1
00:00:00,000 --> 00:00:00,980

2
00:00:00,980 --> 00:00:04,410
>> [MUSIC KUCHEZA]

3
00:00:04,410 --> 00:00:11,147

4
00:00:11,147 --> 00:00:12,230
DAVID J. Malan: All wa kulia.

5
00:00:12,230 --> 00:00:16,440
Hii ni CS50, na hii
ni mwisho wa Wiki 2.

6
00:00:16,440 --> 00:00:18,480
Kwa hiyo leo, tunakwenda
kuendelea kuangalia yetu

7
00:00:18,480 --> 00:00:21,150
jinsi sisi kuwakilisha mambo
chini ya hood-- kusonga mbali

8
00:00:21,150 --> 00:00:23,520
kutoka namba kama integers
na yaliyo maadili uhakika

9
00:00:23,520 --> 00:00:26,810
na kuelekeza nguvu juu ya masharti na
mipango hatimaye kuvutia zaidi.

10
00:00:26,810 --> 00:00:30,140
Lakini tutaweza pia kuangalia
michache ya domain maalum problems--

11
00:00:30,140 --> 00:00:33,620
ya kwanza ambayo itakuwa
kuwa kuwashirikisha cryptography,

12
00:00:33,620 --> 00:00:36,570
sanaa ya scrambling habari,
katika ambayo unaweza kuona hapo juu hapa

13
00:00:36,570 --> 00:00:41,480
ni picha ya Radio Yatima Annie ya
siri avkodare pete kutoka yesteryear.

14
00:00:41,480 --> 00:00:46,490
>> Hii ni kweli aina primitive sana
na aina ya cryptopgraphy mtoto ya kirafiki

15
00:00:46,490 --> 00:00:50,590
ambapo pete hii ina disks-- mbili
ndani ya moja na moja nje.

16
00:00:50,590 --> 00:00:54,740
Na kwa kupokezana mmoja wa wale, unaweza
kimsingi kujipanga barua kama A

17
00:00:54,740 --> 00:00:59,520
kupitia Z na barua nyingine
kama B kupitia A. Kwa maneno mengine,

18
00:00:59,520 --> 00:01:03,730
unaweza literally mzunguko alfabeti,
hivyo kuja juu na ramani kutoka

19
00:01:03,730 --> 00:01:07,820
barua kwa barua ili, kama wewe
alitaka kutuma ujumbe wa siri

20
00:01:07,820 --> 00:01:11,820
kwa mtu kama Annie, unaweza kuandika
chini ujumbe wako na kisha mzunguko

21
00:01:11,820 --> 00:01:15,370
barua, ambapo, kama wewe maana
kusema "A," wewe badala kusema "B,"

22
00:01:15,370 --> 00:01:17,280
wewe maana ya kusema "B,"
wewe badala kusema "C" -

23
00:01:17,280 --> 00:01:20,240
au kitu wajanja kidogo zaidi
kuliko that-- na kisha, hatimaye,

24
00:01:20,240 --> 00:01:24,630
hivyo muda mrefu kama Annie ina avkodare hii
pete, yeye unaweza Decode ujumbe.

25
00:01:24,630 --> 00:01:28,540
Sasa, unaweza kukumbuka, kwa kweli, kwamba hii
ilitumika katika filamu maarufu sana kwamba

26
00:01:28,540 --> 00:01:31,140
ina ad nauseum wakati wa
Msimu wa Krismasi.

27
00:01:31,140 --> 00:01:32,650
Hebu tuangalie hapa.

28
00:01:32,650 --> 00:01:35,294

29
00:01:35,294 --> 00:01:37,210
RALPHIE PARKER: "Kuwa ni
unaojulikana kwa wote kwa muhtasari

30
00:01:37,210 --> 00:01:41,000
kwamba Ralph Parker ni hili maalumu
mwanachama wa Little Yatima Annie Secret

31
00:01:41,000 --> 00:01:44,860
Circle na ni haki ya kila
heshima na faida zinazotokea lazimishwa. "

32
00:01:44,860 --> 00:01:47,410
>> RALPHIE PARKER (akisimulia):
Saini Little Yatima Annie.

33
00:01:47,410 --> 00:01:50,070
Countersigned, Pierre Andre!

34
00:01:50,070 --> 00:01:51,490
Katika wino.

35
00:01:51,490 --> 00:01:55,494
Heshima na faida,
tayari katika umri wa miaka tisa.

36
00:01:55,494 --> 00:01:57,402
>> [MUSIC KUCHEZA]

37
00:01:57,402 --> 00:02:00,470
>> [RADIO chatter]

38
00:02:00,470 --> 00:02:01,470
RALPHIE PARKER: hebu njoo.

39
00:02:01,470 --> 00:02:02,344
Hebu kupata tarehe na hayo.

40
00:02:02,344 --> 00:02:06,029
Mimi hawana haja ya jazz kwamba wote
kuhusu smugglers na maharamia.

41
00:02:06,029 --> 00:02:08,820
RADIO ANNOUNCER: Sikiliza kesho
usiku kwa adventure kuhitimisha

42
00:02:08,820 --> 00:02:11,060
ya Black Pirate meli.

43
00:02:11,060 --> 00:02:14,740
Sasa, ni wakati kwa Annie ya
Ujumbe siri kwa ajili yenu wanachama

44
00:02:14,740 --> 00:02:17,110
ya Circle Secret.

45
00:02:17,110 --> 00:02:20,700
Kumbuka watoto, wanachama tu
Annie ya siri ya Circle

46
00:02:20,700 --> 00:02:23,270
unaweza Decode Annie ya siri ujumbe.

47
00:02:23,270 --> 00:02:27,270
>> Kumbuka, Annie ni kutegemea wewe.

48
00:02:27,270 --> 00:02:30,060
Kuweka pini yako kwa B-2.

49
00:02:30,060 --> 00:02:34,004
Hapa ni message-- 12, 11, 2--

50
00:02:34,004 --> 00:02:36,503
RALPHIE PARKER (akisimulia): I
ni katika wangu siri mkutano wa kwanza.

51
00:02:36,503 --> 00:02:40,041
RADIO ANNOUNCER: --25, 14, 11, 18, 16--

52
00:02:40,041 --> 00:02:42,790
RALPHIE PARKER (akisimulia): Oh,
Pierre mara kwa sauti kubwa usiku wa leo.

53
00:02:42,790 --> 00:02:46,110
Mimi nilikuwa naona kuwa usiku wa leo
ujumbe ulikuwa kweli ni muhimu.

54
00:02:46,110 --> 00:02:47,930
>> RADIO ANNOUNCER: --3, 25.

55
00:02:47,930 --> 00:02:49,940
Hiyo ni ujumbe kutoka Annie mwenyewe.

56
00:02:49,940 --> 00:02:52,182
Kumbuka, usimwambie mtu yeyote.

57
00:02:52,182 --> 00:02:55,077
>> [Panting]

58
00:02:55,077 --> 00:02:57,285
RALPHIE PARKER (akisimulia):
Sekunde tisini baadaye, mimi nina

59
00:02:57,285 --> 00:03:00,090
katika chumba tu katika
nyumba ambapo kijana wa tisa

60
00:03:00,090 --> 00:03:04,380
wanaweza kukaa katika faragha na Decode.

61
00:03:04,380 --> 00:03:04,990
Ah.

62
00:03:04,990 --> 00:03:05,680
"B."

63
00:03:05,680 --> 00:03:06,524
>> [Chuckles]

64
00:03:06,524 --> 00:03:08,684
>> RALPHIE PARKER (akisimulia):
Nilikwenda ijayo.

65
00:03:08,684 --> 00:03:09,610
"E."

66
00:03:09,610 --> 00:03:11,641
neno la kwanza ni "kuwa."

67
00:03:11,641 --> 00:03:12,140
Ndiyo!

68
00:03:12,140 --> 00:03:14,293
Ni alikuwa anakuja rahisi sasa.

69
00:03:14,293 --> 00:03:15,259
"U."

70
00:03:15,259 --> 00:03:16,225
>> [Chuckles]

71
00:03:16,225 --> 00:03:18,157
>> RANDY PARKER: Aw, kuja juu, Ralphie.

72
00:03:18,157 --> 00:03:19,606
I gotta go!

73
00:03:19,606 --> 00:03:21,538
>> RALPHIE PARKER: Mimi itabidi kuwa na haki chini, Ma.

74
00:03:21,538 --> 00:03:22,504
Gee whiz.

75
00:03:22,504 --> 00:03:25,402

76
00:03:25,402 --> 00:03:31,220
"T." "O." "Kuwa na uhakika
kwa. "" Kuwa na uhakika wa "nini?

77
00:03:31,220 --> 00:03:33,981
Nini ilikuwa Little Yatima Annie
anajaribu kusema nini? "Kuwa na uhakika wa" nini?

78
00:03:33,981 --> 00:03:35,522
MOTHER: Ralphie, Randy ina got kwenda.

79
00:03:35,522 --> 00:03:36,735
Je, tafadhali kuja nje?

80
00:03:36,735 --> 00:03:38,190
>> RALPHIE PARKER: zote haki, Mama!

81
00:03:38,190 --> 00:03:39,787
Mimi itabidi kuwa haki ya nje!

82
00:03:39,787 --> 00:03:41,995
RALPHIE PARKER (akisimulia):
Mimi nilikuwa kupata karibu sasa.

83
00:03:41,995 --> 00:03:43,370
mvutano ilikuwa ya kutisha.

84
00:03:43,370 --> 00:03:44,794
Ilikuwa ni nini?

85
00:03:44,794 --> 00:03:47,656
hatima ya sayari
inaweza hutegemea katika mizani.

86
00:03:47,656 --> 00:03:50,518
>> MOTHER: Ralphie, Randy got kwenda!

87
00:03:50,518 --> 00:03:53,635
>> RALPHIE PARKER: Mimi itabidi kuwa na haki
nje, kwa kelele kubwa!

88
00:03:53,635 --> 00:03:55,343
RALPHIE PARKER
(Akisimulia): Karibu hapo!

89
00:03:55,343 --> 00:03:56,520
Vidole yangu akaruka!

90
00:03:56,520 --> 00:03:58,500
Mawazo yangu yalikuwa ni chuma mtego.

91
00:03:58,500 --> 00:03:59,850
Kila pore vibrated.

92
00:03:59,850 --> 00:04:01,806
Ilikuwa ni karibu wazi!

93
00:04:01,806 --> 00:04:02,773
Ndiyo!

94
00:04:02,773 --> 00:04:03,273
Ndiyo!

95
00:04:03,273 --> 00:04:03,773
Ndiyo!

96
00:04:03,773 --> 00:04:04,740
Ndiyo!

97
00:04:04,740 --> 00:04:10,250
>> RALPHIE PARKER: "Kuwa na uhakika
kunywa Ovaltine yako. "

98
00:04:10,250 --> 00:04:10,750
Ovaltine?

99
00:04:10,750 --> 00:04:14,864

100
00:04:14,864 --> 00:04:17,539
kibiashara crummy?

101
00:04:17,539 --> 00:04:19,439
>> [MUSIC KUCHEZA]

102
00:04:19,439 --> 00:04:21,724
>> RALPHIE PARKER: Mwana wa bitch.

103
00:04:21,724 --> 00:04:23,460
>> [Laughing]

104
00:04:23,460 --> 00:04:27,070
>> DAVID J. Malan: Hivyo kwamba basi ni
glimpse katika kile cryptography

105
00:04:27,070 --> 00:04:29,880
inaweza kuwa kwa Haya a
kunywa kutoka yesteryear.

106
00:04:29,880 --> 00:04:30,900
Hivyo tangazo haraka.

107
00:04:30,900 --> 00:04:33,410
Kama wewe ni bure hii
Ijumaa saa 1:15 na ingekuwa

108
00:04:33,410 --> 00:04:36,610
kama kujiunga na sisi kwa CS50
chakula cha mchana, kichwa na URL hii hapa.

109
00:04:36,610 --> 00:04:38,080
Kwanza kuja, kwanza kutumika kama kawaida.

110
00:04:38,080 --> 00:04:41,840
Lakini baada ya muda, tutaweza kuhakikisha kwamba
zaidi mtu yeyote ambaye Ningependa kushiriki

111
00:04:41,840 --> 00:04:43,640
inaweza ratiba ya-busara.

112
00:04:43,640 --> 00:04:45,170
>> Hivyo masharti.

113
00:04:45,170 --> 00:04:47,940
Tuna Zamyla-- ambaye
umefanya sasa alikutana uwezekano mkubwa

114
00:04:47,940 --> 00:04:50,750
Tatizo Set katika 1-- ambao
jina ni yameandikwa hivyo.

115
00:04:50,750 --> 00:04:53,570
Na tuseme wewe typed jina lake
ndani ya programu ya kompyuta ambayo ni

116
00:04:53,570 --> 00:04:55,710
kutumia kitu kama GetString.

117
00:04:55,710 --> 00:04:57,890
Ili retrieve
keystrokes hayo, jinsi

118
00:04:57,890 --> 00:05:01,620
je, sisi kwenda juu ya anayewakilisha
kamba, neno, aya,

119
00:05:01,620 --> 00:05:03,960
au barua nyingi kama hizi hapa?

120
00:05:03,960 --> 00:05:06,790
>> Sisi aliyesema mara ya mwisho kuhusu
integers na matatizo

121
00:05:06,790 --> 00:05:09,960
kwamba kutokea kwa integer kufurika
na yaliyo maadili uhakika

122
00:05:09,960 --> 00:05:12,190
na matatizo ambayo
kutokea ndani ya usahihi.

123
00:05:12,190 --> 00:05:16,080
Pamoja na masharti, sisi angalau
kuwa na kubadilika kidogo zaidi

124
00:05:16,080 --> 00:05:17,970
kwa sababu strings-- tu
katika world-- halisi

125
00:05:17,970 --> 00:05:19,790
inaweza kuwa urefu pretty holela.

126
00:05:19,790 --> 00:05:21,055
Pretty short, pretty muda mrefu.

127
00:05:21,055 --> 00:05:23,680
Lakini hata hivyo, tunakwenda
kupata kwamba kompyuta wakati mwingine

128
00:05:23,680 --> 00:05:27,200
kukimbia nje ya kumbukumbu na hata
kuhifadhi kubwa kamba ya kutosha.

129
00:05:27,200 --> 00:05:30,840
>> Lakini kwa sasa, hebu kuanza taswira
kamba kama kitu katika masanduku hayo

130
00:05:30,840 --> 00:05:31,340
hapa.

131
00:05:31,340 --> 00:05:36,410
Hivyo sita kama masanduku, ambayo kila mmoja
inawakilisha tabia au "char."

132
00:05:36,410 --> 00:05:40,646
Hivyo kukumbuka kwamba "char" - c-h-r-- ni
moja ya kujengwa katika aina data katika C.

133
00:05:40,646 --> 00:05:43,520
Na nini ni nzuri ni kwamba unaweza kutumia
kwamba aina ya kama block jengo,

134
00:05:43,520 --> 00:05:47,880
puzzle kipande, kama wewe, ili kuunda
aina kubwa ya data kwamba tutaweza kuendelea

135
00:05:47,880 --> 00:05:49,410
kuwaita "kamba."

136
00:05:49,410 --> 00:05:53,650
>> Sasa, nini muhimu kuhusu kufikiri
juu ya mambo kama masharti kwa njia hii?

137
00:05:53,650 --> 00:05:57,720
Naam, ni zamu nje kwamba tunaweza
kweli kujiinua muundo huu

138
00:05:57,720 --> 00:06:01,420
kwa kweli kupata wahusika binafsi
katika njia pretty moja kwa moja.

139
00:06:01,420 --> 00:06:04,099
Mimi nina kwenda mbele na kujenga
faili inayoitwa "stringzero.c,"

140
00:06:04,099 --> 00:06:05,765
lakini unaweza kuiita chochote Ningependa.

141
00:06:05,765 --> 00:06:08,500
Na kwenye tovuti bila shaka ni
tayari mfano huu mapema,

142
00:06:08,500 --> 00:06:10,430
hivyo huna haja ya
aina kila kitu nje.

143
00:06:10,430 --> 00:06:13,820
>> Na mimi nina kwenda mbele
na kwanza kufanya int kuu utupu.

144
00:06:13,820 --> 00:06:15,980
Na ndani ya siku chache,
tutaweza kuanza kwa tease mbali

145
00:06:15,980 --> 00:06:19,070
nini utupu ni hapa, kwa nini ni
int karibu na kuu, na kadhalika.

146
00:06:19,070 --> 00:06:21,180
Lakini kwa sasa, hebu kuendelea
nakala kuweka kwamba.

147
00:06:21,180 --> 00:06:23,455
>> Mimi nina kwenda kutangaza string kuitwa s.

148
00:06:23,455 --> 00:06:26,920
Na mimi nina kwenda na kurudi kutoka
GetString chochote aina user katika.

149
00:06:26,920 --> 00:06:29,170
Hii ni kwenda kuwa rahisi
mpango, hakuna maelekezo,

150
00:06:29,170 --> 00:06:31,336
Mimi nina kwenda tu kwa upofu
kutarajia kwamba user anajua

151
00:06:31,336 --> 00:06:32,600
nini cha kufanya ili kuitunza rahisi.

152
00:06:32,600 --> 00:06:34,220
>> Na sasa mimi nina kwenda kuwa kwa kitanzi.

153
00:06:34,220 --> 00:06:37,450
Na ndani ya yangu kwa kitanzi mimi nina
kwenda na int i anapata sifuri.

154
00:06:37,450 --> 00:06:40,660
Na i ni, tena, tu mkataba huo,
index variable kwa kuhesabu,

155
00:06:40,660 --> 00:06:42,350
lakini mimi naweza wito huu chochote mimi nataka.

156
00:06:42,350 --> 00:06:46,275
Mimi nina kwenda kufanya i ni chini than-- vizuri
Jina Zamyla ni barua sita kwa muda mrefu.

157
00:06:46,275 --> 00:06:48,150
Hivyo nina kwenda kwa bidii
kificho kwamba kuna kwa sasa.

158
00:06:48,150 --> 00:06:49,730
>> Na kisha i ++.

159
00:06:49,730 --> 00:06:53,190
Na sasa ndani ya hizi curly
braces mimi nina kwenda kufanya printf,

160
00:06:53,190 --> 00:06:55,460
na nataka magazeti moja
tabia ya wakati huo.

161
00:06:55,460 --> 00:06:58,227
Hivyo nina kwenda kutumia% c kwa
labda mara ya kwanza.

162
00:06:58,227 --> 00:07:00,560
Na kisha nataka magazeti kila
tabia ya juu ya line yake mwenyewe.

163
00:07:00,560 --> 00:07:02,550
Hivyo nina kwenda kuweka
backslash kidogo n huko.

164
00:07:02,550 --> 00:07:03,640
Close quote.

165
00:07:03,640 --> 00:07:06,250
>> Na sasa mimi wanataka kufanya kitu hapa.

166
00:07:06,250 --> 00:07:10,610
Nataka magazeti nje
barua maalum katika kamba,

167
00:07:10,610 --> 00:07:13,670
s, kama mimi nina iterating
kutoka sifuri juu ya hadi sita.

168
00:07:13,670 --> 00:07:17,150
Kwa maneno mengine, nataka
magazeti tabia ya i'th ya s.

169
00:07:17,150 --> 00:07:18,420
Sasa jinsi gani naweza kufanya hili?

170
00:07:18,420 --> 00:07:21,550
>> Naam kiasi kama masanduku katika
uwakilishi hii hapa,

171
00:07:21,550 --> 00:07:25,560
aina ya, conjure up wazo la ndondi
barua katika, unaweza vile vile kufanya hivyo

172
00:07:25,560 --> 00:07:32,630
syntactically katika C kwa kifupi kubainisha,
Nataka magazeti nje s ya i'th tabia.

173
00:07:32,630 --> 00:07:35,640
Kutumia mabano mraba
juu ya keyboard ya kompyuta yako

174
00:07:35,640 --> 00:07:38,910
kwamba juu ya Marekani keyboard ni
kwa ujumla juu ya kurudi muhimu yako.

175
00:07:38,910 --> 00:07:42,630
>> Hivyo hii ni si haki kabisa
hata hivyo, kama unaweza kuwa niliona.

176
00:07:42,630 --> 00:07:44,780
Lakini mimi nina kwenda aina ya
upofu kusonga mbele hapa.

177
00:07:44,780 --> 00:07:47,020
Na mimi nina kwenda kufanya kufanya string 0.

178
00:07:47,020 --> 00:07:50,860
Lakini kabla ya kufanya hivyo, hebu angalia kama sisi
hawezi wanatarajia baadhi ya makosa ya kawaida.

179
00:07:50,860 --> 00:07:52,844
Je, hii ni kwenda kukusanya?

180
00:07:52,844 --> 00:07:54,510
Hapana, mimi kukosa rundo zima la mambo.

181
00:07:54,510 --> 00:07:55,280
Maktaba nikasikia.

182
00:07:55,280 --> 00:07:58,480
>> Hivyo ambayo header files
wanaweza Nataka kuongeza hapa?

183
00:07:58,480 --> 00:07:59,205
Yeah.

184
00:07:59,205 --> 00:08:01,580
>> Watazamaji: Unahitaji
standard I / O [inaudible]

185
00:08:01,580 --> 00:08:02,663
>> DAVID J. Malan: Excellent.

186
00:08:02,663 --> 00:08:06,060
Kwa hiyo mimi haja standard I / O. Kwa nini
kusudi kufanya mimi nataka standard I / O?

187
00:08:06,060 --> 00:08:06,670
Kwa printf.

188
00:08:06,670 --> 00:08:09,220
Hivyo ni pamoja na stdio.h.

189
00:08:09,220 --> 00:08:13,490
Na wewe pia kupendekeza kwamba mimi ni pamoja na
Maktaba kwa sababu gani CS50?

190
00:08:13,490 --> 00:08:14,650
Kuwa na masharti.

191
00:08:14,650 --> 00:08:17,780
Hivyo tutaweza kuona nini
Maktaba CS50 ni kufanya

192
00:08:17,780 --> 00:08:19,260
kujenga wazo hili la kamba.

193
00:08:19,260 --> 00:08:21,930
Lakini kwa sasa, unaweza kufikiria tu
yake kama halisi ya aina data.

194
00:08:21,930 --> 00:08:23,596
>> Hivyo kwamba inaonekana kuwa kidogo kusafishwa up.

195
00:08:23,596 --> 00:08:27,060
Na sasa mimi nina kwenda mbele
na kwa kweli kufanya kufanya string 0.

196
00:08:27,060 --> 00:08:27,700
Imekusanywa.

197
00:08:27,700 --> 00:08:28,370
Hivyo hiyo ni nzuri.

198
00:08:28,370 --> 00:08:32,799
Hivyo basi mimi ./string0 zoom katika ili tuweze
kuona kwa karibu zaidi nini kinatokea.

199
00:08:32,799 --> 00:08:33,850
Kuingia.

200
00:08:33,850 --> 00:08:37,789
Z-A-M-Y-L-A kuingia.

201
00:08:37,789 --> 00:08:39,440
Na tumekuwa kuchapishwa kufanyika kwa jina Zamyla ya.

202
00:08:39,440 --> 00:08:40,409
>> Hivyo hiyo ni nzuri sana.

203
00:08:40,409 --> 00:08:43,220
Hivyo sasa hebu kwenda mbele na
kuendesha programu hii tena,

204
00:08:43,220 --> 00:08:45,659
na aina nje jina Daven ya full.

205
00:08:45,659 --> 00:08:46,450
Surprise, mshangao.

206
00:08:46,450 --> 00:08:48,021
Kuingia.

207
00:08:48,021 --> 00:08:48,520
Hmm.

208
00:08:48,520 --> 00:08:51,750
Sisi si kuchapishwa Daven ya
jina kamili kwanza kwa usahihi.

209
00:08:51,750 --> 00:08:54,250
Sasa hii inapaswa kuwa wazi katika
retrospect kwa sababu ya nini,

210
00:08:54,250 --> 00:08:57,010
aina ya, kijinga uamuzi wa kubuni?

211
00:08:57,010 --> 00:08:59,590
>> Yeah, mimi ngumu coded
sita ndani ya yangu kwa kitanzi.

212
00:08:59,590 --> 00:09:01,610
Sasa mimi kwamba tu kwa sababu
Nilijua jina Zamyla ya

213
00:09:01,610 --> 00:09:02,776
alikuwa anaenda kuwa barua sita.

214
00:09:02,776 --> 00:09:04,720
Lakini bila ya shaka hii ni si
ufumbuzi kwa ujumla.

215
00:09:04,720 --> 00:09:07,720
Hivyo ni zamu nje tunaweza dynamically
kufikiri urefu wa kamba

216
00:09:07,720 --> 00:09:10,440
kwa kupiga kazi kuitwa strlen.

217
00:09:10,440 --> 00:09:12,840
>> Tena, kwa makusudi
ufupi aitwaye tu

218
00:09:12,840 --> 00:09:14,450
kufanya ni rahisi zaidi kwa aina.

219
00:09:14,450 --> 00:09:17,170
Lakini hiyo ni sawa na
kupata urefu wa kamba.

220
00:09:17,170 --> 00:09:23,190
Mimi nina kwenda nyuma katika terminal yangu
dirisha na re-kukimbia compiler.

221
00:09:23,190 --> 00:09:24,170
Lakini ni yelling saa yangu.

222
00:09:24,170 --> 00:09:29,130
Inamuunga kutangaza kazi maktaba
strlen kwa ajili ya aina unsigned int const--

223
00:09:29,130 --> 00:09:29,780
Mimi nina waliopotea.

224
00:09:29,780 --> 00:09:30,590
Kabisa.

225
00:09:30,590 --> 00:09:32,940
>> Hivyo, hasa kama yako
macho kuanza glaze juu

226
00:09:32,940 --> 00:09:36,000
na ujumbe wa makosa kama hii, lengo
uaminifu juu ya maneno machache ya kwanza.

227
00:09:36,000 --> 00:09:38,590
Tunajua tatizo ni katika
mstari wa 8, kama unahitajika hapa.

228
00:09:38,590 --> 00:09:40,500
Na ni katika string-0.c.

229
00:09:40,500 --> 00:09:43,580
Inamuunga kutangaza
kazi maktaba strlen.

230
00:09:43,580 --> 00:09:47,000
Hivyo kwamba kwa ujumla kwenda
kuwa mfano wa ujumbe wa makosa.

231
00:09:47,000 --> 00:09:49,190
Inamuunga kutangaza kitu.

232
00:09:49,190 --> 00:09:53,250
>> Hivyo katika muda mfupi, nini na mimi walionekana
wamefanya kwa heshima na line ya 8, hapa.

233
00:09:53,250 --> 00:09:56,880
Nini kinaweza kuwa suluhisho kuwa hata
kama wewe sijawahi kutumika strlen mwenyewe?

234
00:09:56,880 --> 00:09:58,907
>> Watazamaji: Sehemu ya maktaba tofauti?

235
00:09:58,907 --> 00:10:00,740
DAVID J. Malan: Sehemu
ya maktaba tofauti.

236
00:10:00,740 --> 00:10:02,400
Hivyo ni alitangaza, hivyo kusema.

237
00:10:02,400 --> 00:10:07,510
Imetajwa katika baadhi ya faili
nyingine zaidi ya stdio.h na CS50.h.

238
00:10:07,510 --> 00:10:09,179
Sasa ambapo ni ni defined?

239
00:10:09,179 --> 00:10:12,220
Kwa kuwa waaminifu, wewe ama kuwa na tu
kujua hii mbali juu ya kichwa yako,

240
00:10:12,220 --> 00:10:13,640
au wewe Google huu na kupata nje.

241
00:10:13,640 --> 00:10:18,150
Au unajua hii, nilipofungua up katika CS50
appliance terminal mpango, ambayo

242
00:10:18,150 --> 00:10:22,200
ni tu kubwa, screen toleo kamili ya
nini katika chini ya dirisha gedit ya.

243
00:10:22,200 --> 00:10:24,970
>> Na zinageuka kwamba kuna
vile vile succinct amri, iitwayo

244
00:10:24,970 --> 00:10:29,280
mtu kwa ajili ya mwongozo, ambapo kama wewe aina katika
jina ya kazi na hit Enter,

245
00:10:29,280 --> 00:10:32,240
utasikia kupata nyuma haki
arcane nyaraka.

246
00:10:32,240 --> 00:10:35,299
Ni Nakala tu ni kwamba kwa ujumla
inaonekana kitu kidogo kama hii.

247
00:10:35,299 --> 00:10:37,090
Ni kidogo mno
katika mtazamo wa kwanza.

248
00:10:37,090 --> 00:10:39,048
Lakini kusema ukweli mimi nina kwenda
achilia macho yangu glaze juu

249
00:10:39,048 --> 00:10:41,930
na tu kuelekeza nguvu katika sehemu
Mimi huduma ya juu kwa sasa.

250
00:10:41,930 --> 00:10:42,780
>> Ambayo ni hii.

251
00:10:42,780 --> 00:10:45,470
Ambayo inaonekana kimuundo kama
kitu mimi nina familiar with.

252
00:10:45,470 --> 00:10:48,080
Hakika ukurasa mwanamume, vivyo hivyo
kusema, atakuambia

253
00:10:48,080 --> 00:10:51,590
katika kile header faili kazi
kama strlen inaelezwa.

254
00:10:51,590 --> 00:10:54,170
Hivyo mimi nina kwenda nyuma sasa kwa gedit.

255
00:10:54,170 --> 00:10:59,070
Na mimi nina kwenda mbele na
kuongeza katika hapa #include

256
00:10:59,070 --> 00:11:00,480
na kuokoa faili.

257
00:11:00,480 --> 00:11:04,300
>> Mimi nina kwenda wazi screen na
Kudhibiti L Kama tumekuwa wanashangaa.

258
00:11:04,300 --> 00:11:08,210
Na mimi nina kwenda re-kukimbia kufanya
string.0, inaandaa wakati huu.

259
00:11:08,210 --> 00:11:11,790
./string.0 Zamyla.

260
00:11:11,790 --> 00:11:15,020
Hiyo walionekana kazi Hebu kwenda
mbele na rerun ni pamoja na Davenport.

261
00:11:15,020 --> 00:11:15,860
Kuingia.

262
00:11:15,860 --> 00:11:17,730
Na kwamba, pia, walionekana kazi.

263
00:11:17,730 --> 00:11:21,220
>> Hivyo tunaweza kufanya kidogo bora kuliko hayo,
Hata hivyo, tunaweza kuanza kwa mambo tidy

264
00:11:21,220 --> 00:11:23,257
up kidogo tu.

265
00:11:23,257 --> 00:11:25,590
Na mimi nina kwenda kwa kweli
kuanzisha jambo moja nyingine sasa.

266
00:11:25,590 --> 00:11:28,930
Mimi nina kwenda mbele na
kuokoa hii katika faili tofauti.

267
00:11:28,930 --> 00:11:31,770
Na mimi nina kwenda kuwaita
hii string1.c faili tu

268
00:11:31,770 --> 00:11:34,620
kuwa thabiti na code
wewe utakuwa na uwezo wa kupata online.

269
00:11:34,620 --> 00:11:37,050
>> Na hebu kuzingatia katika juu ya
hasa code huo.

270
00:11:37,050 --> 00:11:39,000
Ni zinageuka kuwa nimekuwa
wamekuwa aina ya kuchukua

271
00:11:39,000 --> 00:11:42,600
kwa nafasi ukweli kwamba mbali yangu,
na kwa upande wake, CS50 appliance

272
00:11:42,600 --> 00:11:47,450
ina mengi ya kumbukumbu, mengi ya
RAM, mengi ya ka wa nafasi

273
00:11:47,450 --> 00:11:48,920
katika ambayo naweza kuhifadhi masharti.

274
00:11:48,920 --> 00:11:53,560
>> Lakini ukweli kama mimi typed kwa muda mrefu
kutosha, na kutosha keystrokes,

275
00:11:53,560 --> 00:11:56,170
Mimi nilikuwa katika nadharia ya aina
katika wahusika zaidi

276
00:11:56,170 --> 00:11:58,830
kuliko kompyuta yangu
kimwili ana kumbukumbu kwa.

277
00:11:58,830 --> 00:11:59,830
Na hili ni tatizo.

278
00:11:59,830 --> 00:12:03,050
Mengi kama int unaweza tu
kuhesabu juu, katika nadharia,

279
00:12:03,050 --> 00:12:06,600
unaweza tu cram wahusika wengi
ndani ya RAM ya kompyuta yako au Random

280
00:12:06,600 --> 00:12:07,920
Access Memory.

281
00:12:07,920 --> 00:12:11,140
>> Kwa hiyo mimi alikuwa bora wanatarajia
tatizo hili, hata

282
00:12:11,140 --> 00:12:13,660
ingawa inaweza kuwa adimu
kona kesi, hivyo kusema.

283
00:12:13,660 --> 00:12:15,670
Haina kutokea kwamba mara nyingi, inaweza kutokea.

284
00:12:15,670 --> 00:12:18,815
Na kama ni hutokea na mimi si
wanatarajia na mpango kwa ajili yake,

285
00:12:18,815 --> 00:12:20,300
mpango wangu naweza kufanya ambaye anajua nini.

286
00:12:20,300 --> 00:12:22,220
Freeze, hutegemea, reboot, chochote.

287
00:12:22,220 --> 00:12:24,490
Kitu kutarajia inaweza kutokea.

288
00:12:24,490 --> 00:12:27,120
>> Basi nini mimi nina kwenda kufanya
sasa, tangu sasa kweli,

289
00:12:27,120 --> 00:12:31,630
ni kabla ya mimi milele upofu
kutumia variable kama s kwamba

290
00:12:31,630 --> 00:12:36,790
imekuwa assigned ya thamani ya kurudi kwa
baadhi ya kazi nyingine kama GetString,

291
00:12:36,790 --> 00:12:40,200
Mimi nina kwenda kuhakikisha
kwamba thamani yake ni halali.

292
00:12:40,200 --> 00:12:44,280
Hivyo najua tu kutoka baada ya kusoma
CS50 ya nyaraka kwa ajili ya GetString,

293
00:12:44,280 --> 00:12:49,020
ambayo hatimaye tutaweza kumweka wewe katika,
kwamba GetString anarudi ishara maalum

294
00:12:49,020 --> 00:12:53,610
kuitwa NULL, N-U-L-L katika kila
kofia, kama kitu fulani kitaenda vibaya.

295
00:12:53,610 --> 00:12:55,650
>> Hivyo kwa kawaida, ni anarudi kamba.

296
00:12:55,650 --> 00:12:59,700
Lakini vinginevyo kama kuirudisha N-U-L-L--
tutaweza hatimaye kuona nini kwamba kweli

297
00:12:59,700 --> 00:13:01,790
means-- kwamba tu njia
kitu mbaya kilichotokea.

298
00:13:01,790 --> 00:13:05,560
Sasa hii inamaanisha, kiasi kama katika Scratch,
Siwezi kuangalia hali hapa katika C,

299
00:13:05,560 --> 00:13:08,830
kama s haina NULL sawa.

300
00:13:08,830 --> 00:13:11,930
Hivyo kama wewe wameweza si hii kuona mbele,
hii ina maana tu haina sawa.

301
00:13:11,930 --> 00:13:15,290
>> Hivyo ni kinyume cha
sawa sawa, ambayo, kukumbuka,

302
00:13:15,290 --> 00:13:18,940
ni tofauti na single
sawa, ambayo ni kazi.

303
00:13:18,940 --> 00:13:23,030
Hivyo kama s haina sawa
NULL, basi tu kufanya

304
00:13:23,030 --> 00:13:25,980
Nataka nitafanya mistari haya ya code.

305
00:13:25,980 --> 00:13:28,080
Hivyo kwa maneno mengine,
kabla ya mimi kupiga mbizi katika upofu

306
00:13:28,080 --> 00:13:30,919
na kuanza iterating
juu ya s, na kutibu ni

307
00:13:30,919 --> 00:13:33,710
kana kwamba ni mlolongo wa
wahusika, mimi nina kwenda kuangalia kwanza,

308
00:13:33,710 --> 00:13:37,900
kusubiri dakika, ni s dhahiri si
sawa na thamani hii maalum, NULL?

309
00:13:37,900 --> 00:13:40,030
>> Kwa sababu kama ni, mambo mabaya yanaweza kutokea.

310
00:13:40,030 --> 00:13:43,080
Na kwa sasa, kudhani mambo kuwa mbaya
kinachotokea maana shambulio mpango wako,

311
00:13:43,080 --> 00:13:45,070
na unaweza si lazima kupona.

312
00:13:45,070 --> 00:13:46,800
Hivyo kusema ukweli, inaonekana uglier.

313
00:13:46,800 --> 00:13:48,660
ni aina ya utata sasa kwa mtazamo saa.

314
00:13:48,660 --> 00:13:50,780
Lakini hii itakuwa zaidi
familiar kabla ya muda mrefu.

315
00:13:50,780 --> 00:13:52,920
>> Lakini mimi nina kwenda kupendekeza
sasa wengine kuboresha moja.

316
00:13:52,920 --> 00:13:54,660
Hiyo ni kuboresha na usahihi.

317
00:13:54,660 --> 00:13:58,800
Mpango wangu ni sasa sahihi zaidi, kwa sababu
katika kesi nadra kuwa kumbukumbu haitoshi

318
00:13:58,800 --> 00:14:01,180
lipo, mimi kushughulikia hilo,
na mimi itabidi kufanya chochote.

319
00:14:01,180 --> 00:14:02,680
Mimi angalau si ajali.

320
00:14:02,680 --> 00:14:05,000
>> Lakini hebu kufanya toleo la mwisho hapa.

321
00:14:05,000 --> 00:14:07,690
Na faili inayoitwa string2.c.

322
00:14:07,690 --> 00:14:10,190
Mimi nina kwenda kuweka kwamba
huo code kwa muda tu,

323
00:14:10,190 --> 00:14:14,210
na mimi nina kwenda kwa kuonyesha hii
line, 11, hapa, kwa muda tu.

324
00:14:14,210 --> 00:14:18,179
Sasa ukweli ni kwamba compilers smart
kama Clang inaweza kurekebisha hili kwa ajili yetu

325
00:14:18,179 --> 00:14:19,970
nyuma ya pazia
bila wetu milele kujua.

326
00:14:19,970 --> 00:14:24,670
Lakini hebu fikiria kuhusu hili
kimsingi kama kubuni tatizo.

327
00:14:24,670 --> 00:14:29,010
>> Mstari wa kanuni ni, bila shaka,
akisema, initialize variable i baadhi kwa 0.

328
00:14:29,010 --> 00:14:30,260
Hiyo ni pretty moja kwa moja.

329
00:14:30,260 --> 00:14:34,691
Na nini tena ni hii
kauli, hapa, i ++, kufanya?

330
00:14:34,691 --> 00:14:37,066
Tumeona hivyo kabla, lakini sisi
hawakuwa kweli kuzungumza juu yake.

331
00:14:37,066 --> 00:14:37,900
>> Watazamaji: incrementing i.

332
00:14:37,900 --> 00:14:39,191
>> DAVID J. Malan: incrementing i.

333
00:14:39,191 --> 00:14:41,890
Kadhalika kila iteration kupitia
kitanzi hii, kila mzunguko,

334
00:14:41,890 --> 00:14:43,570
wewe ni incrementing i kwa moja.

335
00:14:43,570 --> 00:14:45,740
Hivyo anapata kubwa zaidi, na kubwa zaidi, na
kubwa mpaka kitanzi vipoe.

336
00:14:45,740 --> 00:14:46,810
Jinsi gani kusitisha?

337
00:14:46,810 --> 00:14:49,430
Naam kuna katikati huu
hali ambayo tumekuwa kutumika kabla.

338
00:14:49,430 --> 00:14:52,500
Ve kuonekana na katika
walkthroughs katika P kuweka.

339
00:14:52,500 --> 00:14:53,880
>> Lakini ni nini maneno yako?

340
00:14:53,880 --> 00:14:58,352
Kufanya kitanzi yafuatayo ili
muda mrefu kama i ni chini ya nini?

341
00:14:58,352 --> 00:14:59,810
Watazamaji: urefu wa kamba.

342
00:14:59,810 --> 00:15:01,518
DAVID J. Malan:
urefu wa kamba.

343
00:15:01,518 --> 00:15:04,300
Hivyo ni tafsiri pretty cleanly
kwa Kiingereza katika maana hiyo.

344
00:15:04,300 --> 00:15:08,810
Sasa tatizo ni kwamba kila wakati mimi
iterate kwa njia ya kitanzi hii katika nadharia,

345
00:15:08,810 --> 00:15:10,000
Mimi nina kuuliza swali hili.

346
00:15:10,000 --> 00:15:12,250
Ni i chini ya urefu wa kamba s?

347
00:15:12,250 --> 00:15:14,500
Ni i chini ya urefu wa kamba s?

348
00:15:14,500 --> 00:15:18,380
>> Sasa i kubadilisha juu ya kila iteration?

349
00:15:18,380 --> 00:15:18,880
Ni.

350
00:15:18,880 --> 00:15:19,629
Kwa sababu ya ++.

351
00:15:19,629 --> 00:15:21,700
Hivyo kila iteration i ni kupata kubwa.

352
00:15:21,700 --> 00:15:25,411
Lakini ni s kupata kubwa, au
ndogo, au kubadilisha wakati wote?

353
00:15:25,411 --> 00:15:25,910
Hapana

354
00:15:25,910 --> 00:15:30,240
Hivyo katika suala la kubuni, moja ya shoka
pamoja ambayo sisi kujaribu kutathmini code

355
00:15:30,240 --> 00:15:32,610
darasani, hii anahisi aina ya kijinga.

356
00:15:32,610 --> 00:15:34,690
>> Kama wewe ni literally,
juu ya kila iteration

357
00:15:34,690 --> 00:15:37,110
ya kitanzi hii kuuliza
huo damn swali tena,

358
00:15:37,110 --> 00:15:40,770
na tena, na tena, na literally
ni kamwe kwenda na mabadiliko.

359
00:15:40,770 --> 00:15:44,220
Angalau kama mimi si kugusa s na
kujaribu kubadilisha yaliyomo ya s.

360
00:15:44,220 --> 00:15:46,610
Hivyo siwezi kufanya kidogo bora zaidi kuliko haya.

361
00:15:46,610 --> 00:15:49,530
>> Na kile Mimi naenda kufanya ni si
kutangaza moja tu variable i,

362
00:15:49,530 --> 00:15:53,330
lakini variable pili mimi itabidi kiholela,
lakini conventionally, simu yake n.

363
00:15:53,330 --> 00:15:55,940
Mpe n sawa na
kamba urefu wa s.

364
00:15:55,940 --> 00:15:59,090
Na kisha zaidi ya hapa, mimi nina kwenda
kufanya wajanja optimization kidogo, hivyo

365
00:15:59,090 --> 00:16:03,460
kusema, kwamba mwishoni mwa siku
hakuna zaidi sahihi au si chini sahihi

366
00:16:03,460 --> 00:16:04,260
kuliko kabla.

367
00:16:04,260 --> 00:16:05,500
Lakini ni kubuni bora.

368
00:16:05,500 --> 00:16:09,480
Katika ukweli kwamba mimi nina kutumia
muda kidogo, mzunguko wachache CPU, hivyo

369
00:16:09,480 --> 00:16:14,040
kusema, kujibu huo
swali, lakini mara moja tu.

370
00:16:14,040 --> 00:16:17,870
>> Maswali yoyote juu ya kwamba kwa ujumla
kanuni ya kuboresha,

371
00:16:17,870 --> 00:16:21,294
kusema, ufanisi wa programu hiyo?

372
00:16:21,294 --> 00:16:21,991
Yeah?

373
00:16:21,991 --> 00:16:23,699
Watazamaji: Kwa nini
kutumia [inaudible]?

374
00:16:23,699 --> 00:16:25,760

375
00:16:25,760 --> 00:16:27,010
DAVID J. Malan: Swali Good.

376
00:16:27,010 --> 00:16:30,690
Hivyo kwa nini sisi kuweka ++ tarehe ya mwisho ya
i badala ya mwanzo wa i?

377
00:16:30,690 --> 00:16:33,070
Katika kesi hiyo, ina
hakuna madhara kazi.

378
00:16:33,070 --> 00:16:36,670
Na kwa ujumla, mimi huwa na
kutumia postfix operator

379
00:16:36,670 --> 00:16:41,750
ili ni wazi kidogo zaidi kama
kwa wakati operesheni kinachotokea.

380
00:16:41,750 --> 00:16:46,670
>> Kwa wale usio wa kawaida, kuna mwingine
kauli ambapo unaweza kufanya ++ i.

381
00:16:46,670 --> 00:16:48,747
Hizi ni functionally
sawa katika kesi hii

382
00:16:48,747 --> 00:16:51,080
kwa sababu kuna kitu kingine
kuzunguka kwamba incrementation.

383
00:16:51,080 --> 00:16:54,435
Lakini unaweza kuja na
kesi na mstari wa kanuni

384
00:16:54,435 --> 00:16:55,810
katika ambayo kwamba inafanya tofauti.

385
00:16:55,810 --> 00:16:57,810
Hivyo kwa ujumla, hatufanyi
hata kuzungumza kuhusu suala hili moja.

386
00:16:57,810 --> 00:17:00,690
Kwa sababu kusema ukweli, inafanya yako
code sexier, na aina ya slicker,

387
00:17:00,690 --> 00:17:01,776
na wachache wahusika.

388
00:17:01,776 --> 00:17:04,859
Lakini ukweli ni vigumu sana,
Nadhani, hata kwa ajili yangu na wrap akili yangu

389
00:17:04,859 --> 00:17:07,319
kuzunguka wakati mwingine,
utaratibu wa shughuli.

390
00:17:07,319 --> 00:17:09,750
Hivyo kama kando, kama wewe
kweli si kama hii,

391
00:17:09,750 --> 00:17:14,650
ingawa hii ni aina ya sexy
kuangalia, unaweza pia kufanya i + = 1,

392
00:17:14,650 --> 00:17:18,880
ambayo ni toleo uglier ya
wazo moja kwa postfix incrementation.

393
00:17:18,880 --> 00:17:22,250
>> Nasema hili na wewe
lazima kufanya furaha yake,

394
00:17:22,250 --> 00:17:25,140
lakini wewe kuja kuona kanuni kama
kitu kizuri kabla ya muda mrefu.

395
00:17:25,140 --> 00:17:27,160
>> [Kicheko]

396
00:17:27,160 --> 00:17:28,410
>> DAVID J. Malan: Haki?

397
00:17:28,410 --> 00:17:29,360
Yeah.

398
00:17:29,360 --> 00:17:30,480
Swali katikati.

399
00:17:30,480 --> 00:17:32,146
>> Watazamaji: Je, unahitaji kusema int n?

400
00:17:32,146 --> 00:17:34,020
DAVID J. Malan: Je,
si haja ya kusema int n.

401
00:17:34,020 --> 00:17:37,670
Hivyo kwa sababu sisi tayari alisema int,
huna haja ya kusema hivyo tena.

402
00:17:37,670 --> 00:17:41,820
catch ni kwamba n ina
kuwa data aina moja kama i.

403
00:17:41,820 --> 00:17:43,310
Hivyo hiyo ni urahisi hapa.

404
00:17:43,310 --> 00:17:44,058
Yeah.

405
00:17:44,058 --> 00:17:47,806
>> Watazamaji: Je, unaweza kwenda juu ya
magazeti tabia ya s bracket i tena?

406
00:17:47,806 --> 00:17:48,930
DAVID J. Malan: Ndiyo.

407
00:17:48,930 --> 00:17:52,110
Hivyo% c, kukumbuka kutoka mwisho
wakati, ni tu placeholder.

408
00:17:52,110 --> 00:17:53,930
Ina maana kuweka char hapa.

409
00:17:53,930 --> 00:17:56,780
backslash n, bila shaka, tu
njia kuweka line kuvunja hapa.

410
00:17:56,780 --> 00:17:59,540
Hivyo kwamba tu majani, sasa,
kipande cha syntax mpya.

411
00:17:59,540 --> 00:18:03,730
Na hii ni literally kusema, kunyakua
string kuitwa s na kwenda kupata wake

412
00:18:03,730 --> 00:18:06,050
i'th tabia, hivyo kusema.

413
00:18:06,050 --> 00:18:10,590
>> Na mimi kuendelea kusema i'th tabia ya
kwa sababu juu ya kila iteration ya kitanzi hii

414
00:18:10,590 --> 00:18:14,540
ni kana kwamba sisi ni kuchapisha
nje, kwanza s bracket 0,

415
00:18:14,540 --> 00:18:15,780
kama programu anaweza kusema.

416
00:18:15,780 --> 00:18:18,680
Kisha s bracket 1, kisha s
bracket 2, kisha 3, kisha 4.

417
00:18:18,680 --> 00:18:21,610
Lakini bila shaka ni variable,
hivyo mimi tu kueleza ni pamoja na i.

418
00:18:21,610 --> 00:18:23,900
>> Muhimu, ingawa, ni kutambua,
hasa kama wameweza si

419
00:18:23,900 --> 00:18:26,358
wamekuwa acclimating ya dunia hii
ya programu, ambapo sisi wote

420
00:18:26,358 --> 00:18:28,950
wanaonekana kuhesabu kutoka sifuri, gotta
kuanza kuhesabu kutoka sifuri sasa.

421
00:18:28,950 --> 00:18:35,130
Kwa sababu masharti, tabia ya kwanza,
z katika Zamyla ni kwa bora au mbaya

422
00:18:35,130 --> 00:18:40,490
kwenda kuishi katika eneo ya simu sifuri.

423
00:18:40,490 --> 00:18:48,210
>> Haki zote, hivyo basi mimi kuleta
sisi nyuma hapa kwa Zamyla

424
00:18:48,210 --> 00:18:50,746
na kuona nini kweli kwenda
juu ya chini ya Hood.

425
00:18:50,746 --> 00:18:52,370
Hivyo kuna wazo hili la aina akitoa.

426
00:18:52,370 --> 00:18:53,800
Unaweza kuwa na kweli
alicheza na hii tayari,

427
00:18:53,800 --> 00:18:55,970
labda kwa hacker
toleo la P kuweka moja.

428
00:18:55,970 --> 00:19:00,320
Lakini aina akitoa tu inahusu
uwezo katika C na baadhi ya lugha nyingine

429
00:19:00,320 --> 00:19:03,170
kubadili data ya aina moja hadi nyingine.

430
00:19:03,170 --> 00:19:05,450
>> Sasa jinsi gani sisi kuona hii
pretty straightforwardly?

431
00:19:05,450 --> 00:19:08,530
Hivyo hii, kukumbuka, ni mwanzo
alfabeti ya Kiingereza.

432
00:19:08,530 --> 00:19:11,265
Na mazingira, kukumbuka, kutoka
kama wiki iliyopita ni ASCII.

433
00:19:11,265 --> 00:19:13,790
American Standard Code
Habari Interchange.

434
00:19:13,790 --> 00:19:17,080
Ambayo ni njia tu kweli kwa muda mrefu
ramani ya kusema kutoka barua

435
00:19:17,080 --> 00:19:19,370
kwa idadi, na kutoka idadi ya barua.

436
00:19:19,370 --> 00:19:22,940
>> Hivyo kwa njia ya M hapa, dot dot
dot, yanaendana na, kukumbuka,

437
00:19:22,940 --> 00:19:25,582
simu decimal 65 juu ya up.

438
00:19:25,582 --> 00:19:27,290
Na sisi hakuwa na majadiliano
kuhusu hili kwa uwazi,

439
00:19:27,290 --> 00:19:29,850
lakini kwa hakika kuna sawa
namba kwa barua lowercase.

440
00:19:29,850 --> 00:19:30,820
Na hakika, kuna.

441
00:19:30,820 --> 00:19:33,730
dunia aliamua baadhi ya miaka
iliyopita kuwa kidogo, Herufi za chini,

442
00:19:33,730 --> 00:19:35,020
ni kwenda kuwa 97.

443
00:19:35,020 --> 00:19:38,010
Na kidogo b ni kwenda
kuwa 98, na kadhalika.

444
00:19:38,010 --> 00:19:40,200
>> Na kwa wengine muhimu yoyote juu ya
keyboard yako, kuna

445
00:19:40,200 --> 00:19:42,190
kwenda kuwa mfano unaofanana na wa bits.

446
00:19:42,190 --> 00:19:44,540
Au equivalently, idadi decimal.

447
00:19:44,540 --> 00:19:47,110
Hivyo swali katika mkono,
basi, ni jinsi gani tunaweza

448
00:19:47,110 --> 00:19:49,400
kweli kuona hii chini ya Hood?

449
00:19:49,400 --> 00:19:51,539
Hivyo mimi nina kwenda juu ya gedit tena.

450
00:19:51,539 --> 00:19:53,330
Na badala ya aina
hii moja kutoka mwanzo,

451
00:19:53,330 --> 00:19:55,330
Mimi nina kwenda mbele na
tu kufungua kitu

452
00:19:55,330 --> 00:19:58,350
kutoka code leo kuitwa ASCII sifuri.

453
00:19:58,350 --> 00:20:01,210
>> Na ASCII zero inaonekana kama hii.

454
00:20:01,210 --> 00:20:02,710
Basi hebu wrap akili zetu kuzunguka hili.

455
00:20:02,710 --> 00:20:04,969
Hivyo kwanza, nimekuwa maoni
code, ambayo ni nzuri.

456
00:20:04,969 --> 00:20:07,010
Kwa sababu ni literally
kuniambia nini cha kutarajia,

457
00:20:07,010 --> 00:20:08,950
kuonyesha ramani kwa herufi kubwa.

458
00:20:08,950 --> 00:20:13,690
Sasa mimi si kabisa kujua nini mimi
maana na kwamba, hivyo hebu infer.

459
00:20:13,690 --> 00:20:16,870
>> Katika lugha ya Kiingereza, labda
kiasi fulani techie Kiingereza,

460
00:20:16,870 --> 00:20:20,660
nini line 18 itaonekana
kuwa kufanya kwa ajili yetu?

461
00:20:20,660 --> 00:20:21,500
Tu line 18.

462
00:20:21,500 --> 00:20:22,430
Nini ni inducing?

463
00:20:22,430 --> 00:20:25,192
Nini ni kwenda kick off hapa?

464
00:20:25,192 --> 00:20:26,100
>> Watazamaji: kitanzi.

465
00:20:26,100 --> 00:20:26,630
>> DAVID J. Malan: kitanzi.

466
00:20:26,630 --> 00:20:28,463
Na jinsi mara nyingi ni
kwamba kwenda iterate?

467
00:20:28,463 --> 00:20:31,562

468
00:20:31,562 --> 00:20:33,270
Watazamaji: [INTERPOSING VOICES]
mara sita.

469
00:20:33,270 --> 00:20:34,830
DAVID J. Malan: Si mara sita.

470
00:20:34,830 --> 00:20:35,840
Watazamaji: Mara 26.

471
00:20:35,840 --> 00:20:36,560
DAVID J. Malan: Mara 26.

472
00:20:36,560 --> 00:20:37,060
Yeah, sorry.

473
00:20:37,060 --> 00:20:37,960
26 mara kwa mara.

474
00:20:37,960 --> 00:20:38,460
Kwa nini?

475
00:20:38,460 --> 00:20:41,590
Naam, ni kidogo weird, lakini
Nimeanza kuhesabu kutoka 65.

476
00:20:41,590 --> 00:20:43,300
Ambayo ni weird, lakini si vibaya.

477
00:20:43,300 --> 00:20:44,610
Ni si mbaya kwa kusema.

478
00:20:44,610 --> 00:20:46,980
Na mimi nina kufanya hivyo tu
kwa sababu, kwa mfano huu,

479
00:20:46,980 --> 00:20:50,455
Mimi nina aina ya unatarajia
kuwa mji mkuu wa A mara 65.

480
00:20:50,455 --> 00:20:53,330
Sasa hii si kifahari zaidi
njia ya kufanya hili, kwa aina ya maadili ya ngumu

481
00:20:53,330 --> 00:20:56,130
maadili esoteric kwamba hakuna mtu
ni milele inatarajiwa kukumbuka.

482
00:20:56,130 --> 00:21:00,155
>> Lakini kwa sasa, taarifa kwamba mimi nina
kufanya hivyo juu kupitia 65 plus 26.

483
00:21:00,155 --> 00:21:03,030
Kwa sababu inaonekana mimi hawana hata wanataka
kufanya hesabu katika kichwa changu.

484
00:21:03,030 --> 00:21:04,440
Hivyo mimi itabidi basi compiler kufanya hivyo.

485
00:21:04,440 --> 00:21:08,600
Lakini basi juu ya kila kitanzi, kila iteration
ya kitanzi, mimi nina incrementing i.

486
00:21:08,600 --> 00:21:10,196
>> Hivyo sasa hii inaonekana kidogo cryptic.

487
00:21:10,196 --> 00:21:13,320
Lakini tunapaswa kuwa na jengo msingi
vitalu na ambayo kwa kuelewa hili.

488
00:21:13,320 --> 00:21:15,510
% C ni tu placeholder kwa char.

489
00:21:15,510 --> 00:21:19,010
% I ni placeholder kwa int.

490
00:21:19,010 --> 00:21:23,310
Na zinageuka kwamba kwa kutumia hii
syntax mpya, mabano huu, hivyo

491
00:21:23,310 --> 00:21:26,100
kusema, hivyo aina data
ndani ya mabano,

492
00:21:26,100 --> 00:21:32,270
Siwezi nguvu compiler kutibu
i si ni integer, lakini kama char.

493
00:21:32,270 --> 00:21:35,520
>> Hivyo kuonyesha mimi tabia ya
sawa ya idadi hiyo.

494
00:21:35,520 --> 00:21:37,986
Sasa hapa chini, kanuni hii
ni pretty much kufanana.

495
00:21:37,986 --> 00:21:39,860
Mimi nilitaka kufanya
super wazi ukweli

496
00:21:39,860 --> 00:21:42,095
kwamba mimi nina kuanzia saa 97,
ambayo ni Herufi za chini.

497
00:21:42,095 --> 00:21:44,080
On up kupitia barua 26 zaidi.

498
00:21:44,080 --> 00:21:46,970
Na mimi nina doing-- tena,
akitoa i, hivyo kusema.

499
00:21:46,970 --> 00:21:49,160
Au aina akitoa i, hivyo kusema.

500
00:21:49,160 --> 00:21:51,420
>> Kutoka int kwa Char.

501
00:21:51,420 --> 00:21:55,760
Hivyo matokeo ya mwisho ni kwenda kuwa,
kusema ukweli, habari sisi tayari kujua.

502
00:21:55,760 --> 00:21:59,411
Mimi nina kwenda kufanya
ascii-0 dot-- si dot c.

503
00:21:59,411 --> 00:22:02,160
Ilani, pengine alifanya kwamba
kosa kama mimi tu alifanya ajali.

504
00:22:02,160 --> 00:22:03,820
Kufanya ascii-0.

505
00:22:03,820 --> 00:22:06,090
Sasa mimi nina kwenda kufanya ./ascii-0.

506
00:22:06,090 --> 00:22:09,050
Mimi itabidi zoom katika, na kwa bahati mbaya
ni kwenda na kitabu mbali screen.

507
00:22:09,050 --> 00:22:15,060
Lakini sisi tazama chati nzima ambapo
ramani ya 97, ramani b 98,

508
00:22:15,060 --> 00:22:18,931
na kama sisi kitabu juu zaidi
, Bila shaka, ramani ya 65.

509
00:22:18,931 --> 00:22:21,180
Hivyo hii ni tu kusema kwamba
nini tumekuwa kuhubiri,

510
00:22:21,180 --> 00:22:25,310
kuna yanayolinagana hii, ni
kwa kweli kesi katika hali halisi.

511
00:22:25,310 --> 00:22:28,000
Hivyo muundo wa haraka wa hii.

512
00:22:28,000 --> 00:22:31,220
Hebu kufungua ascii-1.c.

513
00:22:31,220 --> 00:22:38,070
Na taarifa hii wajanja, aina
wa, ufafanuzi wa hii.

514
00:22:38,070 --> 00:22:41,770
Hii ni ascii-1.c, na
taarifa jambo hili mambo.

515
00:22:41,770 --> 00:22:45,120
>> Na hii kweli anapata kwa moyo
ya nini kompyuta ni kufanya.

516
00:22:45,120 --> 00:22:48,150
Hata ingawa sisi binadamu ingekuwa
si kuhesabu katika suala la letters--

517
00:22:48,150 --> 00:22:50,380
Mimi si kuanza kufikiri,
haki zote kisha b,

518
00:22:50,380 --> 00:22:52,590
na kutumia hayo kwa kuhesabu vitu kimwili.

519
00:22:52,590 --> 00:22:58,680
Unaweza shaka kusema kwamba mimi nataka
initialize variable kuitwa baadhi c--

520
00:22:58,680 --> 00:23:03,220
lakini mimi naweza kuwa na kuitwa anything-- hii
hivyo c ni initialized katika mji mkuu wa A.

521
00:23:03,220 --> 00:23:07,560
>> Kwa sababu mwisho wa siku, kompyuta
haina huduma nini wewe kuhifadhi,

522
00:23:07,560 --> 00:23:10,170
ni anayejali tu jinsi gani unataka
kuwasilisha taarifa hiyo.

523
00:23:10,170 --> 00:23:13,560
Je, unataka kompyuta kwa
kutafsiri kwamba mfano wa bits?

524
00:23:13,560 --> 00:23:16,320
Hivyo hii si kitu mimi
ingekuwa ujumla kupendekeza kufanya.

525
00:23:16,320 --> 00:23:19,500
Ni kweli tu mfano kwa
kufikisha kwamba unaweza kabisa

526
00:23:19,500 --> 00:23:22,049
initialize integer kwa char.

527
00:23:22,049 --> 00:23:24,090
Kwa sababu chini ya
kofia ya char, bila shaka,

528
00:23:24,090 --> 00:23:26,170
ni tu idadi 0-255.

529
00:23:26,170 --> 00:23:28,540
>> Hivyo unaweza hakika
kuweka ndani ya int.

530
00:23:28,540 --> 00:23:30,890
Na nini hii pia
inaonyesha ni kwamba sisi

531
00:23:30,890 --> 00:23:34,040
unaweza kubadilisha kutoka moja
aina ya mwingine, hapa,

532
00:23:34,040 --> 00:23:36,780
hatimaye uchapishaji kitu kimoja.

533
00:23:36,780 --> 00:23:44,760
Na kwa kweli, hii nami kurekebisha online--
alikuwa na maana ya kusema hayo, tena, hapa.

534
00:23:44,760 --> 00:23:48,610
Hebu safi hii up online, na tutaweza
kuona katika walkthrough online kama inahitajika,

535
00:23:48,610 --> 00:23:50,280
kile kilichokusudiwa huko.

536
00:23:50,280 --> 00:23:50,960
>> OK.

537
00:23:50,960 --> 00:23:53,892
Mfano ili mwisho sasa kuwashirikisha
a na b na kisha tutaweza

538
00:23:53,892 --> 00:23:54,850
kuchukua mambo up notch.

539
00:23:54,850 --> 00:23:58,330
Hivyo, pamoja na na b na
c katika mtaji

540
00:23:58,330 --> 00:24:01,560
na yanayolinagana yake, hebu
kuangalia mfano huu, hapa.

541
00:24:01,560 --> 00:24:02,752
Mwingine code mfano.

542
00:24:02,752 --> 00:24:04,460
Tutaweza kufungua moja ambayo
tayari alifanya, hivyo sisi

543
00:24:04,460 --> 00:24:06,440
hawana aina yake
wote nje kutoka mwanzo.

544
00:24:06,440 --> 00:24:09,420
>> Na taarifa kwa kutarajia
sisi ni kutumia header nyingi

545
00:24:09,420 --> 00:24:13,240
files, kati ya ambayo ni
rafiki yetu mpya, string.h.

546
00:24:13,240 --> 00:24:15,597
Sasa hii inaonekana, kwa mara ya kwanza
mtazamo, kidogo cryptic.

547
00:24:15,597 --> 00:24:18,180
Lakini hebu angalia kama hatuwezi kufikiri
njia ya nini kinaendelea hapa.

548
00:24:18,180 --> 00:24:21,150
Kwanza mimi kupata kamba kutoka kwa mtumiaji,
na mimi kuweka kamba kwamba katika variable

549
00:24:21,150 --> 00:24:22,286
kuitwa s.

550
00:24:22,286 --> 00:24:24,090
Nakala kuweka kutoka kabla.

551
00:24:24,090 --> 00:24:27,250
Katika line 22, mimi nina inaonekana
kufanya nini hasa

552
00:24:27,250 --> 00:24:30,760
Mimi wakati iliyopita, mimi nina iterating
juu ya wahusika katika s.

553
00:24:30,760 --> 00:24:34,780
>> Na mbinu mpya hapa ni kutumia
kamba urefu, optimization madogo

554
00:24:34,780 --> 00:24:37,930
ya kuhifadhi kamba urefu katika n,
badala ya wito strlen tena,

555
00:24:37,930 --> 00:24:38,850
na tena, na tena.

556
00:24:38,850 --> 00:24:41,120
Na tu kuangalia kwamba i ni chini ya n.

557
00:24:41,120 --> 00:24:43,330
Sasa hapa, mambo kupata
kidogo ya kuvutia.

558
00:24:43,330 --> 00:24:45,980
Lakini ni tu ya maombi
mpya wazo hili moja.

559
00:24:45,980 --> 00:24:48,470
Nini katika lugha ya Kiingereza gani
s bracket i kuwakilisha?

560
00:24:48,470 --> 00:24:51,772

561
00:24:51,772 --> 00:24:54,260
>> Watazamaji: kuhesabu kila
tabia ya [inaudible].

562
00:24:54,260 --> 00:24:55,926
>> DAVID J. Malan: kuhesabu kila tabia.

563
00:24:55,926 --> 00:24:58,680
Na hata zaidi kwa ufupi,
s bracket i kuwakilisha nini?

564
00:24:58,680 --> 00:25:00,950
Je, wewe kusema.

565
00:25:00,950 --> 00:25:04,084
Si kuweka wewe juu ya doa hapa.

566
00:25:04,084 --> 00:25:06,375
>> Watazamaji: Well--

567
00:25:06,375 --> 00:25:09,500
DAVID J. Malan: Hivyo kama neno is-- kama
kamba ni Zamyla, ambayo starts--

568
00:25:09,500 --> 00:25:12,380
Watazamaji: --you kukabiliana na
wahusika separately--

569
00:25:12,380 --> 00:25:13,690
DAVID J. Malan: Good.

570
00:25:13,690 --> 00:25:14,190
Hasa.

571
00:25:14,190 --> 00:25:17,940
mraba bracket nukuu utapata
kupata kila tabia mmoja mmoja,

572
00:25:17,940 --> 00:25:21,120
hivyo s bracket 0 ni kwenda kuwa
tabia ya kwanza katika kamba.

573
00:25:21,120 --> 00:25:24,110
s bracket 1 ni kwenda kuwa
pili, na kadhalika.

574
00:25:24,110 --> 00:25:28,050
Hivyo swali mimi nina kuuliza,
hapa, katika hali hii ni nini?

575
00:25:28,050 --> 00:25:33,984
Ni tabia ya i'th ya s zaidi
kuliko au sawa na Herufi za chini?

576
00:25:33,984 --> 00:25:36,400
Na hii ina maana gani, hapa,
na ampersands mara mbili?

577
00:25:36,400 --> 00:25:36,800
Watazamaji (PAMOJA): Na.

578
00:25:36,800 --> 00:25:37,210
DAVID J. Malan: Na.

579
00:25:37,210 --> 00:25:38,418
Ni tu sawa na hii.

580
00:25:38,418 --> 00:25:42,310
Na ni si keyword katika C, una
matumizi, annoyingly, Ampersand Ampersand.

581
00:25:42,310 --> 00:25:47,520
Na hii, kinyume chake, ni kuuliza ni
s ya i'th tabia ya chini ya au sawa

582
00:25:47,520 --> 00:25:49,030
Herufi za chini kwa z?

583
00:25:49,030 --> 00:25:52,440
Na tena, hapa ambapo
kuelewa msingi

584
00:25:52,440 --> 00:25:54,550
utekelezaji wa
kompyuta hufanya akili.

585
00:25:54,550 --> 00:25:57,330
Taarifa kwamba, hata mimi na
dot dot dot zaidi ya hapo,

586
00:25:57,330 --> 00:26:04,410
inaonekana kama njia ya z katika lowercase ni
maadili yote contiguous up kutoka 97 juu ya up.

587
00:26:04,410 --> 00:26:07,820
>> Na moja kwa ajili uppercase kuanzia saa 65.

588
00:26:07,820 --> 00:26:10,410
Hivyo takeaway, basi,
ni kwamba katika Kiingereza,

589
00:26:10,410 --> 00:26:12,760
jinsi gani unaweza kuelezea
nini line 24 anafanya?

590
00:26:12,760 --> 00:26:15,736

591
00:26:15,736 --> 00:26:16,728
Yeah?

592
00:26:16,728 --> 00:26:21,575
>> Watazamaji: Tarehe 24 ni kuangalia kuona
kama kila tabia ni ndogo.

593
00:26:21,575 --> 00:26:24,700
DAVID J. Malan: Ni kuangalia kama
tabia ya kila mmoja ni barua lowercase.

594
00:26:24,700 --> 00:26:28,590
Hivyo hata zaidi kwa ufupi, ni
i'th tabia ya s lowercase?

595
00:26:28,590 --> 00:26:30,690
Hayo ni yote sisi ni
akielezea hapa mantiki,

596
00:26:30,690 --> 00:26:33,750
kidogo isiyoeleweka kirahisi, lakini
hatimaye pretty straightforwardly.

597
00:26:33,750 --> 00:26:36,480
Ni s ya i'th tabia ya lowercase?

598
00:26:36,480 --> 00:26:40,130
>> Kama ni hivyo, na hapa ni ambapo mambo
kupata mawazo kidogo bending

599
00:26:40,130 --> 00:26:44,760
kwa muda tu, kama ni hivyo, kwenda
mbele na magazeti nje tabia.

600
00:26:44,760 --> 00:26:47,360
Hivyo hii ni tu placeholder,
lakini nini tabia?

601
00:26:47,360 --> 00:26:53,710
Kwa nini mimi kufanya s bracket i
minus msemo huu hapa?

602
00:26:53,710 --> 00:26:55,110
>> Naam taarifa muundo hapa.

603
00:26:55,110 --> 00:26:57,380
idadi halisi si jambo sana.

604
00:26:57,380 --> 00:27:02,700
Lakini taarifa kwamba 97 ni
jinsi mbali mbali kutoka 65?

605
00:27:02,700 --> 00:27:03,560
>> Watazamaji: 32.

606
00:27:03,560 --> 00:27:04,480
>> DAVID J. Malan: 32.

607
00:27:04,480 --> 00:27:06,890
Jinsi mbali mbali ni 98 kutoka 66?

608
00:27:06,890 --> 00:27:07,740
>> Watazamaji: 32.

609
00:27:07,740 --> 00:27:09,890
>> DAVID J. Malan: Little c kutoka kubwa C?

610
00:27:09,890 --> 00:27:10,420
32.

611
00:27:10,420 --> 00:27:14,550
Hivyo kuna humle 32 kutoka
barua moja hadi nyingine.

612
00:27:14,550 --> 00:27:17,790
Hivyo kusema ukweli mimi, inaweza
kurahisisha hii kwamba.

613
00:27:17,790 --> 00:27:20,400
Lakini basi mimi nina aina ya vigumu coding
ngazi hii uelewa mdogo

614
00:27:20,400 --> 00:27:21,740
kwamba hakuna msomaji ni milele
kwenda kuelewa.

615
00:27:21,740 --> 00:27:25,080
Hivyo nina kwenda kujumlisha ni kama, mimi
kujua barua lowercase ni kubwa.

616
00:27:25,080 --> 00:27:28,400
Mimi najua mji mkuu wa barua ni
maadili ndogo, hazijaingizwa.

617
00:27:28,400 --> 00:27:33,216
>> Lakini hii ni sawa na ufanisi
akisema Ondoa 32 kutoka s bracket i.

618
00:27:33,216 --> 00:27:35,430
Hivyo katika mazingira ya haya
barua, kama barua

619
00:27:35,430 --> 00:27:38,950
hutokea kwa kuwa, lowercase
a, na mimi Ondoa 32,

620
00:27:38,950 --> 00:27:43,442
nini athari gani kwamba kuwa,
mathematically, juu ya Herufi za chini?

621
00:27:43,442 --> 00:27:44,400
Watazamaji: Capitalizes--

622
00:27:44,400 --> 00:27:45,691
DAVID J. Malan: herufi yake.

623
00:27:45,691 --> 00:27:48,440
Na hakika, hii ni kwa nini wetu
mpango inaitwa capitalize sifuri.

624
00:27:48,440 --> 00:27:51,590
Mpango huu ama
herufi kubwa katika herufi,

625
00:27:51,590 --> 00:27:54,580
baada ya kuangalia kama ni
kweli ya mbili lowercase.

626
00:27:54,580 --> 00:27:59,810
Vinginevyo, katika line 30, je, mimi kufanya kama
si ya mbili lowercase kwamba mimi nina

627
00:27:59,810 --> 00:28:02,852
kuangalia saa fulani
iteration katika kitanzi.

628
00:28:02,852 --> 00:28:03,890
Tu magazeti nje.

629
00:28:03,890 --> 00:28:07,010
>> Hivyo si mabadiliko ya mambo
si kwamba hata lowercase.

630
00:28:07,010 --> 00:28:10,790
Kuzuia mwenyewe
a kidogo kupitia z kidogo.

631
00:28:10,790 --> 00:28:12,730
Sasa hii ni haki arcane.

632
00:28:12,730 --> 00:28:15,230
Lakini mwisho wa siku, hii
ni jinsi sisi, mara moja juu ya muda,

633
00:28:15,230 --> 00:28:16,460
alikuwa na kutekeleza mambo.

634
00:28:16,460 --> 00:28:19,780
Kama mimi badala wazi capitalize
moja, oh kumshukuru mungu.

635
00:28:19,780 --> 00:28:22,320
Kuna kazi
kuitwa juu kwamba unaweza

636
00:28:22,320 --> 00:28:25,410
kufanya kila kitu sisi tu alifanya
katika ngazi ya haki ya chini.

637
00:28:25,410 --> 00:28:28,752
>> Sasa kwa juu ni ya kuvutia
kwa sababu ni alitangaza katika faili,

638
00:28:28,752 --> 00:28:31,210
na ungependa kujua tu hii
kwa kuangalia nyaraka,

639
00:28:31,210 --> 00:28:35,730
au kuambiwa, kusema, katika darasa, ambapo
ipo, katika faili inayoitwa ctype.h.

640
00:28:35,730 --> 00:28:37,630
Hivyo hii ni rafiki mwingine mpya yetu.

641
00:28:37,630 --> 00:28:40,750
Na kwa juu gani hasa
nini jina lake anapendekeza.

642
00:28:40,750 --> 00:28:44,860
>> Unaweza kupita katika, kama hoja, kati ya
mabano haya, baadhi tabia.

643
00:28:44,860 --> 00:28:48,390
Mimi nina kwenda kupita katika tabia ya i'th
ya s kutumia dhana mpya nukuu yetu

644
00:28:48,390 --> 00:28:49,870
kuwashirikisha mabano mraba.

645
00:28:49,870 --> 00:28:53,391
Na kuchukua nadhani, ni nini kurudi
thamani ya juu kwa inaonekana kwenda

646
00:28:53,391 --> 00:28:53,890
kuwa?

647
00:28:53,890 --> 00:28:56,460

648
00:28:56,460 --> 00:28:57,770
barua mji mkuu.

649
00:28:57,770 --> 00:28:58,620
barua mji mkuu.

650
00:28:58,620 --> 00:29:02,330
>> Hivyo kama mimi kupita katika lowercase a,
hopefully, kwa ufafanuzi wa kwa juu,

651
00:29:02,330 --> 00:29:05,600
ni kwenda na kurudi
uppercase A. Vinginevyo,

652
00:29:05,600 --> 00:29:08,590
kama si ya mbili lowercase katika
nafasi ya kwanza, mimi tu magazeti nje.

653
00:29:08,590 --> 00:29:10,800
Na hakika, taarifa
rafiki ya pili hapa.

654
00:29:10,800 --> 00:29:13,840
Si tu kwa juu lipo,
lakini ni ya chini, ambayo

655
00:29:13,840 --> 00:29:16,200
kweli majibu kwamba swali kwa ajili yangu.

656
00:29:16,200 --> 00:29:19,730
>> Sasa mtu aliandika mambo haya,
10s ya miaka iliyopita, unajua nini?

657
00:29:19,730 --> 00:29:23,840
Kutekelezwa kwa juu na ni
kupunguza kwa kutumia kanuni kama hii.

658
00:29:23,840 --> 00:29:27,270
Lakini tena, sambamba na
wazo hili la abstracting mbali,

659
00:29:27,270 --> 00:29:29,190
aina ya, ngazi ya chini
utekelezaji maelezo.

660
00:29:29,190 --> 00:29:32,600
Na kusimama juu ya mabega ya watu
ambaye alikuja mbele yetu, kwa kutumia kazi

661
00:29:32,600 --> 00:29:36,300
kama kwa juu na ni ya chini, ambayo
ajabu ya kutosha ni nicely

662
00:29:36,300 --> 00:29:40,190
jina lake kwa kusema nini wao kufanya, ni
dhana ya ajabu kupitisha.

663
00:29:40,190 --> 00:29:44,040
>> Sasa, ni zinageuka kuwa kama mimi kusoma
mtu kwa ukurasa, kusema, kwa juu,

664
00:29:44,040 --> 00:29:45,010
Mimi kujifunza kitu kingine.

665
00:29:45,010 --> 00:29:46,890
Hivyo mtu toupper.

666
00:29:46,890 --> 00:29:48,050
Ni kidogo mno.

667
00:29:48,050 --> 00:29:51,110
Lakini sikia, hapa ni kwamba kutaja ya
header faili kwamba mimi wanapaswa kutumia.

668
00:29:51,110 --> 00:29:54,460
Kama kando, kwa sababu hii
ni kupotosha, kazi

669
00:29:54,460 --> 00:29:59,070
anatumia ints badala ya chars
kwa sababu ya kuangalia makosa.

670
00:29:59,070 --> 00:30:01,260
Lakini tutaweza labda kuja
nyuma na kwamba katika siku zijazo.

671
00:30:01,260 --> 00:30:05,910
>> Lakini taarifa, hapa, kwa waumini juu
barua c kwa uppercase kama inawezekana.

672
00:30:05,910 --> 00:30:07,674
Hivyo hiyo ni pretty moja kwa moja.

673
00:30:07,674 --> 00:30:09,340
Na sasa hebu kuwa maalum kidogo zaidi.

674
00:30:09,340 --> 00:30:12,750
Hebu tuangalie sehemu ya
mtu chini ya ukurasa thamani kurudi.

675
00:30:12,750 --> 00:30:15,420
thamani akarudi ni kwamba
wa barua waongofu.

676
00:30:15,420 --> 00:30:18,690
Au c, kama kubadilika
haikuwezekana,

677
00:30:18,690 --> 00:30:20,250
ambapo c ni ya awali ya pembejeo.

678
00:30:20,250 --> 00:30:24,140
Ambayo najua kutoka hapa, kutoka
hoja ya kwa juu.

679
00:30:24,140 --> 00:30:25,780
>> Hivyo ni takeaway ya hii nini?

680
00:30:25,780 --> 00:30:28,060
thamani akarudi ni kwamba
wa barua waongofu,

681
00:30:28,060 --> 00:30:32,110
au c, barua ya awali, kama
uongofu hakuwa iwezekanavyo.

682
00:30:32,110 --> 00:30:36,460
Nini kuboresha naweza hiyo
kufanya kwa kubuni kanuni wangu?

683
00:30:36,460 --> 00:30:37,146
Yeah?

684
00:30:37,146 --> 00:30:38,810
>> Watazamaji: Unaweza kuondoa mwingine.

685
00:30:38,810 --> 00:30:40,810
DAVID J. Malan: Mimi unaweza
kuondoa kingine kauli,

686
00:30:40,810 --> 00:30:42,510
na si tu mwingine taarifa.

687
00:30:42,510 --> 00:30:44,150
>> Watazamaji: Unaweza kuondoa [inaudible].

688
00:30:44,150 --> 00:30:46,310
>> DAVID J. Malan: Mimi unaweza
kuondoa uma nzima

689
00:30:46,310 --> 00:30:48,209
katika barabara, akaonekana na kama mwingine kabisa.

690
00:30:48,209 --> 00:30:50,250
Hivyo kweli, basi mimi kufungua
toleo la mwisho la hii,

691
00:30:50,250 --> 00:30:55,540
capitalize-2 na taarifa tu jinsi gani, kama
wewe, sexy, kanuni na sasa ni kupata,

692
00:30:55,540 --> 00:31:00,040
katika kwamba nimepata kupunguzwa kutoka kwa baadhi ya
saba au hivyo mistari ya nne tu,

693
00:31:00,040 --> 00:31:03,850
utendaji kwamba mimi nia
kwa kifupi wito kwa juu,

694
00:31:03,850 --> 00:31:09,410
kupita katika s bracket i, na uchapishaji
nje, na placeholder% c,

695
00:31:09,410 --> 00:31:11,090
kwamba tabia fulani.

696
00:31:11,090 --> 00:31:14,560
>> Sasa arguably, kuna mdudu,
au angalau hatari ya mdudu,

697
00:31:14,560 --> 00:31:15,350
katika mpango huu.

698
00:31:15,350 --> 00:31:18,200
Hivyo tu kurudi
kwa takeaway awali,

699
00:31:18,200 --> 00:31:21,820
kile lazima mimi pengine pia kufanya katika
mpango huu kwa kufanya hivyo imara zaidi,

700
00:31:21,820 --> 00:31:24,974
hivyo kwamba hakuna njia hiyo unaweza
ajali, hata katika kesi nadra?

701
00:31:24,974 --> 00:31:26,390
Watazamaji: Hakikisha siyo null.

702
00:31:26,390 --> 00:31:28,056
DAVID J. Malan: Hakikisha siyo null.

703
00:31:28,056 --> 00:31:31,030
Hivyo kweli, kufanya hii super
sahihi, mimi lazima kufanya kitu kama,

704
00:31:31,030 --> 00:31:35,300
kama s ni si null, basi
kwenda mbele na kutekeleza

705
00:31:35,300 --> 00:31:38,470
mistari haya ya kanuni, ambayo
Naweza kisha Indent kama kwamba,

706
00:31:38,470 --> 00:31:39,870
na kisha kuweka katika brace yangu wa karibu.

707
00:31:39,870 --> 00:31:41,550
Hivyo nzuri tying pamoja wa mawazo mawili.

708
00:31:41,550 --> 00:31:42,429
Yeah?

709
00:31:42,429 --> 00:31:44,470
Watazamaji: Je, unaweza kutumia
a kufanya wakati kitanzi, badala yake?

710
00:31:44,470 --> 00:31:47,270
DAVID J. Malan: Inawezekana
Mimi kufanya wakati kitanzi do?

711
00:31:47,270 --> 00:31:50,020
Watazamaji: --you unataka kuhakikisha
kwamba wewe kweli [inaudible].

712
00:31:50,020 --> 00:31:51,728
DAVID J. Malan: Inawezekana
matumizi do wakati?

713
00:31:51,728 --> 00:31:52,450
Short jibu, hakuna.

714
00:31:52,450 --> 00:31:54,700
Kwa sababu wewe ni kuhusu
kuanzisha kesi nyingine kona.

715
00:31:54,700 --> 00:31:56,660
Kama string ni ya sifuri urefu.

716
00:31:56,660 --> 00:31:59,600
Kama kwa mfano, mimi tu hit
Kuingia, bila hata kuandika Zamyla.

717
00:31:59,600 --> 00:32:02,490
Mimi nina kwenda mkono wewe nyuma halisi
kamba, kama tutaweza hatimaye kuona,

718
00:32:02,490 --> 00:32:03,780
ambayo ina wahusika sifuri.

719
00:32:03,780 --> 00:32:05,630
Bado kamba,
ni tu super short.

720
00:32:05,630 --> 00:32:07,960
Lakini kama wewe kutumia do wakati,
wewe ni kwenda upofu

721
00:32:07,960 --> 00:32:10,050
kujaribu kufanya kitu kwa
heshima kwa kamba kwamba,

722
00:32:10,050 --> 00:32:12,537
na hakuna kitu kinaendelea kuwa huko.

723
00:32:12,537 --> 00:32:18,607
>> Watazamaji: Naam, kama alivyofanya
kufanya [inaudible] wakati s--

724
00:32:18,607 --> 00:32:21,190
DAVID J. Malan: Oh mimi kuona, kuweka
kupata kamba kutoka kwa mtumiaji.

725
00:32:21,190 --> 00:32:23,525
Jibu Hivyo short, wewe
inaweza, na kushika kuwalazimisha

726
00:32:23,525 --> 00:32:26,150
yao kukupa kamba hiyo ni
short kutosha walionao katika kumbukumbu.

727
00:32:26,150 --> 00:32:26,700
Kabisa.

728
00:32:26,700 --> 00:32:27,630
Mimi tu alichagua si kwa.

729
00:32:27,630 --> 00:32:30,505
Kama hawana nipe kamba mimi
wanataka, mimi nina kuacha, mimi nina kutoa up.

730
00:32:30,505 --> 00:32:33,260
Lakini kabisa, kwa ajili hiyo,
unaweza kabisa kufanya hivyo.

731
00:32:33,260 --> 00:32:37,500
>> Hivyo header files maktaba kwamba
sisi ni sasa ukoo na ni hizi, hapa.

732
00:32:37,500 --> 00:32:41,550
Standard I / O, CS50.h, string.h,
ctype.h, na kuna ni kweli, wengine.

733
00:32:41,550 --> 00:32:44,460
Baadhi ya umegundua
maktaba math katika math.h.

734
00:32:44,460 --> 00:32:48,200
Lakini ngoja kuanzisha wewe, sasa, kwa
rasilimali hii kwamba CS50 wafanyakazi, Davin,

735
00:32:48,200 --> 00:32:50,630
na Rob, na Gabe hasa
kuweka pamoja.

736
00:32:50,630 --> 00:32:52,630
Kwamba hivi karibuni kiungo juu ya
tovuti shaka ya.

737
00:32:52,630 --> 00:32:54,870
Ni wito CS50 kumbukumbu.

738
00:32:54,870 --> 00:32:58,230
>> Ambayo tu kukupa haraka
ladha yake, kazi kama ifuatavyo.

739
00:32:58,230 --> 00:33:00,740
Hebu kwenda reference.cs50.net.

740
00:33:00,740 --> 00:33:02,990
Utaona upande wa kushoto
upande orodha balaa

741
00:33:02,990 --> 00:33:04,595
ya kazi ya kwamba kuja na c.

742
00:33:04,595 --> 00:33:07,790
Lakini kama mimi huduma, kwa sasa,
juu ya kitu kama strlen,

743
00:33:07,790 --> 00:33:08,746
Siwezi aina yake huko.

744
00:33:08,746 --> 00:33:10,870
Ni filters chini orodha
kwa kile tu huduma ya juu.

745
00:33:10,870 --> 00:33:11,940
Mimi nina kwenda bonyeza yake.

746
00:33:11,940 --> 00:33:14,740
Na sasa juu ya kushoto,
utaona nini sisi matumaini

747
00:33:14,740 --> 00:33:18,290
ni zaidi moja kwa moja, binadamu
kirafiki maelezo ya jinsi ya

748
00:33:18,290 --> 00:33:19,170
kazi hii matendo.

749
00:33:19,170 --> 00:33:20,600
>> Anarudi urefu wa kamba.

750
00:33:20,600 --> 00:33:24,060
Hapa ni synopsis, hapa ni jinsi gani
matumizi yake katika suala la header ya faili,

751
00:33:24,060 --> 00:33:27,430
na katika suala la nini kazi
inaonekana kama katika suala la hoja yake.

752
00:33:27,430 --> 00:33:30,250
Na kisha hapa, anarudi
urefu wa kamba.

753
00:33:30,250 --> 00:33:34,280
Lakini kwa wale wa wewe vizuri zaidi,
unaweza kweli click zaidi comfy,

754
00:33:34,280 --> 00:33:37,070
na yaliyomo ya hii
ukurasa, sasa, kutakuwa na mabadiliko

755
00:33:37,070 --> 00:33:41,660
kuwa na maadili default ya nini
kupata kwa kutumia ukurasa mwanadamu.

756
00:33:41,660 --> 00:33:44,100
>> Kwa maneno mengine, CS50
kumbukumbu ni kurahisisha

757
00:33:44,100 --> 00:33:46,220
ya mtu kurasa na wafanyakazi, kwa ajili ya wanafunzi.

758
00:33:46,220 --> 00:33:49,320
Hasa, wale chini ya starehe
na katika kati ya, ili

759
00:33:49,320 --> 00:33:51,660
hawana kujaribu wrap
akili yako karibu, kusema ukweli,

760
00:33:51,660 --> 00:33:55,030
baadhi syntax haki cryptic
na nyaraka wakati mwingine.

761
00:33:55,030 --> 00:33:57,650
>> Hivyo kuendelea kuwa katika akili
katika siku zijazo.

762
00:33:57,650 --> 00:33:59,560
Hivyo hapa, tena, ni Zamyla.

763
00:33:59,560 --> 00:34:03,255
Hebu sasa kuuliza swali kwamba
binadamu kidogo zaidi kupatikana.

764
00:34:03,255 --> 00:34:05,380
Shukrani kwa Chang, ambaye imekuwa
uchapishaji tembo zaidi

765
00:34:05,380 --> 00:34:07,090
nonstop kwa siku chache zilizopita.

766
00:34:07,090 --> 00:34:09,730
Tuna nafasi ya kutoa
angalau mmoja wao mbali.

767
00:34:09,730 --> 00:34:13,239
Kama tunaweza kupata kujitolea moja tu
kuja juu hadi kuteka juu ya screen.

768
00:34:13,239 --> 00:34:14,530
Vipi kuhusu hapa?

769
00:34:14,530 --> 00:34:15,340
>> Kuja juu juu.

770
00:34:15,340 --> 00:34:16,720
Jina lako ni nani?

771
00:34:16,720 --> 00:34:17,219
ALEX: Alex.

772
00:34:17,219 --> 00:34:17,760
DAVID J. Malan: Alex.

773
00:34:17,760 --> 00:34:18,259
Wote haki.

774
00:34:18,259 --> 00:34:19,388
Alex, kuja juu up.

775
00:34:19,388 --> 00:34:21,679
Sisi ni juu ya kuona yako
mwandiko juu ya screen hapa.

776
00:34:21,679 --> 00:34:24,325

777
00:34:24,325 --> 00:34:25,570
Haki zote, nzuri ya kukutana na wewe.

778
00:34:25,570 --> 00:34:26,429
>> ALEX: Nice wewe kukutana na wewe.

779
00:34:26,429 --> 00:34:27,512
>> DAVID J. Malan: All wa kulia.

780
00:34:27,512 --> 00:34:28,969
Hivyo, zoezi super rahisi.

781
00:34:28,969 --> 00:34:31,440
Bar ni si juu kwa
kupata tembo leo.

782
00:34:31,440 --> 00:34:33,439
Wewe ni kucheza nafasi ya GetString.

783
00:34:33,439 --> 00:34:35,980
Na mimi nina kwenda tu kukuambia
kamba kwamba wewe wameweza kujipatia.

784
00:34:35,980 --> 00:34:38,080
Na kudhani kwamba,
GetString, wamekuwa kuitwa.

785
00:34:38,080 --> 00:34:42,480
Na binadamu, kama mimi, ina
typed katika Zamyla, Z-A-M-Y-L-A.

786
00:34:42,480 --> 00:34:45,650
Tu kwenda mbele na kuandika Zamyla juu ya
screen kama wewe ingawa waliopata ni

787
00:34:45,650 --> 00:34:47,250
na kuhifadhiwa mahali fulani katika kumbukumbu.

788
00:34:47,250 --> 00:34:52,370

789
00:34:52,370 --> 00:34:55,570
>> Kuondoka chumba kwa nini itakuwa kadhaa
words-- mengine ambayo sawa, kuendelea.

790
00:34:55,570 --> 00:34:59,620
>> [Kicheko]

791
00:34:59,620 --> 00:35:00,800
>> Hivyo Zamyla, Excellent.

792
00:35:00,800 --> 00:35:04,880
Hivyo sasa tuseme kwamba wewe,
GetString, wameitwa tena.

793
00:35:04,880 --> 00:35:09,350
Na kwa sababu hiyo, mimi kutoa, katika
keyboard, na jina la mtu mwingine, Belinda.

794
00:35:09,350 --> 00:35:17,560

795
00:35:17,560 --> 00:35:18,060
Wote haki.

796
00:35:18,060 --> 00:35:22,380
Na sasa wakati mwingine GetString ni
kuitwa, mimi aina katika kitu kama Gabe,

797
00:35:22,380 --> 00:35:27,560
G-A-B-E. Wewe ni kweli kuchukua
kwa moyo random kupata kumbukumbu.

798
00:35:27,560 --> 00:35:29,631
Ambayo ni kuchora kila kitu
kabisa nasibu.

799
00:35:29,631 --> 00:35:30,130
OK.

800
00:35:30,130 --> 00:35:31,104
>> [Kicheko]

801
00:35:31,104 --> 00:35:32,520
ALEX: Sorry handwriting yangu ni mbaya.

802
00:35:32,520 --> 00:35:33,770
DAVID J. Malan: Hapana, hiyo ni sawa.

803
00:35:33,770 --> 00:35:40,480
Na vipi kuhusu Rob, R-O-B. OK.

804
00:35:40,480 --> 00:35:41,020
Good.

805
00:35:41,020 --> 00:35:43,853
Hivyo sikuwa wanatarajia ungependa
aina ya kuweka mambo ya nje kwa njia hii.

806
00:35:43,853 --> 00:35:45,020
Lakini tunaweza kufanya kazi hii.

807
00:35:45,020 --> 00:35:48,810
Hivyo ni jinsi gani wewe kwenda juu ya kuwekewa
nje chars hizi katika kumbukumbu?

808
00:35:48,810 --> 00:35:51,310
Kwa maneno mengine, kama sisi kufikiri ya
hii screen rectangular nyeusi

809
00:35:51,310 --> 00:35:53,550
kama anayewakilisha
kompyuta ya RAM, au kumbukumbu.

810
00:35:53,550 --> 00:35:55,850
>> Na kukumbuka kwamba RAM ni tu
rundo zima la ka,

811
00:35:55,850 --> 00:35:57,480
na ka ni rundo zima la bits.

812
00:35:57,480 --> 00:35:59,350
Na bits ni kwa namna fulani
kutekelezwa, kwa ujumla

813
00:35:59,350 --> 00:36:01,119
na baadhi ya fomu ya
umeme katika vifaa.

814
00:36:01,119 --> 00:36:03,160
Hivyo hiyo ni aina ya
layering tumekuwa aliyesema kuhusu

815
00:36:03,160 --> 00:36:04,510
na sasa wanaweza kuchukua kwa nafasi.

816
00:36:04,510 --> 00:36:07,020
Jinsi gani wewe kwenda juu ya
kuamua wapi kuandika

817
00:36:07,020 --> 00:36:11,634
Rob dhidi ya Gabe dhidi ya
Belinda dhidi ya Zamyla?

818
00:36:11,634 --> 00:36:14,020
>> ALEX: mimi tu alifanya hivyo katika
kuamuru kwamba wewe aliniambia.

819
00:36:14,020 --> 00:36:15,650
>> DAVID J. Malan: Na kwamba ni kweli.

820
00:36:15,650 --> 00:36:20,100
Lakini nini serikali ambapo wewe kuweka
Jina Belinda na jina Gabe ya?

821
00:36:20,100 --> 00:36:20,764
>> ALEX: Hakuna?

822
00:36:20,764 --> 00:36:22,930
DAVID J. Malan: [anacheka]
Hivyo kwamba kazi, hiyo faini.

823
00:36:22,930 --> 00:36:25,290
Hivyo kompyuta ni kidogo
mzuri zaidi kuliko hiyo.

824
00:36:25,290 --> 00:36:29,000
Na hivyo wakati sisi implement-- kukaa huko
kwa tu moment-- wakati sisi kweli

825
00:36:29,000 --> 00:36:31,470
kutekeleza kitu kama
GetString katika kompyuta,

826
00:36:31,470 --> 00:36:34,480
Zamyla inaweza kuwa kuweka nje pretty much
kama alivyofanya juu ya screen, huko.

827
00:36:34,480 --> 00:36:36,660
>> Na nini ni muhimu kwa taarifa
hapa, nini Alex hivyo,

828
00:36:36,660 --> 00:36:40,260
ni kuna aina ya utengenezaji
kati ya kila moja ya maneno haya, sawa?

829
00:36:40,260 --> 00:36:46,580
You hakuwa na kuandika
Z-A-M-Y-L-A-B-E-L-I-N-D-A-G-A-B--

830
00:36:46,580 --> 00:36:49,740
kwa maneno mengine, kuna aina fulani
wa utengo ambayo inaonekana kuwa,

831
00:36:49,740 --> 00:36:52,370
aina ya, random nafasi
kati ya maneno haya mbalimbali.

832
00:36:52,370 --> 00:36:54,120
Lakini hiyo ni nzuri, kwa sababu
sisi wanadamu sasa wanaweza

833
00:36:54,120 --> 00:36:56,470
taswira kwamba haya ni
nne masharti tofauti.

834
00:36:56,470 --> 00:36:59,540
Siyo mlolongo moja tu
ya kura ya wahusika.

835
00:36:59,540 --> 00:37:04,190
Hivyo kompyuta, basi, wakati huo huo,
inaweza kuchukua string kama Zamyla,

836
00:37:04,190 --> 00:37:07,220
kuweka kila ya barua hizo
ndani ya byte ya kumbukumbu.

837
00:37:07,220 --> 00:37:10,400
Lakini idadi hiyo ni kubwa sana,
bila shaka, kuliko wahusika sita.

838
00:37:10,400 --> 00:37:11,690
>> Kuna rundo zima la RAM.

839
00:37:11,690 --> 00:37:15,330
Na hivyo tena, hii
gridi ya masanduku ni kwenda

840
00:37:15,330 --> 00:37:17,560
kuwakilisha nini Alex tu
alifanya hapa juu ya screen.

841
00:37:17,560 --> 00:37:20,937
Na sasa, Alex, tunaweza kutoa
rangi ya bluu au tembo machungwa kutoka Chang.

842
00:37:20,937 --> 00:37:22,270
ALEX: Mimi itabidi kuchukua tembo bluu.

843
00:37:22,270 --> 00:37:23,120
DAVID J. Malan: tembo bluu.

844
00:37:23,120 --> 00:37:25,580
Hivyo duru kubwa ya applause,
kama tunaweza, kwa Alex hapa.

845
00:37:25,580 --> 00:37:26,100
>> [Makofi]

846
00:37:26,100 --> 00:37:26,766
>> ALEX: Asante.

847
00:37:26,766 --> 00:37:28,820
DAVID J. Malan: Asante.

848
00:37:28,820 --> 00:37:36,230
Hivyo takeaway ni kwamba, ingawa
muundo aina ya iliyopita baada ya muda, hapa

849
00:37:36,230 --> 00:37:40,430
juu ya bodi, kulikuwa na hii
utengenezaji wa kati ya masharti mbalimbali

850
00:37:40,430 --> 00:37:42,610
kwamba Alex got kwa ajili yetu.

851
00:37:42,610 --> 00:37:45,230
Sasa kompyuta, kusema ukweli,
inaweza kufanya kitu kimoja.

852
00:37:45,230 --> 00:37:48,210
Wangeweza aina ya plop
masharti mahali popote katika RAM.

853
00:37:48,210 --> 00:37:50,710
Up hapa, zaidi ya hapa,
hapa chini, chini hapa.

854
00:37:50,710 --> 00:37:52,020
>> Wangeweza kufanya hasa kwamba.

855
00:37:52,020 --> 00:37:54,280
Lakini, bila shaka, hiyo ni
pengine si mipango bora.

856
00:37:54,280 --> 00:37:54,780
Haki?

857
00:37:54,780 --> 00:37:57,340
Kama mimi naendelea kuuliza Alex kwa
kupata majina, pengine yeye d

858
00:37:57,340 --> 00:38:01,370
kuweka baadhi ya zaidi hapa chini, labda up
hapa, zaidi ya hapa, zaidi ya hapa, hatimaye

859
00:38:01,370 --> 00:38:02,211
zaidi ya hapa.

860
00:38:02,211 --> 00:38:05,460
Lakini pamoja na kidogo zaidi mipango, kwa hakika,
tunaweza kuweka mambo ya nje zaidi cleanly.

861
00:38:05,460 --> 00:38:07,350
Na hakika, kwamba ni nini kompyuta gani.

862
00:38:07,350 --> 00:38:10,720
>> Lakini catch ni kwamba
kama string ijayo mimi kupata

863
00:38:10,720 --> 00:38:14,050
baada ya Zamyla ni kitu
kama Belinda,

864
00:38:14,050 --> 00:38:17,929
kupendekeza ambapo tupate kuandika
barua b kwa heshima na gridi ya taifa hili?

865
00:38:17,929 --> 00:38:18,720
Wapi ungekwenda?

866
00:38:18,720 --> 00:38:21,480
Na haki ya a,
chini z, chini a?

867
00:38:21,480 --> 00:38:23,204
Gani silika yako ya kwanza kuwa?

868
00:38:23,204 --> 00:38:24,120
Watazamaji: Chini ya z.

869
00:38:24,120 --> 00:38:25,100
DAVID J. Malan: Hivyo chini z.

870
00:38:25,100 --> 00:38:26,530
Na kwamba ni pretty
moja kwa moja, haki?

871
00:38:26,530 --> 00:38:29,321
Ni aina ya nadhifu, ni nini cha kufanya
juu ya keyboard wakati sisi hit Enter,

872
00:38:29,321 --> 00:38:31,770
au barua pepe wakati wa kufanya
Vitone orodha ya mambo.

873
00:38:31,770 --> 00:38:34,310
Lakini ukweli ni kwamba kompyuta
kujaribu kuwa na ufanisi zaidi,

874
00:38:34,310 --> 00:38:37,170
na Cram hakika kama kiasi
data katika RAM kama inawezekana,

875
00:38:37,170 --> 00:38:38,890
hivyo kwamba huna kupoteza ka yoyote.

876
00:38:38,890 --> 00:38:41,545
Hivyo kwamba huna kupoteza
yoyote screen mali isiyohamishika.

877
00:38:41,545 --> 00:38:44,170
Na tatizo, ingawa, ni kwamba
kama sisi literally kuweka barua

878
00:38:44,170 --> 00:38:49,940
b baada ya, jinsi sisi kwenda
kujua ambapo jina Zamyla ya mwisho

879
00:38:49,940 --> 00:38:51,840
na jina Belinda inaanza?

880
00:38:51,840 --> 00:38:55,270
Hivyo binadamu tu mapendekezo, vizuri,
hit Enter muhimu, kimsingi.

881
00:38:55,270 --> 00:38:56,410
Kuiweka chini chini.

882
00:38:56,410 --> 00:38:59,750
Au hata kama Alex hivyo, tu kuanza kuandika
jina ya chini mmoja uliopita,

883
00:38:59,750 --> 00:39:01,583
na chini kwamba mmoja, na
kisha chini ya kwamba moja.

884
00:39:01,583 --> 00:39:02,510
Hiyo ni cue Visual.

885
00:39:02,510 --> 00:39:05,960
>> Kompyuta na mwingine cue Visual,
lakini ni kidogo zaidi succinct.

886
00:39:05,960 --> 00:39:07,840
Ni tabia hii funky.

887
00:39:07,840 --> 00:39:11,890
Backslash 0, ambayo ni labda
kukumbusha ya backslash n,

888
00:39:11,890 --> 00:39:12,640
na kadhalika, sasa.

889
00:39:12,640 --> 00:39:14,120
maalum kutoroka Mwandamano.

890
00:39:14,120 --> 00:39:19,120
Backslash 0 ni njia ya
anayewakilisha nane zero bits katika mfululizo.

891
00:39:19,120 --> 00:39:22,000
0000 0000.

892
00:39:22,000 --> 00:39:26,130
>> njia wewe kueleza kwamba si
hit idadi sifuri juu ya keyboard yako,

893
00:39:26,130 --> 00:39:28,140
kwa sababu katika ukweli kwamba ni char ASCII.

894
00:39:28,140 --> 00:39:30,990
Inaonekana kama idadi, lakini
ni kweli idadi decimal

895
00:39:30,990 --> 00:39:35,910
kwamba inawakilisha mviringo
glyph, typeface mduara.

896
00:39:35,910 --> 00:39:38,410
Wakati huo huo, backslash
zero maana yake, literally

897
00:39:38,410 --> 00:39:40,700
kuweka nane zero ka hapa kwa ajili yangu.

898
00:39:40,700 --> 00:39:42,136
>> Hivyo hii ni kiasi fulani holela.

899
00:39:42,136 --> 00:39:44,260
Tunaweza tumekuwa kutumika yoyote mfano
ya bits, lakini dunia

900
00:39:44,260 --> 00:39:46,610
aliamua baadhi ya miaka
iliyopita, kwamba kuwakilisha

901
00:39:46,610 --> 00:39:49,710
mwisho wa kamba katika kumbukumbu,
tu ya kuweka rundo zima la zeros.

902
00:39:49,710 --> 00:39:51,000
Kwa sababu tunaweza kugundua kwamba.

903
00:39:51,000 --> 00:39:54,790
Sasa hiyo ina maana kwamba hakuna barua ya
alfabeti inaweza kuwakilishwa na zeros.

904
00:39:54,790 --> 00:39:58,480
>> Lakini hiyo ni OK, tumekuwa tayari kuona
kwamba sisi ni kutumia 65 juu ya up katika 97 juu ya up.

905
00:39:58,480 --> 00:40:00,290
Sisi hakuwa na kupata mahali popote
karibu na zeros wote.

906
00:40:00,290 --> 00:40:03,040

907
00:40:03,040 --> 00:40:06,540
Hivyo Belinda katika kumbukumbu ya kompyuta
ni kweli kwenda kwenda hapa.

908
00:40:06,540 --> 00:40:09,764
Nimekuwa inayotolewa katika njano tu
kuteka usikivu wetu kwa hilo.

909
00:40:09,764 --> 00:40:11,680
Na taarifa, pia, hii
ni kabisa holela.

910
00:40:11,680 --> 00:40:12,680
Nimekuwa inayotolewa ni kama gridi ya taifa.

911
00:40:12,680 --> 00:40:14,460
Kama, RAM ni baadhi tu kitu kimwili.

912
00:40:14,460 --> 00:40:17,300
Ni siyo lazima
safu na nguzo, per se.

913
00:40:17,300 --> 00:40:20,490
Ni tu got rundo zima la bytes
kutekelezwa katika vifaa kwa namna fulani.

914
00:40:20,490 --> 00:40:22,817
Lakini kama baada ya Belinda mimi
typed katika jina Gabe ya,

915
00:40:22,817 --> 00:40:25,650
yeye kwenda kuishia hapa katika kumbukumbu,
na kama mimi typed katika jina Daven ya,

916
00:40:25,650 --> 00:40:27,316
kwa mfano, yeye kwenda kuishia hapa.

917
00:40:27,316 --> 00:40:29,310
Na siwezi kuendelea
kuandika majina hata zaidi.

918
00:40:29,310 --> 00:40:32,100
>> Kwa bahati mbaya, kama mimi kujaribu
kuandika jina super muda mrefu,

919
00:40:32,100 --> 00:40:33,730
Mimi ili hatimaye kukimbia nje ya kumbukumbu.

920
00:40:33,730 --> 00:40:37,810
Katika kesi ambayo, GetString ni
kwenda na kurudi null, kama sisi alisema.

921
00:40:37,810 --> 00:40:41,720
Bali nashiriki, angalau katika hili Visual
hapa, sisi hakuwa na kupata kabisa kuwa mbali.

922
00:40:41,720 --> 00:40:45,860
>> Sasa nini ni nzuri ni kwamba hii
ujumla wazo la kutibu mambo

923
00:40:45,860 --> 00:40:49,720
kama kuwa katika masanduku ni
mwakilishi wa hulka ya C

924
00:40:49,720 --> 00:40:52,690
na mengi ya lugha,
inayojulikana kama safu.

925
00:40:52,690 --> 00:40:55,490
safu ni aina nyingine ya data.

926
00:40:55,490 --> 00:40:57,380
Ni muundo data, kama wewe.

927
00:40:57,380 --> 00:41:01,160
Muundo kwa maana ya ni kweli,
aina ya, kuangalia kama sanduku, angalau

928
00:41:01,160 --> 00:41:02,320
katika macho ya akili yako.

929
00:41:02,320 --> 00:41:09,680
safu ni contiguous
mlolongo wa aina kufanana data,

930
00:41:09,680 --> 00:41:11,330
nyuma kwa nyuma kwa nyuma kwa nyuma.

931
00:41:11,330 --> 00:41:14,720
>> Hivyo kamba, katika nyingine
maneno, ni safu ya chars.

932
00:41:14,720 --> 00:41:16,120
safu ya wahusika.

933
00:41:16,120 --> 00:41:19,070
Lakini zinageuka unaweza kuwa na
arrays ya mashada ya mambo.

934
00:41:19,070 --> 00:41:21,870
Kwa kweli, tunaweza kuweka hata
idadi katika safu.

935
00:41:21,870 --> 00:41:23,920
Hivyo namna ambayo
sisi ni kwenda kuanza

936
00:41:23,920 --> 00:41:26,590
kutangaza data hii
muundo unaojulikana kama safu

937
00:41:26,590 --> 00:41:28,250
pia ni kwenda kutumia mabano mraba.

938
00:41:28,250 --> 00:41:31,500
Lakini haya mabano mraba ni kwenda
kuwa na maana tofauti katika muktadha huu.

939
00:41:31,500 --> 00:41:33,450
>> Na hebu angalia ni kama ifuatavyo.

940
00:41:33,450 --> 00:41:36,780
Tuseme kwamba mimi kufunguliwa
up faili mpya hapa.

941
00:41:36,780 --> 00:41:38,535
Na mimi kuokoa hii kama ages.c.

942
00:41:38,535 --> 00:41:41,280

943
00:41:41,280 --> 00:41:43,470
Na mimi itabidi kuokoa hii katika folder yangu hapa.

944
00:41:43,470 --> 00:41:46,130
Na sasa mimi nina kwenda mbele
na kuanza kuandika kitu

945
00:41:46,130 --> 00:41:53,940
kama ni pamoja na CS50.h, ni pamoja na
stdio.h, int kuu utupu.

946
00:41:53,940 --> 00:41:57,370
Na kisha ndani ya hapa, nataka
kwa kwanza na int kuitwa umri.

947
00:41:57,370 --> 00:42:01,371
>> Na mimi nina kwenda kutumia kwamba ili kupata
int kutoka kwa mtumiaji kwa umri wake.

948
00:42:01,371 --> 00:42:04,620
Lakini mpango huu ni maana ya kutumika na
watu mbalimbali, kwa mazingira chochote.

949
00:42:04,620 --> 00:42:05,490
Mimi nimepata line ya watu.

950
00:42:05,490 --> 00:42:08,281
Wote kuwa na aina katika yao
umri kwa baadhi labda, mimi sijui,

951
00:42:08,281 --> 00:42:10,530
ushindani, au tukio
kwamba wameweza aliwasili kwa.

952
00:42:10,530 --> 00:42:13,030
Hivyo mtu mwingine, mimi
haja mwingine kutofautiana.

953
00:42:13,030 --> 00:42:15,790
>> Kwa sababu kama mimi tu kufanya
umri anapata GetInt, hiyo ni

954
00:42:15,790 --> 00:42:18,500
kwenda clobber, au overwrite
umri wa mtu uliopita.

955
00:42:18,500 --> 00:42:19,760
Hivyo kwamba hakuna nzuri.

956
00:42:19,760 --> 00:42:21,790
Hivyo silika yangu ya kwanza
inaweza kuwa, oh, haki ya wote,

957
00:42:21,790 --> 00:42:26,260
kama nataka kupata nyingi ya watu
ages-- hebu kuwaita age1 hii,

958
00:42:26,260 --> 00:42:31,280
int age2 anapata int, int age3 anapata GetInt.

959
00:42:31,280 --> 00:42:35,340
Na sasa mimi nina kwenda kutumia
baadhi pseudocode code hapa.

960
00:42:35,340 --> 00:42:37,679
>> Kufanya kitu kwa wale idadi.

961
00:42:37,679 --> 00:42:40,470
Sisi itabidi kuondoka kwa siku nyingine nini
sisi ni kufanya huko, kwa sababu sisi tu

962
00:42:40,470 --> 00:42:44,200
huduma kwa wakati
kuhusu age1, age2, age3.

963
00:42:44,200 --> 00:42:46,450
Kwa bahati mbaya, mara moja mimi
kukusanya mpango huu

964
00:42:46,450 --> 00:42:51,140
na kuiweka mbele ya watumiaji halisi,
nini kubuni kimsingi maskini

965
00:42:51,140 --> 00:42:53,890
uamuzi mimi wanaonekana kuwa alifanya?

966
00:42:53,890 --> 00:42:54,624
Yeah?

967
00:42:54,624 --> 00:42:55,499
Watazamaji: [inaudible]

968
00:42:55,499 --> 00:42:58,071

969
00:42:58,071 --> 00:42:59,820
DAVID J. Malan: Yeah,
Mimi si hata alijaribu

970
00:42:59,820 --> 00:43:02,028
kufikiri umri jinsi wengi
Je, mimi kwa kweli huduma ya juu?

971
00:43:02,028 --> 00:43:05,380
Kama mimi na watu wachache kuliko tatu hapa,
na umri kwa hiyo chini ya tatu,

972
00:43:05,380 --> 00:43:07,260
Mimi bado upofu wanatarajia tatu.

973
00:43:07,260 --> 00:43:08,720
Hasha watu wanne kuonyesha up.

974
00:43:08,720 --> 00:43:10,990
Mpango wangu tu si hata msaada wao.

975
00:43:10,990 --> 00:43:13,280
>> Na hivyo hii, kwa muda mrefu hadithi
short, ni si tabia nzuri.

976
00:43:13,280 --> 00:43:13,780
Haki?

977
00:43:13,780 --> 00:43:16,530
Mimi nilikuwa kimsingi kuiga na
pasting code tweaking na tu

978
00:43:16,530 --> 00:43:17,430
variable majina.

979
00:43:17,430 --> 00:43:22,410
Na, mungu wangu, kama alikuwa na, na si watatu
milele, lakini 10, au 100, au hata 6500

980
00:43:22,410 --> 00:43:23,820
wanafunzi wa vyuo vikuu, kwa mfano.

981
00:43:23,820 --> 00:43:26,950
Hii si kwenda kuwa hasa
code kifahari, au endelevu.

982
00:43:26,950 --> 00:43:29,200
Wewe ni kwenda kuwa na
kuandika upya mpango kila wakati

983
00:43:29,200 --> 00:43:30,760
namba yako ya mabadiliko watu.

984
00:43:30,760 --> 00:43:35,090
>> Hivyo nashiriki, katika halisi wetu
ages.c faili kwa ajili ya leo,

985
00:43:35,090 --> 00:43:36,970
tuna ufumbuzi zaidi wajanja.

986
00:43:36,970 --> 00:43:39,800
Kwanza, mimi nina kwenda kukopa
kujenga tumekuwa kutumika mara chache,

987
00:43:39,800 --> 00:43:43,744
kufanya hivyo kitanzi wakati, ili kupata
idadi ya watu katika chumba.

988
00:43:43,744 --> 00:43:46,910
Mimi tu kwenda bemba user, tena
na tena, mpaka yeye au yeye anitiaye

989
00:43:46,910 --> 00:43:49,260
thamani ya n kwamba ni integer chanya.

990
00:43:49,260 --> 00:43:51,590
>> Mimi naweza kuwa kutumika, mwisho
wakati ya kupata chanya int.

991
00:43:51,590 --> 00:43:53,720
Lakini hatuna kwamba
kwa kweli, hivyo nilikwenda mbele

992
00:43:53,720 --> 00:43:55,660
na re kutekelezwa wazo hili.

993
00:43:55,660 --> 00:43:58,410
Sasa hapa chini, hii ni hila mpya.

994
00:43:58,410 --> 00:44:02,260
Katika line 27, kama comments
katika line 26 unaonyesha,

995
00:44:02,260 --> 00:44:05,180
kutangaza safu katika ambayo
kuhifadhi umri ya kila mtu.

996
00:44:05,180 --> 00:44:09,320
>> Hivyo kama unataka kupata, si moja int, si
ints mbili, lakini rundo zima la ints.

997
00:44:09,320 --> 00:44:13,800
Hasa n integers, walikuwa n nguvu
kuwa tatu, inaweza kuwa 100, inaweza kuwa 1,000.

998
00:44:13,800 --> 00:44:17,570
syntax, kabisa tu, ni kwa
kusema, nini data aina gani unataka?

999
00:44:17,570 --> 00:44:19,620
Je, unataka simu
kwamba chunk ya kumbukumbu?

1000
00:44:19,620 --> 00:44:23,530
Je, unataka simu gridi ya taifa
kwamba inaonekana kama hii pictorially?

1001
00:44:23,530 --> 00:44:27,700
>> Na katika mabano hapa, unaweza kusema
jinsi kubwa unataka safu kuwa.

1002
00:44:27,700 --> 00:44:30,450
Na hivyo awali, wakati mimi alisema
syntax ni tofauti kidogo hapa,

1003
00:44:30,450 --> 00:44:33,614
bado tuko kutumia mabano mraba,
lakini wakati mimi nina kutangaza safu,

1004
00:44:33,614 --> 00:44:35,530
simu ndani ya
mabano mraba njia

1005
00:44:35,530 --> 00:44:37,610
jinsi kubwa unataka safu kuwa.

1006
00:44:37,610 --> 00:44:42,490
>> Kwa upande mwingine, wakati sisi walikuwa kutumia s
bracket i wakati iliyopita, s, kamba,

1007
00:44:42,490 --> 00:44:46,820
ni kweli safu ya chars, lakini
wakati wewe ni si kutangaza variable,

1008
00:44:46,820 --> 00:44:49,760
kama na hii keyword hapa,
wewe ni tu kupata

1009
00:44:49,760 --> 00:44:54,280
index maalum, maalum
kipengele na kwamba safu.

1010
00:44:54,280 --> 00:44:57,090
Mara baada ya tunajua kwamba, wengine
hii ni moja kwa moja.

1011
00:44:57,090 --> 00:45:00,765
Kama mimi nina mpya kwanza kwenda magazeti nje
nini umri wa mtu simu i.

1012
00:45:00,765 --> 00:45:03,890
Ambapo mimi tu kusema mtu namba moja,
mtu namba mbili, mtu namba tatu.

1013
00:45:03,890 --> 00:45:06,306
>> Na mimi nina kufanya tu hesabu,
ili kama watu wa kawaida,

1014
00:45:06,306 --> 00:45:09,030
sisi kuhesabu kutoka moja kwa ajili ya hii
mpango, na si kutoka sifuri.

1015
00:45:09,030 --> 00:45:13,620
Kisha mimi wito GetInt, lakini mimi kuhifadhi
jibu katika umri bracket i.

1016
00:45:13,620 --> 00:45:16,610
Ambayo ni umri i'th katika safu.

1017
00:45:16,610 --> 00:45:21,640
Hivyo ambapo mara ya mwisho tulikuwa kutibu
masanduku hayo kama chars kwa jina Zamyla ya,

1018
00:45:21,640 --> 00:45:22,490
na wengine.

1019
00:45:22,490 --> 00:45:26,530
Sasa, masanduku hayo ya kuwakilisha
Bits 32, au ka nne

1020
00:45:26,530 --> 00:45:29,510
katika ambayo tunaweza kuhifadhi
int, int, int.

1021
00:45:29,510 --> 00:45:31,890
Yote ambayo, tena,
ni data aina moja.

1022
00:45:31,890 --> 00:45:33,890
>> Sasa mimi kufanya kitu silly,
kama wakati hupita, tu

1023
00:45:33,890 --> 00:45:35,510
kuhalalisha kuandika mpango huu.

1024
00:45:35,510 --> 00:45:40,050
Na kisha chini hapa, mimi tena iterate
juu ya safu akisema mwaka kuanzia sasa,

1025
00:45:40,050 --> 00:45:43,090
mtu mapenzi ya simu moja
kuwa na umri wa miaka kitu.

1026
00:45:43,090 --> 00:45:45,010
Na kufikiri kwamba
math-- I mean, hii

1027
00:45:45,010 --> 00:45:49,260
si sana ngumu arithmetic--
I just kuongeza moja na umri wao.

1028
00:45:49,260 --> 00:45:51,240
Tu kuonyesha, tena, hii.

1029
00:45:51,240 --> 00:45:57,910
>> Kama tu naweza index ndani ya kamba, s,
hivyo unaweza I index katika safu ya milele,

1030
00:45:57,910 --> 00:45:59,950
kama kwamba kuna.

1031
00:45:59,950 --> 00:46:03,340
Hivyo ambapo ni hii kwenda kuwa na kuchukua yetu?

1032
00:46:03,340 --> 00:46:07,070
Hivyo tutaona, hatimaye,
mambo kadhaa katika siku zijazo.

1033
00:46:07,070 --> 00:46:09,510
Moja, wakati huu wote, wakati
kuandika mipango yako mwenyewe,

1034
00:46:09,510 --> 00:46:11,239
kama Mario, tamaa, mikopo.

1035
00:46:11,239 --> 00:46:13,780
Tumekuwa kuandika jina la
mpango na kupiga kuingia.

1036
00:46:13,780 --> 00:46:15,610
Na kisha kupata pembejeo mtumiaji.

1037
00:46:15,610 --> 00:46:18,137
>> Pamoja na GetString, GetInt,
getLongLong, au kama.

1038
00:46:18,137 --> 00:46:20,720
Lakini zinageuka kuwa C inasaidia
kitu kinachoitwa mstari amri

1039
00:46:20,720 --> 00:46:25,740
hoja, ambayo ni kwenda hebu
kweli kupata maneno kwamba aina,

1040
00:46:25,740 --> 00:46:28,570
katika haraka blinking,
baada ya jina mpango wako.

1041
00:46:28,570 --> 00:46:31,430
>> Hivyo katika siku zijazo, wewe
wanaweza aina ya kitu kama Kaisari,

1042
00:46:31,430 --> 00:46:34,950
au ./caesar namba 13, baada ya hapo.

1043
00:46:34,950 --> 00:46:36,070
Tutaweza kuona jinsi kwamba kazi.

1044
00:46:36,070 --> 00:46:37,550
Kwa sababu kwa kweli, katika
tatizo kuweka mbili, sisi ni

1045
00:46:37,550 --> 00:46:39,383
kwenda kuanzisha wewe
kwa kitu kidogo

1046
00:46:39,383 --> 00:46:42,360
kukumbusha ya Ralphie ya
changamoto ya awali ya masomo ya kutengeneza ramani.

1047
00:46:42,360 --> 00:46:43,970
sanaa ya scrambling habari.

1048
00:46:43,970 --> 00:46:46,660
Hii, kwa kweli, ni sana
reminiscent ya nini Ralphie alivyofanya.

1049
00:46:46,660 --> 00:46:51,380
>> Huu ni mfano wa encryption
algorithm kuitwa ROT13, R-O-T 13.

1050
00:46:51,380 --> 00:46:54,910
Ambayo kwa kifupi maana mzunguko
barua katika alfabeti 13 maeneo.

1051
00:46:54,910 --> 00:46:58,309
Na kama wewe kufanya hivyo, utaona sasa
ni nini, labda, maneno ukoo.

1052
00:46:58,309 --> 00:47:01,100
Lakini njia sisi ni kwenda kutumia
hii, hatimaye, ni zaidi kwa ujumla.

1053
00:47:01,100 --> 00:47:04,390
>> Katika P kuweka mbili, katika toleo la kawaida,
utasikia kutekeleza michache ya ciphers,

1054
00:47:04,390 --> 00:47:06,720
mtu mmoja aitwaye Kaisari, na mtu mmoja aitwaye Vigenere.

1055
00:47:06,720 --> 00:47:10,090
Wote wawili ni mzunguko
ciphers, katika kwamba kwa namna fulani wewe

1056
00:47:10,090 --> 00:47:11,826
kugeuka barua moja katika barua tofauti.

1057
00:47:11,826 --> 00:47:12,950
Na Kaisari ni super rahisi.

1058
00:47:12,950 --> 00:47:16,220
Kuongeza moja, unaweza kuongeza 13,
au baadhi ya idadi hadi 26.

1059
00:47:16,220 --> 00:47:19,570
Vigenere gani kwamba juu ya
kwa barua ya msingi.

1060
00:47:19,570 --> 00:47:22,140
Hivyo Vigenere, kama utaona
katika spec, ni salama zaidi.

1061
00:47:22,140 --> 00:47:24,973
>> Lakini mwishoni mwa siku gani
wewe utakuwa na kutekeleza na P kuweka mbili,

1062
00:47:24,973 --> 00:47:29,050
ni kwamba muhimu kwamba matumizi ya wote wawili
kwa encryption na decryption.

1063
00:47:29,050 --> 00:47:32,160
Akizungumzia mchakato wa kumfanya
Nakala wazi, baadhi ujumbe wa awali,

1064
00:47:32,160 --> 00:47:34,490
ndani ya Cypher asilia, ambayo
ni kitu encrypted.

1065
00:47:34,490 --> 00:47:36,220
Na kisha decrypting tena.

1066
00:47:36,220 --> 00:47:38,119
>> Katika hacker toleo,
wakati huo huo, wewe utakuwa na

1067
00:47:38,119 --> 00:47:40,660
kazi na kitu sawa
katika roho, ambapo tutaweza kukupa

1068
00:47:40,660 --> 00:47:44,610
file, kutoka kawaida Linux, au
Mac, Unix au kompyuta iitwayo Etsy

1069
00:47:44,610 --> 00:47:47,800
password, ambayo ina zima
rundo la usernames na nywila.

1070
00:47:47,800 --> 00:47:50,932
Na nywila wale wana kila
wamekuwa encrypted, au heshi,

1071
00:47:50,932 --> 00:47:53,140
hivyo kusema, vizuri zaidi
kama utaona katika spec.

1072
00:47:53,140 --> 00:47:57,090
>> Na hacker toleo changamoto
yenu kwa kuwa na pembejeo kama hii,

1073
00:47:57,090 --> 00:47:58,800
na ngozi password.

1074
00:47:58,800 --> 00:48:02,590
Hiyo ni, kuhesabia nje nini
password ya binadamu kweli alikuwa.

1075
00:48:02,590 --> 00:48:05,570
Kwa sababu, kwa kweli, nywila ni
kwa ujumla si kuhifadhiwa katika wazi,

1076
00:48:05,570 --> 00:48:08,260
na kwa ujumla nywila
lazima kuwa vigumu nadhani.

1077
00:48:08,260 --> 00:48:09,610
Hiyo si mara nyingi kesi.

1078
00:48:09,610 --> 00:48:12,110
>> Na nini Nilidhani tunatarajia kufanya ni
kuhitimisha kwa dakika kadhaa

1079
00:48:12,110 --> 00:48:15,160
mtazamo saa hasa
maskini uchaguzi wa nywila

1080
00:48:15,160 --> 00:48:17,260
kutoka katika filamu unaweza kukumbuka fondly.

1081
00:48:17,260 --> 00:48:18,915
Na kama si, unapaswa kodi.

1082
00:48:18,915 --> 00:48:20,070
>> [VIDEO avspelning]

1083
00:48:20,070 --> 00:48:22,320
>> -Helmet, Wewe fiend, nini kinaendelea?

1084
00:48:22,320 --> 00:48:24,240
Unafanya nini kwa binti yangu?

1085
00:48:24,240 --> 00:48:28,010
>> -Permit Yangu na kuanzisha
kipaji vijana plastiki upasuaji,

1086
00:48:28,010 --> 00:48:30,010
Daktari Phillip Schlotkin.

1087
00:48:30,010 --> 00:48:35,020
kubwa pua kazi mtu katika
ulimwengu mzima na Beverly Hills.

1088
00:48:35,020 --> 00:48:36,140
>> -Wako Highness.

1089
00:48:36,140 --> 00:48:36,820
>> -Nose Kazi?

1090
00:48:36,820 --> 00:48:37,700
Sielewi.

1091
00:48:37,700 --> 00:48:39,070
Yeye tayari alikuwa na pua kazi.

1092
00:48:39,070 --> 00:48:40,800
Ilikuwa yake tamu 16 sasa.

1093
00:48:40,800 --> 00:48:42,590
>> -Hakuna, Ni si nini unafikiri.

1094
00:48:42,590 --> 00:48:44,490
Ni sana, mbaya sana.

1095
00:48:44,490 --> 00:48:48,160
Kama huna nipe
mchanganyiko kwa ngao hewa,

1096
00:48:48,160 --> 00:48:52,748
daktari Schlotkin nitakupa yako
binti nyuma pua yake ya zamani.

1097
00:48:52,748 --> 00:48:53,748
- [Gasps] Nooooooooooooo.

1098
00:48:53,748 --> 00:48:57,684

1099
00:48:57,684 --> 00:48:59,652
Wapi kupata hiyo?

1100
00:48:59,652 --> 00:49:00,640
>> -Zote Haki.

1101
00:49:00,640 --> 00:49:02,506
Mimi nitakuambia, mimi nitakuambia.

1102
00:49:02,506 --> 00:49:03,498
>> -Hakuna, Daddy, hakuna.

1103
00:49:03,498 --> 00:49:04,490
Lazima si.

1104
00:49:04,490 --> 00:49:06,090
>> -You're Haki mpenzi wangu.

1105
00:49:06,090 --> 00:49:07,390
Mimi itabidi miss pua yako mpya.

1106
00:49:07,390 --> 00:49:10,990
Lakini mimi si kuwaambia
mchanganyiko bila kujali.

1107
00:49:10,990 --> 00:49:12,450
>> -Very Vizuri.

1108
00:49:12,450 --> 00:49:14,830
Daktari Schlotkin, kufanya mbaya yako.

1109
00:49:14,830 --> 00:49:15,744
>> -My Radhi.

1110
00:49:15,744 --> 00:49:19,860

1111
00:49:19,860 --> 00:49:20,800
>> -Hakuna!

1112
00:49:20,800 --> 00:49:22,780
Ngoja, ngoja.

1113
00:49:22,780 --> 00:49:24,000
Mimi nitakuambia.

1114
00:49:24,000 --> 00:49:25,830
Mimi nitakuambia.

1115
00:49:25,830 --> 00:49:28,270
>> -I Alijua ingekuwa kazi.

1116
00:49:28,270 --> 00:49:31,390
Haki zote, unipe.

1117
00:49:31,390 --> 00:49:36,220
>> -The Macho ni moja.

1118
00:49:36,220 --> 00:49:36,740
>> -One.

1119
00:49:36,740 --> 00:49:37,473
>> -One.

1120
00:49:37,473 --> 00:49:37,972
-Two.

1121
00:49:37,972 --> 00:49:38,471
-Two.

1122
00:49:38,471 --> 00:49:39,800
-Two.

1123
00:49:39,800 --> 00:49:40,300
Na tatu.

1124
00:49:40,300 --> 00:49:40,800
Na tatu.

1125
00:49:40,800 --> 00:49:41,800
Na tatu.

1126
00:49:41,800 --> 00:49:42,300
-Four.

1127
00:49:42,300 --> 00:49:42,800
-Four.

1128
00:49:42,800 --> 00:49:44,707
-Four.

1129
00:49:44,707 --> 00:49:45,521
-Five.

1130
00:49:45,521 --> 00:49:46,430
-Five.

1131
00:49:46,430 --> 00:49:47,930
-Five.

1132
00:49:47,930 --> 00:49:53,480
-Basi Macho ni moja,
mbili, tatu, nne, tano.

1133
00:49:53,480 --> 00:49:56,140
Hiyo ni stupidest mchanganyiko
Ninayosikia katika maisha yangu.

1134
00:49:56,140 --> 00:49:58,640
Hiyo ni aina ya kitu an
idiot ingekuwa juu ya mizigo yake.

1135
00:49:58,640 --> 00:50:00,000
>> -Thank Wewe, ukuu wako.

1136
00:50:00,000 --> 00:50:01,340
>> [Kijijini Clicks]

1137
00:50:01,340 --> 00:50:02,450
>> -Nini Ulifanya nini?

1138
00:50:02,450 --> 00:50:03,800
>> -I Akageuka mbali ukuta.

1139
00:50:03,800 --> 00:50:05,010
>> -Hakuna, Wewe alifanya si, wewe
akageuka mbali movie nzima.

1140
00:50:05,010 --> 00:50:06,220
>> -I Must've taabu kifungo vibaya.

1141
00:50:06,220 --> 00:50:07,064
>> -Naam, Kuiweka nyuma juu!

1142
00:50:07,064 --> 00:50:07,910
Weka movie nyuma juu!

1143
00:50:07,910 --> 00:50:08,300
>> -Yes, Bwana!

1144
00:50:08,300 --> 00:50:08,799
Naam, bwana.

1145
00:50:08,799 --> 00:50:09,660
-Let Ya kwenda, Arnold.

1146
00:50:09,660 --> 00:50:10,450
Haya, Gretchen.

1147
00:50:10,450 --> 00:50:12,533
Bila shaka unajua mimi itabidi
kuwa na muswada wewe kwa hili.

1148
00:50:12,533 --> 00:50:16,720

1149
00:50:16,720 --> 00:50:17,220
-Naam?

1150
00:50:17,220 --> 00:50:17,802
Je, kazi?

1151
00:50:17,802 --> 00:50:18,510
Wapi mfalme?

1152
00:50:18,510 --> 00:50:20,218
>> -Ni Kazi, bwana, sisi
kuwa na mchanganyiko.

1153
00:50:20,218 --> 00:50:20,740
-Mkuu.

1154
00:50:20,740 --> 00:50:24,810
Sasa tunaweza kuchukua kila pumzi ya mwisho
ya hewa safi kutoka sayari Druidia.

1155
00:50:24,810 --> 00:50:25,890
Nini mchanganyiko?

1156
00:50:25,890 --> 00:50:28,155
>> -One, Mbili, tatu, nne, tano.

1157
00:50:28,155 --> 00:50:29,890
>> -One, Mbili, tatu, nne, tano?

1158
00:50:29,890 --> 00:50:30,390
-Yes.

1159
00:50:30,390 --> 00:50:31,110
-Kwamba Ajabu.

1160
00:50:31,110 --> 00:50:34,550
Mimi nimepata huo
mchanganyiko juu ya mizigo yangu.

1161
00:50:34,550 --> 00:50:37,160
Kuandaa Spaceball 1 kwa
kuondoka haraka.

1162
00:50:37,160 --> 00:50:38,160
>> -Yes, Mheshimiwa.

1163
00:50:38,160 --> 00:50:40,745
>> -Na Mabadiliko
mchanganyiko juu ya mizigo yangu.

1164
00:50:40,745 --> 00:50:41,578
[DOOR KUFUNGA SOUND]

1165
00:50:41,578 --> 00:50:42,064
[Jela ya milango kupiga kofia]

1166
00:50:42,064 --> 00:50:42,550
-Ahh.

1167
00:50:42,550 --> 00:50:43,383
[END video avspelning]

1168
00:50:43,383 --> 00:50:46,700
DAVID J. Malan: Hiyo ni kwa
CS50, tutaweza kuona wewe wiki ijayo.

1169
00:50:46,700 --> 00:50:49,883
NARRATOR: Na sasa, Deep
Mawazo, na Daven Farnham.

1170
00:50:49,883 --> 00:50:53,160

1171
00:50:53,160 --> 00:50:55,860
>> DAVEN FARNHAM: CODING katika C ni
vigumu sana kuliko Scratch.

1172
00:50:55,860 --> 00:50:57,320
printf, Scratch ilikuwa ni uongo.

1173
00:50:57,320 --> 00:50:59,930

1174
00:50:59,930 --> 00:51:01,430
>> [Kicheko soundbite]

1175
00:51:01,430 --> 00:51:02,486