1 00:00:00,000 --> 00:00:03,353 >> [Music kucheza] 2 00:00:03,353 --> 00:00:04,842 3 00:00:04,842 --> 00:00:06,050 DAVID Malan: Hello, kila mtu. 4 00:00:06,050 --> 00:00:07,777 Hii ni supersection CS50. 5 00:00:07,777 --> 00:00:09,860 Sehemu kupewa si kuanza kwa wiki nyingine. 6 00:00:09,860 --> 00:00:11,580 Na hivyo leo, mimi niko hapa with-- 7 00:00:11,580 --> 00:00:12,122 >> MARIA: Maria. 8 00:00:12,122 --> 00:00:14,163 DAVID Malan: --to kweli tuangalie tatizo 9 00:00:14,163 --> 00:00:16,110 kuweka moja, kozi wiki ya kwanza ya nyenzo, 10 00:00:16,110 --> 00:00:19,780 kupata wewe oriented na CS50 IDE, kidogo ya Linux, mfumo wa uendeshaji hiyo ni 11 00:00:19,780 --> 00:00:22,290 mbio juu ya IDE, ikiwa ni pamoja na kuangalia baadhi ya mpito 12 00:00:22,290 --> 00:00:25,730 kutoka Scratch kwa C kuongoza hadi tatizo kuweka moja. 13 00:00:25,730 --> 00:00:28,340 >> Hivyo bila wasiwasi zaidi, katika tatizo kuweka moja, 14 00:00:28,340 --> 00:00:30,520 wewe ni kwenda kuwa kuletwa kwa CS50 IDE, ambayo 15 00:00:30,520 --> 00:00:33,230 ni programu hii ya mtandao msingi mazingira ambayo sisi kutumia ili 16 00:00:33,230 --> 00:00:34,280 kuandika mipango. 17 00:00:34,280 --> 00:00:37,280 Imekuwa ni iliyoundwa na kuangalia sana kukumbusha ya kompyuta ya kawaida 18 00:00:37,280 --> 00:00:39,430 mfumo wa uendeshaji mbio mfumo uitwao Linux. 19 00:00:39,430 --> 00:00:42,440 Lakini ni katika kile kinachoitwa wingu, ambayo ina maana kila mtu katika darasa 20 00:00:42,440 --> 00:00:45,100 Unaweza kweli kuwa yake akaunti mwenyewe na matumizi yake, pia. 21 00:00:45,100 --> 00:00:48,950 >> Kwa hiyo wengi pengine kamwe kutumika Linux mazingira kabla au labda 22 00:00:48,950 --> 00:00:50,447 hata mstari amri mazingira. 23 00:00:50,447 --> 00:00:52,280 Na mstari amri mazingira ni tofauti. 24 00:00:52,280 --> 00:00:53,200 Ni wote textual. 25 00:00:53,200 --> 00:00:54,730 Ni amri zote keyboard. 26 00:00:54,730 --> 00:00:59,480 Na ni hakuna kipanya, hakuna icons, mazungumzo madirisha hapana, hapana menus. 27 00:00:59,480 --> 00:01:00,212 Ni rena asilia. 28 00:01:00,212 --> 00:01:01,920 Hivyo kwa mara ya kwanza, ni namna anahisi kama hatua ya 29 00:01:01,920 --> 00:01:04,434 nyuma katika suala la sophistication. 30 00:01:04,434 --> 00:01:06,600 Lakini kuishia kuwa mengi nguvu zaidi, kwa hakika, 31 00:01:06,600 --> 00:01:08,510 kwa kompyuta mwanasayansi, hatimaye. 32 00:01:08,510 --> 00:01:09,540 >> Hivyo hebu tuangalie. 33 00:01:09,540 --> 00:01:13,850 Mimi hapa katika CS50.io, kupitia ambayo unaweza kuingia katika CS50 IDE. 34 00:01:13,850 --> 00:01:17,414 Na kiasi kama katika Scratch, kuna maeneo matatu ya msingi ya screen hii. 35 00:01:17,414 --> 00:01:20,080 Hivyo upande wa mkono wa kushoto, tuna nini itakuwa browser faili. 36 00:01:20,080 --> 00:01:22,413 Na kuna folder hili katika juu, ambayo ni sasa hivi tupu 37 00:01:22,413 --> 00:01:24,690 tangu mimi got kuondoa wangu wote mafaili kabla supersection. 38 00:01:24,690 --> 00:01:27,599 Na hapo ndipo tutaweza kuokoa files C kwamba sisi kuandika. 39 00:01:27,599 --> 00:01:30,890 Kulia juu, tuna mahali ambapo wote wa kificho yetu kinaendelea kupata kuandikwa. 40 00:01:30,890 --> 00:01:34,610 Na hakika, kama mimi bonyeza pamoja na hayo, hii ni kwenda basi mimi kuchagua New faili. 41 00:01:34,610 --> 00:01:38,310 Na hapa naweza kuanza kuandika C kificho au, kweli, idadi yoyote ya lugha nyingine. 42 00:01:38,310 --> 00:01:42,670 >> Na kisha chini ambapo ni anasema jharvard @ ide50-- na yako mapenzi 43 00:01:42,670 --> 00:01:45,080 kusema kitu kidogo different-- kilichokuwa hii inaitwa? 44 00:01:45,080 --> 00:01:48,644 45 00:01:48,644 --> 00:01:49,310 Terminal dirisha. 46 00:01:49,310 --> 00:01:49,570 Naam. 47 00:01:49,570 --> 00:01:51,810 Hivyo dirisha terminal ni kinachojulikana mstari amri 48 00:01:51,810 --> 00:01:55,540 interface kupitia ambayo unaweza kuingiliana kwa msingi mfumo wa uendeshaji. 49 00:01:55,540 --> 00:01:58,220 Na kwa sasa, tunakwenda kufanya matumizi kidogo sana ya Haya 50 00:01:58,220 --> 00:02:01,170 tu kukusanya, kuangalia ujumbe wa makosa kwamba sisi kuona, 51 00:02:01,170 --> 00:02:02,347 na kuendesha mipango yetu. 52 00:02:02,347 --> 00:02:04,680 Lakini hatimaye, tunakwenda kufanya hivyo zaidi, kama vile. 53 00:02:04,680 --> 00:02:07,490 Na unaweza hata kufunga programu na kusimamia workspace yako 54 00:02:07,490 --> 00:02:09,066 ndani ya CS50 IDE, kama vile. 55 00:02:09,066 --> 00:02:10,440 Lakini zaidi juu ya kwamba wakati mwingine. 56 00:02:10,440 --> 00:02:12,689 >> Basi hebu kwenda mbele na kuandika mpango rahisi sana tu 57 00:02:12,689 --> 00:02:15,064 kupitia kujipima nguvu ya hello.c, ambayo ni labda 58 00:02:15,064 --> 00:02:16,480 rahisi mpango tunaweza kuandika. 59 00:02:16,480 --> 00:02:18,330 Nimekuwa tayari imefungua tabo mpya. 60 00:02:18,330 --> 00:02:24,310 Mimi nina kwenda kwenda mbele na kusema ni pamoja na kiwango io.h. 61 00:02:24,310 --> 00:02:25,325 Kisha int kuu (utupu). 62 00:02:25,325 --> 00:02:28,930 63 00:02:28,930 --> 00:02:35,200 Na kisha printf ("hello, ulimwengu" backslash n, kunukuu karibu, 64 00:02:35,200 --> 00:02:39,480 mabano karibu, na semicolon. 65 00:02:39,480 --> 00:02:39,990 >> Sawa. 66 00:02:39,990 --> 00:02:41,700 Hivyo sasa taarifa dirisha yangu ni untitled. 67 00:02:41,700 --> 00:02:44,840 Hivyo mimi nina haraka sana kwenda kwenda hadi faili, Hifadhi. 68 00:02:44,840 --> 00:02:46,910 Na ni muhimu kwamba Natoa wito huu si "hello." 69 00:02:46,910 --> 00:02:49,243 Hivyo makosa ya kawaida sana, hasa katika tatizo kuweka moja, 70 00:02:49,243 --> 00:02:52,530 ni kuwaita ajali tu yako programu ya "maji" au "tamaa" au "Mario" 71 00:02:52,530 --> 00:02:53,890 au "mikopo" au kama. 72 00:02:53,890 --> 00:02:55,970 Lakini kwa kweli wanataka kufanya kuhakikisha kuwa faili ugani 73 00:02:55,970 --> 00:02:58,928 kwa sababu hii ni njia pekee ambayo compiler na pia kificho mhariri 74 00:02:58,928 --> 00:03:00,710 anajua kwamba uko kweli kuandika C kificho. 75 00:03:00,710 --> 00:03:02,280 Hivyo basi mimi kwenda mbele na bonyeza Hifadhi. 76 00:03:02,280 --> 00:03:05,710 >> Na sasa, pia, nini CS50 IDE amefanya kwa ajili yetu ni pia ni 77 00:03:05,710 --> 00:03:07,120 syntax yalionyesha kila kitu. 78 00:03:07,120 --> 00:03:08,822 Hivyo ni alifanya kila kitu colorful sana. 79 00:03:08,822 --> 00:03:10,780 Na lengo zima la hiyo siyo kazi. 80 00:03:10,780 --> 00:03:14,290 Ni tu kuteka macho yangu vipande conceptually mbalimbali 81 00:03:14,290 --> 00:03:15,310 ya mpango huu. 82 00:03:15,310 --> 00:03:17,570 Basi hebu kwenda mbele na kukusanya hii. 83 00:03:17,570 --> 00:03:19,490 Na siwezi kukusanya hii katika michache ya njia. 84 00:03:19,490 --> 00:03:22,010 Na katika wiki moja, njia umri wa kwenda shule tulivyofanya 85 00:03:22,010 --> 00:03:26,250 ilikuwa literally katika amri line-- "Clang hello.c." 86 00:03:26,250 --> 00:03:27,596 Na kisha mimi hit Enter. 87 00:03:27,596 --> 00:03:29,720 Na kitu inaonekana kutokea katika dirisha wastaafu. 88 00:03:29,720 --> 00:03:32,654 Lakini nini alifanya mabadiliko katika IDE? 89 00:03:32,654 --> 00:03:35,320 Ambapo, tena, IDE tu ina maana Integrated Maendeleo ya Mazingira. 90 00:03:35,320 --> 00:03:38,360 Ni njia dhana ya kusema maendeleo haya shirikishi 91 00:03:38,360 --> 00:03:40,620 mazingira kwa ajili ya kuendeleza programu. 92 00:03:40,620 --> 00:03:42,477 Hivyo nini mabadiliko katika UI? 93 00:03:42,477 --> 00:03:44,310 Ni kitu gani taarifa hiyo ni tofauti, Maria? 94 00:03:44,310 --> 00:03:47,100 >> MARIA: Mimi niliona kitu chini ya IDE50 folder hapa. 95 00:03:47,100 --> 00:03:47,850 >> DAVID Malan: Yeah. 96 00:03:47,850 --> 00:03:50,230 Hivyo hapa, si tu kufanya tuna "hello.c." 97 00:03:50,230 --> 00:03:53,120 Sisi pia kuwa "a.out," ambayo ni aina ya jina bubu kwa mpango. 98 00:03:53,120 --> 00:03:56,430 Lakini kwa kweli, ni jina default kwa Mpango wakati wewe tu kukusanya code yako 99 00:03:56,430 --> 00:03:59,110 na usimwambie compiler nini faili pato. 100 00:03:59,110 --> 00:04:01,790 Hivyo kama nataka kukimbia hii, mimi haja ya kuwaambia compiler-- 101 00:04:01,790 --> 00:04:05,340 au tuseme, mimi haja ya kuwaambia workspace kwamba mimi 102 00:04:05,340 --> 00:04:09,780 wanataka kuendesha programu inayoitwa "a.out." 103 00:04:09,780 --> 00:04:10,550 Kuingia. 104 00:04:10,550 --> 00:04:12,474 Na kuna "hello, dunia. "sasa" ./ ". 105 00:04:12,474 --> 00:04:13,390 ni kweli muhimu. 106 00:04:13,390 --> 00:04:16,050 Hata kama kawaida sisi tu kuandika majina ya amri, 107 00:04:16,050 --> 00:04:19,060 wakati ni mpango wameweza Imeandikwa, huna nataka kusema "./" 108 00:04:19,060 --> 00:04:22,460 kwa sababu hiyo waziwazi anaelezea Linux kwamba unataka kuendesha programu inayoitwa 109 00:04:22,460 --> 00:04:26,930 "a.out" hiyo ni katika hili, ambapo nukta ina maana hii directory kwamba mimi nina sasa 110 00:04:26,930 --> 00:04:31,600 katika, ambayo hufanyika kuwa aitwaye workspace, "a.out. 111 00:04:31,600 --> 00:04:35,410 Kwa sababu kama mimi tu alisema "a.out," kuingia, Mimi nina kwenda kupata "a.out amri si 112 00:04:35,410 --> 00:04:38,035 kupatikana "kwa sababu computer-- kwa sababu mimi zuliwa "a.out," 113 00:04:38,035 --> 00:04:40,910 hakuwa na kuja na computer-- hajui wapi kuangalia kwa ajili yake, 114 00:04:40,910 --> 00:04:43,590 hata kama ni haki chini ya pua yangu, hivyo kusema. 115 00:04:43,590 --> 00:04:44,090 SAWA. 116 00:04:44,090 --> 00:04:49,910 Hivyo tunaweza kubadili hali hii kwa kuwa "Clang-o hujambo hello.c." 117 00:04:49,910 --> 00:04:53,030 Na kama mimi hit Enter, mpango gani hii ni kwenda pato kwa ajili yangu? 118 00:04:53,030 --> 00:04:55,710 Nini jina la faili? 119 00:04:55,710 --> 00:04:57,500 Yeah, katika nyuma. 120 00:04:57,500 --> 00:04:58,479 Hiyo ni sawa. "Habari." 121 00:04:58,479 --> 00:05:00,520 Hivyo "hello" ni kwenda kuwa jina la mpango 122 00:05:00,520 --> 00:05:04,610 kwa sababu tumekuwa kutumika kinachojulikana mstari amri hoja, ambayo ni tu 123 00:05:04,610 --> 00:05:08,120 njia ya kubadili tabia ya compiler kwa kweli pato 124 00:05:08,120 --> 00:05:09,450 maalum faili jina. 125 00:05:09,450 --> 00:05:12,400 Na hakika, kama mimi kuvuta nje na kuangalia juu hapa, 126 00:05:12,400 --> 00:05:17,430 sasa nina si tu "a.out" na "hello.c" lakini pia "hello," vilevile. 127 00:05:17,430 --> 00:05:22,410 Hivyo sasa siwezi kufanya "./hello," kuingia. 128 00:05:22,410 --> 00:05:23,640 Na kuna "hello, ulimwengu." 129 00:05:23,640 --> 00:05:25,640 Lakini lastly-- na hii sasa kuwa mkataba 130 00:05:25,640 --> 00:05:27,590 tunatumia katika muhula, typically-- 131 00:05:27,590 --> 00:05:30,070 ni unaweza pia tu kusema "kufanya hello." 132 00:05:30,070 --> 00:05:33,370 Na hakika, ni kusema ni juu tarehe sababu tayari ipo. 133 00:05:33,370 --> 00:05:37,860 Hebu kwenda mbele na kuondoa, na rm amri, wote "a.out" - 134 00:05:37,860 --> 00:05:39,644 na kusema "kuondoa mara kwa mara faili a.out?" 135 00:05:39,644 --> 00:05:41,810 Hiyo ina maana tu, ni wewe uhakika unataka kufuta? 136 00:05:41,810 --> 00:05:42,880 Mimi nina kwenda kusema ndiyo. 137 00:05:42,880 --> 00:05:46,690 Na kisha mimi nina kwenda kuondoa "hello" lakini si "hello.c." 138 00:05:46,690 --> 00:05:49,920 Mimi nina kwenda kusema "ndiyo" waziwazi, lakini "y" inatosha, kama vile. 139 00:05:49,920 --> 00:05:52,140 >> Na sasa taarifa kama mimi aina ls-- ambayo, kukumbuka, 140 00:05:52,140 --> 00:05:55,540 ina maana list-- ni orodha yote ya mafaili kwenye folda yangu. 141 00:05:55,540 --> 00:05:57,850 Na hakika, kama mimi kuvuta nje na kuangalia juu kushoto, 142 00:05:57,850 --> 00:05:59,730 ni unathibitisha kwamba nini katika folda hii, hata 143 00:05:59,730 --> 00:06:04,990 ingawa ni kinachoitwa kama IDE50 hapa na si workspace, ni tu "hello.c." 144 00:06:04,990 --> 00:06:09,152 Hivyo sasa chini hapa, kama mimi Je, "kufanya hello," kuingia, 145 00:06:09,152 --> 00:06:12,360 sasa naona amri kwa muda mrefu lakini amri ya kisasa zaidi kwamba itakuja 146 00:06:12,360 --> 00:06:13,940 kuwa na manufaa katika wiki ijayo. 147 00:06:13,940 --> 00:06:16,720 Na sasa siwezi kusema "./hello." 148 00:06:16,720 --> 00:06:19,257 >> Basi hebu kuchukua ziara ya haraka baadhi ya Linux wengine amri. 149 00:06:19,257 --> 00:06:21,840 Kisha kwa nini sio sisi kuchukua hatua nyuma na kwa kweli kuangalia C zaidi 150 00:06:21,840 --> 00:06:25,020 ujumla, kipindi cha mpito kutoka Scratch kwa C, na kisha kuhitimisha kwa kuangalia 151 00:06:25,020 --> 00:06:27,305 Tatizo la kwanza katika kuweka katika C. zote haki. 152 00:06:27,305 --> 00:06:30,430 Hivyo mimi nina kwenda mbele na tu safi up workspace yangu na Kudhibiti-L tu 153 00:06:30,430 --> 00:06:31,429 kuweka screen nadhifu. 154 00:06:31,429 --> 00:06:33,520 Lakini hiyo haina kazi athari vinginevyo. 155 00:06:33,520 --> 00:06:35,820 >> Kumbuka kwamba tumeona amri kadhaa sasa. 156 00:06:35,820 --> 00:06:39,900 Hivyo tumeona Clang, ambayo kwa ujumla wewe hautakuwa na kutekeleza manually tena. 157 00:06:39,900 --> 00:06:41,650 Tutaweza badala yake kutumia kufanya. 158 00:06:41,650 --> 00:06:45,290 Lakini pia tuliona ls, ambayo inaonyesha orodha ya files katika saraka yangu. 159 00:06:45,290 --> 00:06:48,750 Na sasa kwa nini ni there-- kuna mawili mafaili sasa, "hello" na "hello.c." 160 00:06:48,750 --> 00:06:52,240 Kwa nini kuna nyota au kinyota baada ya "hello"? 161 00:06:52,240 --> 00:06:54,900 Je, kuwa yanamaanisha, kwa kuzingatia juu ya yale tuliona katika wiki moja? 162 00:06:54,900 --> 00:06:58,852 163 00:06:58,852 --> 00:07:00,400 Je, unafikiri? 164 00:07:00,400 --> 00:07:02,742 Je nyota yanamaanisha? 165 00:07:02,742 --> 00:07:04,614 >> MARIA: For-- mpango "hello"? 166 00:07:04,614 --> 00:07:05,530 DAVID Malan: "Habari *". 167 00:07:05,530 --> 00:07:06,330 Naam. 168 00:07:06,330 --> 00:07:07,760 Oh ndio? 169 00:07:07,760 --> 00:07:08,639 Loo, kutekelezwa. 170 00:07:08,639 --> 00:07:09,180 Hiyo ni sawa. 171 00:07:09,180 --> 00:07:10,890 Hivyo kwamba maana yake ni kwamba "hello" ni kutekelezwa. 172 00:07:10,890 --> 00:07:13,430 Hivyo kweli, kwamba ni kwa nini Siwezi kufanya "./hello." 173 00:07:13,430 --> 00:07:13,930 Sawa. 174 00:07:13,930 --> 00:07:15,179 Hivyo kile kingine naweza kufanya katika hapa? 175 00:07:15,179 --> 00:07:17,290 Naam, ni zamu nje naweza pia kujenga directories. 176 00:07:17,290 --> 00:07:20,924 Hivyo basi mimi kwenda mbele na kujenga, Kwa mfano, "pset1" directory. 177 00:07:20,924 --> 00:07:23,590 Na tatizo kuweka vipimo itakuwa na wewe kufanya hasa hili, 178 00:07:23,590 --> 00:07:25,260 hivyo huna kukumbuka leo. 179 00:07:25,260 --> 00:07:27,340 Lakini "mkdir pset1" inaonekana kuwa na athari hakuna. 180 00:07:27,340 --> 00:07:30,540 Lakini tena, hakuna ujumbe wa kosa kwa ujumla ni jambo jema. 181 00:07:30,540 --> 00:07:34,060 Hivyo kama mimi aina "ls" now-- ah, sasa Nina faili la kutekelezwa aitwaye 182 00:07:34,060 --> 00:07:36,570 "hello," C faili inayoitwa "hello.c." 183 00:07:36,570 --> 00:07:40,860 Na kisha kufyeka trailing, hivyo kusema, maana yake ni kwamba hii ni directory. 184 00:07:40,860 --> 00:07:42,510 >> Hivyo kweli, sasa nataka kufungua. 185 00:07:42,510 --> 00:07:45,730 Na mimi si mara mbili click juu yake kama katika GUI, mazingira graphical. 186 00:07:45,730 --> 00:07:48,550 Mimi badala kusema "cd pset1." 187 00:07:48,550 --> 00:07:49,640 Kuingia. 188 00:07:49,640 --> 00:07:53,100 Hakuna kitu ya kuvutia inaonekana kuwa kilichotokea isipokuwa haraka mdogo wangu 189 00:07:53,100 --> 00:07:57,300 here-- hii ni njia Linux ya kuwakumbusha nami pale nilipo, ili kile folder ni wazi. 190 00:07:57,300 --> 00:08:00,080 Ni kuwaambia tu mimi wazi kinyume na graphically. 191 00:08:00,080 --> 00:08:05,100 Na kama mimi aina "ls," kwa nini mimi kuona mwingine kuchochea mara moja, unafikiri, 192 00:08:05,100 --> 00:08:07,269 wakati mimi orodha ya yaliyomo ya pset1? 193 00:08:07,269 --> 00:08:09,310 MARIA: Pengine hawana kuwa na kitu chochote katika huko. 194 00:08:09,310 --> 00:08:09,630 DAVID Malan: Yeah. 195 00:08:09,630 --> 00:08:11,510 Hivyo basi tuna si wazi kuumba kitu chochote katika huko 196 00:08:11,510 --> 00:08:13,150 kwa sababu mimi tu kuundwa directory. 197 00:08:13,150 --> 00:08:17,690 Sasa, kama mimi alitaka kujenga file-- kwa Mathalani, mimi naweza kuunda faili mpya. 198 00:08:17,690 --> 00:08:20,190 Na kisha mimi naweza kwenda Ila na ila ni kama, 199 00:08:20,190 --> 00:08:23,090 kama, "mario.c" kama wewe ni kufanya toleo la pset moja ya kiwango. 200 00:08:23,090 --> 00:08:27,610 Na kisha, kama yoyote ya Mac au PC, tu kuchagua folder "pset1, Hifadhi. 201 00:08:27,610 --> 00:08:28,740 Na sasa faili ni tupu. 202 00:08:28,740 --> 00:08:31,160 Lakini hebu kuvuta tena kwa mara ya pili. 203 00:08:31,160 --> 00:08:32,470 Hebu kufanya ls hapa. 204 00:08:32,470 --> 00:08:34,470 Sasa tunaona "mario.c". 205 00:08:34,470 --> 00:08:37,850 >> Hivyo kuna wachache amri nyingine ambazo ni thamani ya kuweka akilini zaidi time-- 206 00:08:37,850 --> 00:08:41,200 wazi, au Kudhibiti-L ni nini nimekuwa wamekuwa kupiga; mkdir tumeona; 207 00:08:41,200 --> 00:08:45,240 rm tumeona, kama vile, ambayo ni kwa ajili ya kuondoa au kufuta faili. 208 00:08:45,240 --> 00:08:49,310 Jihadharini unaweza also-- na kama ukiangalia katika tutorials online, itabidi Rm -rf 209 00:08:49,310 --> 00:08:52,630 Ni njia ya kawaida sana ya kusema kufuta folda kwamba ina mambo ndani yake. 210 00:08:52,630 --> 00:08:54,280 Tu kuwa super, super makini. 211 00:08:54,280 --> 00:08:58,780 -rf ina maana recursively kufuta chochote ni 212 00:08:58,780 --> 00:09:01,150 wewe ni kujaribu kufuta na kwa nguvu kufuta. 213 00:09:01,150 --> 00:09:04,630 Hivyo kujirudia njia ikiwa ni pamoja na folder folder na folder na folder, 214 00:09:04,630 --> 00:09:05,690 kufuta yote ya yao. 215 00:09:05,690 --> 00:09:08,680 Na kwa nguvu ina maana hawana hata kuuliza mimi ndiyo au hapana, mimi nipo uhakika? 216 00:09:08,680 --> 00:09:11,960 Hivyo ni njia super hatari ya kufuta kura ya mambo haraka. 217 00:09:11,960 --> 00:09:17,210 Lakini mara nyingi beware-- pia anafanya intrepid mwanafunzi ajali kufuta, kusema, pset 218 00:09:17,210 --> 00:09:18,000 moja, kwa mfano. 219 00:09:18,000 --> 00:09:19,833 >> MARIA: Na kama wao tu kufanya r, wao wanaenda 220 00:09:19,833 --> 00:09:21,870 kuwauliza kuhusu kila faili moja. 221 00:09:21,870 --> 00:09:22,790 >> DAVID Malan: Ni lipi lililo kiasi annoying. 222 00:09:22,790 --> 00:09:23,480 >> MARIA: Naam. 223 00:09:23,480 --> 00:09:25,813 >> DAVID Malan: Hivyo ndiyo sababu hivyo wengi wetu, binafsi pamoja, 224 00:09:25,813 --> 00:09:27,070 am katika tabia ya kutumia -rf. 225 00:09:27,070 --> 00:09:27,861 Lakini ni hatari. 226 00:09:27,861 --> 00:09:29,010 Hivyo mnunuzi Jihadharini. 227 00:09:29,010 --> 00:09:31,050 Na kisha mv ni aina ya kuvutia aitwaye. 228 00:09:31,050 --> 00:09:33,600 Hivyo hii ni amri ya hoja, ambayo anahisi kidogo weird 229 00:09:33,600 --> 00:09:37,260 kwa sababu unaweza kweli kuitumia hoja files kutoka sehemu moja hadi nyingine. 230 00:09:37,260 --> 00:09:39,970 Kwa mfano, tuseme kwamba mimi messed up. 231 00:09:39,970 --> 00:09:43,660 Tuseme kwamba mimi umba faili mpya kwa pset. 232 00:09:43,660 --> 00:09:46,320 Na mimi kuokolewa kama "greedy.c." 233 00:09:46,320 --> 00:09:49,970 Lakini nadhani ajali ila ni katika IDE50-- hivyo katika workspace yangu yenyewe 234 00:09:49,970 --> 00:09:51,580 na si katika pset1. 235 00:09:51,580 --> 00:09:53,960 >> Unaweza kuona kama kiasi juu kushoto. 236 00:09:53,960 --> 00:09:55,284 Kuna "greedy.c." Ndiyo 237 00:09:55,284 --> 00:09:56,450 Na kuna ufumbuzi chache. 238 00:09:56,450 --> 00:09:58,324 Hivyo moja, naweza kutumia super user-kirafiki njia 239 00:09:58,324 --> 00:09:59,740 ya tu akawatoa na kuacha ni. 240 00:09:59,740 --> 00:10:01,910 Na kwamba ingekuwa kweli kurekebisha tatizo hili. 241 00:10:01,910 --> 00:10:04,967 Lakini leo hii, sisi ni kujaribu kuangalia njia zaidi arcane, lakini kwa nguvu 242 00:10:04,967 --> 00:10:05,550 ya kufanya hivyo. 243 00:10:05,550 --> 00:10:07,880 Hivyo basi mimi kuchukua "ls" katika pset1. 244 00:10:07,880 --> 00:10:09,690 Na mimi tu kuona "mario.c." 245 00:10:09,690 --> 00:10:13,450 Hebu kwenda mbele na kufanya "cd ..". 246 00:10:13,450 --> 00:10:15,320 Hivyo CD tena ni mabadiliko directory. 247 00:10:15,320 --> 00:10:18,130 ".." Maana yake nini, ingawa? 248 00:10:18,130 --> 00:10:21,100 Mara ya mwisho mimi alisema "cd pset1 "kwenda katika pset1. 249 00:10:21,100 --> 00:10:24,360 Hivyo wakati mimi kusema "cd ..", je, Mimi kufanya? 250 00:10:24,360 --> 00:10:24,910 Nyuma. 251 00:10:24,910 --> 00:10:25,150 Naam. 252 00:10:25,150 --> 00:10:26,750 >> Hivyo ni kwenda kwa kile kinachoitwa mzazi. 253 00:10:26,750 --> 00:10:29,730 Kwenda ngazi moja hadi, kama exiting nje ya folder. 254 00:10:29,730 --> 00:10:30,500 Hivyo kuingia. 255 00:10:30,500 --> 00:10:31,900 Na hakika, kuangalia nini alifanya. 256 00:10:31,900 --> 00:10:37,070 Ni wakiongozwa mimi tu katika workspace badala ya ndani pset1, ambayo ni katika workspace. 257 00:10:37,070 --> 00:10:39,710 Na sasa kama mimi aina "ls", kuna rundo zima la mambo ya ajabu. 258 00:10:39,710 --> 00:10:41,650 Katika kuna "greedy.c". 259 00:10:41,650 --> 00:10:48,720 Hivyo sasa napenda kutumia mv literally hoja "greedy.c" katika pset1. 260 00:10:48,720 --> 00:10:51,120 Na hivyo mengi ya Linux amri kazi hasa kama hii. 261 00:10:51,120 --> 00:10:54,470 Wao kuchukua hakuna hoja au wao kuchukua moja Hoja au wao kuchukua mbili mstari amri 262 00:10:54,470 --> 00:10:55,449 hoja na kadhalika. 263 00:10:55,449 --> 00:10:57,240 Na katika kesi hii, ni halisi kufanya nini 264 00:10:57,240 --> 00:11:01,670 inasema, angalau succinctly-- hoja ya greedy.c ndani ya pset1. 265 00:11:01,670 --> 00:11:02,310 Kuingia. 266 00:11:02,310 --> 00:11:03,310 Kitu inaonekana kutokea. 267 00:11:03,310 --> 00:11:06,180 Lakini kama mimi kufanya ls tena, tamaa ni gone. 268 00:11:06,180 --> 00:11:12,437 Na kama mimi kufanya "cd pset1", kuingia, na kisha ls tena, sasa ni katika mahali pa haki. 269 00:11:12,437 --> 00:11:14,270 Kama kando, ikiwa kwa baadhi reason-- hasa 270 00:11:14,270 --> 00:11:16,194 kama una vipindi kuunganishwa mtandao 271 00:11:16,194 --> 00:11:18,360 au wewe ni kutembea karibu chuo na Laptop yako mfuniko 272 00:11:18,360 --> 00:11:20,180 kufungwa na kisha kufungua it up tena na workspace yako 273 00:11:20,180 --> 00:11:21,730 Inaonekana kwa kiasi fulani nje ya Sync, hakuna mpango mkubwa. 274 00:11:21,730 --> 00:11:23,646 Reload tu kisakuzi chako dirisha, na ni lazima 275 00:11:23,646 --> 00:11:26,339 resync ili mkono wa kushoto browser faili inaonekana hasa 276 00:11:26,339 --> 00:11:27,380 kama dirisha wastaafu. 277 00:11:27,380 --> 00:11:27,921 Wasiwe na wasiwasi. 278 00:11:27,921 --> 00:11:31,460 Wakati katika shaka, upya ukurasa, hivyo muda mrefu kama umehifadhi mafaili tayari. 279 00:11:31,460 --> 00:11:31,960 SAWA. 280 00:11:31,960 --> 00:11:34,710 Hivyo mv pia inaweza kutumika rename files. 281 00:11:34,710 --> 00:11:36,760 Na hebu tuangalie hii amri ya mwisho hapa. 282 00:11:36,760 --> 00:11:39,950 Hivyo suppose-- na hii ni super kawaida, pia, mapema. 283 00:11:39,950 --> 00:11:46,400 Baadhi ya wanafunzi mara kwa mara kuunda faili kuitwa, hebu say-- nini mtu mwingine? 284 00:11:46,400 --> 00:11:47,730 Kama "WATER.C." 285 00:11:47,730 --> 00:11:51,080 Hivyo mimi itabidi yell, kwa hakuna sababu, katika mechi zote. 286 00:11:51,080 --> 00:11:53,190 Lakini hii si jina sahihi kwa file 287 00:11:53,190 --> 00:11:56,660 kama tu kwa sababu tatizo letu kuweka vipimo Sikuwaambieni 288 00:11:56,660 --> 00:11:59,430 kuokoa faili kama wote kofia "WATER.C." 289 00:11:59,430 --> 00:12:01,320 Badala yake, tunatarajia "water.c" katika lowercase. 290 00:12:01,320 --> 00:12:03,140 Na, kwa kweli, hii ni tatizo kwa sababu check50, 291 00:12:03,140 --> 00:12:04,370 Mpango wewe ni kwenda kukutana katika tatizo 292 00:12:04,370 --> 00:12:07,350 kuweka moja kuwa moja kwa moja vipimo usahihi wa kanuni yako 293 00:12:07,350 --> 00:12:11,615 ni kwenda yell saa wewe kama hawawezi kupata "water.c" katika lowercase wote. 294 00:12:11,615 --> 00:12:12,712 >> Kwa hiyo mimi haja ya kurekebisha hii. 295 00:12:12,712 --> 00:12:14,920 Njia nyingi tofauti kwa kufanya hivyo, kwanza ambayo 296 00:12:14,920 --> 00:12:18,330 itakuwa Udhibiti-click au haki-click jina la faili na kubadili tu Rename. 297 00:12:18,330 --> 00:12:19,740 Kabisa faini ya kufanya hivyo. 298 00:12:19,740 --> 00:12:21,820 Lakini tena, leo, hebu kufanya hivyo kidogo fancier. 299 00:12:21,820 --> 00:12:26,680 Hebu kutumia mv kubadili "WATER.C" na "water.c." 300 00:12:26,680 --> 00:12:30,690 Hivyo unaweza pia kutumia hoja ya kwanza kubadili jina hilo kwa hoja ya pili 301 00:12:30,690 --> 00:12:34,455 kama hoja ya pili ni si, katika kweli, folder au jina directory. 302 00:12:34,455 --> 00:12:35,120 >> Sawa. 303 00:12:35,120 --> 00:12:39,560 Na Mwisho, trick-- kidogo hivyo mimi nina katika workspace yangu directory kwa sasa. 304 00:12:39,560 --> 00:12:43,660 Kama mimi wanataka kupata katika pset moja, Mimi hakika unaweza aina "cd pset1." 305 00:12:43,660 --> 00:12:47,260 Lakini ni hivyo nyeti kwa aina ya "pset1" au tena majina ya faili au directory majina 306 00:12:47,260 --> 00:12:47,980 bado. 307 00:12:47,980 --> 00:12:51,960 Hivyo mara nyingi sana katika Linux, nini unaweza kufanya ni kuanza kuandika "PSE" 308 00:12:51,960 --> 00:12:56,100 na tu kupata kuchoka, kugonga Tab, na basi kompyuta takwimu ni nje kwa ajili yenu. 309 00:12:56,100 --> 00:12:58,190 Super manufaa kwa kupata katika tabia hiyo. 310 00:12:58,190 --> 00:13:01,079 Kupata tu ni kama una faili nyingi au folders kuanzia 311 00:13:01,079 --> 00:13:02,870 na herufi "p" au "ps," unaweza kuwa 312 00:13:02,870 --> 00:13:05,525 aina chache zaidi kabla kompyuta anajua nini cha kufanya. 313 00:13:05,525 --> 00:13:06,820 >> MARIA: Tunapenda njia za mkato. 314 00:13:06,820 --> 00:13:08,695 >> DAVID Malan: Hii mapenzi kuokoa muda sana. 315 00:13:08,695 --> 00:13:11,930 Na pia, kama sisi alisema katika hotuba, wewe Unaweza kitabu juu katika historia, juu na chini, 316 00:13:11,930 --> 00:13:15,461 kupata hivi karibuni kunyongwa amri, kama vile. 317 00:13:15,461 --> 00:13:15,960 Sawa. 318 00:13:15,960 --> 00:13:20,904 Hivyo sasa, hebu kugeuka usikivu wetu nyuma kwa mpango rahisi, hello dunia. 319 00:13:20,904 --> 00:13:22,195 Hivyo tumekuwa compiled hii hasa. 320 00:13:22,195 --> 00:13:24,050 Na sasa kwa nini sio sisi kuchukua Kuangalia aina ya data 321 00:13:24,050 --> 00:13:26,776 na kisha mpito kutoka baadhi sambamba Scratch vitalu C. 322 00:13:26,776 --> 00:13:27,400 MARIA: Ajabu. 323 00:13:27,400 --> 00:13:30,031 Hivyo sasa kwamba umefanya kuanza kuandika mipango katika C, 324 00:13:30,031 --> 00:13:32,530 tunakwenda kuanza kuzungumza kuhusu aina ya data na vigezo. 325 00:13:32,530 --> 00:13:37,570 Hivyo baadhi ya aina data kwamba wanataka kujua kuanzia sasa 326 00:13:37,570 --> 00:13:39,400 ni wale ambao ni yalionyesha katika bluu. 327 00:13:39,400 --> 00:13:42,420 Hivyo tuna int kwanza, ambayo inasimamia kwa integer. 328 00:13:42,420 --> 00:13:46,075 Na kwamba ana integers, kama wewe anaweza kuwa guessed-- hivyo 1, 2, 3, 329 00:13:46,075 --> 00:13:47,950 na integers nyingine yoyote kwamba unaweza kufikiria. 330 00:13:47,950 --> 00:13:48,730 >> DAVID Malan: Na pia hasi. 331 00:13:48,730 --> 00:13:50,220 >> MARIA: Na pia ndio hasi, yep. 332 00:13:50,220 --> 00:13:51,450 Na 0. 333 00:13:51,450 --> 00:13:54,250 Basi tuna ikifungwa, ambayo ni yaliyo idadi uhakika. 334 00:13:54,250 --> 00:13:58,360 Hivyo hiyo ni namba zote halisi ambazo zina pointi alisema. 335 00:13:58,360 --> 00:14:03,960 Hivyo 5.0, 5.2, na hata zaidi tarakimu baada uhakika decimal, 336 00:14:03,960 --> 00:14:05,620 pamoja, na pia hasi ndio. 337 00:14:05,620 --> 00:14:07,530 Basi tuna char ambayo ni tabia. 338 00:14:07,530 --> 00:14:10,240 Hivyo nadhani kuongelea huu katika hotuba leo. 339 00:14:10,240 --> 00:14:15,682 Lakini tuna barua, kwa example-- A, B, C-- ambayo yanaweza kuhifadhiwa kama Char. 340 00:14:15,682 --> 00:14:18,390 Lakini basi tuna alama nyingi zaidi ambayo yanaweza kuhifadhiwa kama Char. 341 00:14:18,390 --> 00:14:22,380 Na wale ni kuhifadhiwa kama ASCII. 342 00:14:22,380 --> 00:14:25,280 >> Na kisha tuna bool, ambayo ni Booleans. 343 00:14:25,280 --> 00:14:29,067 Na wale kutathmini kwa kweli au Uongo au 1 na 0, mtawalia. 344 00:14:29,067 --> 00:14:31,650 DAVID Malan: Na kukumbuka kwamba bool linatokana na maktaba CS50. 345 00:14:31,650 --> 00:14:33,300 Hivyo si kujengwa ndani C, lakini ni super muhimu 346 00:14:33,300 --> 00:14:34,850 kuwa na dhana ya kweli na uongo. 347 00:14:34,850 --> 00:14:36,990 Na hata kama wewe Huenda think-- ukweli na furaha. 348 00:14:36,990 --> 00:14:43,700 Bool kitaalam mahitaji bits ngapi, kweli, kuwakilisha Kweli dhidi ya uongo? 349 00:14:43,700 --> 00:14:47,910 Jinsi wengi bits unafikiri ungependa haja, maximally? 350 00:14:47,910 --> 00:14:48,790 Naam, moja tu. 351 00:14:48,790 --> 00:14:52,077 Hivyo zinageuka kuwa C hawezi kukupa moja tu kidogo. 352 00:14:52,077 --> 00:14:54,160 Kitengo ndogo ya hatua unaweza kupata ni nane. 353 00:14:54,160 --> 00:14:57,090 Hivyo ni fujo kidogo wao uko kutumia Byte nzima, au bits nane, 354 00:14:57,090 --> 00:14:58,340 kuiwakilisha Kweli au uongo. 355 00:14:58,340 --> 00:15:01,807 Lakini hiyo ni njia tu ni kutekelezwa katika C na maktaba CS50. 356 00:15:01,807 --> 00:15:04,890 MARIA: Na kisha wale ambao tuko si kwenda kuzungumza kuhusu kama sana 357 00:15:04,890 --> 00:15:08,060 haki now-- mara mbili, hiyo ni kwa ikifungwa kubwa. 358 00:15:08,060 --> 00:15:09,811 Muda mrefu muda mrefu na mfupi ni pia kwa integers. 359 00:15:09,811 --> 00:15:10,643 DAVID Malan: Kwa hakika. 360 00:15:10,643 --> 00:15:13,190 Katika toleo hacker ya pset moja, sisi kweli matumizi ya muda mrefu kwa muda mrefu. 361 00:15:13,190 --> 00:15:15,801 Lakini kwa toleo la kawaida, ni lazima kuwa muhimu. 362 00:15:15,801 --> 00:15:16,300 MARIA: Moto. 363 00:15:16,300 --> 00:15:17,361 SAWA. 364 00:15:17,361 --> 00:15:20,110 Hivyo operators-- unapaswa kuwa pengine ukoo na zaidi ya haya. 365 00:15:20,110 --> 00:15:22,620 Aidha, +; kutoa, -. 366 00:15:22,620 --> 00:15:24,070 Kwa kuzidisha, tuna *. 367 00:15:24,070 --> 00:15:25,900 Hivyo si X kwamba sisi kawaida kutumia. 368 00:15:25,900 --> 00:15:27,840 Idara, tuna backslash. 369 00:15:27,840 --> 00:15:31,380 Na modulo ni alama yetu ya mwisho kwamba sisi ni kwenda kuzungumza kuhusu hivi sasa. 370 00:15:31,380 --> 00:15:35,610 Ni alama ambayo inaruhusu sisi kuchukua salio ya mgawanyiko. 371 00:15:35,610 --> 00:15:40,630 Hivyo kama tuna 4% 2, 4 umegawanyika na 2 ni 2 na salio ya 0. 372 00:15:40,630 --> 00:15:41,740 Hivyo 4% 2 ni 0. 373 00:15:41,740 --> 00:15:42,950 4% 3 ni 1. 374 00:15:42,950 --> 00:15:44,870 4% 5 ni 4, kama unaweza kuwa guessed. 375 00:15:44,870 --> 00:15:48,860 Na kumbukeni kutumia yote haya waendeshaji kutumia sheria PEMDAS. 376 00:15:48,860 --> 00:15:54,060 >> DAVID Malan: Hivyo kuwa wazi, kama wewe kufanya 4% 2, kwa nini ni kwamba 0, hasa? 377 00:15:54,060 --> 00:15:57,480 >> MARIA: Kwa sababu 4 kugawanywa na 2 ni 2 na salio ya 0. 378 00:15:57,480 --> 00:16:00,752 Hivyo modulo inatupa kwamba salio kama kinyume na matokeo ya mgawanyiko. 379 00:16:00,752 --> 00:16:02,960 DAVID Malan: Na hakika, nini tutaweza kupata hii muhimu 380 00:16:02,960 --> 00:16:05,640 kwa ni kwamba katika baadhi ya matatizo hiyo ni si lazima moja, 381 00:16:05,640 --> 00:16:08,040 kama unataka kuwa athari za kuzuia mwenyewe 382 00:16:08,040 --> 00:16:10,720 kwa mbalimbali ya idadi kama 0 kupitia kitu, 383 00:16:10,720 --> 00:16:13,904 unaweza kutumia modulo kufungia mapema kuliko kama bilioni 2 384 00:16:13,904 --> 00:16:16,320 au bilioni 4 thamani kwamba tumekuwa aliyesema kuhusu katika hotuba. 385 00:16:16,320 --> 00:16:16,870 >> MARIA: Naam. 386 00:16:16,870 --> 00:16:19,429 Na hata katika "tamaa" tupate. 387 00:16:19,429 --> 00:16:21,345 DAVID Malan: Ndiyo, katika tatizo kuweka moja, kama vile. 388 00:16:21,345 --> 00:16:22,520 MARIA: Yeah, ni nzuri. 389 00:16:22,520 --> 00:16:24,340 DAVID Malan: Good ladha. 390 00:16:24,340 --> 00:16:25,750 MARIA: Sorry. 391 00:16:25,750 --> 00:16:28,590 Boolean expressions-- hivyo kwa waendeshaji Boolean, 392 00:16:28,590 --> 00:16:31,770 sisi ni kwenda kuzungumza kuhusu zote ya hizi kwamba unaweza kuona hapa. 393 00:16:31,770 --> 00:16:35,310 Hivyo sasa hivi, tuna mbili ishara sawa waliotajwa kwa usawa. 394 00:16:35,310 --> 00:16:38,650 Basi hizo kwa kulinganisha. 395 00:16:38,650 --> 00:16:40,830 Hadi sasa, tumekuwa tu kuonekana moja sawa na ishara. 396 00:16:40,830 --> 00:16:44,870 Hapo ndipo sisi kuwapa thamani ya kutofautiana. 397 00:16:44,870 --> 00:16:50,160 Hivyo kama tumeona int n = 5, kisha tumekuwa kupewa 5 kwa n kutofautiana. 398 00:16:50,160 --> 00:16:55,600 Lakini kama tunataka kutumia == kwa kulinganisha, tunaweza kuangalia kama n == 5. 399 00:16:55,600 --> 00:16:58,310 Na kama n == 5, kisha hiyo ni kweli. 400 00:16:58,310 --> 00:17:01,950 >> Waendeshaji hivyo Boolean kuruhusu sisi, kimsingi, 401 00:17:01,950 --> 00:17:04,670 kutathmini Boolean Maneno ya Kweli au Si kweli. 402 00:17:04,670 --> 00:17:07,819 Hivyo si equals-- tuna alama ya kushangaa na usawa. 403 00:17:07,819 --> 00:17:14,240 Hivyo tunaweza pia kuangalia kama n haina sawa 5-- hivyo n! = 5. 404 00:17:14,240 --> 00:17:17,640 Chini ya, chini ya au sawa na, kubwa kuliko, zaidi au sawa na, 405 00:17:17,640 --> 00:17:20,720 na kisha tuna mantiki NA na mantiki AU. 406 00:17:20,720 --> 00:17:24,060 Na wale kuruhusu sisi kutathmini nyingi Boolean maneno pamoja 407 00:17:24,060 --> 00:17:27,930 kimsingi kuja pamoja kama moja nzima Boolean kujieleza. 408 00:17:27,930 --> 00:17:34,970 Hivyo kama tunataka kupata idadi, kusema, ambayo ni kubwa kuliko 5 lakini chini ya 15 409 00:17:34,970 --> 00:17:39,810 wakati huo huo, tunataka kutumia mantiki NA operator ili kuona kama n ni 410 00:17:39,810 --> 00:17:42,937 kubwa kuliko 5 && n chini ya 15. 411 00:17:42,937 --> 00:17:44,770 DAVID Malan: Na hapa, pia, ni kweli rahisi 412 00:17:44,770 --> 00:17:47,290 mapema kwa ajali tu kutumia ampersand moja 413 00:17:47,290 --> 00:17:48,572 au moja wima bar. 414 00:17:48,572 --> 00:17:51,280 Na pengine compiler mapenzi yell saa wewe kwa sababu wao kweli 415 00:17:51,280 --> 00:17:52,530 kuwa na maana tofauti sana. 416 00:17:52,530 --> 00:17:55,660 Kwa wale wadadisi, wao uko kutumika kwa ajili ya shughuli bitwise, 417 00:17:55,660 --> 00:17:57,197 kazi ya bits mtu binafsi. 418 00:17:57,197 --> 00:17:58,780 Lakini wewe kufanya unataka jozi wao hapa. 419 00:17:58,780 --> 00:18:01,560 Na super muhimu ni kwamba Wa kwanza, ishara sawa, 420 00:18:01,560 --> 00:18:05,270 ambayo ni alama usawa kama kinyume na zoezi operator. 421 00:18:05,270 --> 00:18:08,552 >> MARIA: Na bar wima ni ziko kati ya Futa na marejeo. 422 00:18:08,552 --> 00:18:09,260 DAVID Malan: Ndiyo. 423 00:18:09,260 --> 00:18:11,420 Juu ya kawaida ya Marekani keyboard. 424 00:18:11,420 --> 00:18:13,190 >> MARIA: Yep. 425 00:18:13,190 --> 00:18:15,890 Basi hebu tuzame kwenye masharti kauli. 426 00:18:15,890 --> 00:18:18,300 Katika Scratch, wameweza tayari kuona, pengine, 427 00:18:18,300 --> 00:18:22,730 kama kauli kwamba kuruhusu kuangalia kama kitu fulani ni kweli, basi 428 00:18:22,730 --> 00:18:23,660 kufanya kitu kingine. 429 00:18:23,660 --> 00:18:28,410 Hivyo unaweza kuwa alitaka kuangalia kama sprite yako ni 430 00:18:28,410 --> 00:18:31,410 kugusa baadhi sprite mwingine au mpaka wa screen yako. 431 00:18:31,410 --> 00:18:35,520 Na kisha unaweza kuwa alitaka kumaliza mchezo au kufanya kitu kingine. 432 00:18:35,520 --> 00:18:40,000 Hivyo syntax kwa kuwa ni "kama (hali)." 433 00:18:40,000 --> 00:18:46,820 Hivyo kama sprite yako ni kugusa kitu, basi ni ndani ya braces curly. 434 00:18:46,820 --> 00:18:48,980 >> Basi tuna ikiwa-kingine kauli. 435 00:18:48,980 --> 00:18:54,080 Kingine inaruhusu sisi kufanya kitu kama hali kwamba sisi 436 00:18:54,080 --> 00:18:55,870 kuangalia kwa katika mwanzo si kweli. 437 00:18:55,870 --> 00:19:01,530 Hivyo kama sprite ni kugusa mpaka kufanya hivyo, mwingine kufanya kitu kingine. 438 00:19:01,530 --> 00:19:04,030 Hivyo vinginevyo kufanya kitu kingine. 439 00:19:04,030 --> 00:19:07,530 Basi tuna mfano mfupi kwa hili. 440 00:19:07,530 --> 00:19:11,551 Hivyo kama (military_time <12), sisi wanataka printf "Habari za asubuhi!" 441 00:19:11,551 --> 00:19:13,300 Mwingine tunakwenda printf "Habari za jioni!" 442 00:19:13,300 --> 00:19:14,860 Basic mfano. 443 00:19:14,860 --> 00:19:15,680 >> DAVID Malan: Mwema. 444 00:19:15,680 --> 00:19:16,760 >> MARIA: Moto. 445 00:19:16,760 --> 00:19:18,560 Hivyo basi, tuna kauli kubadili. 446 00:19:18,560 --> 00:19:21,960 Kubadili kauli kwa ujumla can kuruhusu sisi kufanya mengi ya kitu kimoja 447 00:19:21,960 --> 00:19:25,070 kwamba sisi tu kuongelea kuhusu na kama kauli. 448 00:19:25,070 --> 00:19:29,440 Kwa mfano, sasa hivi tuna mkuu fomu ya taarifa kubadili 449 00:19:29,440 --> 00:19:33,870 ambayo inaruhusu sisi kuchukua kutofautiana kuitwa n 450 00:19:33,870 --> 00:19:37,670 na kulinganisha kwa mengi ya maadili tofauti, ambayo sisi hapa 451 00:19:37,670 --> 00:19:40,010 wametoa wito constant1, constant2. 452 00:19:40,010 --> 00:19:41,150 Tunaweza kuwa na mengi zaidi. 453 00:19:41,150 --> 00:19:42,930 Na wale walioitwa kesi. 454 00:19:42,930 --> 00:19:46,280 >> Hivyo kama tuna kubadili statement-- na matendo huu 455 00:19:46,280 --> 00:19:50,580 tu kwa integers-- tuna kutofautiana katika kesi hii ndiyo n. 456 00:19:50,580 --> 00:19:53,840 Kama n kutofautiana ni sawa na constant1, sisi 457 00:19:53,840 --> 00:19:59,720 nitafanya baadhi snippet ya maadili ya au kitu ambacho tunataka kufanya. 458 00:19:59,720 --> 00:20:01,280 Na kisha tunataka kuvunja. 459 00:20:01,280 --> 00:20:04,820 Hivyo mapumziko ina maana kwamba Kauli kubadili 460 00:20:04,820 --> 00:20:08,120 kuacha utekelezaji ikiwa n ni sawa na constant1, 461 00:20:08,120 --> 00:20:09,752 na kisha mpango wako utaendelea. 462 00:20:09,752 --> 00:20:11,835 Itakuwa kujinasua kutoka katika kubadili kauli na itabidi 463 00:20:11,835 --> 00:20:13,520 kuendelea kufanya kitu kingine. 464 00:20:13,520 --> 00:20:17,204 >> Hata hivyo, n haina sawa constant1, basi kesi kwa constant2 465 00:20:17,204 --> 00:20:17,870 kuchunguzwa. 466 00:20:17,870 --> 00:20:21,750 Hivyo kama n sawa na constant2, kwamba wengine snippet ya maadili ya itatekelezwa. 467 00:20:21,750 --> 00:20:23,850 Na kisha kutakuwa na kuvunja kama kwamba ni sawa na hiyo. 468 00:20:23,850 --> 00:20:27,580 Na kisha tunaweza kuwa also-- si lazima, though-- kesi ya msingi, 469 00:20:27,580 --> 00:20:32,290 ambayo itafanyika ikiwa n haina sawa yoyote ya kesi kwa kuwa waliotajwa. 470 00:20:32,290 --> 00:20:35,400 Na katika kesi ya msingi, sisi pia hawana haja ya mapumziko lazima 471 00:20:35,400 --> 00:20:39,271 kwa sababu kauli kubadili watajua kwamba inahitaji mwisho baada ya chaguo-msingi 472 00:20:39,271 --> 00:20:40,270 kesi kama hiyo kesi. 473 00:20:40,270 --> 00:20:42,140 >> DAVID Malan: Lakini stylistically, sisi daima kuiweka katika huko. 474 00:20:42,140 --> 00:20:42,540 >> MARIA: Naam. 475 00:20:42,540 --> 00:20:42,710 >> DAVID Malan: Yeah. 476 00:20:42,710 --> 00:20:44,750 Hivyo hasa wakati mapya nje, hasa kama miongoni mwa wale chini 477 00:20:44,750 --> 00:20:47,458 vizuri, napenda binafsi tu kupendekeza fimbo na ikiwa 478 00:20:47,458 --> 00:20:51,564 na ikiwa-elses na kama-kingine-kama-elses na kadhalika kama tu 479 00:20:51,564 --> 00:20:53,480 kwa sababu wao ni mdogo moja kwa moja zaidi. 480 00:20:53,480 --> 00:20:56,142 Hii ni optimization nzuri, au wakati mwingine hata aesthetically ni 481 00:20:56,142 --> 00:20:57,350 hufanya kificho someka zaidi. 482 00:20:57,350 --> 00:20:59,599 Na kwa kweli, pengine katikati ya muhula tutaona tatizo 483 00:20:59,599 --> 00:21:02,504 kuweka ambapo ni tu inaonekana zaidi na rahisi kusoma kwa binadamu 484 00:21:02,504 --> 00:21:03,670 kwa kutumia kauli kubadili. 485 00:21:03,670 --> 00:21:05,460 Lakini msiwe na wasiwasi juu clinging hii mapema mno. 486 00:21:05,460 --> 00:21:05,680 >> MARIA: Naam. 487 00:21:05,680 --> 00:21:08,840 Kama una mengi ya kama kauli, inaweza tu kuwa someka sana. 488 00:21:08,840 --> 00:21:10,965 Ni wanaweza kuwa haraka sana kwa wewe kwenda kwa njia hiyo. 489 00:21:10,965 --> 00:21:13,230 Hivyo kubadili kauli wanaweza kuwa muhimu sana, pia. 490 00:21:13,230 --> 00:21:17,900 Na pia, do not remember-- hawana kusahau kuweka mapumziko katika huko. 491 00:21:17,900 --> 00:21:20,330 >> DAVID Malan: Je, si kumbuka hii. 492 00:21:20,330 --> 00:21:24,890 >> MARIA: Kwa sababu basi unaweza kuanguka kupitia kutoka kesi moja hadi jingine. 493 00:21:24,890 --> 00:21:27,930 Basi hebu kusema kwamba kesi constant1 hawakuwa na taarifa mapumziko ndani yake. 494 00:21:27,930 --> 00:21:31,920 Kisha tupate kuanguka kwa njia ya ndani ya kesi constant2. 495 00:21:31,920 --> 00:21:35,070 Na hatutaki kufanya hivyo ikiwa tumekuwa tayari kufikiwa kesi constant1 496 00:21:35,070 --> 00:21:37,830 na ni sawa na n. 497 00:21:37,830 --> 00:21:45,100 >> Hivyo, kwa mfano, kama tuna kutofautiana n kwamba lina idadi darasani, 498 00:21:45,100 --> 00:21:48,990 na tunataka kuona nini kwamba tabaka la is-- ikiwa n sawa na 50, 499 00:21:48,990 --> 00:21:51,957 tunakwenda magazeti "CS50 ni Kuanzishwa kwa Sayansi ya Kompyuta I. " 500 00:21:51,957 --> 00:21:53,040 Kisha tunakwenda kuvunja. 501 00:21:53,040 --> 00:21:53,920 Na hiyo ni yake. 502 00:21:53,920 --> 00:21:55,950 Hata hivyo, n ni sawa hadi 51, tunakwenda 503 00:21:55,950 --> 00:21:58,494 magazeti "CS51 ni Kuanzishwa kwa Sayansi ya Kompyuta II. " 504 00:21:58,494 --> 00:21:59,910 Kisha, tena, tunakwenda kuvunja. 505 00:21:59,910 --> 00:22:05,080 Hata hivyo, kama kisha sisi kuweka 124, 61, yoyote idadi mengine ambayo unaweza kufikiria, 506 00:22:05,080 --> 00:22:06,890 au mpango si kwenda kutambua kwamba. 507 00:22:06,890 --> 00:22:09,010 Hivyo ni kwenda kusema, "Samahani, mimi nina si ukoo na darasa hilo. " 508 00:22:09,010 --> 00:22:10,009 Na itakuja kuvunja. 509 00:22:10,009 --> 00:22:12,847 DAVID Malan: Hivyo unaweza kweli kuona the ikiwa, mwingine kama, mwingine wazo hapa. 510 00:22:12,847 --> 00:22:15,430 Ni syntax tofauti tu kwa akielezea halisi wazo moja. 511 00:22:15,430 --> 00:22:17,690 >> MARIA: Hasa. 512 00:22:17,690 --> 00:22:19,480 Sasa tuna waendeshaji yetu ternary. 513 00:22:19,480 --> 00:22:24,900 Waendeshaji hivyo ternary na tatu parts-- hali, 514 00:22:24,900 --> 00:22:27,220 kitu cha kufanya ikiwa hali hiyo ni kweli, 515 00:22:27,220 --> 00:22:29,730 na kisha kitu cha kufanya kama hali hiyo ni ya uongo. 516 00:22:29,730 --> 00:22:33,400 Hivyo unaweza kuona, kimsingi, syntax ya kwamba hapa. 517 00:22:33,400 --> 00:22:37,792 Tuna alama swali, na kisha the-- je, sisi wito huu? 518 00:22:37,792 --> 00:22:38,750 DAVID Malan: matumbo. 519 00:22:38,750 --> 00:22:39,100 MARIA: Colon. 520 00:22:39,100 --> 00:22:39,599 Asante. 521 00:22:39,599 --> 00:22:41,880 Pole. 522 00:22:41,880 --> 00:22:45,800 Basi hebu tuangalie mfano wetu kuona kama tunaweza kufanya maana ya Haya 523 00:22:45,800 --> 00:22:47,840 class_num == 50. 524 00:22:47,840 --> 00:22:52,580 Hivyo hapa tunaona Boolean operator yetu == ambayo inalinganishwa class_num kutofautiana 525 00:22:52,580 --> 00:22:53,100 50. 526 00:22:53,100 --> 00:22:55,150 Maduka hivyo class_num integer. 527 00:22:55,150 --> 00:22:58,180 Na kama hiyo integer sawa 50, basi tuko 528 00:22:58,180 --> 00:23:02,810 kwenda kuhifadhi "Daudi Malan" ndani ya profesa kamba. 529 00:23:02,810 --> 00:23:05,912 Kama darasa idadi hana sawa 50, "Yule Daudi Malan" 530 00:23:05,912 --> 00:23:07,120 ni kwenda kuwa profesa. 531 00:23:07,120 --> 00:23:08,630 >> DAVID Malan: Asante. 532 00:23:08,630 --> 00:23:12,110 Na hivyo hii inaonekana sawa na nini, unaweza kusema, katika mtazamo wa kwanza? 533 00:23:12,110 --> 00:23:17,930 534 00:23:17,930 --> 00:23:19,960 >> MARIA: Kwangu mimi inaonekana kama-kingine kama kauli. 535 00:23:19,960 --> 00:23:20,709 >> DAVID Malan: Yeah. 536 00:23:20,709 --> 00:23:24,020 Na kwa kweli, hii ni aina ya pretty mjengo moja, 537 00:23:24,020 --> 00:23:27,520 hivyo kusema, kwa ajili ya utekelezaji hasa mantiki ya kama-kingine 538 00:23:27,520 --> 00:23:29,010 lakini kufanya kila kitu katika hatua moja. 539 00:23:29,010 --> 00:23:29,860 >> MARIA: Hasa. 540 00:23:29,860 --> 00:23:30,360 Naam. 541 00:23:30,360 --> 00:23:33,520 Hivyo kama-kingine kauli nguvu kuchukua nafasi kubwa mno. 542 00:23:33,520 --> 00:23:36,283 Wapate kuwa muda mrefu sana kwa kitu rahisi kama hii. 543 00:23:36,283 --> 00:23:38,350 Hivyo hii inaweza kuwa sana succinct na nzuri sana. 544 00:23:38,350 --> 00:23:40,880 545 00:23:40,880 --> 00:23:46,820 Hivyo sasa tunakwenda katika kuangalia utekelezaji kitu tena na tena, 546 00:23:46,820 --> 00:23:50,060 hivyo kuangalia kwa hali mara nyingi 547 00:23:50,060 --> 00:23:53,510 na kisha kuendelea kufanya kitu wakati hali hiyo ni kweli. 548 00:23:53,510 --> 00:23:56,740 Hivyo hii inatuleta vizuri katika wakati matanzi. 549 00:23:56,740 --> 00:23:59,270 >> Kwa upande wa kushoto, tuna wakati wetu wa kwanza kitanzi. 550 00:23:59,270 --> 00:24:03,840 Hivyo wakati kitu ni kweli, kufanya kitu tena na tena. 551 00:24:03,840 --> 00:24:08,850 Ili kuhakikisha taarifa kwamba yetu hali hapa ni Ilisahihishwa kwa juu. 552 00:24:08,850 --> 00:24:14,150 Ambapo pamoja na loop-- yetu ya pili tunatoa wito kwamba do-wakati loop-- sisi kufanya kitu, 553 00:24:14,150 --> 00:24:15,890 kisha sisi kuangalia kwa hali hiyo. 554 00:24:15,890 --> 00:24:17,980 Na kama hali hiyo inaendelea kuwa kweli, 555 00:24:17,980 --> 00:24:20,150 sisi kurudi nyuma na kufanya kitu tena. 556 00:24:20,150 --> 00:24:23,360 Hivyo Tofauti kubwa ni ambapo hali ni checked kwa. 557 00:24:23,360 --> 00:24:29,260 Na kanuni kamwe kuwa kunyongwa kama hali si 558 00:24:29,260 --> 00:24:30,430 kweli na kitanzi wakati. 559 00:24:30,430 --> 00:24:33,050 Ambapo pamoja na kufanya-wakati kitanzi, tuna kificho 560 00:24:33,050 --> 00:24:35,380 kwamba ni lazima ifanyike angalau mara moja. 561 00:24:35,380 --> 00:24:37,470 Na kisha wakati hali inaendelea kuwa kweli, 562 00:24:37,470 --> 00:24:39,960 tunaweza kurudi nyuma na iterate tena ndani. 563 00:24:39,960 --> 00:24:43,625 Hivyo kwa nini unafikiri tunataka kutumia a do-wakati kitanzi juu ya kitanzi wakati? 564 00:24:43,625 --> 00:24:48,221 565 00:24:48,221 --> 00:24:48,720 Kulia. 566 00:24:48,720 --> 00:24:52,600 Hivyo kama tunataka kuchochea user kwa aina fulani ya pembejeo, 567 00:24:52,600 --> 00:24:55,400 kama tunataka kuwaomba kuingia jina yao, 568 00:24:55,400 --> 00:24:57,342 tunataka angalau waombe mara moja. 569 00:24:57,342 --> 00:24:59,050 Na kama hawana kuingia jina kwamba, sisi siyo 570 00:24:59,050 --> 00:25:00,740 kwenda kuwauliza tena kwa sababu sisi tayari kujua hilo. 571 00:25:00,740 --> 00:25:02,656 Lakini kama hawana kuingia majina yao, au kama 572 00:25:02,656 --> 00:25:05,787 kuingia kitu ambacho ni wazi si jina, 573 00:25:05,787 --> 00:25:08,120 sisi bado wanataka kuendelea kuwauliza kwa jina lao. 574 00:25:08,120 --> 00:25:10,710 >> DAVID Malan: Na katika hotuba tulikuwa moja kama hii kwa kupata chanya int 575 00:25:10,710 --> 00:25:13,550 mfano, ambapo kuna kitu kuangalia kwa mara ya kwanza kwa sababu una hata 576 00:25:13,550 --> 00:25:14,190 wamezipata int. 577 00:25:14,190 --> 00:25:16,680 Hivyo tunataka kufanya Haya kupata int kutoka user-- 578 00:25:16,680 --> 00:25:18,860 kisha kuangalia ni, pengine, tena na tena na tena. 579 00:25:18,860 --> 00:25:21,030 >> MARIA: Hasa. 580 00:25:21,030 --> 00:25:22,060 Kwa loops-- sawa. 581 00:25:22,060 --> 00:25:25,842 Kwa mizunguko unaweza kuruhusu sisi kufanya karibu kila halisi kitu kimoja, kama vile. 582 00:25:25,842 --> 00:25:27,300 Ni kweli halisi kitu kimoja. 583 00:25:27,300 --> 00:25:30,190 Hivyo kuna kitu kwamba unaweza kufanya na kwa mizunguko 584 00:25:30,190 --> 00:25:32,840 kwamba bila kuwa na uwezo cha kufanya na wakati matanzi. 585 00:25:32,840 --> 00:25:36,900 Lakini kwa mizunguko inaweza kuonekana kidogo kidogo ngumu zaidi syntactically 586 00:25:36,900 --> 00:25:39,730 kwa sababu wana sehemu tatu ndani ya kile 587 00:25:39,730 --> 00:25:42,990 Ilikuwa kabla tu hali na wakati matanzi. 588 00:25:42,990 --> 00:25:48,260 Hivyo sehemu ya kwanza kwamba wewe bahari, kushoto-wengi, tuna "int dwarves = 0." 589 00:25:48,260 --> 00:25:51,490 Hivyo hii ni mahali ambapo sisi initialize variable yetu. 590 00:25:51,490 --> 00:25:55,210 >> Basi tuna semicolon na "dwarves <7." 591 00:25:55,210 --> 00:25:57,100 Hivyo hii ni mahali ambapo nje hali kweli ni. 592 00:25:57,100 --> 00:26:00,170 Hivyo kwamba ni nini tunataka kuwa kuweka tu katika wakati loop-- 593 00:26:00,170 --> 00:26:01,880 "wakati dwarves <7." 594 00:26:01,880 --> 00:26:05,380 Hapa, kwamba huenda katika katikati ya kwa kitanzi yetu. 595 00:26:05,380 --> 00:26:07,190 Hivyo "dwaves <7." 596 00:26:07,190 --> 00:26:11,350 Na kisha sehemu yetu ya mwisho ni "dwarves ++," ambayo ni ambapo sisi update kutofautiana yetu. 597 00:26:11,350 --> 00:26:15,470 Kwa hiyo, jambo muhimu kutambua ni kwamba hii 598 00:26:15,470 --> 00:26:22,010 ni kwenda kwenda kwa njia hii kwa kitanzi mara saba na kutekeleza mara saba. 599 00:26:22,010 --> 00:26:24,020 Hivyo tuna saba dwarves, na wao uko wote 600 00:26:24,020 --> 00:26:26,020 kwenda kusema, "Mimi niko hapa kuwasaidia, Snow White " 601 00:26:26,020 --> 00:26:28,860 kwa sababu wao wako tayari kuwasaidia Snow White. 602 00:26:28,860 --> 00:26:33,600 >> Pamoja wakati tanzi, sisi ingekuwa amefanya initialization na uboreshaji 603 00:26:33,600 --> 00:26:37,490 si ndani ya hali, tena, lakini ama kabla au ndani ya kitanzi wakati 604 00:26:37,490 --> 00:26:40,210 kuhakikisha kwamba we-- kwa sababu sisi daima haja sehemu hizo. 605 00:26:40,210 --> 00:26:42,835 Hivyo ili kuhakikisha kuwa tuna nao, tunataka wameweza bado aliongeza yao 606 00:26:42,835 --> 00:26:44,580 juu ya, si tu ndani ya mabano. 607 00:26:44,580 --> 00:26:47,288 >> DAVID Malan: Na hivyo inaonekana like-- katika hotuba, kwa mfano, 608 00:26:47,288 --> 00:26:50,250 Mimi karibu kila mara kutumia, kama, i na n na vigezo pretty boring. 609 00:26:50,250 --> 00:26:53,050 Inaonekana kama unaweza kutumia zaidi cleverly aitwaye vigezo, pia. 610 00:26:53,050 --> 00:26:56,300 >> MARIA: Yeah, ni kweli nzuri sana kutumia vigezo kidogo zaidi maelezo 611 00:26:56,300 --> 00:26:59,400 kwa sababu hasa kama mtu mwingine ni kusoma code-- yako labda wewe ni grader 612 00:26:59,400 --> 00:27:00,940 au kama wewe ni kushirikiana na somebody-- 613 00:27:00,940 --> 00:27:03,481 unataka kuhakikisha kwamba wao kuelewa nini unafanya. 614 00:27:03,481 --> 00:27:05,750 615 00:27:05,750 --> 00:27:06,400 >> SAWA. 616 00:27:06,400 --> 00:27:11,435 Hivyo hii ni kitu funky-- sana kwa kitanzi ndani ya kwa kitanzi. 617 00:27:11,435 --> 00:27:13,060 Sijui kama tumeona hii kabla. 618 00:27:13,060 --> 00:27:13,830 Pengine si. 619 00:27:13,830 --> 00:27:17,750 Lakini tunaweza kweli kuwa Haya hivyo loops badala ya mizunguko. 620 00:27:17,750 --> 00:27:25,130 Hivyo haina mtu yeyote wanataka labda kutembea yangu kwa njia ya nini kinaendelea hapa? 621 00:27:25,130 --> 00:27:28,240 622 00:27:28,240 --> 00:27:29,490 DAVID Malan: Mimi itabidi kuchukua kumchoma. 623 00:27:29,490 --> 00:27:29,970 MARIA: Moto. 624 00:27:29,970 --> 00:27:30,636 DAVID Malan: Sawa. 625 00:27:30,636 --> 00:27:34,690 Hivyo, spoiler-- tunataka magazeti mambo hiyo ni katika chini mkono wa kulia kona 626 00:27:34,690 --> 00:27:35,190 huko. 627 00:27:35,190 --> 00:27:35,450 >> MARIA: Haki. 628 00:27:35,450 --> 00:27:35,710 Ndio ndio. 629 00:27:35,710 --> 00:27:38,043 >> DAVID Malan: Hivyo tumekuwa tu kuweka kwamba pato sampuli huko. 630 00:27:38,043 --> 00:27:42,590 Hivyo siwezi kudai kutoka topmost kitanzi kwamba wewe ni 631 00:27:42,590 --> 00:27:45,680 iterating juu ya safu yttersta kitanzi, hivyo kusema. 632 00:27:45,680 --> 00:27:48,107 Na wewe ni iterating juu nguzo na ndani kabisa kitanzi. 633 00:27:48,107 --> 00:27:50,190 Na shirikishi, hii lazima hopefully hufanya akili 634 00:27:50,190 --> 00:27:52,070 kwa sababu kwa asili ya kila mpango tumeona 635 00:27:52,070 --> 00:27:55,570 kabla, printf, ambayo ni kazi sisi ni kutumia, hatimaye, 636 00:27:55,570 --> 00:27:58,190 ina uwezo wa magazeti mambo nje kimsingi mstari kwa mstari. 637 00:27:58,190 --> 00:27:59,960 Kama, mara moja umefanya outputted mstari mpya, kuna 638 00:27:59,960 --> 00:28:02,876 hakuna mara dufu nyuma na uchapishaji kitu juu katika screen, angalau 639 00:28:02,876 --> 00:28:04,530 si kwa kutumia printf kama hii. 640 00:28:04,530 --> 00:28:07,750 >> Na hivyo katika suala hilo, inafanya maana hiyo yttersta kitanzi 641 00:28:07,750 --> 00:28:10,930 lazima akimaanisha mistari kwa sababu kwa kila kutolewa mstari, 642 00:28:10,930 --> 00:28:13,650 wewe ni kwenda kutaka magazeti nje XXXXX, na kisha 643 00:28:13,650 --> 00:28:15,520 hoja juu ya mstari unaofuata, XXXXX. 644 00:28:15,520 --> 00:28:17,317 Hivyo safu kuja kwanza. 645 00:28:17,317 --> 00:28:19,150 Na kisha ndani ya kila mstari, magazeti nguzo. 646 00:28:19,150 --> 00:28:21,160 Kama alijaribu kufanya hivyo kinyume, ingekuwa pengine si 647 00:28:21,160 --> 00:28:21,690 kuja nje kama unakusudia. 648 00:28:21,690 --> 00:28:22,190 >> MARIA: Naam. 649 00:28:22,190 --> 00:28:24,950 Sisi tu hawakuweza kurudi safu ya awali na printf. 650 00:28:24,950 --> 00:28:27,658 >> DAVID Malan: Na nini kuvutia kwa mazungumzo ya leo kuhusu wigo, 651 00:28:27,658 --> 00:28:31,600 kweli, ni kwamba mstari ni int hiyo ni alitangaza katika juu kabisa kitanzi. 652 00:28:31,600 --> 00:28:34,030 Lakini taarifa kwamba ni bado ndani ya, hivyo kusema, 653 00:28:34,030 --> 00:28:35,982 braces curly kwamba mara moja kufuata, 654 00:28:35,982 --> 00:28:38,440 hata kama ni si kitaalam ndani ya braces wale curly. 655 00:28:38,440 --> 00:28:41,750 Hivyo mstari ni katika wigo kwa ukamilifu wa snippet ya kificho, 656 00:28:41,750 --> 00:28:44,690 wote ndani ya nje kwa kitanzi na ndani ya ndani kwa kitanzi. 657 00:28:44,690 --> 00:28:48,050 Lakini kwa kulinganisha, ambapo ni safu katika wigo? 658 00:28:48,050 --> 00:28:49,810 Kutofautiana safu? 659 00:28:49,810 --> 00:28:51,310 Yeah, tu katika ndani ya kitanzi. 660 00:28:51,310 --> 00:28:54,280 Na hiyo ni sawa kwa sababu hatuna kupata ni nje ya braces curly wake. 661 00:28:54,280 --> 00:28:57,280 Wote sisi kufanya ni magazeti nje mpya mstari mwishoni sana huko. 662 00:28:57,280 --> 00:28:58,670 Hivyo kwamba kwa kweli ni sawa. 663 00:28:58,670 --> 00:29:03,740 >> Hivyo hii ina athari, inaonekana kama, ya kufanya safu tatu na nguzo nne. 664 00:29:03,740 --> 00:29:04,370 >> MARIA: Haki. 665 00:29:04,370 --> 00:29:06,270 Hivyo kwanza sisi kwenda kwa njia ya mstari wetu wa kwanza. 666 00:29:06,270 --> 00:29:10,520 Na tu katika mstari wetu wa kwanza, tunafanya nguzo nne ndani ya safu ya kwanza. 667 00:29:10,520 --> 00:29:11,980 Hivyo sisi magazeti nje wanne X. 668 00:29:11,980 --> 00:29:15,800 Na kisha tunaweza kujinasua kwa kitanzi, tangu tumekuwa tayari kuchapishwa nne X. 669 00:29:15,800 --> 00:29:17,100 Na sisi magazeti mstari mpya. 670 00:29:17,100 --> 00:29:19,920 Na kisha sisi kwenda kwa njia ya sawa mchakato kwa safu mbili zaidi 671 00:29:19,920 --> 00:29:21,170 kufanya jumla ya tatu. 672 00:29:21,170 --> 00:29:23,530 >> DAVID Malan: Na ni thamani kubainisha ni tu artifact ya maandishi, ukweli 673 00:29:23,530 --> 00:29:25,680 kwamba sampuli pato kuonekana sana mirefu, 674 00:29:25,680 --> 00:29:27,520 kana kwamba kuna zaidi safu ya nguzo. 675 00:29:27,520 --> 00:29:29,824 Lakini ni kwa sababu tu X ni mirefu kuliko ilivyo kote. 676 00:29:29,824 --> 00:29:32,740 Hayo ni yote yale yanayotokea huko, pamoja na nafasi nyeupe kati ya mistari. 677 00:29:32,740 --> 00:29:33,281 >> MARIA: Haki. 678 00:29:33,281 --> 00:29:34,792 Baridi. 679 00:29:34,792 --> 00:29:35,750 DAVID Malan: zote haki. 680 00:29:35,750 --> 00:29:39,830 Hivyo haraka kuangalia tatizo kuweka moja, kuchukua maswali yoyote, na kisha kuahirisha? 681 00:29:39,830 --> 00:29:40,330 Sawa. 682 00:29:40,330 --> 00:29:43,164 Hivyo katika tatizo kuweka moja, kuna tatu changamoto za msingi, hatimaye. 683 00:29:43,164 --> 00:29:44,955 Lakini kwanza, utapata kwamba tatizo kuweka 684 00:29:44,955 --> 00:29:47,900 vipimo, kama ilivyo kwa wengi psets hii kuanguka, ni kwenda kutembea wewe 685 00:29:47,900 --> 00:29:50,691 kupitia chache joto-up mazoezi, kumweka wewe nje rasilimali chache 686 00:29:50,691 --> 00:29:52,440 kwamba wanaweza au si tumeona tayari. 687 00:29:52,440 --> 00:29:54,440 Kwa mfano, CS50 ina Suite ya kaptula, 688 00:29:54,440 --> 00:29:56,481 ambayo ni video fupi, si tofauti na hii, lakini hiyo 689 00:29:56,481 --> 00:29:58,460 ni mada sana specific-- labda dakika tano, 690 00:29:58,460 --> 00:30:02,360 Dakika 10 katika urefu juu ya mizunguko au juu ya hali ya juu ya algorithms au 691 00:30:02,360 --> 00:30:04,125 au baadaye zaidi mada ya juu, kama vile. 692 00:30:04,125 --> 00:30:06,000 Na sisi ujumla kupachika wale katika tatizo 693 00:30:06,000 --> 00:30:07,950 seti ili wanafunzi na rasilimali ambazo 694 00:30:07,950 --> 00:30:10,840 kufanya mapitio ya vifaa kwamba wanaweza kuwa tayari kuja katika hotuba au sehemu. 695 00:30:10,840 --> 00:30:13,220 Lakini njia hii ni umakini zaidi na zaidi fingertips yao. 696 00:30:13,220 --> 00:30:15,928 >> Sisi pia huwa na kuiweka katika tatizo seti mambo kuitwa walkthroughs. 697 00:30:15,928 --> 00:30:20,790 Hivyo karibu wote wa mifano nifanye nini katika hotuba, juu ya hatua hapa, sisi pia 698 00:30:20,790 --> 00:30:24,565 kuwa na risasi juu ya kamera katika kuendeleza polepole zaidi, 699 00:30:24,565 --> 00:30:28,760 walkthrough ionekane zaidi na mimi kwenye mbali yangu ya kwamba kanuni, mstari kwa mstari 700 00:30:28,760 --> 00:30:31,427 ili darasani, tutaweza mara nyingi skim kwa njia kitu au mtu 701 00:30:31,427 --> 00:30:33,260 Itakuwa interject na kujibu swali. 702 00:30:33,260 --> 00:30:35,820 Lakini siyo lazima kuzama katika kwa kila mtu katika watazamaji. 703 00:30:35,820 --> 00:30:38,230 Hivyo utapata kificho walkthroughs kwa zaidi ya mifano 704 00:30:38,230 --> 00:30:40,950 tuyafanyayo hapa katika hotuba ili uweze wanaweza kutembea kwa njia hiyo kwa kasi yako mwenyewe 705 00:30:40,950 --> 00:30:43,580 na rewind au kufunga mbele au ruka kabisa, kama Ningependa. 706 00:30:43,580 --> 00:30:45,356 >> Kuna mara nyingi ni chache maswali kujipima nguvu kwamba 707 00:30:45,356 --> 00:30:47,105 kuuliza wewe kutatua ya kuimarisha nyenzo hii 708 00:30:47,105 --> 00:30:50,250 na kuhakikisha kuwa uko comfy kabla kuendelea na mapumziko ya pset. 709 00:30:50,250 --> 00:30:51,700 Na kisha, bila shaka, kuna pset yenyewe. 710 00:30:51,700 --> 00:30:53,450 Na moja ya mambo sisi sana kwa makusudi 711 00:30:53,450 --> 00:30:57,202 kufanya katika CS50 ni karibu kila uninteresting au kielimu uninteresting 712 00:30:57,202 --> 00:30:58,910 hatua mitambo kwamba unaweza kuwa na kufanya 713 00:30:58,910 --> 00:31:00,519 ni karibu kila mara vizuri sana kumbukumbu. 714 00:31:00,519 --> 00:31:03,560 Katika kipindi cha muda mrefu, tutaweza kuanza kuuliza maswali zaidi ya kejeli 715 00:31:03,560 --> 00:31:06,187 kama unakumbuka jinsi ya kufanya hivi au hivi? 716 00:31:06,187 --> 00:31:08,520 Lakini kwa ujumla, utapata kwamba tatizo seti kupata wewe 717 00:31:08,520 --> 00:31:10,269 kupitia mashine kitu ili 718 00:31:10,269 --> 00:31:14,160 kuvutia, changamoto akili ni hatimaye kushoto na wewe mwanafunzi. 719 00:31:14,160 --> 00:31:17,390 >> Kwa kuwa alisema, Zamyla, ambaye sisi naendelea akimaanisha leo katika hotuba, 720 00:31:17,390 --> 00:31:20,190 ni moja ya wafanyakazi wetu wa muda mrefu mwanachama ambaye pia ana walkthroughs 721 00:31:20,190 --> 00:31:24,520 juu ya matatizo maalum pset kama Mario na tamaa, ingawa si maji mwaka huu. 722 00:31:24,520 --> 00:31:26,540 Na ni katika wale walkthroughs kwamba yeye mara nyingi 723 00:31:26,540 --> 00:31:29,450 inatoa baadhi ya vidokezo na tricks kwa jinsi ya kuendelea, kamwe kuwaambia 724 00:31:29,450 --> 00:31:31,810 hasa nini cha kufanya, lakini rather-- kama hali, 725 00:31:31,810 --> 00:31:35,200 kama wewe will-- kutoa angalau michache ya mawazo ili ni juu yako, 726 00:31:35,200 --> 00:31:37,830 hatimaye, kuamua jinsi ya kuzitumia. 727 00:31:37,830 --> 00:31:41,200 >> MARIA: aina ya kama ngazi ya juu uelewa wa mantiki ya kile 728 00:31:41,200 --> 00:31:42,220 sisi ni kuuliza wewe kufanya. 729 00:31:42,220 --> 00:31:42,485 >> DAVID Malan: Hasa. 730 00:31:42,485 --> 00:31:44,190 Na, kwa kweli, Zamyla ya walkthroughs ni maana 731 00:31:44,190 --> 00:31:46,190 kujibu mara nyingi aliuliza swali la wapi 732 00:31:46,190 --> 00:31:48,610 kufanya mimi alianza, hasa wakati specifikationer haya kwa muda mrefu ni 733 00:31:48,610 --> 00:31:51,960 ngumu kidogo kutokana na maandishi yote na picha za kuwa wana ndani yao. 734 00:31:51,960 --> 00:31:54,890 >> Hivyo water.c, utapata baada ya umefanya kukamilika yake, 735 00:31:54,890 --> 00:31:56,920 ni kweli kiasi moja kwa moja. 736 00:31:56,920 --> 00:31:58,882 Kabisa ni rundo ya wewe kwenda bang 737 00:31:58,882 --> 00:32:01,840 vichwa vyenu dhidi ya ukuta kujaribu kufikiri kwa nini siyo kuandaa 738 00:32:01,840 --> 00:32:03,450 au kwa nini siyo mbio usahihi. 739 00:32:03,450 --> 00:32:05,040 Lakini mara wewe ni kosa na hali hiyo na mara moja umefanya 740 00:32:05,040 --> 00:32:07,620 alitumia muda kumenyana na yoyote ya mende kwamba unaweza kuwa, 741 00:32:07,620 --> 00:32:09,490 utapata kwamba ni mfupi sana mpango huo. 742 00:32:09,490 --> 00:32:11,770 Ni kifanyike katika chache tu mstari wa kanuni, ambao wengi 743 00:32:11,770 --> 00:32:15,030 tumeona hapa katika hotuba tayari, kama wewe kukusanyika haki ujenzi wa vitalu. 744 00:32:15,030 --> 00:32:16,810 >> Na kama tunashauri hapa, ni kwenda kuuliza 745 00:32:16,810 --> 00:32:22,250 bayana dakika ngapi mtu ni kuchukua oga juu ya chuo. 746 00:32:22,250 --> 00:32:24,779 Sisi bayana katika tatizo kuweka kiwango cha mtiririko wa maji 747 00:32:24,779 --> 00:32:27,320 katika, kama, chini ya kuoga mtiririko kichwa, kiasi kama Seinfeld kipande cha 748 00:32:27,320 --> 00:32:29,180 tuliona jana au kinyume yake. 749 00:32:29,180 --> 00:32:30,971 Na kisha wewe tu na kufanya kidogo ya math, 750 00:32:30,971 --> 00:32:34,710 really-- hesabu kwa kutumia C kuwaambia sisi ni wangapi, takribani, chupa za maji 751 00:32:34,710 --> 00:32:37,720 ni kwamba sawa na kama tuko kuchukua oga n dakika. 752 00:32:37,720 --> 00:32:41,389 >> Sasa, katika mario.c, hii ni kwenda kuwa mpango kidogo tena. 753 00:32:41,389 --> 00:32:42,930 Ni bado si kwenda kuwa hii kwa muda mrefu. 754 00:32:42,930 --> 00:32:45,130 Mistari michache tu tena kuliko water.c. 755 00:32:45,130 --> 00:32:48,230 Lakini itakuja kuwa na nafasi recreate umri wa shule Mario 756 00:32:48,230 --> 00:32:50,670 piramidi kutoka Super Mario Brothers au baadhi ya kufuatilia juu ya. 757 00:32:50,670 --> 00:32:53,510 Siyo kwenda kuangalia kama prettier au kama rangi kama kwamba moja huko. 758 00:32:53,510 --> 00:32:56,468 Sisi ni kwenda tu kutumia hashtags kidogo kama sisi hapa kwenye screen 759 00:32:56,468 --> 00:32:58,120 kutumia maandishi ASCII. 760 00:32:58,120 --> 00:33:00,362 Lakini itakuwa takriban wazo moja. 761 00:33:00,362 --> 00:33:02,570 Na itakuja kuwa zoezi kwamba katika mtazamo wa kwanza 762 00:33:02,570 --> 00:33:04,720 Inaonekana pretty simple-- tu magazeti piramidi rahisi. 763 00:33:04,720 --> 00:33:07,345 Lakini kuna sifa wanandoa hapa ambayo ni ya kuvutia. 764 00:33:07,345 --> 00:33:12,400 Taarifa kwamba makali rightmost ya piramidi kweli ina upana mbili. 765 00:33:12,400 --> 00:33:14,570 Hivyo kuna mbili sawa urefu nguzo, ambayo 766 00:33:14,570 --> 00:33:16,804 inafanya zinahitaji kidogo kidogo ya fikra kufanya 767 00:33:16,804 --> 00:33:19,720 kuhakikisha kupata kwamba hasa haki, kama kinyume na tu kikamilifu angled 768 00:33:19,720 --> 00:33:20,220 mstari. 769 00:33:20,220 --> 00:33:23,340 Hivyo hiyo ni kidogo ya kesi kona lakini mechi mchezo halisi. 770 00:33:23,340 --> 00:33:27,610 >> Na pia ni yasiyo ya wazi kwa mara ya kwanza mtazamo jinsi ya magazeti nafasi nyeupe. 771 00:33:27,610 --> 00:33:29,430 Hivyo wakati mimi kuangalia sampuli here-- pato 772 00:33:29,430 --> 00:33:32,440 na pia ni katika spec-- ni aina ya inaonekana kama mstatili, 773 00:33:32,440 --> 00:33:35,120 lakini diagonal ya Mstatili imekuwa kung'olewa mbali, 774 00:33:35,120 --> 00:33:37,320 na ni tu nafasi nyeupe, hivyo kusema. 775 00:33:37,320 --> 00:33:40,100 Na hivyo aliomba mara nyingi swali hapa ni siku zote, vizuri, 776 00:33:40,100 --> 00:33:43,302 jinsi gani mimi hoja hashtags zaidi ya haki? 777 00:33:43,302 --> 00:33:44,760 Au jinsi gani mimi magazeti nafasi tupu? 778 00:33:44,760 --> 00:33:46,860 Na ni kweli rahisi kuliko wanafunzi wengi kufikiri. 779 00:33:46,860 --> 00:33:47,360 Sawa? 780 00:33:47,360 --> 00:33:51,620 Unaweza takriban ni kuibua na tu kupiga nafasi bar mara moja au mbili 781 00:33:51,620 --> 00:33:52,700 au mara tatu. 782 00:33:52,700 --> 00:33:56,260 >> Na hivyo hata kama kwa printf sisi karibu Daima magazeti nje kamba au int 783 00:33:56,260 --> 00:33:59,950 au neno kama "hello, dunia "au mfululizo wa maneno, 784 00:33:59,950 --> 00:34:03,560 unaweza pia tu magazeti kunukuu, nafasi, unquote. 785 00:34:03,560 --> 00:34:06,320 Na kwamba kwa kweli kutoa wewe nafasi nyeupe huko. 786 00:34:06,320 --> 00:34:08,330 Hivyo kuendelea kuwa katika akili na hawana overthink hii. 787 00:34:08,330 --> 00:34:10,570 Wewe kweli na kuamua mstari kwa mstari kwa mstari, 788 00:34:10,570 --> 00:34:14,280 si tofauti na mfano wako wakati iliyopita, ni wangapi kati ya wale 789 00:34:14,280 --> 00:34:18,420 nguzo inapaswa kuwa nafasi nyeupe na jinsi wengi wao wanapaswa kuwa hashtags. 790 00:34:18,420 --> 00:34:21,560 Itachukua muda kidogo, lakini ni hatimaye mantiki puzzle ya kila aina. 791 00:34:21,560 --> 00:34:22,060 >> MARIA: Naam. 792 00:34:22,060 --> 00:34:25,060 Lakini mantiki ya kwenda mstari kwa mstari ni kwenda kuwa muhimu sana hapa. 793 00:34:25,060 --> 00:34:25,810 DAVID Malan: Yeah. 794 00:34:25,810 --> 00:34:28,976 Nadhani sampuli kificho wewe gave-- hata ingawa haikuwa mpango kamili. 795 00:34:28,976 --> 00:34:34,247 Bado unahitaji int kuu na tena utupu na # ni pamoja na stdio.h, 796 00:34:34,247 --> 00:34:35,580 mengi ya mambo kutoka hotuba. 797 00:34:35,580 --> 00:34:37,629 Lakini ujenzi wa vitalu wanaonekana kuwa huko. 798 00:34:37,629 --> 00:34:39,920 Na kisha mwisho ni kitu zaidi kidogo algorithmic. 799 00:34:39,920 --> 00:34:43,210 Hivyo ni zinageuka kuwa wakati wowote kwenda katika CVS au ghala yoyote urahisi 800 00:34:43,210 --> 00:34:47,810 na mtu mikono yenu kwa bili cashier au kama sarafu mabadiliko, 801 00:34:47,810 --> 00:34:50,620 zinageuka kuwa wao, binadamu, kama au wao kujua au la, 802 00:34:50,620 --> 00:34:53,300 pengine kwa kutumia nini aitwaye algorithm tamaa, 803 00:34:53,300 --> 00:34:58,170 ambapo kama wewe ni deni lake, kusema, $ 21 katika mabadiliko kwa sababu kwa sababu fulani 804 00:34:58,170 --> 00:35:01,580 wewe kununua kitu ghali sana na muswada kubwa sana katika CVS, 805 00:35:01,580 --> 00:35:05,910 itakuwa ni kweli annoying kama cashier alitoa wewe single 21 au, mbaya 806 00:35:05,910 --> 00:35:07,629 bado, mengi yote ya sarafu. 807 00:35:07,629 --> 00:35:10,670 Badala yake, ni nini mtu timamu ni pengine ni kwenda kufanya ni wao wanaenda 808 00:35:10,670 --> 00:35:14,224 kunyakua $ 20- $ na kisha 1-bili, na mkono wewe bili mbili tu katika kesi hiyo. 809 00:35:14,224 --> 00:35:17,390 MARIA: Kwa hiyo wao ni kutafuta ili kupunguza mabadiliko ambayo wao kutoa nyuma yenu. 810 00:35:17,390 --> 00:35:17,850 DAVID Malan: Hasa. 811 00:35:17,850 --> 00:35:19,540 Na mpango huo na sarafu, kama vile. 812 00:35:19,540 --> 00:35:23,040 Kama wewe ni deni lake, wanasema, $ 0.50, hopefully wewe hawataki 50 pennies. 813 00:35:23,040 --> 00:35:25,500 Wewe badala wanataka wawili robo, kwa mfano. 814 00:35:25,500 --> 00:35:27,540 Sasa, hii haina kudhani kwamba cashier ina 815 00:35:27,540 --> 00:35:29,940 kutosha ya kila dhehebu kwamba yeye au yeye kutaka kukupa. 816 00:35:29,940 --> 00:35:32,148 Lakini hatuwezi kuruhusu kudhani kama kiasi katika tatizo hilo. 817 00:35:32,148 --> 00:35:35,590 Na lengo, hatimaye, ni kwa kutekeleza katika C kificho algorithm tamaa. 818 00:35:35,590 --> 00:35:37,344 Hivyo mtumiaji anaruhusiwa aina katika kiasi gani 819 00:35:37,344 --> 00:35:40,510 mabadiliko yeye au yeye zinadaiwa na dola na senti, baadhi ya aina ya hatua yaliyo 820 00:35:40,510 --> 00:35:41,590 thamani pengine. 821 00:35:41,590 --> 00:35:45,530 Na kisha una kufanya hesabu na kufikiri algorithmically, vizuri, 822 00:35:45,530 --> 00:35:49,020 jinsi wengi sarafu naweza kutoa wewe ya chini kukupa 823 00:35:49,020 --> 00:35:50,270 hasa kwamba kiasi cha mabadiliko. 824 00:35:50,270 --> 00:35:53,470 Lakini kuna kwenda kuwa chache sehemu gumu hapa, sawa? 825 00:35:53,470 --> 00:35:56,236 Kama kuna zima kutokuwa sahihi suala hilo. 826 00:35:56,236 --> 00:35:56,860 MARIA: Hasa. 827 00:35:56,860 --> 00:35:59,114 Hatua hivyo yaliyo maadili na kutokuwa sahihi. 828 00:35:59,114 --> 00:36:00,780 Je, sisi majadiliano juu ya hili katika hotuba leo? 829 00:36:00,780 --> 00:36:02,340 >> DAVID Malan: Sisi alifanya Mara ya mwisho katika hotuba. 830 00:36:02,340 --> 00:36:03,506 Kuongelea kutokuwa sahihi. 831 00:36:03,506 --> 00:36:08,840 Na wewe hawataki kudanganya mtumiaji ni kiasi gani cha badiliko yeye au yeye zinadaiwa. 832 00:36:08,840 --> 00:36:11,290 Na hivyo walkthrough, katika tatizo kuweka vipimo, 833 00:36:11,290 --> 00:36:15,990 kutoa baadhi ya mawazo, hatimaye, kama kwa jinsi gani unaweza kukabiliana na wale kutokuwa sahihi 834 00:36:15,990 --> 00:36:17,280 makosa, uwezekano. 835 00:36:17,280 --> 00:36:21,050 Ni zaweza kuepukwa, kwa hakika, kwa pembejeo tunazungumzia. 836 00:36:21,050 --> 00:36:23,590 Na, kwa kweli, pennies-- labda tutaweza kuahirisha kwa Zamyla, 837 00:36:23,590 --> 00:36:25,136 Nadhani, kwa mbinu huko. 838 00:36:25,136 --> 00:36:27,760 Hivyo hatimaye, utapata maendeleo ya matatizo ya wiki hii, 839 00:36:27,760 --> 00:36:30,700 kwanza ambayo ni pretty ndogo, kisha kati, kubwa basi kidogo. 840 00:36:30,700 --> 00:36:33,200 Lakini wote kutumia jengo vitalu kutoka wiki hii iliyopita, 841 00:36:33,200 --> 00:36:35,280 kutoka supersection hii, tatizo kuweka vipimo 842 00:36:35,280 --> 00:36:36,710 unaweka katika rasilimali wasiohesabika. 843 00:36:36,710 --> 00:36:41,000 Lakini bado, kama wakati wote wanajitahidi, hasa miongoni mwa wale chini ya starehe 844 00:36:41,000 --> 00:36:42,917 na hakuna historia ya awali, kuja masaa ya ofisi 845 00:36:42,917 --> 00:36:44,958 juu ya Jumatatu na Jumanne na Jumatano na Alhamisi. 846 00:36:44,958 --> 00:36:46,950 Kwenda CS50 Jadili kupitia tovuti kozi ya, 847 00:36:46,950 --> 00:36:49,080 kupitia ambayo unaweza kuzungumza pamoja na wafanyakazi na wanafunzi. 848 00:36:49,080 --> 00:36:51,670 >> Lakini hatimaye, nadhani Ushauri bora ni kuanza tu mapema. 849 00:36:51,670 --> 00:36:54,711 Si ni aina ya darasa kwamba lazima kuanzia psets Jumatano 850 00:36:54,711 --> 00:36:56,640 usiku, au mbaya Alhamisi usiku. 851 00:36:56,640 --> 00:36:59,067 >> MARIA: Ushauri wangu bora ni kwa wameanza na Jumatatu. 852 00:36:59,067 --> 00:36:59,900 DAVID Malan: Jumatatu. 853 00:36:59,900 --> 00:37:02,490 Hivyo kama wewe si kuanza already-- hakuna. 854 00:37:02,490 --> 00:37:04,732 Lakini hata kama si Jumatatu, kisha Jumanne. 855 00:37:04,732 --> 00:37:05,690 Mapema bora. 856 00:37:05,690 --> 00:37:08,605 Na hiyo ndiyo sababu Bila shaka ina siku nyingi marehemu ni 857 00:37:08,605 --> 00:37:10,535 kukupa kidogo ya shinikizo kisaikolojia 858 00:37:10,535 --> 00:37:13,684 kuanza mapema lakini bado basi mambo yatakuwa wakati mambo kuchukua muda mrefu 859 00:37:13,684 --> 00:37:14,350 kuliko wewe kutarajia. 860 00:37:14,350 --> 00:37:17,950 >> MARIA: Na unataka kufanya matumizi ya masaa ya ofisi kama vile unaweza, pia. 861 00:37:17,950 --> 00:37:20,291 >> DAVID Malan: Maswali yoyote? 862 00:37:20,291 --> 00:37:20,790 Sawa. 863 00:37:20,790 --> 00:37:22,930 Naam, kwa nini sio sisi kuahirisha hapa? 864 00:37:22,930 --> 00:37:23,487