1
00:00:00,000 --> 00:00:02,670
[Powered by Google Translate] Sehemu ya tatizo Kuweka 2: Haka Edition

2
00:00:02,670 --> 00:00:04,910
Rob Bowden, Chuo Kikuu cha Harvard

3
00:00:04,910 --> 00:00:07,410
Hii ni CS50. CS50.TV

4
00:00:07,410 --> 00:00:15,770
Kwa hiyo, mimi nina Rob. Mimi nina mwandamizi katika Kirkland. Huu ni mwaka wa tatu yangu TFing CS50.

5
00:00:15,770 --> 00:00:22,220
Ni mara ya kwanza kwamba sisi ni kubadilisha kutoka sehemu jadi-hotuba-style,

6
00:00:22,220 --> 00:00:25,610
ambapo sisi tu aina ya mapitio kile kilichotokea katika hotuba na kisha guys kuuliza maswali,

7
00:00:25,610 --> 00:00:32,250
sasa kwa kuwa mengi zaidi tatizo-msingi, ambapo sisi kutumia Spaces, na -

8
00:00:32,250 --> 00:00:37,410
Oh, hivyo wazo ni kwenda zilizounganishwa nilipowatuma na kisha wewe utakuwa katika nafasi yangu.

9
00:00:37,410 --> 00:00:42,410
Je, mtu yeyote kuwa mbali? Sawa.

10
00:00:42,410 --> 00:00:47,050
Hivyo sisi ni kwenda kuwa na kutumia hii, na sisi ni kwenda kufanya matatizo kuishi katika sehemu

11
00:00:47,050 --> 00:00:50,740
na kujadili nao na kuhesabia nje nini makosa

12
00:00:50,740 --> 00:00:56,390
na mimi ili kuvuta up baadhi ya code yako, na mimi ili kujadili mawazo yako.

13
00:00:56,390 --> 00:01:02,140
Hivyo ina mtu alikuwa na shida?

14
00:01:02,140 --> 00:01:07,000
Unaweza kuzungumza upande; mimi sijui kama tutaweza kuwa na sababu kwa ajili hiyo.

15
00:01:07,000 --> 00:01:12,270
Sasa, kama supersection uliopita, kama walikuwa katika darasa kwamba, unajua nini hiyo ni juu.

16
00:01:12,270 --> 00:01:19,200
Juu ya yote ya seti P kuna kwenda kuwa hizi sehemu.

17
00:01:19,200 --> 00:01:22,550
Hivyo P-set 2, specifikationer, Nadhani kuona jambo P-set 1 tayari.

18
00:01:22,550 --> 00:01:27,400
Lakini tunaweza kuangalia P-set 2 kwa nini tuko kwenda kwenda juu ya leo.

19
00:01:27,400 --> 00:01:29,460
Na utaona sehemu ya maswali.

20
00:01:29,460 --> 00:01:37,530
Hivyo hii itakuwa katika yote ya P-seti; kutakuwa sehemu ya maswali.

21
00:01:37,530 --> 00:01:41,340
Hadi sasa tumekuwa alisema, "Fikiria fursa hii ya kufanya mazoezi."

22
00:01:41,340 --> 00:01:44,940
Huwezi kuwa na kuulizwa kuwasilisha mpango huu.

23
00:01:44,940 --> 00:01:48,480
Wazo ni kwamba hawa wanatakiwa aina ya kusaidia kupata kuanza kwa kuweka tatizo.

24
00:01:48,480 --> 00:01:53,220
Nadhani katika toleo Hacker, mengi yao wanatakiwa tu kuwa mpya, ya kuvutia mambo ya kujifunza.

25
00:01:53,220 --> 00:01:58,590
Wanaweza kuwa na moja kwa moja husika na kuweka tatizo.

26
00:01:58,590 --> 00:02:01,810
Na hivi sasa sisi siyo kuwa wewe kuwasilisha yao, lakini katika nadharia,

27
00:02:01,810 --> 00:02:07,480
kwa seti baadaye tatizo, unaweza kuwasilisha yao, na hivyo unaweza ama kuja sehemu

28
00:02:07,480 --> 00:02:10,380
au kutazama sehemu ya kupata majibu, au unaweza tu kupata yao juu yako mwenyewe

29
00:02:10,380 --> 00:02:16,350
kama huna wanaona kama kufurahia uwepo wangu.

30
00:02:16,350 --> 00:02:21,010
Hivyo - Nadhani hii ni moja ya kwanza.

31
00:02:21,010 --> 00:02:29,280
Oh. Pia, chini ya sehemu hizi za maswali sisi pia kuuliza maswali kuhusu kaptula.

32
00:02:29,280 --> 00:02:33,440
Basi, mimi nadhani, katika nadharia, wewe wanatakiwa kuangalia hizi kabla ya kuja kwa sehemu,

33
00:02:33,440 --> 00:02:38,550
lakini ni faini kama huna, tutaweza kwenda juu yao anyway.

34
00:02:38,550 --> 00:02:42,590
Basi, tunaweza kuanza na haya: "Jinsi gani kitanzi wakati tofauti na kitanzi do-wakati?

35
00:02:42,590 --> 00:02:46,210
Wakati ni muhimu hasa mwisho? "

36
00:02:46,210 --> 00:02:49,390
Hivyo mtu yeyote kuwa yoyote -?

37
00:02:49,390 --> 00:02:52,730
[Mwanafunzi] do-wakati kitanzi daima nitafanya angalau mara moja.

38
00:02:52,730 --> 00:03:02,950
Ndiyo. Hivyo kwamba ni tofauti. kitanzi wakati - I'll tu kufanya hivyo hapa - wakati kitanzi, tuna hali

39
00:03:02,950 --> 00:03:19,760
haki hapa, ambapo do-wakati, huna hali mpaka sisi kupata chini hapa.

40
00:03:19,760 --> 00:03:24,130
Na hivyo, wakati mpango wako s utekelezaji, na anapata kwa kitanzi wakati,

41
00:03:24,130 --> 00:03:26,380
mara moja hundi kama hali hii ni kweli.

42
00:03:26,380 --> 00:03:30,710
Kama hali hiyo siyo kweli, itakuwa tu ruka juu ya kitanzi kabisa.

43
00:03:30,710 --> 00:03:34,390
Do-wakati kitanzi, kama mpango wa utekelezaji, anapata na "kufanya."

44
00:03:34,390 --> 00:03:37,920
Hakuna kinachotokea katika hatua hii, tu inaendelea utekelezaji.

45
00:03:37,920 --> 00:03:42,690
Kisha wakati hits "wakati," kama hali ni ya kweli, hivyo itabidi kitanzi nyuma na kufanya hivyo tena

46
00:03:42,690 --> 00:03:46,730
na tena na tena mpaka hali si kweli na kisha tu falls kupitia.

47
00:03:46,730 --> 00:03:50,600
Hivyo, tofauti kuwa, kwamba huu unaweza ruka haki, tangu mwanzo sana.

48
00:03:50,600 --> 00:03:56,770
Hii lazima executes mara moja na kisha inaweza kutekeleza mara zaidi kama hali bado ni kweli.

49
00:03:56,770 --> 00:04:03,720
Hivyo kitanzi wakati tu kufanya hivyo mara moja, au - wakati kitanzi - sisi wanaweza haja ya kufanya hivyo wakati wote,

50
00:04:03,720 --> 00:04:07,900
tangu haraka kama sisi kupata hiyo, kama hali ni uongo, tutaweza tu ruka haki juu yake.

51
00:04:07,900 --> 00:04:11,770
Wakati kufanya-wakati kitanzi, sisi nitafanya hivyo mara moja, lazima.

52
00:04:11,770 --> 00:04:14,560
Kisha, wakati sisi kupata hali, sisi kuangalia kama ni kweli au uongo.

53
00:04:14,560 --> 00:04:19,790
Kama ni kweli, tutaweza kufanya hivyo tena; kama ni uongo, tutaweza tu kuendelea kwenda.

54
00:04:19,790 --> 00:04:24,680
Hivyo wakati ni muhimu hasa masika?

55
00:04:24,680 --> 00:04:31,190
Hivyo naweza kusema kwamba katika ukamilifu wa miaka 4, miaka 3, chochote,

56
00:04:31,190 --> 00:04:38,780
kwamba nimekuwa programu, mimi sikutumia hii, kama, chini ya mara 10.

57
00:04:38,780 --> 00:04:43,140
Na pengine 5 kati yao ni katika CS50 wakati sisi ni kuanzisha matanzi kufanya-wakati.

58
00:04:43,140 --> 00:04:47,510
Hivyo wakati wewe kutumika kufanya-wakati matanzi?

59
00:04:47,510 --> 00:04:49,510
Wakati ni - yeah?

60
00:04:49,510 --> 00:04:53,180
[Mwanafunzi] Wakati wewe ni kujaribu kupata pembejeo user, au kitu unataka kuangalia -

61
00:04:53,180 --> 00:04:59,700
Yeah. Hivyo kufanya-wakati tanzi, mtumiaji pembejeo ni moja kubwa.

62
00:04:59,700 --> 00:05:03,160
Hiyo ndiyo siku ya kwanza ya wanandoa tatizo seti, wakati unataka kuuliza user, kama,

63
00:05:03,160 --> 00:05:08,520
"Nipe kamba," huwezi kuendelea mpaka kupata ile kamba.

64
00:05:08,520 --> 00:05:12,980
Na hivyo, lazima, haja ya kuuliza kwa kamba angalau mara moja.

65
00:05:12,980 --> 00:05:16,950
Lakini basi kama wao kujibu kitu mbaya, basi unahitaji kitanzi nyuma na kuuliza tena.

66
00:05:16,950 --> 00:05:20,810
Lakini zaidi ya pembejeo user, ni nadra sana kwamba mimi kukutana kesi

67
00:05:20,810 --> 00:05:27,170
ambapo nataka kitanzi "angalau mara moja" lakini pengine zaidi.

68
00:05:27,170 --> 00:05:33,370
Maswali au -? Kuna mtu yeyote kutumika kufanya-wakati kitanzi popote mwingine?

69
00:05:33,370 --> 00:05:36,780
Sawa. Hivyo moja ya pili ni, "Je, Undeclared kitambulisho

70
00:05:36,780 --> 00:05:43,310
kawaida zinaonyesha kama outputted na Clang? "

71
00:05:43,310 --> 00:05:47,380
Hivyo ni aina gani ya maadili inaweza mimi kuandika kupata 'kitambulisho Undeclared?'

72
00:05:47,380 --> 00:05:49,550
[Mwanafunzi] Hayo x = 2?

73
00:05:49,550 --> 00:05:52,650
Hivyo tunaweza tu kujaribu katika hapa, x = 2.

74
00:05:52,650 --> 00:06:04,830
Tutaweza kukimbia hii - oh, sikuweza bonyeza yake. Hivyo hapa sisi kupata - wote haki.

75
00:06:04,830 --> 00:06:07,100
"Matumizi ya x Undeclared kitambulisho."

76
00:06:07,100 --> 00:06:11,610
Basi hiyo ni kitambulisho Undeclared, hazibadiliki.

77
00:06:11,610 --> 00:06:13,910
Itakuwa mara nyingi kuwaita variable kitambulisho.

78
00:06:13,910 --> 00:06:17,300
Hivyo nisifahamu ni kweli variable, haina kujua ni nini.

79
00:06:17,300 --> 00:06:19,380
Hivyo ni kitambulisho.

80
00:06:19,380 --> 00:06:26,060
Hivyo ni kwa nini Undeclared? Yeah.

81
00:06:26,060 --> 00:06:32,190
Hivyo kwa kuwa wazi juu ya istilahi, tamko la variable

82
00:06:32,190 --> 00:06:37,360
ni wakati wewe kusema "x int," au "string y," lolote.

83
00:06:37,360 --> 00:06:41,910
initialization ya kutofautiana, au zoezi la kutofautiana,

84
00:06:41,910 --> 00:06:44,510
ni wakati wewe kusema "x = 2."

85
00:06:44,510 --> 00:06:52,950
Hivyo tunaweza kufanya haya katika hatua tofauti, int x, x = 2, na mpaka - tunaweza kuwa na rundo la stuff katika hapa -

86
00:06:52,950 --> 00:07:00,350
lakini mpaka mstari huu hutokea, x bado uninitialized, lakini imekuwa alitangaza.

87
00:07:00,350 --> 00:07:06,760
Na hivyo tunaweza kufanya hivyo ni wazi katika mstari 1, na sasa tunatangaza na initializing.

88
00:07:06,760 --> 00:07:10,730
Maswali?

89
00:07:10,730 --> 00:07:18,390
Na hatimaye, "Kwa nini ni Cipher Kaisari si salama sana?"

90
00:07:18,390 --> 00:07:23,830
Hivyo kwanza, haina mtu yeyote unataka kusema nini Cipher Kaisari ni?

91
00:07:23,830 --> 00:07:28,100
[Mwanafunzi] Kaisari Cipher tu ni kwamba wewe ramani, wewe kuhama kila herufi,

92
00:07:28,100 --> 00:07:34,420
idadi fulani ya barua kwenda juu, na hoja juu ya nyuma, na ni si salama sana kwa sababu

93
00:07:34,420 --> 00:07:42,260
kuna tu 26 chaguzi inawezekana na wewe tu na kujaribu kila 1 ya wale mpaka kupata.

94
00:07:42,260 --> 00:07:45,470
Oh. Hivyo, mimi lazima kurudia?

95
00:07:45,470 --> 00:07:51,600
Cipher Kaisari, it's - I mean, wewe utakuwa ni kushughulika na juu ya matatizo ambayo wewe -

96
00:07:51,600 --> 00:07:56,110
au mimi nadhani toleo la kawaida ya kuweka tatizo si kwamba katika toleo hacker.

97
00:07:56,110 --> 00:08:01,550
Kadhalika toleo la kawaida kwa kuweka tatizo, wewe kupata ujumbe kama "dunia Hello,,"

98
00:08:01,550 --> 00:08:08,410
na wewe pia kuwa na idadi kama 6, na wewe kuchukua kwamba ujumbe, na kila tabia ya mtu binafsi,

99
00:08:08,410 --> 00:08:11,310
wewe ni mzunguko na nyadhifa 6 katika alfabeti.

100
00:08:11,310 --> 00:08:16,560
Hivyo 'h' katika hujambo bila kuwa h-i-j-k-l-m-n.

101
00:08:16,560 --> 00:08:19,600
Hivyo barua ya kwanza itakuwa n. Sisi kufanya kitu kimoja na e.

102
00:08:19,600 --> 00:08:23,530
Kama tuna, kama, z au kitu, basi sisi wrap nyuma karibu na '.'

103
00:08:23,530 --> 00:08:29,280
Lakini tabia ya kila anapata waliendesha 6 wahusika baadaye katika alfabeti, na si salama sana

104
00:08:29,280 --> 00:08:35,440
tangu kuna uwezekano tu 26 kwa jinsi njia nyingi unaweza wrap barua moja.

105
00:08:35,440 --> 00:08:42,919
Hivyo unaweza tu kujaribu yote 26 ya kwao na, pengine, kwa ujumbe mrefu wa kutosha,

106
00:08:42,919 --> 00:08:46,860
tu 1 ya mambo hayo kutokea 26 ni kwenda kuwa legible,

107
00:08:46,860 --> 00:08:50,300
na moja legible ni kwenda kuwa ujumbe halisi.

108
00:08:50,300 --> 00:08:56,240
Hivyo si njia nzuri sana ya encrypting chochote wakati wote.

109
00:08:56,240 --> 00:08:59,070
Lisilohusiana na kaptula hizo, "Ni nini kazi?"

110
00:08:59,070 --> 00:09:03,370
Hivyo kile ni kazi? Ndiyo.

111
00:09:03,370 --> 00:09:11,640
[Mwanafunzi] Ni kama kipande tofauti ya kificho kwamba unaweza kupiga kupitia na kisha kupata thamani ya kurudi kwa chochote.

112
00:09:11,640 --> 00:09:18,160
Yeah. Hivyo mimi itabidi kujibu ni kwa kujibu pia ijayo - au kurudia na pia tu kujibu moja ijayo.

113
00:09:18,160 --> 00:09:22,410
Unaweza kutumia kazi badala ya kuiga na pasting code juu na juu tena.

114
00:09:22,410 --> 00:09:27,200
Tu kuchukua kwamba code, kuiweka katika fuction, na kisha unaweza kuwaita tu kazi

115
00:09:27,200 --> 00:09:29,870
popote umekuwa kuiga na pasting.

116
00:09:29,870 --> 00:09:33,350
Hivyo kazi ni muhimu.

117
00:09:33,350 --> 00:09:35,860
Hivyo sasa tutaweza kufanya matatizo halisi.

118
00:09:35,860 --> 00:09:46,490
moja ya kwanza. Hivyo wazo la kwanza ni, wewe kupita kamba, na bila kujali -

119
00:09:46,490 --> 00:09:52,060
au gani kusema yote lowercase? Haisemi wote lowercase.

120
00:09:52,060 --> 00:09:57,730
Hivyo ujumbe inaweza kuwa kitu chochote, na - oh no. Ni gani.

121
00:09:57,730 --> 00:10:01,610
"Kwa unyenyekevu, unaweza kudhani kwamba mtumiaji mapenzi tu pembejeo barua lowercase na mazingira."

122
00:10:01,610 --> 00:10:08,180
Hivyo sisi kupita ujumbe na barua tu lowercase na kisha sisi Alternate

123
00:10:08,180 --> 00:10:15,450
kati ya mji mkuu na ndogo - sisi mabadiliko string kuwa mji mkuu na ndogo, alternating.

124
00:10:15,450 --> 00:10:22,920
Hivyo kabla ya sisi kukupa pili hata kupiga mbizi katika tatizo,

125
00:10:22,920 --> 00:10:32,420
nini ni jambo la kwanza kwamba tunahitaji kufanya nini?

126
00:10:32,420 --> 00:10:36,900
Oh, nini mimi bonyeza tu juu? Oh, mimi tu clicked kwenye email katika hapa.

127
00:10:36,900 --> 00:10:42,870
Hivyo kitu ya kwanza tunahitaji kufanya - mimi kuangalia moja sahihi?

128
00:10:42,870 --> 00:10:49,320
Je, hii ni sehemu ya huu?

129
00:10:49,320 --> 00:10:51,320
Hapana, wale bado huko, ingawa.

130
00:10:51,320 --> 00:10:55,160
Okay, bado hapa.

131
00:10:55,160 --> 00:11:03,160
Sasa hatuwezi kudhani -? Ndiyo. Hapa hatuwezi kudhani kwamba ni tu lowercase na mazingira.

132
00:11:03,160 --> 00:11:07,770
Hivyo sasa inabidi kushughulika na ukweli kwamba barua inaweza kuwa chochote sisi unataka yao kuwa.

133
00:11:07,770 --> 00:11:11,910
Na hivyo jambo la kwanza tunataka kufanya ni kupata tu ujumbe.

134
00:11:11,910 --> 00:11:19,790
Sisi tu wanahitaji kupata kamba, kamba s = GetString, okay.

135
00:11:19,790 --> 00:11:24,890
Sasa tatizo hili, kuna wanandoa wa njia za kufanya hivyo.

136
00:11:24,890 --> 00:11:29,840
Lakini sisi ni kwenda wanataka kutumia waendeshaji bitwise hapa.

137
00:11:29,840 --> 00:11:35,280
Je, kuna watu ambao ama walikuwa si katika supersection,

138
00:11:35,280 --> 00:11:37,480
au kitu, na hawajui nini bitwise operators ni?

139
00:11:37,480 --> 00:11:41,710
Au jinsi wanavyohusiana na ASCII katika njia yoyote?

140
00:11:41,710 --> 00:11:45,650
[Mwanafunzi] Mimi si wakati supersection, lakini Mimi najua kile bitwise operators ni.

141
00:11:45,650 --> 00:11:49,560
Sawa. Hivyo basi mimi si kwenda juu ya misingi ya yao, lakini mimi itabidi kueleza

142
00:11:49,560 --> 00:11:51,830
nini tunakwenda wanataka kutumia hapa.

143
00:11:51,830 --> 00:11:59,680
Hivyo '': binary uwakilishi wa mji mkuu, idadi ni 65.

144
00:11:59,680 --> 00:12:07,560
Mimi tu kwenda kuangalia - 41 ni kwenda kuwa 01,000,001.

145
00:12:07,560 --> 00:12:14,170
Hivyo kwamba wanapaswa kuwa 65 katika decimal; hivyo hii ni ya uwakilishi binary ya mji mkuu wa tabia A.

146
00:12:14,170 --> 00:12:19,440
Sasa, uwakilishi binary ya tabia Herufi za chini ''

147
00:12:19,440 --> 00:12:33,350
ni kwenda kuwa kitu kimoja, karibu. Ni kwamba - 6, yeah. Hii ni haki.

148
00:12:33,350 --> 00:12:37,670
Hivyo binary mji mkuu, binary lowercase '.'

149
00:12:37,670 --> 00:12:43,940
Hivyo taarifa kwamba tofauti kati na '' ni hii kidogo moja.

150
00:12:43,940 --> 00:12:49,440
Na hii hufanyika kuwa ni kidogo 32, kidogo anayewakilisha idadi 32.

151
00:12:49,440 --> 00:12:53,910
Na kwamba inafanya hisia tangu ni 65; '' ni 97.

152
00:12:53,910 --> 00:12:56,610
Tofauti kati yao ni 32.

153
00:12:56,610 --> 00:13:03,770
Hivyo sasa tunajua tunaweza kubadili kutoka kwa '' kwa kuchukua

154
00:13:03,770 --> 00:13:09,710
na bitwise ORing, pamoja na - kwamba inaonekana kama 1.

155
00:13:09,710 --> 00:13:20,900
Hii ni bitwise AU, na 00100000, na kwamba kutakuwa na kutupa '.'

156
00:13:20,900 --> 00:13:26,850
Na tunaweza kupata kutoka 'A' na kwa bitwise ANDing

157
00:13:26,850 --> 00:13:33,700
na 11, 0 katika nafasi hiyo, 11,111.

158
00:13:33,700 --> 00:13:43,840
Hivyo hii itakuwa kisha kutupa nini hasa '' ilikuwa; lakini kufuta nje hii kidogo ya mtu binafsi,

159
00:13:43,840 --> 00:13:50,070
hivyo tutaweza kuwa na 01000001, mimi sijui kama mimi kuhesabiwa haki.

160
00:13:50,070 --> 00:13:56,750
Lakini mbinu hii ya bitwise ORing kupata kutoka mji mkuu wa Herufi za chini,

161
00:13:56,750 --> 00:14:02,080
na bitwise ANDing kupata kutoka lowercase kwa mkuu ni si ya kipekee ya A.

162
00:14:02,080 --> 00:14:06,510
Yote ya barua, K vs k, Z vs z,

163
00:14:06,510 --> 00:14:10,080
wote ni kwenda tu kidogo tofauti na hii moja.

164
00:14:10,080 --> 00:14:16,290
Na hivyo unaweza kutumia hii kubadili kutoka barua yoyote lowercase kwa barua yoyote mtaji na kinyume chake.

165
00:14:16,290 --> 00:14:26,670
Sawa. Hivyo njia rahisi ya kupata kutoka hilo - hivyo badala ya kuwa na

166
00:14:26,670 --> 00:14:32,170
kuandika chochote 1011111 ni - njia rahisi ya anayewakilisha idadi hii, na hii si moja

167
00:14:32,170 --> 00:14:39,710
kwamba mimi akaenda juu katika supersection, lakini tilde (~) ni mwingine operator bitwise.

168
00:14:39,710 --> 00:14:42,520
Nini ~ gani ni inaonekana katika uwakilishi kidogo.

169
00:14:42,520 --> 00:14:45,630
Hebu kuchukua idadi yoyote.

170
00:14:45,630 --> 00:14:53,130
Hii ni baadhi tu ya idadi binary, na kile ~ haina ni kama tu flips wote wa bits.

171
00:14:53,130 --> 00:15:00,630
Hivyo hii ilikuwa 1, sasa 0, hii ni 0, sasa 1, 010,100.

172
00:15:00,630 --> 00:15:08,320
Basi hiyo ni ~ wote gani. Hivyo 32 ni kwenda kuwa idadi - kujikwamua kwamba -

173
00:15:08,320 --> 00:15:23,320
hivyo 32 ni kwenda kuwa idadi 00,100,000, na hivyo ~ ya hii ni kwenda kuwa

174
00:15:23,320 --> 00:15:29,980
idadi hii hapa kwamba mimi ANDed '' kwa.

175
00:15:29,980 --> 00:15:35,600
Je, kila mtu kuona kwamba? Hii ni pretty kawaida, kama wakati unataka kufikiri

176
00:15:35,600 --> 00:15:40,740
kwa ajili ya mambo ya baadaye ili sisi tupate kuwa kuona, wakati tunataka kuona kama -

177
00:15:40,740 --> 00:15:44,710
au tunataka kila kitu, kila moja kidogo kuweka isipokuwa kwa 1

178
00:15:44,710 --> 00:15:47,910
wewe huwa na kufanya ~ ya kidogo kwamba sisi si unataka kuweka.

179
00:15:47,910 --> 00:15:53,090
Hivyo hatutaki 32 kidogo kuweka, hivyo hatuna ~ ya 32.

180
00:15:53,090 --> 00:15:57,790
Sawa. Hivyo tunaweza kutumia wale wote hapa.

181
00:15:57,790 --> 00:16:03,000
Haki wote, hivyo ni faini kama wewe si kosa, tutakuwa polepole kutembea juu ya pamoja,

182
00:16:03,000 --> 00:16:11,870
au kutembea juu ya hili, hivyo - kwa njia hii. Kutembea kwa njia hii.

183
00:16:11,870 --> 00:16:20,790
Hivyo tuna string yetu, na tunataka kitanzi juu ya kila tabia katika string kwamba na kufanya kitu kwa hayo.

184
00:16:20,790 --> 00:16:26,710
Hivyo ni jinsi kufanya sisi kitanzi juu ya kamba? Tufanye kutumia?

185
00:16:26,710 --> 00:16:30,980
Sitakuja kufanya hivyo hapa. Yeah.

186
00:16:30,980 --> 00:16:42,940
Hivyo nina iterator yangu, na yeye alisema, lakini jinsi gani mimi kujua jinsi wengi wahusika ni katika kamba?

187
00:16:42,940 --> 00:16:47,030
Strlen (s), kisha i + +.

188
00:16:47,030 --> 00:16:49,860
Hivyo kile nimepata kufanyika hapa ni si njia bora ya kufanya mambo.

189
00:16:49,860 --> 00:16:51,860
Je, mtu yeyote kujua kwa nini?

190
00:16:51,860 --> 00:16:55,290
Kwa sababu wewe ni kuangalia lugha ya kamba kila wakati.

191
00:16:55,290 --> 00:17:06,859
Hivyo sisi ni kwenda kutaka hoja strlen, mimi naweza kusema hapa juu int urefu = strlen (s),

192
00:17:06,859 --> 00:17:11,900
na kisha gani i <urefu, na katika kesi hawajaona hivyo kabla,

193
00:17:11,900 --> 00:17:20,410
Mimi naweza pia kufanya int i = 0, urefu = strlen (s).

194
00:17:20,410 --> 00:17:25,010
Na hivyo hii ni kiasi fulani vyema, tangu sasa nimekuwa vikwazo wigo

195
00:17:25,010 --> 00:17:29,150
urefu wa kutofautiana tu hii 'kwa' kitanzi, badala ya kutamka hivyo kabla

196
00:17:29,150 --> 00:17:34,990
na kwamba daima lipo, na katika kesi hukutaka kukamata nini hiyo ni mbaya,

197
00:17:34,990 --> 00:17:39,410
au kwa nini awali ilikuwa mbaya, it's - kuanza saa kwa kitanzi.

198
00:17:39,410 --> 00:17:43,380
I checked hali hiyo. Ni i <urefu wa s?

199
00:17:43,380 --> 00:17:46,790
Hivyo urefu wa s, hebu kazi na "hello" wakati wote.

200
00:17:46,790 --> 00:17:49,670
Hivyo urefu wa s, h-e-l-l-o. Urefu ni 5.

201
00:17:49,670 --> 00:17:57,580
Hivyo i = 0, urefu ni 5, hivyo i si <5, hivyo kitanzi inaendelea.

202
00:17:57,580 --> 00:18:02,750
Kisha sisi kwenda tena. Sisi kuangalia hali. Ni i <urefu wa hujambo?

203
00:18:02,750 --> 00:18:08,390
Basi hebu angalia urefu wa hello. H-e-l-l-o. Hiyo ni 5; i si <5, hivyo sisi kuendelea tena.

204
00:18:08,390 --> 00:18:13,330
Hivyo sisi ni kuhesabu, sisi ni kuhesabu hello, kwa kila iteration ya kitanzi,

205
00:18:13,330 --> 00:18:17,380
hata mawazo ni kamwe kwenda na mabadiliko; ni daima itakuwa 5.

206
00:18:17,380 --> 00:18:22,530
Hivyo sisi kumbuka tu 5 hadi mbele, na sasa kila kitu ni bora.

207
00:18:22,530 --> 00:18:24,990
Hivyo iterating zaidi string nzima.

208
00:18:24,990 --> 00:18:31,470
Nini tunataka kufanya kwa kila tabia ya kamba?

209
00:18:31,470 --> 00:18:38,510
[Mwanafunzi akizungumza, unintelligible]

210
00:18:38,510 --> 00:18:47,000
Yeah. Hivyo, kama tabia ni zisizo za kialfabeti, basi sisi nataka tu ruka juu yake.

211
00:18:47,000 --> 00:18:52,300
Kwa sababu sisi tu huduma kuhusu barua alphabetic; hatuwezi capitalize idadi.

212
00:18:52,300 --> 00:19:10,850
Hivyo ni jinsi gani tunaweza kufanya hili? Hivyo hali yetu, hivyo kama tunataka kitu - kuangalia kama ni herufi.

213
00:19:10,850 --> 00:19:14,060
Hivyo ni jinsi gani sisi kuangalia hii?

214
00:19:14,060 --> 00:19:18,720
[Mwanafunzi] Unaweza tu kutumia kazi ni alpha.

215
00:19:18,720 --> 00:19:23,160
Ni kwamba pamoja na katika aidha ya hizi, au ni pamoja na kama, char.h au kitu?

216
00:19:23,160 --> 00:19:32,710
Hebu si kutumia ni alfa na kazi, na kutumia wazi - hivyo tuna s [i],

217
00:19:32,710 --> 00:19:40,460
kwamba ni tabia ya nane ya s, kumbuka kwamba string ni safu ya wahusika,

218
00:19:40,460 --> 00:19:43,180
hivyo tabia ya nane ya s.

219
00:19:43,180 --> 00:19:49,280
Sasa, kama ni barua mji mkuu, tunajua ina kuwa katika mbalimbali maalum.

220
00:19:49,280 --> 00:19:54,370
Na ni nini mbalimbali kwamba?

221
00:19:54,370 --> 00:20:07,860
Yeah. Hivyo kama s [i] ni ≥ 65, na s [i] ni ≤ 90, nifanye nini badala yake?

222
00:20:07,860 --> 00:20:18,470
Yeah. Hivyo unapaswa kabisa kamwe hata haja ya kujua maadili ASCII ya kitu chochote milele.

223
00:20:18,470 --> 00:20:25,640
Kamwe kufikiria idadi 65, 90, 97 na 102, au chochote ni.

224
00:20:25,640 --> 00:20:32,470
Huna haja - 112 -? Huna haja ya kujua wale wakati wote. Hiyo ni vibaya mno.

225
00:20:32,470 --> 00:20:41,940
Tu kutumia herufi moja-quote, moja quote constants. Hivyo '' na chini ya 90 ni 'Z.'

226
00:20:41,940 --> 00:20:47,930
Na hii ni kikubwa zaidi - mimi bila kujua mbali juu ya kichwa yangu kwamba Z ni 90.

227
00:20:47,930 --> 00:20:52,690
Najua mbali juu ya kichwa yangu kwamba 'Z' ni mji mkuu Z.

228
00:20:52,690 --> 00:21:02,100
Hivyo kwa muda mrefu kama hii ni katika aina mbalimbali ya mji mkuu na mji mkuu Z, au tuweze kuangalia kwa lowercase,

229
00:21:02,100 --> 00:21:17,010
Au kama ni katika mbalimbali ≥ 'a' na ≤ z.

230
00:21:17,010 --> 00:21:19,010
Basi hiyo ni hali yetu.

231
00:21:19,010 --> 00:21:22,520
style kwa ambapo kuweka mambo haya hutofautiana.

232
00:21:22,520 --> 00:21:29,520
Nitafanya hivyo kama hii.

233
00:21:29,520 --> 00:21:31,520
Sasa, je, tunataka kufanya?

234
00:21:31,520 --> 00:21:39,530
Tunajua barua hii ni tabia, tabia ya alfabeti.

235
00:21:39,530 --> 00:21:46,270
Hivyo tunahitaji Alternate kati ya kama hii lazima sasa kuwa barua mtaji au barua lowercase.

236
00:21:46,270 --> 00:21:48,820
Jinsi gani sisi kuweka wimbo wa moja ambayo sisi nataka kuwa?

237
00:21:48,820 --> 00:21:55,520
[Mwanafunzi sauti, unintelligible]

238
00:21:55,520 --> 00:21:59,150
Hivyo ndiyo, lakini napenda kuangalia.

239
00:21:59,150 --> 00:22:04,910
Module 0-2 alikuwa alisema, ilikuwa pendekezo kutupwa nje, na nakubaliana na hilo.

240
00:22:04,910 --> 00:22:11,780
Ila taarifa kwamba, kama - ni kesi hii? Yeah.

241
00:22:11,780 --> 00:22:18,270
Ni kila mtu mwingine, lakini hatuwezi moduli 2 ya i, au i Mod 2, tangu

242
00:22:18,270 --> 00:22:22,950
taarifa kwamba E ni mji mkuu na '' ni herufi ndogo? Lakini kuna nafasi kutenganisha yao?

243
00:22:22,950 --> 00:22:27,150
Hivyo ni kwenda kuwa Mod sawa 2, lakini wao ni tofauti kesi.

244
00:22:27,150 --> 00:22:29,150
[Mwanafunzi swali, unintelligible]

245
00:22:29,150 --> 00:22:34,690
Yeah. Hivyo sisi ni kwenda tu kuweka kuhesabu.

246
00:22:34,690 --> 00:22:38,730
Tunaweza pia kufanya hivyo katika hapa kama sisi alitaka; kwamba ili kupata unwieldy kidogo

247
00:22:38,730 --> 00:22:41,300
katika maazimio kwa kitanzi; mimi itabidi kuweka it up hapa.

248
00:22:41,300 --> 00:22:48,840
Hivyo kuhesabu int = kuanza saa 0.

249
00:22:48,840 --> 00:22:54,070
Na hivyo kwa sasa, mimi naenda uhesabu alfabeti wahusika tulikuwa.

250
00:22:54,070 --> 00:22:59,550
Hivyo sisi ni inevitably kwenda kuhesabu + + tangu sisi kupatikana mwingine tabia alfabeti.

251
00:22:59,550 --> 00:23:09,130
Lakini, sasa wewe ni kusema kama kuhesabu Mod 2.

252
00:23:09,130 --> 00:23:12,590
Basi nini kama kuhesabu Mod 2? Oh. Mimi itabidi kufanya == 0 kwa sasa.

253
00:23:12,590 --> 00:23:21,740
Tutaweza pia kwenda juu ya hilo. Hivyo kama kuhesabu Mod 2 == 0, basi ni nini?

254
00:23:21,740 --> 00:23:27,830
[Wanafunzi jibu, unintelligible]

255
00:23:27,830 --> 00:23:32,750
Hivyo tunataka kwa kuishia uppercase.

256
00:23:32,750 --> 00:23:37,520
Kuna kesi 2; kubwa na ndogo ni kesi 2.

257
00:23:37,520 --> 00:23:40,990
Hivyo kama tuko katika lowercase sisi haja ya kufanya hivyo uppercase.

258
00:23:40,990 --> 00:23:43,710
Kama ni uppercase hatuna haja ya kufanya kitu chochote.

259
00:23:43,710 --> 00:23:50,760
Lakini, kuna njia - shouldn't have flipped -

260
00:23:50,760 --> 00:23:54,800
kwamba hatuna hata haja ya kuangalia kama ni uppercase au lowercase?

261
00:23:54,800 --> 00:24:02,240
Tunaweza kufanya nini kwa siku zote kuhakikisha kwamba sisi daima kuishia katika uppercase?

262
00:24:02,240 --> 00:24:07,830
Hivyo taarifa tulichokifanya kwa lowercase ''; nini kama sisi alifanya hivyo sawa exact kitu kwa uppercase?

263
00:24:07,830 --> 00:24:11,900
Je uppercase mabadiliko, au anafanya mabadiliko ya thamani?

264
00:24:11,900 --> 00:24:23,100
Yeah. Hivyo barua yoyote mtaji bitwise ANDed na ~ 32 ni kwenda kuwa huo uppercase tabia

265
00:24:23,100 --> 00:24:29,220
kwa sababu kwa tabia yoyote uppercase kidogo 32 si kuweka.

266
00:24:29,220 --> 00:24:40,920
Hivyo kama tunataka kuleta tabia s [i], sisi nataka iwe lowercase au uppercase.

267
00:24:40,920 --> 00:24:46,890
Hivyo kama ilikuwa lowercase, ni sasa uppercase, kama ilikuwa uppercase, bado uppercase, na hiyo ni yake.

268
00:24:46,890 --> 00:24:54,290
Mimi alisema hii katika supersection: Unaweza kutumia 32 kama unataka, lakini mimi huwa wanapendelea kufanya '' -,

269
00:24:54,290 --> 00:25:01,150
badala ya 32 wazi tu, kwa sababu inaweza kuwa yoyote kidogo nyingine.

270
00:25:01,150 --> 00:25:03,610
Baada ya kidogo 32, inaweza kuwa yoyote ya hizi, au tunataka kuwa kutosha

271
00:25:03,610 --> 00:25:05,840
idadi ya kuwakilisha yote ya wahusika.

272
00:25:05,840 --> 00:25:09,110
Hivyo kama wewe kupata kidogo 32, inaweza kuwa ni kidogo 64, inaweza kuwa ni kidogo 128.

273
00:25:09,110 --> 00:25:13,990
Yoyote ya bits wale inaweza kuwa kidogo kwamba tofauti kati ya kubwa na ndogo.

274
00:25:13,990 --> 00:25:18,350
Mimi lazima haja ya kujua kwamba ni kidogo 32.

275
00:25:18,350 --> 00:25:27,130
Naweza kutumia hii 'a' - kupata kidogo kwamba hutofautiana kati ya mbili

276
00:25:27,130 --> 00:25:33,000
bila wanaohitaji kutegemea idadi uchawi kwamba ni 32.

277
00:25:33,000 --> 00:25:38,770
Na hivyo sasa, mwingine kuhesabu ilikuwa isiyo ya kawaida, na hivyo nini nataka kufanya?

278
00:25:38,770 --> 00:25:43,920
[Mwanafunzi majibu, unintelligible]

279
00:25:43,920 --> 00:25:45,920
[Mwanafunzi] Nini hiyo?

280
00:25:45,920 --> 00:25:49,850
Nitawafanyieni katika pili 1.

281
00:25:49,850 --> 00:25:55,690
Hivyo sasa kama nataka - mimi nataka kuhakikisha tabia ni sasa lowercase,

282
00:25:55,690 --> 00:26:04,140
na hivyo naweza AU na 32, na 32, maana yake '' - A.

283
00:26:04,140 --> 00:26:06,510
Lakini taarifa, kwa hoja hiyo kama moja ya awali, kwamba kama

284
00:26:06,510 --> 00:26:11,670
barua tayari alikuwa lowercase, basi ORing na 32 tu anaendelea kuwa Herufi za chini.

285
00:26:11,670 --> 00:26:16,220
Ni hajabadilika tabia ya awali.

286
00:26:16,220 --> 00:26:19,910
Lakini sasa mimi hawana kuepuka akisema, "Kama ni lowercase, tu kusahau kuhusu hilo,

287
00:26:19,910 --> 00:26:23,650
kama ni uppercase, basi mabadiliko hayo. "

288
00:26:23,650 --> 00:26:26,900
Ni rahisi zaidi kufanya kazi hii.

289
00:26:26,900 --> 00:26:33,190
[Mwanafunzi] Laiti mkakati wa kutoa mapato uppercase kutoka kazi lowercase kama si 32?

290
00:26:33,190 --> 00:26:35,330
Kama ilikuwa, kama, 34 au kitu?

291
00:26:35,330 --> 00:26:41,840
Hivyo, unahitaji kujua kwamba tofauti kati ya 2 ni -? >> 1 kidogo.

292
00:26:41,840 --> 00:26:49,840
Ni inaweza kuwa zaidi ya 1 kidogo, kwa muda mrefu kama aina ya sarafu chini ya msimamo huu ni sawa.

293
00:26:49,840 --> 00:26:58,500
Hivyo tunahitaji angalau herufi 26 - au, kuna 26 wahusika.

294
00:26:58,500 --> 00:27:04,590
Hivyo tunahitaji idadi angalau 26 ili kuwakilisha tofauti -

295
00:27:04,590 --> 00:27:07,650
Tofauti kati na 'ina kuwa angalau 26,

296
00:27:07,650 --> 00:27:10,760
au mwingine tunataka kuwa kuwakilishwa namba zote mtaji.

297
00:27:10,760 --> 00:27:18,630
Hiyo ina maana kwamba, kama tunataka kuanza saa 1, itakuja kutumia yote ya bits hizi,

298
00:27:18,630 --> 00:27:23,900
wote wa bits hizi kwanza 5, kuwakilisha kila kitu kwa njia ya Z.

299
00:27:23,900 --> 00:27:32,170
Hiyo ndiyo sababu kidogo ijayo, au hii kidogo, kidogo ijayo ni moja hiyo waliochaguliwa kutofautisha kati na '.'

300
00:27:32,170 --> 00:27:40,930
Hiyo pia ni kwa nini, katika meza ASCII, kuna 5 alama kutenganisha herufi kubwa kutoka barua lowercase.

301
00:27:40,930 --> 00:27:49,050
Tangu wale ni ishara, 5 ziada huleta juu 32 kuwa tofauti baina yao.

302
00:27:49,050 --> 00:27:51,840
[Mwanafunzi] Basi tunaweza kufanya hivyo, kwa sababu ASCII iliyoundwa kwa njia hiyo.

303
00:27:51,840 --> 00:27:57,280
Ndiyo. Lakini ASCII - tofauti pia inaweza kuwa wote wawili wa bits haya.

304
00:27:57,280 --> 00:28:12,040
Kama, kama walikuwa 10000001, na '' ilikuwa 11100001 - mimi kusahau, chochote.

305
00:28:12,040 --> 00:28:18,100
Lakini ikiwa ni hii, basi sisi inaweza kutumia '- A.

306
00:28:18,100 --> 00:28:22,650
Ni sasa tu na tofauti kati ya 'bado ni haya bits 2.

307
00:28:22,650 --> 00:28:32,240
Nadhani imeandikwa 48. Je, ni 32 + 64? Nadhani ni?

308
00:28:32,240 --> 00:28:40,160
Bado ingekuwa 2 bits; kila tabia moja, kama, Z na z, K na k,

309
00:28:40,160 --> 00:28:45,160
wangeweza bado kuwa sawa bits halisi kuweka isipokuwa kwa wale bits 2.

310
00:28:45,160 --> 00:28:48,870
Hivyo kwa muda mrefu kama hiyo ni kweli daima, bila ya kujali kama sisi ni kutumia ASCII au baadhi mfumo mwingine,

311
00:28:48,870 --> 00:28:53,050
muda mrefu kama kuna tu kuweka idadi ya vipande ambayo ni tofauti kwa ajili ya tabia ya kila,

312
00:28:53,050 --> 00:28:55,050
basi kazi nzuri.

313
00:28:55,050 --> 00:29:06,110
Ni kwamba tu 32 ilianzishwa kwa sababu ni moja ya kwanza sisi inaweza uwezekano kutumia. >> Cool.

314
00:29:06,110 --> 00:29:14,520
Mimi huwa wanapendelea, katika kesi hawajaona, kama block ni line moja tu,

315
00:29:14,520 --> 00:29:24,280
unaweza kujikwamua ya braces curly; hivyo mimi huwa wanapendelea kufanya hili.

316
00:29:24,280 --> 00:29:34,010
Pia, unajua jinsi gani tunaweza kufanya mambo kama s [i] + = 1?

317
00:29:34,010 --> 00:29:41,090
Unaweza pia kufanya s [i] bitwise NA = 32.

318
00:29:41,090 --> 00:29:46,400
Na bitwise AU = 32.

319
00:29:46,400 --> 00:29:51,490
Pia, kuhesabu Mod 2 == 0.

320
00:29:51,490 --> 00:30:00,900
Basi kumbuka kwamba - mimi si kuandika ni - thamani yoyote yasiyo ya sifuri ni kweli, na 0 ni uongo.

321
00:30:00,900 --> 00:30:07,880
Hivyo "kama kuhesabu Mod 2 == 0" ni sawa na kusema "kama si kuhesabu Mod 2."

322
00:30:07,880 --> 00:30:11,580
Mimi pengine ingekuwa tu kuachwa mistari na alisema, "kama kuhesabu Mod 2,

323
00:30:11,580 --> 00:30:15,350
je AU 1, mwingine kufanya NA 1, "ili kwamba mimi hakuwa na haja ya" si. "

324
00:30:15,350 --> 00:30:18,650
Lakini hii kazi tu kama vizuri.

325
00:30:18,650 --> 00:30:25,660
Na kile kingine naweza kufanya hapa?

326
00:30:25,660 --> 00:30:29,060
Unaweza kuchanganya yao na ternary kama alitaka, lakini basi d tu kufanya mambo messier

327
00:30:29,060 --> 00:30:33,770
na pengine zaidi vigumu kusoma, hivyo tutakuwa na si kufanya hivyo.

328
00:30:33,770 --> 00:30:37,330
Mtu yeyote kuwa mapendekezo yoyote mengine?

329
00:30:37,330 --> 00:30:41,580
Ni kwamba tatizo yote aliuliza kwa? Oh yeah.

330
00:30:41,580 --> 00:30:51,070
Hivyo kujikwamua mistari haya ya tupu, sasa tutaweza magazeti f,% s kuwa moja kwa masharti,

331
00:30:51,070 --> 00:30:56,620
Sisi magazeti f, s.

332
00:30:56,620 --> 00:30:59,330
Sasa hebu kukimbia. Je, mimi kufanya kitu chochote kibaya?

333
00:30:59,330 --> 00:31:03,200
Hiyo ni \ ", mimi nataka n.

334
00:31:03,200 --> 00:31:07,840
Sawa. Sasa tutaweza kukimbia. Ni pengine itabidi yell saa yangu.

335
00:31:07,840 --> 00:31:11,250
Strlen ni katika string.h.

336
00:31:11,250 --> 00:31:14,290
Hivyo hii ni kitu kizuri kuhusu Clang ni anakwambia nini ni katika,

337
00:31:14,290 --> 00:31:19,140
badala ya GCC ambayo tu anasema, "Hey, wewe wamesahau kitu, sijui ni kitu gani."

338
00:31:19,140 --> 00:31:29,220
Lakini hii kuniambia, "Wewe ni pamoja na maana ya string.h."

339
00:31:29,220 --> 00:31:32,130
Hivyo sikuweza kuchochea kwa kitu chochote, hivyo si kusema chochote.

340
00:31:32,130 --> 00:31:42,540
Lakini tutaweza kufanya mfano wao, "Shukrani 4 kuongeza".

341
00:31:42,540 --> 00:31:47,880
Hiyo inaonekana haki. Hooray.

342
00:31:47,880 --> 00:31:52,370
Hivyo kurejea kuu yako, mimi karibu kamwe kufanya hivyo.

343
00:31:52,370 --> 00:31:57,110
Ni hiari. Na kuu ni kazi tu kwa ajili ya ambayo ni ya hiari.

344
00:31:57,110 --> 00:32:07,140
Kama huna kurudi kitu chochote kutoka kuu, ni kudhani kuwa wewe maana kurudi 0.

345
00:32:07,140 --> 00:32:13,070
Maswali?

346
00:32:13,070 --> 00:32:20,980
Sawa. Hivyo sasa tatizo la pili.

347
00:32:20,980 --> 00:32:24,810
"Kumbuka kutoka hotuba wiki 2 wa pili kwamba swapping maadili 2 vigezo 'kwa kupita

348
00:32:24,810 --> 00:32:30,780
wale vigezo 2 kwa kazi (hata kama kuitwa byta) haina hasa kazi, angalau si bila 'kuyatumia.' "

349
00:32:30,780 --> 00:32:37,020
Na kupuuza kuyatumia mpaka sisi kupata kwao.

350
00:32:37,020 --> 00:32:40,070
Tunataka wabadilishane vigezo 2; sisi siyo kutumia kazi ya kufanya.

351
00:32:40,070 --> 00:32:43,410
Bado tuko kwenda kufanya hivyo katika kuu kama inavyosema.

352
00:32:43,410 --> 00:32:48,360
Lakini kwa kutumia vigezo wale 2, hatutaki kutumia variable muda.

353
00:32:48,360 --> 00:32:50,770
Kuna 2 njia za kufanya hivi.

354
00:32:50,770 --> 00:32:56,310
Unaweza kufanya hivyo kwa kutumia waendeshaji yako jadi binary.

355
00:32:56,310 --> 00:33:00,180
Hivyo haina mtu yeyote kujua njia ya haraka na chafu ya kufanya hivyo?

356
00:33:00,180 --> 00:33:07,650
Inawezekana kweli kuchukua dakika ya kufikiri. Kama mimi na -

357
00:33:07,650 --> 00:33:12,130
Mimi itabidi kuweka tatizo juu kama wao kuomba. Hivyo kama nina vigezo 2,, ambayo ni tu integer

358
00:33:12,130 --> 00:33:17,800
kwamba wao nipe, na Jumla B variable, ambayo ni mwingine integer kwamba mimi nina aliyopewa.

359
00:33:17,800 --> 00:33:22,700
Hivyo kama nina vigezo hizi 2, sasa mimi nataka byta yao.

360
00:33:22,700 --> 00:33:31,550
jadi, kwa kutumia waendeshaji yako ya kawaida binary, I mean, kama +, -, ÷.

361
00:33:31,550 --> 00:33:36,630
Si bitwise waendeshaji ambayo kutenda juu ya binary.

362
00:33:36,630 --> 00:33:39,600
Hivyo kwa kutumia -, +, ÷, na wale wote.

363
00:33:39,600 --> 00:33:52,980
Tunaweza wabadilishane kwa kufanya kitu kama = a + b, na b = a - b, a = a - b.

364
00:33:52,980 --> 00:34:04,260
Hivyo, sanity kuangalia, na kisha tutaweza kuona kwa nini kazi hiyo.

365
00:34:04,260 --> 00:34:13,320
Hebu sema = 7, b = 3, kisha + b ni kwenda kuwa 10.

366
00:34:13,320 --> 00:34:18,820
Hivyo sisi ni sasa kuweka 10 =, na kisha sisi ni kufanya b = a - b.

367
00:34:18,820 --> 00:34:30,250
Hivyo sisi ni kufanya b = a - b, ambayo ni kwenda kuwa 7, na b = a - b tena,

368
00:34:30,250 --> 00:34:38,650
au = a - b. Ambayo ni kwenda kuwa 10-7 ambayo ni 3.

369
00:34:38,650 --> 00:34:44,850
Hivyo sasa, kwa usahihi, '' ilikuwa 7, b mara 3, na sasa ni 7 na b '' ni 3.

370
00:34:44,850 --> 00:34:48,679
Hivyo kwamba aina ya mantiki; '' ni mchanganyiko wa namba 2.

371
00:34:48,679 --> 00:34:53,000
Katika hatua hii, '' ni mchanganyiko, na kisha sisi ni subtracting nje b awali,

372
00:34:53,000 --> 00:34:56,860
na kisha sisi ni subtracting nje nini mara ya awali '.'

373
00:34:56,860 --> 00:35:01,150
Lakini hii haina kazi kwa namba zote.

374
00:35:01,150 --> 00:35:08,880
Kuona hii, hebu fikiria mfumo; hivyo sisi kufikiri ya kawaida integers kama bits 32.

375
00:35:08,880 --> 00:35:13,050
Hebu kazi juu ya kitu tu kama bits 4.

376
00:35:13,050 --> 00:35:15,450
Hopefully mimi kuja na mfano mzuri sasa.

377
00:35:15,450 --> 00:35:18,680
Kwa hiyo, mimi kujua, hii itakuwa rahisi.

378
00:35:18,680 --> 00:35:26,720
Hebu sema wetu 2 idadi ni 1111, na 1111, hivyo tuko katika binary hivi sasa.

379
00:35:26,720 --> 00:35:34,630
Katika decimals halisi, kama unataka kufikiria ni kwa njia hiyo, = 15 na b = 15.

380
00:35:34,630 --> 00:35:37,630
Na hivyo sisi kutarajia, baada ya sisi byta yao - hawana hata kuwa idadi sawa,

381
00:35:37,630 --> 00:35:41,140
lakini mimi alifanya hivyo kwa njia hii.

382
00:35:41,140 --> 00:35:47,100
Hebu kufanya nao si namba moja. Hebu kufanya 1111 na 0001.

383
00:35:47,100 --> 00:35:51,860
Hivyo = 15 na b = 1.

384
00:35:51,860 --> 00:35:57,670
Baada ya sisi byta yao, sisi kutarajia '' kuwa na 1 b kuwa 15.

385
00:35:57,670 --> 00:36:01,780
Hivyo hatua yetu ya kwanza ni = a + b.

386
00:36:01,780 --> 00:36:08,770
Idadi yetu ni 4 tu bits mbalimbali, hivyo ',' ambayo ni 1111, + b, ambayo ni 0001,

387
00:36:08,770 --> 00:36:16,780
ni kwenda kuishia kuwa 10,000, lakini sisi tu bits 4.

388
00:36:16,780 --> 00:36:22,540
Hivyo sasa = 0.

389
00:36:22,540 --> 00:36:34,080
Na sasa tunataka kuweka b = a - b - kweli, hii bado kazi nje kikamilifu.

390
00:36:34,080 --> 00:36:39,630
= A - hebu angalia kama hii kazi nje kikamilifu - b.

391
00:36:39,630 --> 00:36:53,720
Hivyo basi b = 0-1, ambayo bado ingekuwa 15, na kisha = a - b, ambayo itakuwa ni 1.

392
00:36:53,720 --> 00:36:56,210
Labda hii haina kazi.

393
00:36:56,210 --> 00:36:59,020
Najisikia kama kuna sababu haifanyi kazi kwa kutumia mara kwa mara.

394
00:36:59,020 --> 00:37:06,400
Sawa, hivyo kufanya kazi kwa kudhani kuwa haifanyi kazi na shughuli za mara kwa mara binary,

395
00:37:06,400 --> 00:37:15,040
nami kuangalia kwa - Mimi Google kuona kama ni kweli.

396
00:37:15,040 --> 00:37:23,490
Hivyo tunataka kufanya hivyo kwa kutumia kampuni za bitwise, na kidokezo hapa ni XOR.

397
00:37:23,490 --> 00:37:28,780
Hivyo, kuanzisha XOR (^) kama hawajaona bado.

398
00:37:28,780 --> 00:37:34,610
Ni, tena, operator bitwise hivyo ni vitendo kidogo kidogo, na it's -

399
00:37:34,610 --> 00:37:39,910
Kama una bits 0 na 1, basi hii itakuwa 1.

400
00:37:39,910 --> 00:37:45,230
Kama una bits 1 na 0, utakuwa ni 1, una bits 0 0 na utakuwa 0,

401
00:37:45,230 --> 00:37:47,640
na kama una bits 1 na 1 utakuwa 0.

402
00:37:47,640 --> 00:37:56,180
Hivyo ni kama AU. Kama mojawapo ya bits ni kweli, ni 1, lakini tofauti na AU, haiwezi kuwa wote bits kwamba ni kweli.

403
00:37:56,180 --> 00:37:59,320
AU ingekuwa hii kuwa 1, XOR ingekuwa hii kuwa 0.

404
00:37:59,320 --> 00:38:02,250
Hivyo sisi ni kwenda wanataka kutumia XOR hapa.

405
00:38:02,250 --> 00:38:09,960
Fikiria juu yake kwa dakika; nitakacho Google.

406
00:38:09,960 --> 00:38:16,230
Naam, huwezi kusoma kwamba, mimi nina sasa juu ya ukurasa XOR byta algorithm.

407
00:38:16,230 --> 00:38:21,340
Hopefully hii kueleza kwa nini mimi can't -

408
00:38:21,340 --> 00:38:34,190
Hii ni hasa algorithm kwamba sisi tu alivyofanya.

409
00:38:34,190 --> 00:38:37,330
Mimi bado hawaoni ni kwa nini - Mimi lazima tu ilichukua mfano mbaya,

410
00:38:37,330 --> 00:38:44,940
lakini kesi hii ambapo 'kilichotokea kwa kuwa 0, baada ya kupata bits 5, hivyo sasa' ni 0,

411
00:38:44,940 --> 00:38:48,730
kwamba ni kile kinachoitwa "integer kufurika."

412
00:38:48,730 --> 00:38:54,370
Kulingana na Wikipedia, "Tofauti byta XOR, tofauti hii inahitaji kwamba anatumia mbinu baadhi

413
00:38:54,370 --> 00:38:59,780
kuhakikisha kwamba x + y haina kusababisha kufurika integer. "

414
00:38:59,780 --> 00:39:08,350
Hivyo hii ina matatizo, hii ilikuwa integer kufurika, lakini mimi alifanya kitu kibaya.

415
00:39:08,350 --> 00:39:10,520
Mimi nina uhakika. Nitajaribu kuja na mwingine mmoja.

416
00:39:10,520 --> 00:39:13,640
[Mwanafunzi] Naam, ni si integer kufurika wakati wewe ni kujaribu kuweka namba katika huko

417
00:39:13,640 --> 00:39:16,640
kubwa kuliko kiasi cha bits una zilizotengwa?

418
00:39:16,640 --> 00:39:23,730
Yeah. Tuna bits 4. That's - tulikuwa na bits 4, sisi basi kujaribu kuongeza 1 kwa hivyo, hivyo sisi kuishia na bits 5.

419
00:39:23,730 --> 00:39:26,690
Lakini kidogo tu tano yanakatwa, yeah.

420
00:39:26,690 --> 00:39:28,970
Ni nguvu kweli -

421
00:39:28,970 --> 00:39:33,010
[Mwanafunzi] Je, hiyo kutupa wewe makosa, au gani kwamba - itakuwa kwamba kutupa kosa?

422
00:39:33,010 --> 00:39:40,720
No Hivyo hakuna makosa. Wakati wewe kupata ngazi ya kanisa, kidogo maalum

423
00:39:40,720 --> 00:39:47,020
mahali fulani kwamba ni kuweka alisema kuna kufurika, lakini katika C wewe aina ya si tu kukabiliana na kwamba.

424
00:39:47,020 --> 00:39:55,160
Wewe kweli hawawezi kukabiliana nayo isipokuwa wewe kutumia maelekezo maalum mkutano katika C.

425
00:39:55,160 --> 00:39:58,110
Hebu fikiria kuhusu byta XOR.

426
00:39:58,110 --> 00:40:02,220
Na nadhani makala ya Wikipedia inaweza pia wamekuwa wakisema kwamba -

427
00:40:02,220 --> 00:40:07,310
Hivyo ni pia akalileta hesabu msimu, hivyo mimi nadhani ilikuwa, katika nadharia, kufanya hesabu byggelement

428
00:40:07,310 --> 00:40:11,160
wakati mimi alisema kuwa 0-1 ni 15 tena.

429
00:40:11,160 --> 00:40:15,410
Hivyo kwamba kunaweza - juu ya processor mara kwa mara kwamba anafanya 0-1 = 15.

430
00:40:15,410 --> 00:40:20,430
Tangu sisi kuishia katika 0, sisi Ondoa 1, hivyo basi tu Wraps nyuma karibu na 1111.

431
00:40:20,430 --> 00:40:28,930
Hivyo algorithm hii ili kweli kazi, + b, - b, b - a; ambayo inaweza kuwa faini.

432
00:40:28,930 --> 00:40:34,030
Lakini kuna baadhi ya wasindikaji ambayo si kufanya hivyo, na hivyo itakuwa ni faini katika wale wale maalum.

433
00:40:34,030 --> 00:40:39,880
XOR byta kazi juu ya processor yoyote. Sawa.

434
00:40:39,880 --> 00:40:42,280
Wazo ni kwamba, ni walidhani kuwa sawa, ingawa.

435
00:40:42,280 --> 00:40:50,120
Ambapo sisi ni kutumia XOR kwa namna fulani kupata taarifa ya wote ndani ya 1 ya vigezo,

436
00:40:50,120 --> 00:40:54,120
na kisha kuvuta habari nje ya vigezo ya mtu binafsi tena.

437
00:40:54,120 --> 00:41:04,330
Hivyo haina mtu yeyote kuwa na mawazo / jibu?

438
00:41:04,330 --> 00:41:14,540
[Mwanafunzi jibu, unintelligible]

439
00:41:14,540 --> 00:41:22,220
Hivyo hii lazima kazi, na pia, ni XOR unaofanyika.

440
00:41:22,220 --> 00:41:27,620
Bila kujali ambayo ili hizi namba 2 kutokea kwa kuwa katika hapa,

441
00:41:27,620 --> 00:41:30,100
matokeo haya ni kwenda kuwa sawa.

442
00:41:30,100 --> 00:41:35,800
Hivyo ^ b ni b ^ a.

443
00:41:35,800 --> 00:41:51,860
Unaweza pia kuona hii imeandikwa kama ^ = b, b ^ = a, a ^ = b tena.

444
00:41:51,860 --> 00:42:00,200
Hivyo hii ni haki, na kuona kwa nini hii kazi, kufikiri ya sarafu.

445
00:42:00,200 --> 00:42:10,400
Kutumia idadi smallish, hebu kusema 11,001, na 01,100.

446
00:42:10,400 --> 00:42:12,790
Hivyo hii ni '', hii ni kwa b.

447
00:42:12,790 --> 00:42:15,540
Hivyo ^ = b.

448
00:42:15,540 --> 00:42:22,380
Sisi wanaenda kuweka = 'A' na XOR ya mambo haya 2.

449
00:42:22,380 --> 00:42:32,920
Hivyo 1 ^ 0 ni 1; 1 ^ 1 ni 0; 0 ^ 1 ni 1, na 0 0 ^ ni 0; 1 ^ 0 ni 1.

450
00:42:32,920 --> 00:42:37,380
Hivyo ',' kama ukiangalia idadi decimal, itakavyo kuwa -

451
00:42:37,380 --> 00:42:41,160
wewe si kwenda kuona mengi ya uhusiano kati ya awali 'na mpya', '

452
00:42:41,160 --> 00:42:45,600
lakini kuangalia bits, '' sasa ni kama matundu ya habari

453
00:42:45,600 --> 00:42:49,970
wa wote asili 'na b awali.

454
00:42:49,970 --> 00:42:57,930
Hivyo kama sisi kuchukua b ^, tunaona kwamba sisi kuishia katika asili '.'

455
00:42:57,930 --> 00:43:08,910
Na kama sisi kuchukua asili '' ^ mpya ',' tunaona sisi kuishia katika b awali.

456
00:43:08,910 --> 00:43:18,380
Hivyo (a ^ b) ^ b = awali '.'

457
00:43:18,380 --> 00:43:27,910
Na (a ^ b) ^ a = b awali.

458
00:43:27,910 --> 00:43:37,010
Kuna - njia nyingine ya kuona hii ni kitu chochote XOR yenyewe ni daima 0.

459
00:43:37,010 --> 00:43:45,020
Hivyo 1101 ^ 1101, bits wote wataenda kuwa sawa.

460
00:43:45,020 --> 00:43:47,920
Hivyo kuna kamwe kwenda kuwa kesi ambapo 1 ni 0 na nyingine ni 1.

461
00:43:47,920 --> 00:43:51,080
Hivyo hii ni 0000.

462
00:43:51,080 --> 00:43:57,240
sawa na hii. (^ B) ^ b ni kama ^ (b ^ b).

463
00:43:57,240 --> 00:44:03,680
(B ^ b) ni kwenda kuwa 0; ^ 0 ni kwenda tu kuwa ',' tangu bits wote ni 0.

464
00:44:03,680 --> 00:44:08,050
Hivyo wale tu kwamba ni kwenda kuwa ambapo 'awali ilikuwa 1 - alikuwa ndio.

465
00:44:08,050 --> 00:44:12,070
Na wazo sawa hapa, mimi nina uhakika pretty pia ni unaofanyika.

466
00:44:12,070 --> 00:44:17,590
Yeah. Sikuweza kusema kabla ya kuwa ni unaofanyika.

467
00:44:17,590 --> 00:44:24,680
^ ',' Na ni associative, hivyo sasa (b ^ a) ^ a.

468
00:44:24,680 --> 00:44:28,970
Na tunaweza kufanya b ^ (a ^ a).

469
00:44:28,970 --> 00:44:31,540
Na hivyo tena, sisi kupata b awali.

470
00:44:31,540 --> 00:44:37,120
Hivyo '' sasa ni mchanganyiko wa b 'na kwa pamoja.

471
00:44:37,120 --> 00:44:49,660
Kutumia combo wetu mpya 'tunasema b = combo' '^ b awali, sisi kupata asili'. '

472
00:44:49,660 --> 00:45:05,170
Na sasa combo = '' ^ b mpya, ambayo ilikuwa ya awali - au ambayo sasa ni nini ilikuwa '' au b.

473
00:45:05,170 --> 00:45:13,620
Hiyo ni kesi hii chini hapa. Hii ni = b, umri b.

474
00:45:13,620 --> 00:45:16,550
Hivyo sasa kila kitu ni nyuma ili swapped.

475
00:45:16,550 --> 00:45:22,960
Kama sisi kweli inaonekana katika bits, b = a ^ b, ni kwenda XOR hizi 2,

476
00:45:22,960 --> 00:45:33,920
na jibu ni kwenda kuwa hii, na kisha = a ^ b ni XORing hizi 2 na jibu ni hili.

477
00:45:33,920 --> 00:45:41,090
Maswali? Sawa. Hivyo moja ya mwisho ni kiasi fulani kwa kiasi kikubwa magumu zaidi.

478
00:45:41,090 --> 00:45:43,180
[Mwanafunzi] Nadhani yeye ana swali kuhusu hilo. >> Oh, sorry.

479
00:45:43,180 --> 00:45:49,380
[Mwanafunzi] Nini kweli kasi? Kama wewe kutumia hii XOR, au ni kama wewe kutangaza variable mpya?

480
00:45:49,380 --> 00:45:55,190
Hiyo ni nini kweli kasi, kutangaza variable mpya au kutumia XOR wabadilishane?

481
00:45:55,190 --> 00:45:59,600
Jibu ni, katika uwezekano wote, variable muda.

482
00:45:59,600 --> 00:46:05,780
Na kwamba ni kwa sababu mara moja ni compiled chini - hivyo katika ngazi ya kanisa,

483
00:46:05,780 --> 00:46:12,320
hakuna kitu kama vigezo mitaa au vigezo yoyote muda au yoyote ya mambo haya.

484
00:46:12,320 --> 00:46:16,060
Wao ni kama tu - kuna kumbukumbu, na kuna madaftari.

485
00:46:16,060 --> 00:46:20,920
Madaftari ni ambapo mambo ni juhudi kinachotokea.

486
00:46:20,920 --> 00:46:24,750
Huwezi kuongeza mambo 2 katika kumbukumbu; wewe kuongeza 2 mambo katika madaftari.

487
00:46:24,750 --> 00:46:28,160
Na wewe kuleta mambo kutoka katika kumbukumbu madaftari na kisha kuongeza yao,

488
00:46:28,160 --> 00:46:33,180
na basi unaweza kuweka yao nyuma katika kumbukumbu, lakini hatua zote hufanyika katika madaftari.

489
00:46:33,180 --> 00:46:38,750
Hivyo wakati wewe ni kutumia muda variable mbinu, kwa kawaida kinachotokea ni

490
00:46:38,750 --> 00:46:42,810
nambari hizi 2 ni tayari katika madaftari.

491
00:46:42,810 --> 00:46:46,570
Na kisha kutoka kwamba uhakika juu, baada ya umefanya swapped yao,

492
00:46:46,570 --> 00:46:51,540
hivyo itabidi tu kuanza kutumia rejesta nyingine.

493
00:46:51,540 --> 00:46:56,510
Popote wewe amekuwa kutumia b, hivyo itabidi tu kutumia daftari kwamba alikuwa tayari hifadhi '.'

494
00:46:56,510 --> 00:47:02,180
Hivyo hana haja ya kufanya kitu chochote kwa kweli kufanya byta. Yeah?

495
00:47:02,180 --> 00:47:05,690
[Mwanafunzi] Lakini pia inachukua zaidi ya kumbukumbu, haki?

496
00:47:05,690 --> 00:47:10,280
Itakuwa tu kuchukua zaidi ya kumbukumbu kama anahitaji kuhifadhi kwamba variable muda.

497
00:47:10,280 --> 00:47:14,830
Kama kama wewe matumizi ya baadaye kwamba variable muda tena mahali fulani,

498
00:47:14,830 --> 00:47:18,920
basi - au wewe hawawajui kitu variable kwamba muda mfupi.

499
00:47:18,920 --> 00:47:24,630
Hivyo kama katika hatua yoyote katika muda ',' b katika temp kuwa na maadili tofauti au kitu,

500
00:47:24,630 --> 00:47:30,680
basi ni kwenda na maeneo tofauti katika kumbukumbu, lakini ni kweli kwamba

501
00:47:30,680 --> 00:47:34,800
kuna mengi ya ndani ambayo itakuwa vigezo tu kuwepo katika madaftari.

502
00:47:34,800 --> 00:47:44,370
Katika kesi ambayo, ni kamwe kuweka katika kumbukumbu, na hivyo wewe kamwe kupoteza kumbukumbu.

503
00:47:44,370 --> 00:47:58,620
Sawa. Swali la mwisho ni kidogo zaidi.

504
00:47:58,620 --> 00:48:04,850
Hivyo hapa, katika hii appliance CS50, kuna kamusi.

505
00:48:04,850 --> 00:48:12,390
Na sababu hii ni kwa sababu [?? B66] Kibonyezo cha kusahihisha kipo wapi wewe utakuwa kuandika

506
00:48:12,390 --> 00:48:15,780
kutumia meza hash au inajaribu au baadhi muundo data.

507
00:48:15,780 --> 00:48:22,660
Wewe utaenda kuandika kusahihisha Spell, na mtaenda kuwa na kutumia hii kamusi kufanya hivyo.

508
00:48:22,660 --> 00:48:28,280
Lakini kwa tatizo hili, sisi ni kwenda tu kuangalia juu ya kuona kama ni neno moja katika kamusi.

509
00:48:28,280 --> 00:48:31,250
Hivyo badala ya hifadhi ya kamusi nzima katika muundo baadhi data

510
00:48:31,250 --> 00:48:35,180
na kisha kuangalia juu ya hati yote ili kuona kama kitu chochote ambacho misspelled,

511
00:48:35,180 --> 00:48:38,490
sisi tu wanataka kupata 1 neno. Hivyo tunaweza tu Scan zaidi ya kamusi nzima

512
00:48:38,490 --> 00:48:44,300
na kama sisi kamwe kupata neno katika kamusi nzima, basi ilikuwa si huko.

513
00:48:44,300 --> 00:48:52,150
Kama sisi Scan zaidi ya kamusi nzima na wala kuona neno, basi sisi ni nzuri, sisi kupatikana.

514
00:48:52,150 --> 00:48:56,580
Ni anasema hapa kwamba tunataka kuanza kuangalia katika hafla ya C ya faili-utunzaji,

515
00:48:56,580 --> 00:48:59,930
tangu tunataka kusoma dictionary,

516
00:48:59,930 --> 00:49:07,680
lakini mimi nitakupa dokezo hapa kama ambayo kazi unapaswa kufikiria.

517
00:49:07,680 --> 00:49:11,510
Nitaandika juu yao Spaces.

518
00:49:11,510 --> 00:49:20,490
Hivyo ndio kuu utasikia wanataka kuangalia ni f wazi na kisha, inevitably, f imefungwa,

519
00:49:20,490 --> 00:49:26,540
ambayo kwenda katika mwisho wa programu yako, na f Scan f.

520
00:49:26,540 --> 00:49:31,060
Unaweza pia kutumia f kusoma, lakini pengine hawataki

521
00:49:31,060 --> 00:49:34,200
kwa sababu ya kuwa - wewe wala kuishia wanaohitaji kwamba.

522
00:49:34,200 --> 00:49:41,880
F Scan f ni nini wewe kwenda kuwa na kutumia kwa Scan zaidi ya kamusi.

523
00:49:41,880 --> 00:49:46,370
Na hivyo hawana haja ya Kanuni up ufumbuzi, kujaribu tu na kama Pseudo-code njia yako

524
00:49:46,370 --> 00:50:05,200
kwa ufumbuzi, na kisha tutaweza kujadili.

525
00:50:05,200 --> 00:50:14,110
Na kweli, tangu mimi tayari aliwapa hawa, kama kwenda ndani yoyote terminal au shell appliance yako,

526
00:50:14,110 --> 00:50:18,250
Napenda - Mimi kawaida - kama hawajaona bado, sijui kama alivyofanya katika darasa,

527
00:50:18,250 --> 00:50:23,490
lakini mtu, hivyo kurasa mtu, ni muhimu kwa ajili ya pretty kuangalia kiasi pretty kazi yoyote.

528
00:50:23,490 --> 00:50:27,330
Hivyo siwezi kufanya, kama, mtu f, Scan f.

529
00:50:27,330 --> 00:50:32,300
Hii sasa ni info kuhusu familia Scan f ya kazi.

530
00:50:32,300 --> 00:50:37,070
Mimi naweza pia kufanya f mtu, wazi, na kwamba kutakuwa na nipe maelezo ya kwamba.

531
00:50:37,070 --> 00:50:40,750
Hivyo kama unajua nini kazi ni kwa kutumia, au wewe ni kusoma code

532
00:50:40,750 --> 00:50:43,000
na unaweza kuona baadhi ya kazi na wewe ni kama, "Je, hii nini?"

533
00:50:43,000 --> 00:50:45,280
Tu mtu kwamba kazi jina.

534
00:50:45,280 --> 00:50:47,340
Kuna michache ya mifano weird ambapo unaweza kusema

535
00:50:47,340 --> 00:50:51,620
kama. mtu 2 kwamba kazi jina, au mtu 3 kwamba jina kazi,

536
00:50:51,620 --> 00:50:58,230
lakini wewe tu kufanya hivyo kama mtu kazi jina haina kutokea kwa kazi mara ya kwanza.

537
00:50:58,230 --> 00:51:03,010
[Mwanafunzi] Hivyo nina kusoma ukurasa mtu kwa ajili ya wazi, lakini mimi bado wamechanganyikiwa juu ya jinsi ya kutumia hiyo na mpango.

538
00:51:03,010 --> 00:51:06,170
Sawa. mengi ya kurasa mtu ni chini ya msaada.

539
00:51:06,170 --> 00:51:08,470
Wao ni kufaa zaidi kama tayari kujua nini kufanya

540
00:51:08,470 --> 00:51:12,670
na kisha wewe tu haja ya kukumbuka amri ya hoja au kitu.

541
00:51:12,670 --> 00:51:17,640
Au wanaweza kukupa overview ujumla, lakini baadhi yao ni sana balaa.

542
00:51:17,640 --> 00:51:22,220
Kama f Scan f, pia. Ni inakupa habari kwa wote wa kazi hizo,

543
00:51:22,220 --> 00:51:28,120
na 1 line chini hapa kinachotokea kwa kusema, "F Scan f anayesoma kutoka hatua string au mkondo."

544
00:51:28,120 --> 00:51:32,360
Lakini f kufungua. Hivyo, jinsi gani sisi kutumia f wazi?

545
00:51:32,360 --> 00:51:38,470
wazo la mpango ambayo inahitaji kufanya faili I / O ni kwamba

546
00:51:38,470 --> 00:51:45,070
wewe kwanza haja ya kufungua faili unataka kufanya mambo kwa, na inevitably,

547
00:51:45,070 --> 00:51:51,220
kusoma mambo kutoka faili hilo na kufanya mambo pamoja nao.

548
00:51:51,220 --> 00:51:55,350
F wazi ni nini sisi kutumia kufungua faili.

549
00:51:55,350 --> 00:52:04,190
kitu sisi kupata nyuma, ili kile faili gani tunataka kufungua, ni inatupa -

550
00:52:04,190 --> 00:52:11,970
katika hapa anasema "/ user / sehemu / Dict / maneno."

551
00:52:11,970 --> 00:52:16,740
Hii ni faili kwamba tunataka kufungua, na tunataka kufungua -

552
00:52:16,740 --> 00:52:21,440
tuna kupanga bayana kama tunataka kufungua kusoma au kama tunataka kufungua kuandika.

553
00:52:21,440 --> 00:52:26,490
Kuna wanandoa ya mchanganyiko na stuff, lakini tunataka kufungua hili kwa ajili ya kusoma.

554
00:52:26,490 --> 00:52:29,380
Tunataka kusoma kutoka faili.

555
00:52:29,380 --> 00:52:34,290
Hivyo nini kurudi hili? Kuirudisha nyota faili (*),

556
00:52:34,290 --> 00:52:37,260
na mimi itabidi kuonyesha kila kitu katika f variable, hivyo *,

557
00:52:37,260 --> 00:52:40,840
tena, ni pointer, lakini hatutaki kukabiliana na kuyatumia.

558
00:52:40,840 --> 00:52:46,470
Unaweza kufikiri ya f kama, f sasa ni kutofautiana utaenda kutumia kuwakilisha faili.

559
00:52:46,470 --> 00:52:49,850
Hivyo kama unataka kusoma kutoka faili, unaweza kusoma kutoka f.

560
00:52:49,850 --> 00:52:54,820
Kama unataka karibu ya SVG, wewe karibu f.

561
00:52:54,820 --> 00:53:00,350
Hivyo mwisho wa mpango wakati sisi inevitably unataka kufunga faili, tunapaswa kufanya nini?

562
00:53:00,350 --> 00:53:06,750
Tunataka kuifunga f.

563
00:53:06,750 --> 00:53:12,600
Hivyo sasa mwisho faili kazi kwamba sisi ni kwenda wanataka kutumia ni Scan f, f Scan f.

564
00:53:12,600 --> 00:53:20,930
Na nini kwamba hana ni scans juu ya faili kuangalia mfano kwa mechi.

565
00:53:20,930 --> 00:53:39,100
Kuangalia ukurasa mtu hapa, tunaona int f Scan f, kupuuza thamani ya kurudi kwa sasa.

566
00:53:39,100 --> 00:53:45,230
Hoja ya kwanza ni * faili mkondo, hivyo hoja ya kwanza tunakwenda wanataka kupitisha ni f.

567
00:53:45,230 --> 00:53:47,900
Sisi ni skanning zaidi f.

568
00:53:47,900 --> 00:53:53,680
Hoja ya pili ni string format.

569
00:53:53,680 --> 00:53:58,310
Mimi nitakupa string format hivi sasa.

570
00:53:58,310 --> 00:54:05,180
Nadhani sisi kutokea kwa kusema, 127s \ n, mengi ya kwamba lazima.

571
00:54:05,180 --> 00:54:12,490
wazo la nini kwamba string format ni, ni unaweza kufikiria f Scan kama kinyume cha f magazeti.

572
00:54:12,490 --> 00:54:17,160
Hivyo magazeti f, magazeti f sisi pia kutumia aina hii ya parameter format,

573
00:54:17,160 --> 00:54:25,000
lakini katika f magazeti nini tuko kufanya ni - hebu angalia sawa.

574
00:54:25,000 --> 00:54:32,550
Hivyo magazeti f, na huko ni kweli pia f magazeti f, ambapo hoja ya kwanza ni kwenda kuwa f.

575
00:54:32,550 --> 00:54:40,980
Wakati magazeti f, tunaweza kusema kitu kama, "magazeti 127s \ n" na kisha kama sisi kupita baadhi kamba,

576
00:54:40,980 --> 00:54:44,050
itakavyo magazeti hii kamba na kisha mstari mpya.

577
00:54:44,050 --> 00:54:49,690
Nini 127 njia, nina uhakika pretty, lakini sijawahi vikwazo mwenyewe kwa hiyo,

578
00:54:49,690 --> 00:54:52,470
Wewe bila hata haja ya kusema '127 'katika f magazeti,

579
00:54:52,470 --> 00:54:57,090
lakini nini maana ni magazeti kwanza wahusika 127.

580
00:54:57,090 --> 00:54:59,350
Hivyo nina uhakika pretty hiyo kesi. Unaweza Google kwa ajili hiyo.

581
00:54:59,350 --> 00:55:03,000
Lakini katika moja ijayo nina karibu chanya maana yake ni kwamba.

582
00:55:03,000 --> 00:55:08,880
Hivyo hii ni magazeti kwanza wahusika 127, ikifuatiwa na mstari mpya.

583
00:55:08,880 --> 00:55:14,680
F Scan f sasa, badala ya kuangalia kutofautiana na uchapishaji yake,

584
00:55:14,680 --> 00:55:22,620
ni kwenda kuangalia string baadhi, na kuhifadhi mfano ndani ya kutofautiana.

585
00:55:22,620 --> 00:55:26,360
Hebu kweli matumizi Scan f katika mfano tofauti.

586
00:55:26,360 --> 00:55:31,670
Hivyo hebu sema tulikuwa baadhi int, x = 4,

587
00:55:31,670 --> 00:55:41,110
na sisi alitaka kujenga string maandishi - alitaka kujenga string

588
00:55:41,110 --> 00:55:44,250
kwamba ilikuwa kama, hii itakuja baadaye sana,

589
00:55:44,250 --> 00:55:49,020
kitu ambacho kama tu 4.jpg.

590
00:55:49,020 --> 00:55:51,870
Hivyo hii inaweza kuwa mpango ambapo utakuwa na jumla ya kukabiliana,

591
00:55:51,870 --> 00:55:56,420
jumla kukabiliana i, na unataka kuokoa rundo la images.

592
00:55:56,420 --> 00:56:02,430
Hivyo unataka kuokoa i.jpg, ambapo i ni baadhi iteration ya kitanzi wako.

593
00:56:02,430 --> 00:56:05,500
Hivyo ni jinsi gani sisi kufanya hii string kwa kuwa JPEG?

594
00:56:05,500 --> 00:56:11,720
Kama alitaka magazeti 4.jpg, tunaweza kusema tu magazeti f,% d.jpg,

595
00:56:11,720 --> 00:56:14,410
na basi ingekuwa magazeti kwa kuwa JPEG.

596
00:56:14,410 --> 00:56:20,050
Lakini kama tunataka kuokoa 4.jpg kamba, sisi kutumia Scan f.

597
00:56:20,050 --> 00:56:30,860
Hivyo string s - kweli sisi can't - tabia, char s, hebu kwenda 100.

598
00:56:30,860 --> 00:56:35,400
Hivyo mimi tu alitangaza baadhi ya safu ya wahusika 100,

599
00:56:35,400 --> 00:56:39,830
na kwamba ni nini sisi ni inevitably kwenda kuwa hifadhi ya kwamba JPEG in

600
00:56:39,830 --> 00:56:47,920
Hivyo sisi ni kwenda kutumia Scan f, na format, jinsi sisi kusema% d.jpg

601
00:56:47,920 --> 00:56:54,980
ili magazeti 4.jpg, muundo wa hii ni kwenda kuwa% d.jpg.

602
00:56:54,980 --> 00:57:04,020
Hivyo ni format% d.jpg, nini tunataka kuchukua nafasi% d na ni x,

603
00:57:04,020 --> 00:57:06,590
na sasa tunahitaji kuhifadhi kwamba string mahali fulani.

604
00:57:06,590 --> 00:57:12,500
Na pale ambapo sisi ni kwenda kuhifadhi hii string ni katika safu ya.

605
00:57:12,500 --> 00:57:21,640
Hivyo baada ya line hii ya maadili, s, ikiwa sisi magazeti f,% s ya s variable,

606
00:57:21,640 --> 00:57:26,280
itakavyo magazeti 4.jpg.

607
00:57:26,280 --> 00:57:38,930
Hivyo f Scan f ni sawa kama Scan f, ila sasa ni kuangalia juu ya faili hii

608
00:57:38,930 --> 00:57:43,600
kwa nini kuhifadhi katika s.

609
00:57:43,600 --> 00:57:46,160
Hiyo ni nini hoja ya mwisho itakuja kuwa.

610
00:57:46,160 --> 00:57:54,170
Tunataka kuhifadhi - "Scan f familia ya scans kazi katika wote kulingana na muundo kama walijaribu chini.

611
00:57:54,170 --> 00:58:02,450
Kama yoyote ni kuhifadhiwa katika pointi mahali unaweza kurudi - "

612
00:58:02,450 --> 00:58:12,910
Hapana, sisi inaweza kuwa nzuri. Hebu fikiria kwa pili.

613
00:58:12,910 --> 00:58:26,350
Hivyo Scan f haina - nini heck ni kazi ambayo hana kwamba?

614
00:58:26,350 --> 00:58:31,650
Hivyo Scan f si kwenda kuchukua integer na kufanya dot jpg.

615
00:58:31,650 --> 00:58:43,490
Ni kwenda [mumbles].

616
00:58:43,490 --> 00:58:49,360
Ila variable int katika string int C.

617
00:58:49,360 --> 00:58:55,940
Nini ni variable hii, au ni nini kazi hii iitwayo?

618
00:58:55,940 --> 00:59:04,950
Ndiyo. That's - ndiyo. Hivyo kile nilikuwa na kufafanua kwa wewe kabla ilikuwa s magazeti f,

619
00:59:04,950 --> 00:59:09,820
ambayo - kwamba inafanya mengi zaidi akili, kwa nini mimi alisema ilikuwa zaidi kama f magazeti.

620
00:59:09,820 --> 00:59:14,700
Scan f bado ni aina ya kama f magazeti, lakini s magazeti f ni kwenda Scan juu ya

621
00:59:14,700 --> 00:59:17,510
na kuchukua nafasi ya vigezo na sasa kuhifadhi katika kamba.

622
00:59:17,510 --> 00:59:19,620
Badala ya uchapishaji hilo, ni maduka yake katika kamba.

623
00:59:19,620 --> 00:59:25,070
Hivyo kupuuza kwamba kabisa. Unaweza bado kufikiria specifier format kama kama wa f magazeti.

624
00:59:25,070 --> 00:59:34,510
Hivyo sasa, kama sisi alitaka kufanya kitu 4.jpg, tunataka kufanya s magazeti f, x ya hili.

625
00:59:34,510 --> 00:59:38,520
Basi nini Scan f ni kufanya - kile swali lako kwenda kuwa?

626
00:59:38,520 --> 00:59:40,820
[Mwanafunzi] Nina kuchanganyikiwa tu juu ya nini sisi ni kujaribu kufanya haki hapa

627
00:59:40,820 --> 00:59:43,450
na kwamba JPEG. Je, unaweza kueleza kwamba 1 zaidi ya muda?

628
00:59:43,450 --> 00:59:52,710
Hivyo hii ilikuwa - ni chini relevent kwa f Scan f sasa; hopefully, itakuwa kumfunga nyuma katika baadhi ya aina ya njia.

629
00:59:52,710 --> 01:00:02,240
Lakini kile Mimi awali alikuwa amekusudia kuonyesha ilikuwa - hii ni kweli moja kwa moja muhimu kwa [haya? F5]

630
01:00:02,240 --> 01:00:08,520
Wewe utaenda kuwa wanatumia magazeti f, ambapo, kusema tuna images 100,

631
01:00:08,520 --> 01:00:13,630
na unataka kusoma picha 1.jpg, 2.jpg, 3.jpg.

632
01:00:13,630 --> 01:00:21,520
Hivyo ili kufanya hivyo, unahitaji f wazi, na kisha una kupita katika string kwamba unataka kufungua.

633
01:00:21,520 --> 01:00:30,020
Hivyo tunataka unataka kufungua 1.jpg; ili kujenga string kwamba ni 1.jpg,

634
01:00:30,020 --> 01:00:37,660
magazeti sisi kufanya s f% d.jpg-sisi hakufanya kwa int i = 0.

635
01:00:37,660 --> 01:00:46,580
i <40, i + +.

636
01:00:46,580 --> 01:00:51,130
Hivyo s magazeti f% d.jpg ya i.

637
01:00:51,130 --> 01:00:56,320
Hivyo baada ya mstari huu, sasa variable au s safu ni kwenda 1.jpg.

638
01:00:56,320 --> 01:01:10,610
Au, 0.jpg, 1.jpg, 2.jpg. Na hivyo tunaweza kufungua, kwa upande mwingine, kila picha kwa ajili ya kusoma.

639
01:01:10,610 --> 01:01:19,550
Hivyo kwamba ni nini s magazeti f gani. Je, unaweza kuona nini s magazeti f sasa ni kufanya?

640
01:01:19,550 --> 01:01:25,720
[Mwanafunzi] Sawa, hivyo ni kuchukua - inajenga kamba, something.jpg, na kisha maduka hayo.

641
01:01:25,720 --> 01:01:30,360
Ndiyo. Ni inajenga - hii ni mwingine string format, kama tu Scan f na f magazeti,

642
01:01:30,360 --> 01:01:37,530
ambapo ni kuwekeza yote ya vigezo katika hoja ya pili, inaweza kuwa ni kinyume na i.

643
01:01:37,530 --> 01:01:42,280
Labda - I mean, hiyo kesi. Lakini chochote utaratibu wa hoja ni.

644
01:01:42,280 --> 01:01:45,440
Ni kwenda Insert wote wa vigezo katika string format

645
01:01:45,440 --> 01:01:52,250
na kisha kuhifadhi katika buffer yetu, sisi wito kwamba buffer, ni mahali ambapo sisi ni hifadhi ya kamba.

646
01:01:52,250 --> 01:02:00,750
Hivyo sisi ni hifadhi ndani ya s string usahihi-formatted, d% baada ya kubadilishwa na 4.

647
01:02:00,750 --> 01:02:08,080
[Mwanafunzi] Hivyo kama sisi alifanya hivyo, ni f variable tu kwenda kuwa reassigned?

648
01:02:08,080 --> 01:02:18,110
Ndiyo. Hivyo tunapaswa kufunga f awali kabla ya kufanya hivyo.

649
01:02:18,110 --> 01:02:22,810
Lakini - na kisha pia, kama kulikuwa na si f kufungua hapa, basi tutakuwa haja ya kusema -

650
01:02:22,810 --> 01:02:29,280
Yeah. Lakini itakuwa ni wazi mia files tofauti.

651
01:02:29,280 --> 01:02:37,360
[Mwanafunzi] Lakini sisi bila kuwa na uwezo wa kupata au - sawa.

652
01:02:37,360 --> 01:02:44,230
Sawa. Hivyo Scan f, f Scan f, ni aina ya wazo moja,

653
01:02:44,230 --> 01:02:53,610
lakini badala yake, badala ya hifadhi hiyo ndani ya kamba, ni zaidi kama wewe ni sasa

654
01:02:53,610 --> 01:03:02,420
kwenda juu ya kuumwa na muundo vinavyolingana dhidi string kwamba na kuhifadhi matokeo katika vigezo.

655
01:03:02,420 --> 01:03:11,290
Unaweza kutumia f Scan kuchanganua juu ya kitu kama 4.jpg, na kuhifadhi 4 integer ndani ya x int Jumla.

656
01:03:11,290 --> 01:03:13,430
Hiyo ni nini tunaweza kutumia Scan f kwa.

657
01:03:13,430 --> 01:03:16,300
F Scan f anaenda kufanya kuwa katika mstari amri.

658
01:03:16,300 --> 01:03:19,200
Mimi kwa kweli pretty sure hii ni nini maktaba CS50 gani.

659
01:03:19,200 --> 01:03:29,050
Hivyo wakati wewe kusema, "kupata int," ni Scan f-ing juu - Scan f ni njia ya kupata mtumiaji pembejeo.

660
01:03:29,050 --> 01:03:34,670
F Scan f ni kwenda kufanya kitu kimoja lakini kwa kutumia faili Scan juu.

661
01:03:34,670 --> 01:03:41,090
Hiyo hapa, sisi ni juu ya skanning faili hii.

662
01:03:41,090 --> 01:03:45,460
mfano sisi ni kujaribu mechi ni baadhi string kwamba ni wahusika 127 kwa muda mrefu

663
01:03:45,460 --> 01:03:48,100
ikifuatiwa na mstari mpya

664
01:03:48,100 --> 01:03:54,770
Hivyo nina uhakika pretty tunaweza hata kusema tu "mechi s," tangu katika kamusi

665
01:03:54,770 --> 01:03:57,770
sisi kutokea kwa kuwa, sisi ni uhakika hakuna neno ni kwamba kwa muda mrefu,

666
01:03:57,770 --> 01:04:03,310
na pia f Scan f, nadhani, itakuwa kuacha katika mstari mpya bila kujali.

667
01:04:03,310 --> 01:04:06,970
Lakini tutaweza ni pamoja na mstari mpya katika mechi, na -

668
01:04:06,970 --> 01:04:13,960
[Mwanafunzi] Kama sisi hawakuwa ni pamoja na mstari mpya, bila kupata sehemu ya neno?

669
01:04:13,960 --> 01:04:22,900
Ni - kila - kuangalia kamusi -

670
01:04:22,900 --> 01:04:26,200
Hivyo katika kamusi, haya yote ni ya maneno yetu.

671
01:04:26,200 --> 01:04:30,500
Kila mmoja ni juu ya mstari mpya.

672
01:04:30,500 --> 01:04:32,510
f Scan ni kwenda kuchukua neno hili.

673
01:04:32,510 --> 01:04:38,750
Kama hatuwezi ni pamoja na mstari mpya, basi inawezekana kwamba ijayo Scan f tu kusoma mstari mpya.

674
01:04:38,750 --> 01:04:44,180
Lakini ikiwa ni pamoja na mstari mpya basi tu kupuuza mstari mpya.

675
01:04:44,180 --> 01:04:49,440
Lakini tutaweza kamwe kupata sehemu ya neno, kwani sisi ni daima kusoma hadi mstari mpya, bila kujali.

676
01:04:49,440 --> 01:04:54,530
[Mwanafunzi] Lakini nini kama wewe tafuta kwa neno "cissa," kama cissa.

677
01:04:54,530 --> 01:04:57,380
Je, ni kupata kwamba, na kusema ni mechi?

678
01:04:57,380 --> 01:05:05,110
Hivyo hapa sisi - itakuwa kusoma katika - hii ni hatua nzuri kwa kweli.

679
01:05:05,110 --> 01:05:10,660
Sisi ni kamwe kutumia sasa - neno sisi ni kuangalia kwa ni ya kwanza ya mstari amri hoja.

680
01:05:10,660 --> 01:05:16,460
Hivyo kamba, neno = argv 1.

681
01:05:16,460 --> 01:05:20,020
Hivyo string sisi ni kuangalia kwa ni argv 1.

682
01:05:20,020 --> 01:05:23,290
Sisi si kutafuta neno wakati wote katika Scan f yetu.

683
01:05:23,290 --> 01:05:28,030
Nini tunafanya kwa Scan f ni kupata kila neno katika kamusi,

684
01:05:28,030 --> 01:05:34,320
na kisha mara moja kwamba tuna neno tunakwenda kutumia strcmp kwa kulinganisha yao.

685
01:05:34,320 --> 01:05:39,210
Sisi ni kwenda kulinganisha neno yetu na nini sisi kusoma tu in

686
01:05:39,210 --> 01:05:45,110
Hivyo inevitably, tunakwenda kuishia kufanya rundo la Scan FS

687
01:05:45,110 --> 01:05:52,130
mpaka tu hivyo hutokea kwamba f Scan atarudi -

688
01:05:52,130 --> 01:05:54,800
itakuwa kurudi moja, kwa muda mrefu kama ina kuendana neno jipya,

689
01:05:54,800 --> 01:06:01,360
na atarudi kitu kingine kwa haraka kama ni imeshindwa mechi neno.

690
01:06:01,360 --> 01:06:08,440
Sisi ni kusoma zaidi ya kamusi nzima, hifadhi mstari kwa mstari kila neno katika s kutofautiana.

691
01:06:08,440 --> 01:06:17,240
Kisha sisi ni kulinganisha neno na s, na kama kulinganisha == 0,

692
01:06:17,240 --> 01:06:21,650
strcmp kinachotokea kuleta 0 ikiwa mechi kilichofanyika.

693
01:06:21,650 --> 01:06:31,510
Hivyo kama ilikuwa 0, basi tunaweza magazeti f, kuwianishwa,

694
01:06:31,510 --> 01:06:35,370
au neno ni katika kamusi, au chochote unataka magazeti f.

695
01:06:35,370 --> 01:06:41,450
Na kisha - sisi hawataki f karibu tena na tena.

696
01:06:41,450 --> 01:06:50,410
Hii ni aina ya kitu tunataka kufanya, na sisi si kuangalia tu kwa neno katika kamusi.

697
01:06:50,410 --> 01:06:56,660
Hivyo tunaweza kufanya kwamba, kama sisi alitaka kuangalia kwa mfano wao, cissa, kama wewe alisema kabla,

698
01:06:56,660 --> 01:07:00,260
kama sisi alitaka kuangalia kwa mfano kwamba, basi ingekuwa kushindwa katika kesi

699
01:07:00,260 --> 01:07:08,010
kwa sababu hiyo siyo kweli neno, lakini moja ya maneno katika kamusi kinachotokea kwa kuwa katika siku hiyo.

700
01:07:08,010 --> 01:07:13,560
Hivyo itakuwa mechi neno hili, lakini hii subset ya neno ni neno lenyewe.

701
01:07:13,560 --> 01:07:17,250
Lakini si kwamba jinsi tunayatumia; sisi ni kusoma katika kila neno

702
01:07:17,250 --> 01:07:19,740
na kisha kulinganisha neno ya sisi kuwa na neno hilo.

703
01:07:19,740 --> 01:07:25,780
Hivyo sisi ni daima kulinganisha maneno kamili.

704
01:07:25,780 --> 01:07:29,620
Siwezi kutuma nje ufumbuzi kukamilika baadaye.

705
01:07:29,620 --> 01:07:32,050
Hii ni aina ya jibu sahihi karibu, nadhani.

706
01:07:32,050 --> 01:07:34,720
[Mwanafunzi maoni, unintelligible]

707
01:07:34,720 --> 01:07:40,870
Oh, je, mimi kujikwamua kwamba kabla? Char, nadhani sisi alisema 127 - I kusahau kile kubwa ni.

708
01:07:40,870 --> 01:07:44,100
Tutaweza tu kufanya 128, hivyo sasa s ni muda wa kutosha.

709
01:07:44,100 --> 01:07:46,570
Hatuna haja ya magazeti ya kitu chochote.

710
01:07:46,570 --> 01:07:56,440
Sisi ni pia atataka tufunge faili wetu, na kwamba lazima kuhusu jibu sahihi.

711
01:07:56,440 --> 01:07:59,440
CS50.TV