xena normalment
tfittex xi ħaġa ftit bħal din.

897
00:41:02,710 --> 00:41:05,330
U mbagħad biss fil-ġimgħa jew
hekk aktar tard, huwa l-Fiera CS50

898
00:41:05,330 --> 00:41:08,270
li xi plus 2000
istudenti u l-istaff u l-fakultà

899
00:41:08,270 --> 00:41:11,910
membri minn madwar il-kampus
u madwar kampus din is-sena

900
00:41:11,910 --> 00:41:15,620
ġejjin biex tara u delight fil-
kisbiet ta 'studenti CS50, li

901
00:41:15,620 --> 00:41:16,140
issa huwa inti.

902
00:41:16,140 --> 00:41:19,000
>> U fil-fatt, filwaqt li din is-sena aħna ser
ikunu tistieden u busing ħadd

903
00:41:19,000 --> 00:41:22,460
fil fil-Yale li jixtiequ li toħroġ
Cambridge din is-Sibt għal Puzzle CS50

904
00:41:22,460 --> 00:41:26,410
Jum, u aħna ser nagħmlu l-istess ħaġa eżatt
f'Diċembru għas-Hackathon CS50

905
00:41:26,410 --> 00:41:30,080
sabiex il-Harvard u Yale istudenti
ikollhom sehem bl-istess mod fiż-żewġ ta 'dawn l-avvenimenti.

906
00:41:30,080 --> 00:41:33,630
>> Aħna se torganizza wkoll fieri CS50 fil
Cambridge u fi New Haven din is-sena

907
00:41:33,630 --> 00:41:36,480
sabiex l-istudenti fuq iż-żewġ
kampus u l-istaff u l-fakultà

908
00:41:36,480 --> 00:41:39,260
jistgħu jaraw lil rispettiv
tlestija kampus s.

909
00:41:39,260 --> 00:41:41,540
U dawk kisbiet
se jinduċu tali memorja

910
00:41:41,540 --> 00:41:45,440
billi dan u dan u finalment
dan, fejn lilkom kollha

911
00:41:45,440 --> 00:41:48,460
joħorġu mis-klassi liebes ftit
xi ħaġa li inti kienu nisperaw

912
00:41:48,460 --> 00:41:52,680
kuntenti jew kburi ngħid li jien ħa CS50.

913
00:41:52,680 --> 00:41:55,220
>> Iżda qabel dan u
qabel naqdu kejk,

914
00:41:55,220 --> 00:41:58,980
konna jitqiegħdu together-- grazzi għall CS50 s
tim tal-produzzjoni u ċertu awto

915
00:41:58,980 --> 00:42:03,120
stick,-okkażjoni waħda li nużaw
affarijiet bħal dawn for-- meta aħna mibgħuta lilha

916
00:42:03,120 --> 00:42:05,380
mhux biss hawn biex Cambridge
iżda wkoll lejn New Haven

917
00:42:05,380 --> 00:42:08,760
biex tiġbor xi hellos ftit mill-
persunal kors u kollha ta 'l-folks

918
00:42:08,760 --> 00:42:12,640
inti se jiltaqa kemm hawn u fi New
Haven matul ix-xhur li ġejjin.

919
00:42:12,640 --> 00:42:15,449
>> Ippermettuli li jintroduċu
ftit aktar tal-persunal CS50 s.

920
00:42:15,449 --> 00:42:16,990
MARKA Zuckerberg: Did li jagħmluha go?

921
00:42:16,990 --> 00:42:18,266
Oh, li għaddej.

922
00:42:18,266 --> 00:42:20,910
Li għaddej.

923
00:42:20,910 --> 00:42:21,570
Ooh.

924
00:42:21,570 --> 00:42:23,170
Yarr!

925
00:42:23,170 --> 00:42:25,350
>> [Daqq tal-mużika Andy Grammatika, "GĦASEL, I'M
 TAJBA "]

926
00:42:25,350 --> 00:42:29,672

927
00:42:29,672 --> 00:42:32,152
>> MARY: Dan huwa Caitlin.

928
00:42:32,152 --> 00:42:34,515
C'est Jay, u jien Marija.

929
00:42:34,515 --> 00:42:35,140
Sato: Hi, guys.

930
00:42:35,140 --> 00:42:35,640
Jien Sato.

931
00:42:35,640 --> 00:42:36,264
MICHAEL G .: Hi.

932
00:42:36,264 --> 00:42:37,181
Jisimni Michael, G.

933
00:42:37,181 --> 00:42:38,014
Doug LLOYD: jien ma.

934
00:42:38,014 --> 00:42:38,540
No

935
00:42:38,540 --> 00:42:39,310
Jien Doug Lloyd.

936
00:42:39,310 --> 00:42:41,757
Ma nistax nemmen li jien azjenda
a selfie stick dritt issa.

937
00:42:41,757 --> 00:42:42,340
Speaker 4: Hi.

938
00:42:42,340 --> 00:42:42,560
Speaker 5: Hi.

939
00:42:42,560 --> 00:42:43,307
Speaker 6: Hello.

940
00:42:43,307 --> 00:42:44,023
Speaker 7: Hi.

941
00:42:44,023 --> 00:42:44,648
Speaker 8: Hey.

942
00:42:44,648 --> 00:42:46,436
Aħna mdendlin fil-Yale.

943
00:42:46,436 --> 00:42:48,910
Aħna verament eċċitati għall
dan is-semestru għaliex dan huwa

944
00:42:48,910 --> 00:42:50,840
l-ewwel darba huwa ġejjin li Yale.

945
00:42:50,840 --> 00:42:53,012
Huwa ser tkun biża '!

946
00:42:53,012 --> 00:42:55,928
>> [Ddoqq il-mużika]

947
00:42:55,928 --> 00:43:02,190

948
00:43:02,190 --> 00:43:04,664
>> JACOB SCHERBA: Jisimni Jacob Scherba.

949
00:43:04,664 --> 00:43:08,310
Jien eċċitati biex jgħallmu
CS50 għaliex naħseb

950
00:43:08,310 --> 00:43:11,429
iġġib xjenza tal-kompjuter li
nies fi u mod imminenti.

951
00:43:11,429 --> 00:43:13,220
Speaker 9: Ninsab verament
eċċitati biex jgħallmu CS50

952
00:43:13,220 --> 00:43:17,717
minħabba I ħa l-klassi tas-sena,
u huwa wieħed mill-aħjar klassijiet.

953
00:43:17,717 --> 00:43:18,425
Speaker 10: Yeah.

954
00:43:18,425 --> 00:43:20,476
Parir tiegħi huwa li għandek tieħu CS50.

955
00:43:20,476 --> 00:43:23,350
JACOB SCHERBA: I għażlet CS għaliex
Naħseb li huwa gost u kreattivi mod

956
00:43:23,350 --> 00:43:25,314
sabiex isolvu problemi li jsiru b'mod li analitiku.

957
00:43:25,314 --> 00:43:28,480
Speaker 11: Back I meta kien ftit
freshman u jibża 'xjenza tal-kompjuter

958
00:43:28,480 --> 00:43:30,229
u jibżgħu li jagħmlu
inġinerija u għalf,

959
00:43:30,229 --> 00:43:34,091
kien l-ewwel klassi iebes I ħa,
u kien ukoll klassi favorit tiegħi qatt.

960
00:43:34,091 --> 00:43:36,090
Doug LLOYD: Dan huwa tiegħi
disa 'CS50 tagħlim sena.

961
00:43:36,090 --> 00:43:37,482
Li jagħmel me ħoss tant qodma!

962
00:43:37,482 --> 00:43:38,690
Dejjem hemm xi ħaġa ġdida.

963
00:43:38,690 --> 00:43:39,550
Dejjem hemm xi ħaġa eċċitanti.

964
00:43:39,550 --> 00:43:43,077
Dejjem hemm sfidi ġodda li jiffaċċjaw il-
studenti ġodda, u huwa gost biex jgħinuhom

965
00:43:43,077 --> 00:43:44,910
u li l-esperjenza dawk
isfidi magħhom

966
00:43:44,910 --> 00:43:45,925
u jgħinhom isolvu l-problemi tagħhom.

967
00:43:45,925 --> 00:43:47,955
>> Speaker 12: Meta I-ewwel
tgħallmu kif jagħmlu CS,

968
00:43:47,955 --> 00:43:49,413
kien simili tagħlim ta 'l-enerġija super.

969
00:43:49,413 --> 00:43:53,749
U biex tara li fl-istudenti l-oħra
u biex tgħinhom permezz ta 'dak il-proċess

970
00:43:53,749 --> 00:43:55,665
hija waħda mill-aktar
affarijiet ppremjati stajt qatt.

971
00:43:55,665 --> 00:43:58,706
>> Speaker 7: I għażlet CS għaliex fil-
bidu, I kien konċentratur matematika

972
00:43:58,706 --> 00:44:00,497
u I ħa CS50 u
waqa 'fl-imħabba miegħu.

973
00:44:00,497 --> 00:44:02,455
I wkoll ħassew li ma
CS, I jista 'jibni affarijiet.

974
00:44:02,455 --> 00:44:04,410
U li, ħsibt, kien
aspett verament jibred.

975
00:44:04,410 --> 00:44:08,156
>> Speaker 13: Xi pariri għal prodotti ġodda
-istudenti hu li tmur ħinijiet tal-uffiċċju

976
00:44:08,156 --> 00:44:09,573
u hang out ma 'l-TFS biża.

977
00:44:09,573 --> 00:44:11,906
Speaker 14: Ibda tiegħek P-settijiet
kmieni, mur ħinijiet tal-uffiċċju,

978
00:44:11,906 --> 00:44:13,457
jsiru frends ma TF tiegħek.

979
00:44:13,457 --> 00:44:14,165
Speaker 15: Yeah.

980
00:44:14,165 --> 00:44:16,164
Kollox qalet.

981
00:44:16,164 --> 00:44:17,997
Speaker 16: Ma jkun
jibżgħux jistaqsu għall-għajnuna.

982
00:44:17,997 --> 00:44:18,980
Speaker 17: Yeah.

983
00:44:18,980 --> 00:44:22,052
Speaker 18: Ibda tiegħek P-settijiet kmieni.

984
00:44:22,052 --> 00:44:23,760
Speaker 19: Huwa
esperjenza soċjali kbar.

985
00:44:23,760 --> 00:44:25,112
Agħmel ħafna ħbieb b'dan il-mod.

986
00:44:25,112 --> 00:44:26,570
Speaker 14: Mur taqsima Hu gost.

987
00:44:26,570 --> 00:44:28,050
Speaker 11: I mean, tmurx għaliha.

988
00:44:28,050 --> 00:44:28,770
Huwa tassew diffiċli.

989
00:44:28,770 --> 00:44:30,581
Int ser toħroġ minnha
dak li inti tpoġġi fis dan,

990
00:44:30,581 --> 00:44:32,580
imma hija verament gost
klassi speċjalment jekk int

991
00:44:32,580 --> 00:44:35,496
lesti li jqiegħdu l-ħin fis dan, iżda
dan jgħin jekk inti tpoġġi ħin fis dan.

992
00:44:35,496 --> 00:44:38,336
Int ser tingħata ħafna aktar
barra minnha aktar tard.

993
00:44:38,336 --> 00:44:38,960
MIKE: Jien Mike.

994
00:44:38,960 --> 00:44:39,882
Camille: Ninsab Camille.

995
00:44:39,882 --> 00:44:40,590
HANYA: Ninsab Hanya.

996
00:44:40,590 --> 00:44:41,310
MATT: Ninsab Matt.

997
00:44:41,310 --> 00:44:42,140
PETER: I am Peter.

998
00:44:42,140 --> 00:44:42,620
PHILLIP: Ninsab Phillip.

999
00:44:42,620 --> 00:44:43,495
PATRICK: Ninsab Patrick.

1000
00:44:43,495 --> 00:44:45,234
ROB Bowden: Ninsab Rob Bowden.

1001
00:44:45,234 --> 00:44:47,150
BRIAN SCASSELLATI: My
isem huwa SCAS, u this--

1002
00:44:47,150 --> 00:44:49,958
KOLLHA: --is CS50.

1003
00:44:49,958 --> 00:44:50,806
Speaker 20: Fl Yale.

1004
00:44:50,806 --> 00:44:51,639
Speaker 21: Fl Yale.

1005
00:44:51,639 --> 00:44:52,840
[Laughing]

1006
00:44:52,840 --> 00:44:54,270
DAVID Malan: Li lilha għall CS50.

1007
00:44:54,270 --> 00:44:59,000
Aħna se tara int mill-Yale fuq
Ġimgħa, Puzzle Jum nhar is-Sibt.

1008
00:44:59,000 --> 00:45:00,475
Kejk issa hija servuta.

1009
00:45:00,475 --> 00:45:01,640
Dan huwa CS50.

1010
00:45:01,640 --> 00:45:05,314

1011
00:45:05,314 --> 00:45:10,992
>> [Ddoqq il-mużika]

1012
00:45:10,992 --> 00:47:00,434