1 00:00:00,000 --> 00:00:03,440 >> [Daqq ta mużika] 2 00:00:03,440 --> 00:01:57,217 3 00:01:57,217 --> 00:02:00,710 >> [Applause] 4 00:02:00,710 --> 00:02:05,700 5 00:02:05,700 --> 00:02:09,669 >> DAVID J. Malan: Dan huwa CS50, Introduzzjoni Harvard University 6 00:02:09,669 --> 00:02:12,370 għall-intellettwali intrapriżi ta 'xjenza tal-kompjuter 7 00:02:12,370 --> 00:02:14,180 u l-arti ta 'programmazzjoni. 8 00:02:14,180 --> 00:02:17,530 Issa jekk inti fost dawk li kull sena huma seduta hawn 9 00:02:17,530 --> 00:02:21,450 bi ftit ta 'nervituri fil-moħħ tiegħek, bħal li inti ma taħseb li jagħmlu parti minn hawn, 10 00:02:21,450 --> 00:02:24,270 taħseb li l-aktar ħadd seduta madwar inti 11 00:02:24,270 --> 00:02:27,730 jaf ferm aktar milli suppost, huwa tabilħaqq aktar komda milli suppost fil-kompjuter 12 00:02:27,730 --> 00:02:30,430 xjenza jew kompjuters b'mod aktar ġenerali, tirrealizza 13 00:02:30,430 --> 00:02:36,140 li 78% tal-istudenti li issa tieħu CS50 ma jkollhom ebda esperjenza minn qabel. 14 00:02:36,140 --> 00:02:39,570 >> Tabilħaqq, hemm 100 dots hemm dwar il-wiri, 78 minnhom 15 00:02:39,570 --> 00:02:43,540 huma ħodor solidi, li jfisser li inti, jekk int fost dik demografika, 16 00:02:43,540 --> 00:02:46,420 huma fil-kumpanija tajba ħafna hawn fuq barra. 17 00:02:46,420 --> 00:02:50,320 U jekk inti minflok fost l- 22% ta 'studenti CS50 li jagħmlu tabilħaqq 18 00:02:50,320 --> 00:02:53,920 jkollhom esperjenza minn qabel, kemm jekk fil- iskola għolja jew xi programm ieħor, 19 00:02:53,920 --> 00:02:56,430 tirrealizza li inti, wisq, se jiġi kkontestat fil-kors. 20 00:02:56,430 --> 00:02:59,930 >> Mhux biss għandna binarji differenti għall-istudenti anqas komdu u aktar 21 00:02:59,930 --> 00:03:03,789 komdu bl-istess mod fit-taqsimiet, aħna wkoll l-hekk imsejħa edizzjonijiet Hacker 22 00:03:03,789 --> 00:03:06,080 tal-aktar problema settijiet li se jisfida dawk l-istudenti 23 00:03:06,080 --> 00:03:09,650 ma 'dak esperjenza addizzjonali biex jesploraw materjal simili 24 00:03:09,650 --> 00:03:12,140 iżda minn aktar perspettiva sofistikati. 25 00:03:12,140 --> 00:03:13,900 >> Imma dak li huwa xjenza tal-kompjuter? 26 00:03:13,900 --> 00:03:17,750 Well, finalment, dak li għaddej biex kwistjoni kif inti jesploraw il-qasam mhuwiex 27 00:03:17,750 --> 00:03:20,500 tant fejn inti tispiċċa relattiva għall-klassi tiegħek, 28 00:03:20,500 --> 00:03:25,350 imma fejn inti yourself jispiċċaw fl 12 ġimgħa versus fejn inti tibda hawn 29 00:03:25,350 --> 00:03:26,720 fil żero ġimgħa. 30 00:03:26,720 --> 00:03:31,850 Issa kompjuter science-- sew, ejja sejħa hija l-xjenza ta 'computation-- 31 00:03:31,850 --> 00:03:35,910 fejn kompjutazzjoni hija verament ftit mod fancy ta 'tgħid, jieħdu xi input, 32 00:03:35,910 --> 00:03:39,460 produzzjoni ta 'xi output, u jagħmlu dan permezz ta 'algoritmi running, 33 00:03:39,460 --> 00:03:43,700 settijiet ta 'struzzjonijiet sabiex isolvi xi problema fuq dawk l-inputs 34 00:03:43,700 --> 00:03:48,460 sabiex jipproduċu xi output jew soluzzjoni li inti interessat. 35 00:03:48,460 --> 00:03:51,310 >> Allura aħna reċentement kellhom okkażjoni biex jivvjaġġaw barra 36 00:03:51,310 --> 00:03:53,170 biex California biex jilħqu ma 'alumna. 37 00:03:53,170 --> 00:03:54,650 Isimha huwa Susan Wojcicki. 38 00:03:54,650 --> 00:03:57,190 U hi tixtieq li jitkellmu lilek hawn fuq video 39 00:03:57,190 --> 00:04:01,690 li jixhdu li kemm applikabbli anki biss togħma ta 'kompjuter 40 00:04:01,690 --> 00:04:03,770 xjenza fil- livell introduttorja jista 'jkun. 41 00:04:03,770 --> 00:04:06,870 Anki jekk inti ma jmorrux fuq biex isegwu xjenza tal-kompjuter bħala qasam, 42 00:04:06,870 --> 00:04:09,330 jew saħansitra inġinerija, jew ZOKK b'mod aktar ġenerali, 43 00:04:09,330 --> 00:04:12,360 tkun taf tara, fil-fatt, kif ċertu kors hekk influwenzati ħajja tagħha. 44 00:04:12,360 --> 00:04:16,630 U hi biss biss ħa meta hi kien anzjan hawn fil-Harvard College. 45 00:04:16,630 --> 00:04:19,482 >> Jekk nistgħu dim-dwal għall Susan. 46 00:04:19,482 --> 00:04:20,690 SUSAN Wojcicki: Hello, dinja. 47 00:04:20,690 --> 00:04:22,100 Jien Susan Wojcicki. 48 00:04:22,100 --> 00:04:24,110 Jien il-CEO ta 'YouTube. 49 00:04:24,110 --> 00:04:29,150 And I ħa CS50 meta I kien anzjan fil-Harvard fl-1990. 50 00:04:29,150 --> 00:04:31,220 I kien attwalment storja u l-letteratura maġġuri. 51 00:04:31,220 --> 00:04:36,760 >> U fis-sajf junior tiegħi, I induna li forsi I 52 00:04:36,760 --> 00:04:39,060 riedu jitgħallmu xi ħaġa dwar il-kompjuters. 53 00:04:39,060 --> 00:04:40,930 U hekk, Wasalt lura. 54 00:04:40,930 --> 00:04:42,500 I ħa CS50. 55 00:04:42,500 --> 00:04:46,940 Kien diffiċli, iżda kienet il- aktar klassi aqwa I ħa. 56 00:04:46,940 --> 00:04:49,630 >> Huwa biddel kif naħseb dwar kollox. 57 00:04:49,630 --> 00:04:55,810 U meta I gradwat minn Harvard fl-1990, I marru għall Silicon Valley. 58 00:04:55,810 --> 00:04:57,140 U sibt xogħol. 59 00:04:57,140 --> 00:05:00,150 U stajt ilhom jaħdmu fil tech qatt peress. 60 00:05:00,150 --> 00:05:02,650 DAVID J. Malan: Issa dak Susan ma jsemmi f'dan il-video, 61 00:05:02,650 --> 00:05:05,340 li kien attwalment fil tagħha garaxx li Google innifsu kien 62 00:05:05,340 --> 00:05:07,420 mwaqqfa mill Larry u Sergey. 63 00:05:07,420 --> 00:05:11,169 >> Issa aħna wkoll laħqu l-ħbieb tagħna fi code.org, organizzazzjoni li 64 00:05:11,169 --> 00:05:13,460 matul l-aħħar sena kienet jkollna nies partikolarment 65 00:05:13,460 --> 00:05:16,520 eċċitati dwar ix-xjenza tal-kompjuter u l-programmazzjoni, b'mod partikolari. 66 00:05:16,520 --> 00:05:20,590 Iżda ta 'min jinnota li l-ipprogrammar mhix xjenza tal-kompjuter per se. 67 00:05:20,590 --> 00:05:22,090 Xjenza tal-kompjuter mhuwiex programmazzjoni. 68 00:05:22,090 --> 00:05:24,560 Pjuttost ipprogrammar huwa biss tool-- magħhom kollha inti 69 00:05:24,560 --> 00:05:27,510 se jkunu kollha wisq ukoll familjari billi end-- semestru tal 70 00:05:27,510 --> 00:05:30,650 tali li inti tista 'tapplika ma biss għall-korsijiet futuri fil CS 71 00:05:30,650 --> 00:05:33,670 imma biex kwalunkwe oqsma minn minn fejn int ġejjin, fl-istudji umanistiċi, 72 00:05:33,670 --> 00:05:36,090 xjenzi soċjali, naturali xjenza, jew simili. 73 00:05:36,090 --> 00:05:39,740 >> Tabilħaqq, jippermettu oħra ftit alumni u l-kollegi tagħhom 74 00:05:39,740 --> 00:05:43,400 li jkellem lill-applikabbiltà tal-qasam li jistenna. 75 00:05:43,400 --> 00:05:52,340 76 00:05:52,340 --> 00:05:57,350 >> Bill Gates: I kien 13 meta I ewwel ltqajna aċċess għall-kompjuter. 77 00:05:57,350 --> 00:06:00,485 >> JACK DORSEY: My ġenituri mixtrija me a Macintosh fl-1984 78 00:06:00,485 --> 00:06:01,640 meta I kien tmien-il sena qodma. 79 00:06:01,640 --> 00:06:02,990 >> MARKA Zuckerberg: I ​​kien fis-sitt grad. 80 00:06:02,990 --> 00:06:04,670 >> SPEAKER 1: tgħallimt għall-kodiċi fil-kulleġġ. 81 00:06:04,670 --> 00:06:09,080 >> RUCHI SANGHVI: sena Freshman, l-ewwel semestru, Intro biex Computer Science. 82 00:06:09,080 --> 00:06:11,850 >> Bill Gates: I kiteb programm li lagħbu tic tac toe. 83 00:06:11,850 --> 00:06:14,100 >> DREW HOUSTON: Naħseb li kien bidu pretty umli. 84 00:06:14,100 --> 00:06:16,370 Naħseb li l-ewwel programm I kiteb talab affarijiet simili, 85 00:06:16,370 --> 00:06:17,820 x'hemm kulur favorit tiegħek? 86 00:06:17,820 --> 00:06:18,696 Jew kemm qodma int? 87 00:06:18,696 --> 00:06:21,070 ELENA SILENOK: I-ewwel tgħallmu kif jagħmlu ċirku aħdar 88 00:06:21,070 --> 00:06:23,670 u kwadru aħmar jidhru fuq l-iskrin. 89 00:06:23,670 --> 00:06:25,420 Gabe Newell: L-ewwel time I attwalment kellu 90 00:06:25,420 --> 00:06:27,360 xi ħaġa toħroġ u jgħidu, hello, dinja. 91 00:06:27,360 --> 00:06:29,710 U jien għamel kompjuter tagħmel dan. 92 00:06:29,710 --> 00:06:30,850 Kien biss zaskakuje. 93 00:06:30,850 --> 00:06:33,224 >> MARKA Zuckerberg: Titgħallem kif għall-programm ma tibda off 94 00:06:33,224 --> 00:06:35,450 bħala li jixtiequ jitgħallmu kollha ta 'xjenza tal-kompjuter 95 00:06:35,450 --> 00:06:38,630 jew li jippruvaw kaptan dan dixxiplina jew xi ħaġa bħal dik. 96 00:06:38,630 --> 00:06:41,591 Hija biss beda off minħabba I riedu jagħmlu dan ħaġa waħda sempliċi. 97 00:06:41,591 --> 00:06:44,340 I riedu jagħmlu xi ħaġa li kien gost għalija nnifsi u aħwa tiegħi. 98 00:06:44,340 --> 00:06:46,399 >> U jien kiteb dan il-programm ftit. 99 00:06:46,399 --> 00:06:48,440 U mbagħad bażikament biss miżjud ftit lilha. 100 00:06:48,440 --> 00:06:49,930 U mbagħad meta I meħtieġa biex jitgħallmu xi ħaġa ġdida, 101 00:06:49,930 --> 00:06:52,210 Fittixt it up, jew fil ktieb jew fuq l-internet, 102 00:06:52,210 --> 00:06:53,240 u mbagħad miżjud ftit lilha. 103 00:06:53,240 --> 00:06:56,300 >> DREW HOUSTON: Huwa verament ma b'differenza daqq ta 'strument jew xi ħaġa 104 00:06:56,300 --> 00:07:00,007 jew playing sport. 105 00:07:00,007 --> 00:07:01,090 DAVID J. Malan: Kull dritt. 106 00:07:01,090 --> 00:07:04,120 Allura ejjew issa attwalment adsa ftit aktar profonda. 107 00:07:04,120 --> 00:07:07,430 Liema huma dawn l-inputs u l-outputs li aħna qed jitkellem dwar hawn? 108 00:07:07,430 --> 00:07:09,110 >> Allura kif madwar xi ħaġa sempliċi? 109 00:07:09,110 --> 00:07:12,120 You know probabbilment, anke jekk ikollok ebda familjarità ma 'xjenza tal-kompjuter 110 00:07:12,120 --> 00:07:16,570 tkun xi tkun, li l-kompjuters jużaw b'xi mod u jifhem biss żerijiet u dawk. 111 00:07:16,570 --> 00:07:20,500 Imma kif jista 'dan possibilment tingħata kif desktops ħafna tal-lum u laptops simili 112 00:07:20,500 --> 00:07:21,280 tista 'tagħmel? 113 00:07:21,280 --> 00:07:24,310 >> Il DNA tal-ġurnata, l-unika alfabett li huma jifhmu 114 00:07:24,310 --> 00:07:26,410 huwa żero jew wieħed. 115 00:07:26,410 --> 00:07:27,470 Ukoll, jikkunsidraw dan. 116 00:07:27,470 --> 00:07:30,840 Aħna, bnedmin, għandhom tendenza li jużaw l- sistema deċimali. "Diċembru" jfisser 10. 117 00:07:30,840 --> 00:07:33,970 U li 10 għaliex għandna 10 numri, 0 permezz disgħa. 118 00:07:33,970 --> 00:07:36,180 >> Issa kompjuters, b'kuntrast, għandhom tendenza li jużaw binarja. 119 00:07:36,180 --> 00:07:37,270 "Bi" jfisser żewġ. 120 00:07:37,270 --> 00:07:39,560 Allura dawn għandhom tendenza li jużaw biss żero u wieħed. 121 00:07:39,560 --> 00:07:42,680 Iżda jirriżulta, li anke biss ma 'żerijiet u dawk, li 122 00:07:42,680 --> 00:07:45,900 huwa alfabett kbira biżżejjed li biex jirrappreżentaw l-aktar 123 00:07:45,900 --> 00:07:48,490 kull biċċa ta 'data li trid, jekk huwa numru, 124 00:07:48,490 --> 00:07:52,100 jekk huwa ittra, jekk huwa grafika jew video fuq l-iskrin. 125 00:07:52,100 --> 00:07:57,140 >> Ikkunsidra, per eżempju, kif aħna bnedmin tipikament jinterpretaw dan in-numru hawnhekk. 126 00:07:57,140 --> 00:08:00,010 Dan huwa biss tlieta ċifri, wieħed, tnejn, tlieta. 127 00:08:00,010 --> 00:08:04,570 Imma nafu dan in-numru innately issa bħala 123. 128 00:08:04,570 --> 00:08:05,510 Iżda għaliex huwa li? 129 00:08:05,510 --> 00:08:07,570 >> Ukoll, jekk taħseb lura biex forsi l-iskola grad, 130 00:08:07,570 --> 00:08:11,700 inti probabilment ġew mgħallma biex jaħsbu ta ' dawn in-numri bħala li jkunu kolonni, 131 00:08:11,700 --> 00:08:14,700 fejn il-wieħed huwa fil-mijiet post, it-tnejn huwa fil-post għexieren, 132 00:08:14,700 --> 00:08:16,360 u t-tliet huwa fil-dawk post. 133 00:08:16,360 --> 00:08:17,790 Għaliex huwa li attwalment utli? 134 00:08:17,790 --> 00:08:19,665 Well, jaħsbu dwar il- aritmetika sempliċi super 135 00:08:19,665 --> 00:08:22,219 li aħna kollha kienu tagħmel għas-snin issa. 136 00:08:22,219 --> 00:08:24,510 Effettivament, jekk inti ħadthom ltqajna waħda fil-post mijiet, 137 00:08:24,510 --> 00:08:29,610 inti tagħmel l-matematika quick 100 darbiet 1 plus 10 darbiet 2-- 138 00:08:29,610 --> 00:08:33,059 għaliex tnejn huwa fl-għexieren place-- plus 1 żminijiet 3-- 139 00:08:33,059 --> 00:08:34,830 minħabba tlieta huwa fil-dawk post. 140 00:08:34,830 --> 00:08:37,039 Allura, naturalment, jekk aħna attwalment immoltiplika dan out, 141 00:08:37,039 --> 00:08:39,600 dak li aħna qed verament jirrappreżentaw ma 'dan wieħed pattern-- 142 00:08:39,600 --> 00:08:46,150 tnejn three-- huwa 100 plus 20 plus 3, li, naturalment, huwa 123. 143 00:08:46,150 --> 00:08:51,130 >> Issa binarju, u kompjuters verament, fundamentalment jitkellmu l-istess lingwa 144 00:08:51,130 --> 00:08:51,680 li nagħmlu. 145 00:08:51,680 --> 00:08:53,400 Huma biss ikollhom alfabett iżgħar. 146 00:08:53,400 --> 00:08:57,100 Allura kompjuters biss ikollhom żerijiet u dawk għad-dispożizzjoni tagħhom. 147 00:08:57,100 --> 00:09:02,500 Allura billi aħna bnedmin għandhom essenzjalment setgħat ta '10 f'kull wieħed minn dawn places-- 148 00:09:02,500 --> 00:09:06,810 10 għall-żero, 10 għall-waħda, għaxra biex it-tnejn, giving you 110 u 100 149 00:09:06,810 --> 00:09:07,700 rispettivament. 150 00:09:07,700 --> 00:09:12,140 >> Minħabba kompjuters biss għandhom żewġ valuri huma jistgħu jifhmu, żero u wieħed, 151 00:09:12,140 --> 00:09:16,600 huma għandhom jużaw valuri differenti f'dawn il-kolonni, waħda, tnejn, erbgħa. 152 00:09:16,600 --> 00:09:20,480 U jekk aħna jinżammu għaddejjin, tmienja, 16, 32, 64, u ibqa 'sejjer hekk. 153 00:09:20,480 --> 00:09:24,220 Iżda l-mudell u l- mentalità huwa eżattament l-istess. 154 00:09:24,220 --> 00:09:27,340 >> Allura billi din il-loġika, xi ħadd, kif se I tmur dwar tirrappreżenta n-numru 155 00:09:27,340 --> 00:09:28,530 wieħed binarju? 156 00:09:28,530 --> 00:09:33,080 Jekk inti stajt qatt ħsibt anke dwar dan qabel, x'hemm imsaren tiegħek jgħidu? 157 00:09:33,080 --> 00:09:33,777 >> UDJENZA: One. 158 00:09:33,777 --> 00:09:34,610 DAVID J. Malan: One. 159 00:09:34,610 --> 00:09:35,660 Eżattament. 160 00:09:35,660 --> 00:09:38,100 Aħna biss bżonn ta 'wieħed fil- dawk post minħabba l-żerijiet 161 00:09:38,100 --> 00:09:40,610 biżżejjed biex tagħtina la ta 'erba lanqas tnejn. 162 00:09:40,610 --> 00:09:42,440 Allura wieħed ħinijiet wieħed ugwali wieħed. 163 00:09:42,440 --> 00:09:43,940 Issa l-affarijiet jiksbu ftit interessanti. 164 00:09:43,940 --> 00:09:46,830 Jekk irrid jirrappreżentaw fil Binarju-numru two-- iżda, 165 00:09:46,830 --> 00:09:49,790 darb'oħra, anki jekk inti stajt qatt mitkellma din il-lingwa qabel, 166 00:09:49,790 --> 00:09:54,680 kif do we jirrappreżentaw fil binarja l-valur aħna bnedmin magħrufa bħala tnejn? 167 00:09:54,680 --> 00:09:55,570 Zero wieħed zero. 168 00:09:55,570 --> 00:09:57,620 Just tpoġġi l-wieħed fil- kolonna li inti jriduhom. 169 00:09:57,620 --> 00:09:59,560 >> Issa huwa jkollna pretty faċli probabbilment issa. 170 00:09:59,560 --> 00:10:02,950 Mela jekk jien tixtieq li jirrappreżentaw three-- m'hemm kolonna ebda tlieta tal. 171 00:10:02,950 --> 00:10:06,770 Għalhekk, għal darb'oħra, I jistgħu issa jżidu dawn il-valuri flimkien mill-tqegħid waħda hawn. 172 00:10:06,770 --> 00:10:10,320 Allura 2 darbiet 1 plus 1 ħinijiet 1 huwa, ovvjament, 3. 173 00:10:10,320 --> 00:10:13,480 >> Issa l-affarijiet jiksbu ftit gost fil li dawk issa saru żerijiet. 174 00:10:13,480 --> 00:10:15,480 U biex jirrappreżentaw erba, I nikseb dan. 175 00:10:15,480 --> 00:10:19,310 U jekk aħna inkrement bil-mod here-- li jkun ħamsa. 176 00:10:19,310 --> 00:10:20,700 Dan ikun sitta. 177 00:10:20,700 --> 00:10:22,100 Dan ikun sebgħa. 178 00:10:22,100 --> 00:10:25,310 >> Imma issa I jidhru li jkollhom run fis-problema. 179 00:10:25,310 --> 00:10:30,520 Kif jista I tmur dwar jirrappreżentaw eight-- tkun il-valur li jmiss. 180 00:10:30,520 --> 00:10:31,900 Yeah, għalhekk għandna bżonn bits ġodda. 181 00:10:31,900 --> 00:10:33,899 U, tabilħaqq, jekk inti stajt jinstemgħu din il-frażi qabel, 182 00:10:33,899 --> 00:10:37,380 bits, li jinsab biss qasir għal ċifri binarju, żero jew wieħed. 183 00:10:37,380 --> 00:10:41,520 >> U so I jiġri li jkun jirrappreżenta biss tliet bits dawn hawn. 184 00:10:41,520 --> 00:10:44,900 Imma kieku kelli mod ta 'ħażna ma tliet bits differenti, iżda erba, 185 00:10:44,900 --> 00:10:47,250 żgur I jista 'jirrappreżenta tmienja, u mbagħad disa, u mbagħad 186 00:10:47,250 --> 00:10:49,400 10, u saħansitra ogħla u ogħla. 187 00:10:49,400 --> 00:10:52,140 >> Iżda dan mbagħad jitlob in kwistjoni kif nistgħu 188 00:10:52,140 --> 00:10:54,540 go dwar jirrappreżentaw dawn affarijiet fl-ewwel post. 189 00:10:54,540 --> 00:10:56,950 Hija ħaġa waħda li tiġbed minnhom up here fuq slide, 190 00:10:56,950 --> 00:11:00,660 imma kif taħseb li jirrappreżentawhom jekk int apparat mekkaniku? 191 00:11:00,660 --> 00:11:04,390 X'inhu kompjuter jagħmlu biex jirrappreżentaw l-inputs u l-outputs li 192 00:11:04,390 --> 00:11:09,020 fundamentalment jiddefinixxu komputazzjoni fl-aħħar tal-ġurnata? 193 00:11:09,020 --> 00:11:12,090 >> Ukoll, dak dwar xi ħaġa super sempliċi bħal din? 194 00:11:12,090 --> 00:11:13,200 Huwa biss bozza tad-dawl. 195 00:11:13,200 --> 00:11:15,460 U nista jikkawżaw dan bozza tad-dawl li jmorru fuq 196 00:11:15,460 --> 00:11:17,920 billi ddawwar xi elettriku fuq u li jippermettu elettroni 197 00:11:17,920 --> 00:11:22,585 għall-fluss permezz, li tbiddel tagħha istat jew il-valur tagħha, biex ngħidu hekk. 198 00:11:22,585 --> 00:11:24,460 Per eżempju, dan huwa lampa desk iskola antika 199 00:11:24,460 --> 00:11:27,250 hawn ma 'wieħed bħal bozza tad-dawl ġewwa ta 'dan. 200 00:11:27,250 --> 00:11:29,940 U d-dritt issa huwa mhux verament tagħmel xejn utli. 201 00:11:29,940 --> 00:11:32,680 Imma malli I plagg fis socket elettriku 202 00:11:32,680 --> 00:11:36,390 u mbagħad jużaw dan switch-- jew nistgħu anke sejħa hija transistor 203 00:11:36,390 --> 00:11:39,970 jew jaħsbu bħala such-- I issa jistgħu jirrappreżentaw jew 204 00:11:39,970 --> 00:11:44,120 dan il-valur, fejn l-bozza tad-dawl ovvjament off, jew dan il-valur. 205 00:11:44,120 --> 00:11:46,060 Dan il-valur jew il dan il-valur. 206 00:11:46,060 --> 00:11:47,520 Dan il-valur u oħrajn. 207 00:11:47,520 --> 00:11:51,220 >> Allura ġewwa ta 'kompjuter, preżumibbilment, huma biċċiet ħafna iżgħar ta 'hardware, 208 00:11:51,220 --> 00:11:52,970 iżda li fl-aħħar tal-ġurnata sempliċiment għandek 209 00:11:52,970 --> 00:11:55,360 għall-użu electricity-- forsi jaqbdu it-- 210 00:11:55,360 --> 00:11:59,730 u mbagħad jew iżommu xi ħaġa fuq jew iżommu xi ħaġa off. 211 00:11:59,730 --> 00:12:02,021 Of course, dan mhuwiex partikolarment interessanti li tagħmel 212 00:12:02,021 --> 00:12:03,270 biss bi bozza tad-dawl wieħed. 213 00:12:03,270 --> 00:12:06,726 >> Fil-fatt, kif għolja tista I joqgħod fil binarja ma 'dan il-fanal desk hawn? 214 00:12:06,726 --> 00:12:07,420 >> UDJENZA: One. 215 00:12:07,420 --> 00:12:08,545 >> DAVID J. Malan: One, id-dritt? 216 00:12:08,545 --> 00:12:11,020 I bżonn aktar lampi desk jekk I fil-fatt tixtieq li jgħoddu ogħla. 217 00:12:11,020 --> 00:12:12,210 Iżda nistgħu nagħmlu aħjar minn dik. 218 00:12:12,210 --> 00:12:14,460 Minħabba li l-bozoz tad-dawl li konna jitqiegħdu fil dawn l-affarijiet 219 00:12:14,460 --> 00:12:17,730 huma bozoz tad-dawl fil-fatt fancier milli imgħoddi jippermetti. 220 00:12:17,730 --> 00:12:20,310 U dawn qed attwalment bozoz tad-dawl f'netwerk. 221 00:12:20,310 --> 00:12:23,160 U għenieqed ta 'kumpaniji tagħmel dawn l-affarijiet dawn il-jiem. 222 00:12:23,160 --> 00:12:25,190 >> Iżda jirriżulta li dan wieħed b'mod partikolari 223 00:12:25,190 --> 00:12:27,680 tiġi flimkien ma 'li biha karatteristika tista 'tbiddel kuluri tiegħu. 224 00:12:27,680 --> 00:12:30,810 Allura per eżempju, jekk inti adorned kamra dorm tiegħek 225 00:12:30,810 --> 00:12:33,200 bi ftit ta 'dawn dawl basal, jiddependi fuq il-burdata tiegħek, 226 00:12:33,200 --> 00:12:35,366 jiddependi fuq li tidħol fi, jiddependi fuq it-temp, 227 00:12:35,366 --> 00:12:37,360 jiddependi fuq il-ħin tal-ġurnata, inti tista 'attwalment 228 00:12:37,360 --> 00:12:40,300 Tibdilx il-kuluri tal- il-basal fil-kamra tiegħek. 229 00:12:40,300 --> 00:12:43,740 U dan għaliex dawn dawl basal u ohrajn bhalu jkollhom x'hemm 230 00:12:43,740 --> 00:12:48,010 imsejħa API, applikazzjoni interface programmazzjoni, li 231 00:12:48,010 --> 00:12:50,920 huwa suġġett li magħhom inti ser tkun ukoll familjari mal sa tmiem semestru tal. 232 00:12:50,920 --> 00:12:53,710 >> U dan huwa biss fancy, mod mistur ta 'tgħid, 233 00:12:53,710 --> 00:12:57,570 inti tista 'programm dawn dawl basal li jagħmlu offerti tiegħek. 234 00:12:57,570 --> 00:13:00,360 Inti tista 'tibgħathom messaġġi bħad inti, bniedem, 235 00:13:00,360 --> 00:13:03,640 tista 'tibgħat messaġġ lil web server qal, agħti lili aħbarijiet tal-lum 236 00:13:03,640 --> 00:13:05,110 jew jagħtu me email tiegħi. 237 00:13:05,110 --> 00:13:08,010 >> Tista 'tibgħat aktar arcane messaġġi għal dawn bozoz tad-dawl 238 00:13:08,010 --> 00:13:09,700 li jgħidu, dawwar fuq u itfi. 239 00:13:09,700 --> 00:13:11,370 Imma dak li mhux kollha li interessanti. 240 00:13:11,370 --> 00:13:14,280 Tista 'tgħid, jduru fuq aħmar, jduru fuq aħdar, imbagħad fuq blu, 241 00:13:14,280 --> 00:13:15,990 kollha bl-istess bozza tad-dawl. 242 00:13:15,990 --> 00:13:20,990 U inti tista 'anki, bi ftit aktar sofistikati, jgħidu, dawwar lilek innifsek għal ikħal 243 00:13:20,990 --> 00:13:24,710 meta huwa jum gloomy barra, per eżempju. 244 00:13:24,710 --> 00:13:27,910 Hija tista 'attwalment garża fis API temp u nsib 245 00:13:27,910 --> 00:13:32,260 dak l-temp huwa, jew iż-żmien tal-ġurnata, jew jqajjem oħra bħal dawn. 246 00:13:32,260 --> 00:13:35,550 >> Allura, fil-fatt, tnejn mill Membri tal-persunal stess CS50'S, 247 00:13:35,550 --> 00:13:38,827 Dan Bradley u Ansel Duff hawn, ġentilment akkwistati 248 00:13:38,827 --> 00:13:40,410 us mazz sħiħ ta 'dawn bozoz tad-dawl. 249 00:13:40,410 --> 00:13:42,910 U huma mibnija l CS50 ewwel basal qatt binarja, 250 00:13:42,910 --> 00:13:46,850 fejn konna rappreżentati here-- ma 'dawn magnets-- ftit jilgħab 251 00:13:46,850 --> 00:13:49,780 l-placeholders varji aħna allużjoni għall biss daqsxejn ilu. 252 00:13:49,780 --> 00:13:52,572 >> Allura mod fuq hawnhekk huwa l- dawk il-post, tnejn, erbgħa. 253 00:13:52,572 --> 00:13:54,030 U aħna ma tara ogħla minn dak. 254 00:13:54,030 --> 00:13:55,613 Imma, naturalment, dawn qed setgħat ta 'tnejn. 255 00:13:55,613 --> 00:13:59,490 Tmien, 16, 32, 64, u 128. 256 00:13:59,490 --> 00:14:03,320 Mela jekk jien issa tixtieq li jkun ftit fancier milli jużaw dan is-swiċċ iskola antika, 257 00:14:03,320 --> 00:14:07,310 Għandi hawn fuq dan iPad interface sempliċi super 258 00:14:07,310 --> 00:14:10,440 li Dan Bradley, ex student u issa tagħlim sħabi, 259 00:14:10,440 --> 00:14:13,510 programed jużaw xi HTML u JavaScript, li 260 00:14:13,510 --> 00:14:15,685 huma markup u l-programmazzjoni lingwi rispettivament. 261 00:14:15,685 --> 00:14:17,560 U inti tista 'probabbilment see-- anki fil-back-- 262 00:14:17,560 --> 00:14:21,670 hemm big plus u minus big, plus wieħed buttuna għal kull wieħed minn dawn il-basal. 263 00:14:21,670 --> 00:14:25,740 U dak li dan se ippermettuli do hija, per eżempju, ikklikkja l-plus 264 00:14:25,740 --> 00:14:28,250 u issa jirrappreżentaw, ta Naturalment, liema numru? 265 00:14:28,250 --> 00:14:28,750 Wieħed. 266 00:14:28,750 --> 00:14:30,220 U nista 'hit darb'oħra. 267 00:14:30,220 --> 00:14:31,480 Żewġ. 268 00:14:31,480 --> 00:14:32,800 Tliet. 269 00:14:32,800 --> 00:14:33,950 Erba. 270 00:14:33,950 --> 00:14:35,200 Ta 'ħames. 271 00:14:35,200 --> 00:14:36,360 Sitta. 272 00:14:36,360 --> 00:14:36,880 Seba. 273 00:14:36,880 --> 00:14:40,740 >> U hawn issa aħna nikseb li qlib, iżda aħna għandna r-raba 'daqsxejn dan iż-żmien, 274 00:14:40,740 --> 00:14:42,180 hekk issa għandna tmien. 275 00:14:42,180 --> 00:14:44,000 Allura aħna tista 'tagħmel dan għal żmien pjuttost twil. 276 00:14:44,000 --> 00:14:46,530 Fil-fatt, bħala twarrib, kif għoli nistgħu għadd? 277 00:14:46,530 --> 00:14:48,318 Kulħadd? 278 00:14:48,318 --> 00:14:49,270 >> UDJENZA: 255. 279 00:14:49,270 --> 00:14:51,420 >> DAVID J. Malan: 255, id-dritt? 280 00:14:51,420 --> 00:14:54,900 Tinkwetax wisq dwar il-matematika għall- issa, iżda li numru pretty deċenti. 281 00:14:54,900 --> 00:14:59,140 Iżda fil-fatt ma marbut biss kif ħafna biċċiet ta 'informazzjoni, 282 00:14:59,140 --> 00:15:01,760 bħal ittra, jew grafika li nistgħu jirrappreżentaw. 283 00:15:01,760 --> 00:15:02,697 >> Imma l-ebda kwistjoni għal issa. 284 00:15:02,697 --> 00:15:04,530 Jien ser jimxi 'l quddiem u jibdluhom kollha off. 285 00:15:04,530 --> 00:15:09,670 U jekk I jistgħu, nixtieq li jistaqsu għal voluntier, l-ewwel volunteer-- tagħna 286 00:15:09,670 --> 00:15:11,342 oh, hello-- fuq il-palk. 287 00:15:11,342 --> 00:15:14,050 Il-qabda hija li inti għandek tkun komdu jidhru, kif inti ċar 288 00:15:14,050 --> 00:15:17,421 huma fuq quddiem tal-klassi kollha tiegħek, kif ukoll fuq l-internet. 289 00:15:17,421 --> 00:15:20,420 U let me tfittex ftit lil hinn the-- kif madwar hawn fil-shirt bajda? 290 00:15:20,420 --> 00:15:20,920 U l-idejn up. 291 00:15:20,920 --> 00:15:22,071 Come fuq up. 292 00:15:22,071 --> 00:15:22,820 X'inhu l-isem tiegħek? 293 00:15:22,820 --> 00:15:23,760 >> UDJENZA: Jackie. 294 00:15:23,760 --> 00:15:24,718 >> DAVID J. Malan: Jackie. 295 00:15:24,718 --> 00:15:25,820 Jackie, come fuq up. 296 00:15:25,820 --> 00:15:29,820 Allura dak li hemm ukoll fuq dan iPad huwa buttuna imsejjaħ Game Mode. 297 00:15:29,820 --> 00:15:32,570 U dan Game Mode huwa ser ippermettuli input 298 00:15:32,570 --> 00:15:35,780 bil-quddiem ta 'informazzjoni partikolari numru, in-numri aħna bnedmin huma 299 00:15:35,780 --> 00:15:36,760 familjari magħhom. 300 00:15:36,760 --> 00:15:39,820 U allura inti ser jiġu kkontestati hawn biex tuża l-buttuni 301 00:15:39,820 --> 00:15:42,140 fuq il-wieħed top-- għall kull wieħed minn dawn bulbs-- 302 00:15:42,140 --> 00:15:45,050 li attwalment insemmu l-mudell ta 'bozoz tad-dawl 303 00:15:45,050 --> 00:15:46,970 li jirrappreżenta n-numru in kwistjoni. 304 00:15:46,970 --> 00:15:47,790 >> U jien sorry, dak li kien l-isem tiegħek mill-ġdid? 305 00:15:47,790 --> 00:15:48,250 >> UDJENZA: Jackie. 306 00:15:48,250 --> 00:15:48,620 >> DAVID J. Malan: Jackie. 307 00:15:48,620 --> 00:15:48,920 Kull dritt. 308 00:15:48,920 --> 00:15:49,740 Tajjeb li jissodisfaw inti. 309 00:15:49,740 --> 00:15:54,580 >> So let me go quddiem u programm għad-dinja biex tara d-numru 15. 310 00:15:54,580 --> 00:15:56,360 Aħna ser jżommha żgħir fl-ewwel hawn. 311 00:15:56,360 --> 00:15:58,240 U jien se jmorru fil Game Mode. 312 00:15:58,240 --> 00:16:01,160 U jien ser jispeċifikaw, tagħtina l-numru 15. 313 00:16:01,160 --> 00:16:01,900 >> OK. 314 00:16:01,900 --> 00:16:05,510 U issa ma 'kulħadd watching-- jekk inti tixtieq li forsi toqgħod b'dan il-mod, 315 00:16:05,510 --> 00:16:09,970 minħabba li se line up-- jimxi 'l quddiem u toggle-tmien buttuni tul il-quċċata 316 00:16:09,970 --> 00:16:12,530 biex inbiddlu l-basal fuq jew off kif tara xieraq. 317 00:16:12,530 --> 00:16:13,530 >> UDJENZA: OK. 318 00:16:13,530 --> 00:16:17,720 >> DAVID J. Malan: U l-ebda qerq billi jolqot plus 15 darbiet. 319 00:16:17,720 --> 00:16:19,275 Oh, aħna se tagħmel dan. 320 00:16:19,275 --> 00:16:20,069 >> UDJENZA: Oh, stenna. 321 00:16:20,069 --> 00:16:20,610 Jien hekk sorry. 322 00:16:20,610 --> 00:16:22,660 >> DAVID J. Malan: Tista 'wkoll dawran l-bozoz tad-dawl fuq individwalment 323 00:16:22,660 --> 00:16:24,076 ma kull wieħed minn dawn buttuni fuq nett. 324 00:16:24,076 --> 00:16:24,844 UDJENZA: Oh, OK. 325 00:16:24,844 --> 00:16:27,429 Għalhekk ikun like-- 326 00:16:27,429 --> 00:16:28,220 DAVID J. Malan: OK. 327 00:16:28,220 --> 00:16:29,100 Allura issa għandna tmien. 328 00:16:29,100 --> 00:16:31,280 Mela ejja nieqaf għall- udjenza li jidħlu hawn. 329 00:16:31,280 --> 00:16:34,300 Dak in-numru huwa Jackie li bħalissa jirrappreżentaw? 330 00:16:34,300 --> 00:16:34,800 11. 331 00:16:34,800 --> 00:16:35,730 Allura aħna qed kważi hemm. 332 00:16:35,730 --> 00:16:38,360 333 00:16:38,360 --> 00:16:39,630 U eċċellenti. 334 00:16:39,630 --> 00:16:41,487 Allura aħna għandna l-ewwel rebbieħ tagħna. 335 00:16:41,487 --> 00:16:42,445 Prosit. 336 00:16:42,445 --> 00:16:48,200 >> U ħsibna aħna'd jkollhom xi jingħataw b'xejn fabulous. 337 00:16:48,200 --> 00:16:50,860 Jekk inti tixtieq li jkun wieħed tali dorm kamra hawn fuq il-kampus, 338 00:16:50,860 --> 00:16:56,126 inti tista yourself għandek proġett finali jużaw issa dan API, grazzi għall Jackie. 339 00:16:56,126 --> 00:16:57,050 Allura now-- 340 00:16:57,050 --> 00:16:58,902 >> [Applause] 341 00:16:58,902 --> 00:17:01,690 342 00:17:01,690 --> 00:17:04,839 >> --if nistgħu, wieħed aktar bħal madwar ta 'dan. 343 00:17:04,839 --> 00:17:07,690 Oh, issa kulħadd jixtieq xi bozoz tad-dawl. 344 00:17:07,690 --> 00:17:11,790 Għall-hekk imsejħa edizzjoni Hacker, aħna qed tmur biex jirranka it up a-- oh, 345 00:17:11,790 --> 00:17:12,770 yeah, ma tikkommettix ruħha. 346 00:17:12,770 --> 00:17:16,010 I think int ġejjin up issa jekk idek għaddej isfel. 347 00:17:16,010 --> 00:17:16,800 X'inhu l-isem tiegħek? 348 00:17:16,800 --> 00:17:17,424 >> UDJENZA: Alex. 349 00:17:17,424 --> 00:17:19,440 DAVID J. Malan: Alex, come fuq matul hawn. 350 00:17:19,440 --> 00:17:26,190 Allura għal Alex, aħna ser programm f'għadd ftit akbar. 351 00:17:26,190 --> 00:17:27,790 Forsi fl-ordni. 352 00:17:27,790 --> 00:17:29,110 In-numru 50. 353 00:17:29,110 --> 00:17:29,744 >> UDJENZA: OK. 354 00:17:29,744 --> 00:17:31,660 DAVID J. Malan: Iżda, kif I said-- u inti tista ' 355 00:17:31,660 --> 00:17:33,580 tixtieq li toqgħod hawn hekk li l-buttuni linja up 356 00:17:33,580 --> 00:17:37,115 kif inti expect-- imma jien ma sejħa dan il-Hacker edizzjoni. 357 00:17:37,115 --> 00:17:47,125 Xorti tajba So--! 358 00:17:47,125 --> 00:17:48,416 >> [Rires] 359 00:17:48,416 --> 00:17:58,570 360 00:17:58,570 --> 00:18:02,050 >> Inti se tkun kapaċi li jduru lilhom off jekk you-- OK. 361 00:18:02,050 --> 00:18:02,880 Eċċellenti. 362 00:18:02,880 --> 00:18:03,675 Wonderful. 363 00:18:03,675 --> 00:18:04,341 Prosit. 364 00:18:04,341 --> 00:18:08,730 >> [Applause] 365 00:18:08,730 --> 00:18:10,355 I suppose I għandhom iħallsu up. 366 00:18:10,355 --> 00:18:11,830 Prosit lil Alex ukoll. 367 00:18:11,830 --> 00:18:12,330 OK. 368 00:18:12,330 --> 00:18:15,550 >> Allura l-takeaway aħħari hawnhekk huwa wieħed jittama, franchement, 369 00:18:15,550 --> 00:18:18,109 l simplicity-- l sempliċità magħhom 370 00:18:18,109 --> 00:18:20,650 inti tista 'tikseb xi dawl sbieħ basal, apparentament [inaudible]. 371 00:18:20,650 --> 00:18:23,000 Iżda huma jirrappreżentaw, finalment, l-istess ideat 372 00:18:23,000 --> 00:18:26,310 li magħhom aħna bnedmin huma diġà wisq familjari. 373 00:18:26,310 --> 00:18:28,660 Allura dak li jista 'l-jmiss pass 'jkun fil-progressjoni 374 00:18:28,660 --> 00:18:30,920 ta 'tipprova tagħmel xi ħaġa interessanti ma 'data 375 00:18:30,920 --> 00:18:34,950 u li jirrappreżentaw inputs li huma mhux biss numri iżda huma forsi ittri jew aktar? 376 00:18:34,950 --> 00:18:37,820 >> Ukoll, jirriżulta li l- dinja tal-kompjuter, għal bosta snin, 377 00:18:37,820 --> 00:18:43,300 sempliċiment adotta arbitrarja iżda standard konsistenti li l-mapep numri 378 00:18:43,300 --> 00:18:44,610 għall-ittri tal-alfabett. 379 00:18:44,610 --> 00:18:47,120 Per eżempju, hawnhekk hija silta minn dak mapping. 380 00:18:47,120 --> 00:18:48,350 Huwa sejjaħ ASCII. 381 00:18:48,350 --> 00:18:53,220 A-S-C-I-I. U li hija sempliċement tabella li mapep letters-- uppercase 382 00:18:53,220 --> 00:18:56,600 f'dan case-- biex Deċimali numri. 383 00:18:56,600 --> 00:18:57,890 >> Imma x'inhu l-implikazzjoni? 384 00:18:57,890 --> 00:19:01,090 Ukoll, jekk inti fil-fatt tixtieq li jirrappreżentaw xi ħaġa simili email jew xi test 385 00:19:01,090 --> 00:19:03,310 fuq paġna web, inti ovvjament tixtieq li juru 386 00:19:03,310 --> 00:19:06,100 l-ittri tal-bniedem tal- alfabett, mhux in-numri. 387 00:19:06,100 --> 00:19:09,140 Allura jiddependi fuq il- kuntest tal-programm 388 00:19:09,140 --> 00:19:12,600 li utent qed tuża, jekk huwa web browser jew klijent email, 389 00:19:12,600 --> 00:19:16,090 numri jista 'ċertament tkun interpretata bħala ittri. 390 00:19:16,090 --> 00:19:20,290 Jiġifieri, mudelli ta 'bits jistgħu faċilment jiġi interpretat bħala ittri. 391 00:19:20,290 --> 00:19:24,700 >> U hekk dak li nistgħu jkollhom hija l-ittra A benesseri 392 00:19:24,700 --> 00:19:28,410 rappreżentati kif 65, B li jkunu rrappreżentati bħala 66. 393 00:19:28,410 --> 00:19:30,900 Mela jekk għandna super kelma qasir, bħall hi, 394 00:19:30,900 --> 00:19:35,740 dak kompjuter kieku finalment jaħżen fil deċimali imma verament fl binarju, 395 00:19:35,740 --> 00:19:40,070 jużaw xi sekwenza ta 'bits, lieva daqsxejn ta 'elettriku b'xi mod, 396 00:19:40,070 --> 00:19:44,010 tkun l-żewġ numri 72 u 73. 397 00:19:44,010 --> 00:19:46,780 >> Iżda l-mudell ta 'bits li jirrappreżenta dawk il-valuri. 398 00:19:46,780 --> 00:19:49,820 Allura dawn imbagħad huma kif nistgħu jirrappreżentaw inputs tagħna u l-outputs. 399 00:19:49,820 --> 00:19:52,630 U huwa biżżejjed li jingħad, nistgħu do rappreżentazzjonijiet aktar kumplessi 400 00:19:52,630 --> 00:19:56,450 finalment ma 'affarijiet bħal grafika, videos, mużika, u aktar 401 00:19:56,450 --> 00:19:58,190 kif aħna ser tara aktar tard dan it-terminu. 402 00:19:58,190 --> 00:20:00,630 >> Allura li biss tħalli mbagħad algoritmi, dawn is-settijiet 403 00:20:00,630 --> 00:20:03,490 ta 'struzzjonijiet li magħhom aħna qed jissolvew problemi attwali. 404 00:20:03,490 --> 00:20:05,820 Aħna qed tgħaddi fl inputs għall algoritmi. 405 00:20:05,820 --> 00:20:09,630 U dawk algoritmi qed jipproduċu outputs, l-outputs nisperaw korretta 406 00:20:09,630 --> 00:20:14,160 u wieħed jittama, wisq, effiċjenti outputs miġbura. 407 00:20:14,160 --> 00:20:16,890 Fi kliem ieħor, huwa ħaġa waħda biex jimplimentaw xi ħaġa korrett. 408 00:20:16,890 --> 00:20:20,790 Hija ħaġa oħra li jimplimentaw xi ħaġa sew jew b'mod effiċjenti. 409 00:20:20,790 --> 00:20:23,690 >> Per eżempju, dimostrazzjoni wieħed li aħna qed fond ta 'fil-kors 410 00:20:23,690 --> 00:20:24,460 huwa dan wieħed. 411 00:20:24,460 --> 00:20:26,345 Imma dawn l-affarijiet huma jkollna dejjem aktar diffiċli li ssib. 412 00:20:26,345 --> 00:20:28,930 Iżda dan huwa tabilħaqq iskola antika ktieb tat-telefon, ġewwa li minnhom 413 00:20:28,930 --> 00:20:32,580 huma 1,000 paġni plus ta ' ismijiet u numri tat-telefon. 414 00:20:32,580 --> 00:20:34,830 U jekk jien ridt li tfittex up xi ħadd f'dan il-ktieb tat-telefon, 415 00:20:34,830 --> 00:20:38,640 I tista 'sempliċiment tagħmel algoritmu naive ħafna. 416 00:20:38,640 --> 00:20:42,150 I jistgħu jiftħu l-ewwel paġna, u I tista 'tibda biex tfittex, ngħidu aħna, xi ħadd 417 00:20:42,150 --> 00:20:43,130 jismu Mike Smith. 418 00:20:43,130 --> 00:20:46,160 U jekk huwa ma fuq l-ewwel paġna, I-progress għat-tieni, 419 00:20:46,160 --> 00:20:49,120 u mbagħad it-tielet, u mbagħad għar-raba ', u oħrajn, 420 00:20:49,120 --> 00:20:51,430 sal I finalment issib Mike Smith. 421 00:20:51,430 --> 00:20:53,010 >> Issa huwa li algorithm korretta? 422 00:20:53,010 --> 00:20:53,896 >> UDJENZA: Iva. 423 00:20:53,896 --> 00:20:54,248 >> DAVID J. Malan: Yeah. 424 00:20:54,248 --> 00:20:56,039 Jekk hu fil hemm, I ser eventwalment issib lilu. 425 00:20:56,039 --> 00:20:58,820 Iżda huwa forsi mhux ħafna effiċjenti, ċertament mhux mgħaġġel, 426 00:20:58,820 --> 00:21:01,200 għaliex, my god, għaliex jien ħela flipping ħin tiegħi 427 00:21:01,200 --> 00:21:04,500 kollha permezz ta 'dawn il-paġni meta I jistgħu ċertament tagħmel dan fiżikament aktar mgħaġġel? 428 00:21:04,500 --> 00:21:08,210 >> Well, ottimizzazzjoni żgħir, hekk li jitkellmu, jista 'jkun ma wieħed page fi żmien, 429 00:21:08,210 --> 00:21:11,610 iżda tnejn, erba, sitta, tmienja, 10. 430 00:21:11,610 --> 00:21:12,725 Still korretta? 431 00:21:12,725 --> 00:21:14,030 >> UDJENZA: No 432 00:21:14,030 --> 00:21:17,040 >> DAVID J. Malan: Allura l-ebda jekk I għal Pereżempju skip fuq Mike Smith. 433 00:21:17,040 --> 00:21:20,530 Iżda sakemm I back pedala paġna waħda, jekk I jaqbżu lilu, 434 00:21:20,530 --> 00:21:25,240 forsi nistgħu jikkoreġu dak inkella jistgħu jkunu gotcha. 435 00:21:25,240 --> 00:21:26,020 >> Iżda huwa aħjar? 436 00:21:26,020 --> 00:21:27,469 Huwa aktar mgħaġġel? 437 00:21:27,469 --> 00:21:28,010 I mean, yeah. 438 00:21:28,010 --> 00:21:30,950 Huwa litteralment darbtejn aktar malajr jekk I do żewġ paġni kull darba. 439 00:21:30,950 --> 00:21:35,720 Mela jekk jien oriġinarjament kien 1,000 paġni, issa I biss għandek flip 500 darba, 440 00:21:35,720 --> 00:21:39,429 mhumiex kompletament 1,000 paġni li tikseb potenzjalment fl-agħar każ 441 00:21:39,429 --> 00:21:41,220 sa l-aħħar tat-telefon ktieb, fejn xi ħadd 442 00:21:41,220 --> 00:21:44,380 bħall Mike Smith jew xi ħadd ma ' isem aktar tard jistgħu attwalment ikunu. 443 00:21:44,380 --> 00:21:46,540 >> Imma, naturalment, aħna bnedmin ċertament mhumiex 444 00:21:46,540 --> 00:21:49,250 se tkun qed twettaq dan, ċertament mhux fil dan il-punt fil-ħajja tagħna. 445 00:21:49,250 --> 00:21:51,454 X'inhu raġonevoli bniedem probabbli se jagħmlu? 446 00:21:51,454 --> 00:21:52,870 UDJENZA: Mur dritti għal The9 tal S. 447 00:21:52,870 --> 00:21:53,860 DAVID J. Malan: Mur dritti għall-tal-S? 448 00:21:53,860 --> 00:21:55,563 Kif nista go straight għall-tal-S? 449 00:21:55,563 --> 00:21:57,342 >> UDJENZA: RIP min-nofs. 450 00:21:57,342 --> 00:21:59,050 DAVID J. Malan: Well, hemm l-ebda mmarkar. 451 00:21:59,050 --> 00:22:02,116 Allura, iva, jekk kien hemm tabilħaqq tikketta jew tab twaħħal għall S, 452 00:22:02,116 --> 00:22:03,240 għandna jaqbżu hemm dritt. 453 00:22:03,240 --> 00:22:05,420 Iżda huwa pjuttost innokwa. 454 00:22:05,420 --> 00:22:08,480 Allura l-aħjar I tista 'tagħmel huwa bejn wieħed u ieħor għat-taqsima S jew forsi bejn wieħed u ieħor 455 00:22:08,480 --> 00:22:09,650 fis-nofs. 456 00:22:09,650 --> 00:22:12,110 Iżda l-takeaway ċavetta now-- u l-intuwizzjoni 457 00:22:12,110 --> 00:22:14,430 li inti ħadt għall mogħtija għas-snin probably-- 458 00:22:14,430 --> 00:22:17,103 hija li dak do you issa jafu dwar din il-problema? 459 00:22:17,103 --> 00:22:19,320 >> UDJENZA: [inaudible] 460 00:22:19,320 --> 00:22:22,290 >> DAVID J. Malan: Mike Smith huwa żgur mhux Din it-taqsima tal-problema 461 00:22:22,290 --> 00:22:25,600 għax Smith jiġi wara l-nofs li huwa bejn wieħed u ieħor it-taqsima M, 462 00:22:25,600 --> 00:22:26,510 jidher li jkun. 463 00:22:26,510 --> 00:22:30,340 Allura kif inti tista raw fil Visitas, nistgħu issa litteralment 464 00:22:30,340 --> 00:22:31,737 tiċrita din il-problema fil nofs. 465 00:22:31,737 --> 00:22:32,320 UDJENZA: Woo! 466 00:22:32,320 --> 00:22:33,690 DAVID J. Malan: Huwa jkollna aktar faċli u aktar faċli. 467 00:22:33,690 --> 00:22:34,666 [Applause] 468 00:22:34,666 --> 00:22:36,618 Hemm inti tmur. 469 00:22:36,618 --> 00:22:39,060 [Rires] 470 00:22:39,060 --> 00:22:41,870 U issa I fundamentalment jkollhom l-istess problema, 471 00:22:41,870 --> 00:22:43,866 imma hija litteralment nofs bħala kbar. 472 00:22:43,866 --> 00:22:45,240 Jien xorta tfittex Mike Smith. 473 00:22:45,240 --> 00:22:47,950 And I daresay, I xorta jistgħu tfittex għalih bl-istess mod, 474 00:22:47,950 --> 00:22:51,200 qsim il-problema fil nofs darb'oħra, dmugħ il-problema mill-ġdid 475 00:22:51,200 --> 00:22:54,140 fil nofs, li issa tħalli lili ma problema kwart tad-daqs, 476 00:22:54,140 --> 00:22:58,710 drammatiku tarmi li nofs bogħod, u irrepeti dan il-proċess ġdid u għal darb'oħra 477 00:22:58,710 --> 00:23:01,150 u għal darb'oħra, glancing stabbiliti f'kull punt biex tara 478 00:23:01,150 --> 00:23:03,400 jekk Mike Smith huwa fuq il-paġna in kwistjoni. 479 00:23:03,400 --> 00:23:06,190 >> Issa jekk I tagħmel dan id-dritt, finalment I ser issib myself 480 00:23:06,190 --> 00:23:11,085 mal biss paġna waħda li fuqha Mike Smith hija jekk hu tabilħaqq fil-ktieb tat-telefon. 481 00:23:11,085 --> 00:23:13,510 Of course, I jistgħu qatt sejħa Mike darb'oħra. 482 00:23:13,510 --> 00:23:18,800 Iżda l-punt hawnhekk hija li jekk bdejna 1,000 paġni, l-ewwel algoritmu tiegħi, 483 00:23:18,800 --> 00:23:21,620 flip-paġna, forsi 1,000 times-- definittivament inqas għaliex dan huwa 484 00:23:21,620 --> 00:23:26,430 isem S u mhux isem Z, iżda bħala ħafna bħala 1,000 paġni potenzjalment. 485 00:23:26,430 --> 00:23:27,590 >> It-tieni algoritmu, aħjar. 486 00:23:27,590 --> 00:23:28,480 500 paġni. 487 00:23:28,480 --> 00:23:31,230 It-tielet algoritmu, għalkemm, kemm passi ikun jidher 488 00:23:31,230 --> 00:23:35,520 jieħdu biex jaqsam paġna 1,000 ktieb tat-telefon fil nofs bħal dik? 489 00:23:35,520 --> 00:23:37,000 10, jagħtu jew jieħu. 490 00:23:37,000 --> 00:23:40,770 Allura biss mill flipping permezz ta 'dak ktieb tat-telefon, l-għadis u conquering, 491 00:23:40,770 --> 00:23:46,130 biex ngħidu hekk, 10 darbiet, se nagħmel tiegħi mod isfel sa wieħed biss paġna waħda. 492 00:23:46,130 --> 00:23:48,880 >> U hekk aħna tista 'qbid dan intwizzjoni issa ftit grafikament 493 00:23:48,880 --> 00:23:51,320 jekk inti biss tikkunsidra din il-graff super sempliċi. 494 00:23:51,320 --> 00:23:55,470 Aħna fuq l-assi-x, jew orizzontali assi, huwa d-daqs tal-problema tiegħi, 495 00:23:55,470 --> 00:23:57,100 l-għadd ta 'paġni fil-ktieb tat-telefon. 496 00:23:57,100 --> 00:23:59,040 U xjenzjati tal-kompjuter ġeneralment simili għal sejħa 497 00:23:59,040 --> 00:24:02,180 -daqs ta 'n problema, fejn n huwa biss ftit varjabbli li 498 00:24:02,180 --> 00:24:04,310 represents-- f'dan case-- numru ta 'paġni. 499 00:24:04,310 --> 00:24:07,412 >> Il vertikali, jew y-axis, hawnhekk huwa se jkun il-ħin biex issolvi, 500 00:24:07,412 --> 00:24:09,870 forsi l-għadd ta 'dawriet paġna, forsi l-għadd ta 'sekonda 501 00:24:09,870 --> 00:24:11,960 jew minuti, ikun xi unità tiegħek ta 'miżura huwa. 502 00:24:11,960 --> 00:24:14,337 U hekk din il-linja ħamra tirrappreżenta l-ewwel algoritmu, 503 00:24:14,337 --> 00:24:16,670 għaliex hemm 00:59 relazzjoni bejn numru 504 00:24:16,670 --> 00:24:18,880 ta 'paġni u l-ammont ta' ħin li tieħu. 505 00:24:18,880 --> 00:24:22,240 >> Jekk Verizon jirdoppja l-għadd ta ' paġni fil-ktieb tat-telefon sena d-dieħla, 506 00:24:22,240 --> 00:24:24,590 running tiegħi time-- il ħin meħtieġ biex tesegwixxi 507 00:24:24,590 --> 00:24:27,610 li l-ewwel algorithm-- jirdoppja fl-agħar każ. 508 00:24:27,610 --> 00:24:30,690 Iżda t-tieni algoritmu, fejn jien flipping permezz tnejn, 509 00:24:30,690 --> 00:24:33,650 teħtieġ inqas ħin għall- problema daqs partikolari. 510 00:24:33,650 --> 00:24:36,090 Mela jekk ikolli dan ħafna avviż paġni here-- 511 00:24:36,090 --> 00:24:38,870 li l-linja isfar jissuġġerixxi inqas ħin biex issolvi. 512 00:24:38,870 --> 00:24:42,490 U fil-fatt, dan jirrappreżenta, aħna ser ngħidu, n matul tnejn. 513 00:24:42,490 --> 00:24:47,717 >> Imma x'inhu l-forma tat-tielet u l-kurva finali li jmur għand look like? 514 00:24:47,717 --> 00:24:50,800 Yeah, huwa tabilħaqq għaddej biex look-- I ma nafx dak li inti kienu se ngħid. 515 00:24:50,800 --> 00:24:52,300 Imma ejja ara dak inti kienu se ngħid. 516 00:24:52,300 --> 00:24:53,280 >> UDJENZA: Bħall dik. 517 00:24:53,280 --> 00:24:57,060 >> DAVID J. Malan: Huwa ser look like dan, exactly-- slope-- logaritmika 518 00:24:57,060 --> 00:24:59,770 fejn inti għandek din l-inklinazzjoni kurjuż. 519 00:24:59,770 --> 00:25:01,235 Huwa m'għadux linja dritta. 520 00:25:01,235 --> 00:25:05,000 U x'hemm konvinċenti dwar dan hija li anki jekk il-graff issa tiġi maqtugħa, 521 00:25:05,000 --> 00:25:07,790 inti tista estrapolati fil tiegħek f'moħħu li dik il-linja ħadra mhux 522 00:25:07,790 --> 00:25:10,060 ser iżżid fil għoli kollha li ħafna 523 00:25:10,060 --> 00:25:13,500 kif inti jipproċedi iżjed stabbilit li assi orizzontali. 524 00:25:13,500 --> 00:25:15,890 >> Tabilħaqq, Verizon, għal Pereżempju, jista 'jirdoppja 525 00:25:15,890 --> 00:25:19,100 l-għadd ta 'paġni fil-phone ktieb bejn din is-sena u s-sena d-dieħla 526 00:25:19,100 --> 00:25:22,140 minn 1,000 sa l-2000 paġni, iżda l-ebda big deal. 527 00:25:22,140 --> 00:25:24,960 Ma 'din it-tielet u finali, hemm algoritmu intuwittivi 528 00:25:24,960 --> 00:25:26,209 ta 'diviżjoni u conquering. 529 00:25:26,209 --> 00:25:29,000 Huwa ser jieħu me kif ħafna aktar passi sena d-dieħla biex issib xi ħadd 530 00:25:29,000 --> 00:25:29,700 simili Mike Smith? 531 00:25:29,700 --> 00:25:30,560 >> UDJENZA: One. 532 00:25:30,560 --> 00:25:31,230 >> DAVID J. Malan: Hemm wieħed biss. 533 00:25:31,230 --> 00:25:34,430 U jistgħu jikkwadrupla dan, huwa ser tieħu me biss żewġ passi aktar 534 00:25:34,430 --> 00:25:35,210 u ibqa 'sejjer hekk. 535 00:25:35,210 --> 00:25:38,730 U hekk dan huwa xhieda li kemm xi disinn bir-reqqa 536 00:25:38,730 --> 00:25:42,437 u xi apprezzament għal dak inputs tiegħek huma jistgħu jagħmlu saħansitra aħjar. 537 00:25:42,437 --> 00:25:44,270 Issa aħna qed qerq a ftit fis-sens 538 00:25:44,270 --> 00:25:46,350 li aħna qed jitqawwa suppożizzjoni. 539 00:25:46,350 --> 00:25:48,500 X'inhu suppożizzjoni tiegħi dwar il-ktieb tat-telefon tagħna 540 00:25:48,500 --> 00:25:52,720 li permessi me li jaqsam u jirbħu b'dan il-mod intuwittivi u għadhom korretta? 541 00:25:52,720 --> 00:25:53,705 >> UDJENZA: [inaudible] 542 00:25:53,705 --> 00:25:54,580 DAVID J. Malan: Yeah. 543 00:25:54,580 --> 00:25:55,440 Għalhekk ġiet ordnata. 544 00:25:55,440 --> 00:25:57,392 Kien alphabetized mill il-kumpanija ktieb tat-telefon. 545 00:25:57,392 --> 00:26:00,100 Kieku kien sabiex każwali, li tkun enfer ta 'ktieb tat-telefon, 546 00:26:00,100 --> 00:26:02,850 iżda ċertament mhux se jsellef ruħha li l-algoritmu 547 00:26:02,850 --> 00:26:05,950 I użati, għaliex inti qatt ma biss jiġri madwar Mike Smith 548 00:26:05,950 --> 00:26:09,210 jekk inti tinżamm diviż fi nofs b'dan il-mod b'kumbinazzjoni. 549 00:26:09,210 --> 00:26:12,060 >> Mela ejja issa jifformalizzaw x'hemm b'mod ċar intuwittivi. 550 00:26:12,060 --> 00:26:13,950 Allura xi ħaġa imsejħa pseudocode huwa fejn aħna ser 551 00:26:13,950 --> 00:26:15,780 tibda xi wħud mill-problemi inizjali tagħna. 552 00:26:15,780 --> 00:26:20,410 U dan huwa mod ġeneriku ta jiddeskrivu algoritmu jew programm tal-kompjuter, 553 00:26:20,410 --> 00:26:24,150 ma jużawx C, jew C ++ jew Java, jew kwalunkwe lingwa speċifika, 554 00:26:24,150 --> 00:26:27,430 iżda biss bl-użu Ingliż, bil li kwalunkwe bniedem jista 'jkun familjari. 555 00:26:27,430 --> 00:26:31,220 >> U nistgħu jiktbu l pseudocode għal din il-problema kif ġej. 556 00:26:31,220 --> 00:26:33,520 Pass wieħed, aqbad il-ktieb tat-telefon. 557 00:26:33,520 --> 00:26:35,840 Pass tnejn, miftuħa għall nofs ta 'ktieb tat-telefon. 558 00:26:35,840 --> 00:26:37,730 Pass tlieta, tħares lejn l-ismijiet. 559 00:26:37,730 --> 00:26:40,630 Pass erba, jekk Smith hija fost names-- 560 00:26:40,630 --> 00:26:42,960 >> U issa dan huwa jibnu interessanti. 561 00:26:42,960 --> 00:26:44,290 Huwa punt ta 'deċiżjoni. 562 00:26:44,290 --> 00:26:47,920 Huwa furketta fit-triq, jekk inti se, fergħa, biex ngħidu hekk. 563 00:26:47,920 --> 00:26:50,810 So jien ser-inċiż biss billi konvenzjoni step-- 564 00:26:50,810 --> 00:26:53,950 mhux five-- li huwa li jiġifieri, I ser sejħa Mike. 565 00:26:53,950 --> 00:26:57,290 Allura dan indentazzjoni, totalment konvenzjoni bniedem arbitrarja, imma hija 566 00:26:57,290 --> 00:27:01,160 sempliċiment maħsuba biex twassal semantikament li jekk Smith hija fost ismijiet, 567 00:27:01,160 --> 00:27:03,310 imbagħad I għandhom sejħa Mike. 568 00:27:03,310 --> 00:27:06,630 >> Sadanittant fil-pass sitt, avviż li l-indentazzjoni marret. 569 00:27:06,630 --> 00:27:10,980 Allura inkella huwa l-furketta ieħor fil- triq, it-triq l-oħra I tista 'tivvjaġġa. 570 00:27:10,980 --> 00:27:14,130 Mela inkella jekk Smith huwa aktar kmieni fil-ktieb, x'hemm 571 00:27:14,130 --> 00:27:16,964 pass li jmiss tiegħi probabbilment se jkun hawn? 572 00:27:16,964 --> 00:27:18,380 UDJENZA: Inti tmur għall-naħa tax-xellug. 573 00:27:18,380 --> 00:27:21,004 DAVID J. Malan: Yeah, hekk mur in-nofs xellugi tal-ktieb tat-telefon. 574 00:27:21,004 --> 00:27:24,140 Armi l nofs tal-lemin jekk Smith huwa kmieni fil-ktieb. 575 00:27:24,140 --> 00:27:27,140 Allura miftuħa għall-nofs ta ' in-nofs xellugi tal-ktieb. 576 00:27:27,140 --> 00:27:30,240 >> U mbagħad pass tmienja, mur għal-linja tlieta. 577 00:27:30,240 --> 00:27:34,520 U dan huwa loop kurjuż jien jinduċu, a recursion biex ngħidu hekk. 578 00:27:34,520 --> 00:27:35,990 Iżda aktar fuq li fil-futur. 579 00:27:35,990 --> 00:27:39,590 >> Jien jużaw istess algoritmu tiegħi, istess pseudocode tiegħi, 580 00:27:39,590 --> 00:27:43,020 biex isolvu l-istess problema mill-ġdid minħabba li l-unika ħaġa li biddel 581 00:27:43,020 --> 00:27:46,550 huwa d-daqs tal-problema, mhux għan tiegħi, u mhux il-persuna 582 00:27:46,550 --> 00:27:47,340 I infittex. 583 00:27:47,340 --> 00:27:51,610 So I tista 'użu mill-ġdid l-algoritmu li stajt diġà definiti. 584 00:27:51,610 --> 00:27:53,580 >> Else jekk Smith ikun aktar tard fil book-- inti tista 585 00:27:53,580 --> 00:27:56,200 guess-- miftuħa għall-nofs ta ' il-nofs tal-lemin tal-ktieb. 586 00:27:56,200 --> 00:27:58,350 U għal darb'oħra, mur għal-linja tlieta. 587 00:27:58,350 --> 00:28:01,480 Else-- x'inhu l-linja finali f'dan il-programm se jkun? 588 00:28:01,480 --> 00:28:03,580 Jekk huwa ma fost il- ismijiet fuq il-paġna jien 589 00:28:03,580 --> 00:28:06,870 fuq, jekk huwa ma kmieni fil il-ktieb, u hu mhux aktar tard 590 00:28:06,870 --> 00:28:09,899 fil-ktieb, liema do I know huwa veru dwar Mike Smith issa? 591 00:28:09,899 --> 00:28:11,190 UDJENZA: He mhux fil-ktieb. 592 00:28:11,190 --> 00:28:12,731 DAVID J. Malan: He mhux fil-ktieb. 593 00:28:12,731 --> 00:28:16,040 Allura l-aħjar I tista 'tagħmel huwa biss jċedu u jieqfu dan il-programm. 594 00:28:16,040 --> 00:28:16,540 Kull dritt. 595 00:28:16,540 --> 00:28:20,350 Allura f'dan il-punt, ejja tagħti tour malajr ta 'xi wħud mill dak li jistenna. 596 00:28:20,350 --> 00:28:23,620 U fil-fatt, jien ssieħbu hawn minn numru ta 'staff CS50. 597 00:28:23,620 --> 00:28:26,940 Jekk dawn folks jistgħu kollha jissieħbu me up here fuq il-palk. 598 00:28:26,940 --> 00:28:28,900 >> [Applause] 599 00:28:28,900 --> 00:28:35,280 600 00:28:35,280 --> 00:28:38,170 >> Mind you, dan huwa biss subsett ta 'staff CS50, 601 00:28:38,170 --> 00:28:42,380 peress li kull sena għandna kważi 100 staff membri fl-irwoli ta 'l-assistenti kors, 602 00:28:42,380 --> 00:28:44,410 tagħlim fellows, u aktar. 603 00:28:44,410 --> 00:28:45,700 Come fuq up. 604 00:28:45,700 --> 00:28:48,820 Allura dawn se jingħaqdu magħna hawn awkwardly għal ftit mument 605 00:28:48,820 --> 00:28:54,230 kif aħna tagħti tour whirlwind ta 'dak għandek tistenna hawn fil-kors. 606 00:28:54,230 --> 00:28:59,640 >> Allura l-ewwel u qabel kollox, għandna SAT / UNS bħala l-għażla gradazzjoni fil-kors. 607 00:28:59,640 --> 00:29:03,180 Dan huwa maħsub deliberatament li tkun għażla li biha 608 00:29:03,180 --> 00:29:05,570 jekk inti daqsxejn inċerti li tkun fil-kors, 609 00:29:05,570 --> 00:29:09,390 u inti tibża failure-- anki jekk franchement nuqqas ifisser jolqtu ħażin GPA tiegħek, 610 00:29:09,390 --> 00:29:13,180 jkollna B u mhux A-- li hija preċiżament dak, ċertament għal portal 611 00:29:13,180 --> 00:29:15,750 kors bħal CS50 u oħrajn korsijiet ta 'introduzzjoni, 612 00:29:15,750 --> 00:29:17,540 din l-għażla gradazzjoni hija maħsuba biex jippermettu. 613 00:29:17,540 --> 00:29:19,930 >> I helhjärtat jinkoraġġixxu students-- speċjalment 614 00:29:19,930 --> 00:29:23,090 jekk fuq il-fence-- biex jibdew il- kors SAT / UNS, anki jibqgħu SAT / UNS. 615 00:29:23,090 --> 00:29:27,310 Iżda int tista 'ċertament jaqilbu għal ittra grad mill-ħames Tnejn it-terminu. 616 00:29:27,310 --> 00:29:31,560 >> Franchement, lura meta I kien freshman fl-1995, 617 00:29:31,560 --> 00:29:34,630 I myself ma anki tieħu CS50 minħabba I ma jiksbu l-nerv 618 00:29:34,630 --> 00:29:36,540 li attwalment pass marda fil-klassi. 619 00:29:36,540 --> 00:29:40,020 Deher dominju wisq familjari lili u verament biss 620 00:29:40,020 --> 00:29:43,080 għal dawk il-ħbieb ta 'mini, franchement, li kien programmazzjoni 621 00:29:43,080 --> 00:29:45,570 peress li kienu sitt jew forsi 10-il sena qodma. 622 00:29:45,570 --> 00:29:48,640 U kien biss minħabba I kien kapaċi li jieħdu CS50 fil-jum tiegħi 623 00:29:48,640 --> 00:29:52,720 fil-verżjoni ekwivalenti ta ' SAT / pass UNS-- / jonqsu lura fil-day-- 624 00:29:52,720 --> 00:29:53,850 li anke I ħa 50. 625 00:29:53,850 --> 00:29:57,440 U b'xi mod jew ieħor, jien hawn darb'oħra miegħek illum. 626 00:29:57,440 --> 00:30:00,690 >> Issa sadanittant x'iktar inti għandu jżomm f'moħħu dwar 50 627 00:30:00,690 --> 00:30:01,910 huwa iskrizzjoni simultanja. 628 00:30:01,910 --> 00:30:03,785 Kuntrarjament għal xnigħat li inti tista smajt, 629 00:30:03,785 --> 00:30:07,650 inti tista ', fil-fatt, fl-istess ħin jinkitbu fil CS50 u klassi oħra li 630 00:30:07,650 --> 00:30:12,150 jiltaqa 'l-istess jew xi jikkoinċidu time bħala CS50 tal-lekċers dritt hawn. 631 00:30:12,150 --> 00:30:16,420 Ara l-sillabu għall-partikolaritajiet ta 'l-implimentazzjoni tagħhom. 632 00:30:16,420 --> 00:30:19,540 >> Lectures, sadanittant, kuntrarjament għall x'hemm uffiċjalment fil-katalogu, 633 00:30:19,540 --> 00:30:22,060 ġeneralment se biss jiltaqgħu għal ftit siegħa. 634 00:30:22,060 --> 00:30:24,240 Fit-okkażjoni aħna jistgħu run ftit twil. 635 00:30:24,240 --> 00:30:26,800 Iżda jżomm f'moħħu li l- għan fil CS50 s lectures 636 00:30:26,800 --> 00:30:28,980 huwa li jagħtuk ħarsa ġenerali kunċettwali, 637 00:30:28,980 --> 00:30:31,830 nisperaw xi dimostrazzjonijiet, forsi anki xi jingħataw b'xejn, 638 00:30:31,830 --> 00:30:34,390 ta 'dak li jistenna għall il-ġimgħa li ġej. 639 00:30:34,390 --> 00:30:37,730 >> U għalhekk fil lectures, aħna ser tesplora dawk is-suġġetti u eżempji flimkien, 640 00:30:37,730 --> 00:30:41,420 jġibu istudenti up fuq il-palk, u persunal up fuq il-palk spiss kemm nistgħu, 641 00:30:41,420 --> 00:30:43,740 għal ftit ftit sigħat kull ġimgħa. 642 00:30:43,740 --> 00:30:47,435 Sezzjonijiet, sadanittant, se jkun offruti minn dawn folks here-- ħafna 643 00:30:47,435 --> 00:30:50,060 minnhom tagħlim fellows, xi minnhom se kors assistants-- 644 00:30:50,060 --> 00:30:51,160 jiġri kull ġimgħa. 645 00:30:51,160 --> 00:30:52,940 >> U x'hemm importanti li jżomm f'moħħu huwa li aħna 646 00:30:52,940 --> 00:30:55,920 ma have-- ma b'differenza Ewwel Ljieli, il-mużika class-- 647 00:30:55,920 --> 00:30:59,220 binarji differenti ta 'sezzjonijiet għal studenti anqas komdu, aktar 648 00:30:59,220 --> 00:31:01,150 komdu, u x'imkien bejniethom. 649 00:31:01,150 --> 00:31:03,559 U franchement, inti taf jekk int inqas komdi. 650 00:31:03,559 --> 00:31:05,600 U inti probabilment taf jekk int aktar komda. 651 00:31:05,600 --> 00:31:09,920 U jekk int ma verament ċert, int b'definizzjoni x'imkien bejniethom. 652 00:31:09,920 --> 00:31:12,850 Allura meta niġu żmien għat-taqsima fil-ġimgħa jew hekk, kull l-sillabu, 653 00:31:12,850 --> 00:31:14,070 aħna ser jgħidlek din il-kwistjoni. 654 00:31:14,070 --> 00:31:16,890 U inti tista 'awto-tagħżel Ibbażat fuq livell tiegħek kumdità stess 655 00:31:16,890 --> 00:31:22,220 u jkun ma students-- tkun ma aħdar dots-- simili fl-livell ta 'kumdità lilek. 656 00:31:22,220 --> 00:31:25,710 >> Sadanittant, aħna għandna problema settijiet, li se finalment 657 00:31:25,710 --> 00:31:28,310 jiddefinixxu l-esperjenza tiegħek f'dan il-kors. 658 00:31:28,310 --> 00:31:30,370 Huma qed offruti tipikament fl-edizzjonijiet multipli. 659 00:31:30,370 --> 00:31:34,150 A edizzjoni standard li aħna nistennew aktar kull student fil-kors biex jindirizzaw 660 00:31:34,150 --> 00:31:37,900 iżda wkoll l-hekk imsejħa edizzjoni Hacker li joffri l-ebda forma ta 'kreditu addizzjonali 661 00:31:37,900 --> 00:31:41,980 outright imma verament id-drittijiet bragging ngħid li inti ippruvati u ttrattati 662 00:31:41,980 --> 00:31:45,250 edizzjonijiet Hacker tal-kors li approċċ il-materjal simili 663 00:31:45,250 --> 00:31:47,370 iżda minn angolu aktar sofistikati. 664 00:31:47,370 --> 00:31:49,480 >> Dak li noffru għall- edizzjoni standard, għal, 665 00:31:49,480 --> 00:31:51,420 darb'oħra, il-maġġoranza super ta 'studenti, mhumiex 666 00:31:51,420 --> 00:31:54,060 biss walk-throughs, li huma videos mmexxija mill-persunal tal-kors tal- 667 00:31:54,060 --> 00:31:57,840 li verament jimxu miegħek permezz tal- problemi kors u d-disinn possibbli 668 00:31:57,840 --> 00:31:58,910 implimentazzjonijiet. 669 00:31:58,910 --> 00:32:01,434 U aħna wkoll, wara l- fatt, joffru postmortems, 670 00:32:01,434 --> 00:32:03,350 biha jekk int mintix kif inti jista 'jkollhom 671 00:32:03,350 --> 00:32:05,930 jew kellha tkun solvuti xi problema, il-persunal tat-tagħlim 672 00:32:05,930 --> 00:32:08,640 se jimxu miegħek permezz dawk fuq video ukoll. 673 00:32:08,640 --> 00:32:14,350 >> Sadanittant, dak li jistenna wisq huma ħamest ijiem tard u l-fatt 674 00:32:14,350 --> 00:32:16,680 li aħna se qatra tiegħek problema aktar baxx sett score. 675 00:32:16,680 --> 00:32:20,370 Aħna ċertament japprezzaw li bi skambju għall-ammont ta 'xogħol li 50 Jistenna 676 00:32:20,370 --> 00:32:24,020 tal inti, il-ħajja gets fil-mod kultant, jekk mhux ħames darbiet. 677 00:32:24,020 --> 00:32:26,150 U hekk dan se joffri inti daqsxejn ta 'flessibilità, 678 00:32:26,150 --> 00:32:29,400 testendi l-iskadenza tiegħek minn, ngħidu aħna, Il-Ħamis f'nofsinhar biex il-Ġimgħa f'nofsinhar. 679 00:32:29,400 --> 00:32:33,150 Ara l-sillabu għall- dettalji tal-implimentazzjoni tiegħu. 680 00:32:33,150 --> 00:32:34,702 >> Issa dak li issa jistenna? 681 00:32:34,702 --> 00:32:36,660 U huwa biss li jseħħu lili issa biss kemm żmien 682 00:32:36,660 --> 00:32:38,333 Jien li inti guys toqgħod hawn fuq il-palk. 683 00:32:38,333 --> 00:32:39,060 >> [Rires] 684 00:32:39,060 --> 00:32:41,867 >> DAVID J. Malan: Iżda aħna ser tingħata biex il-finitura klimatiċi qabel twil. 685 00:32:41,867 --> 00:32:43,700 Allura dak li jistenna f'termini mis-settijiet problema? 686 00:32:43,700 --> 00:32:47,099 Well, forsi teaser ta 'dak li aħna kollha għamlet aħħar sena ma predeċessuri tiegħek. 687 00:32:47,099 --> 00:32:49,140 Fl-ewwel sett problema sena li għaddiet, aħna introdotti 688 00:32:49,140 --> 00:32:51,630 Scratch, a grafika lingwa ta 'programmar li 689 00:32:51,630 --> 00:32:54,570 ihallik program litteralment mill jittrattienu u twaqqa biċċiet puzzle, 690 00:32:54,570 --> 00:32:57,220 bħal dawn, li huma reminixxenti tal-constructs 691 00:32:57,220 --> 00:32:59,260 se tara wieħed biss ġimgħa għalhekk, meta aħna jaqilbu 692 00:32:59,260 --> 00:33:01,870 għal aktar tradizzjonali lingwa, magħrufa bħala C. 693 00:33:01,870 --> 00:33:03,930 >> Sena li għaddiet ipproċediet li dan is-sett problema, 694 00:33:03,930 --> 00:33:06,720 jinvolvu għall kriptografija, l-scrambling ta 'informazzjoni 695 00:33:06,720 --> 00:33:10,410 li jżomm milli governattiva jew ħbieb " għajnejn li inti ma tridx tara. 696 00:33:10,410 --> 00:33:12,540 Encoded hawnhekk hija messaġġ li dalwaqt int 697 00:33:12,540 --> 00:33:15,740 se jkunu jistgħu decrypt jew de-ġirja. 698 00:33:15,740 --> 00:33:17,960 >> Tbegħid kienet problema sett aħħar sena, fejn 699 00:33:17,960 --> 00:33:21,530 inti tuża dawn ġdid ta 'programmar misjuba ħiliet biex fil-fatt jimplimentaw 700 00:33:21,530 --> 00:33:24,840 logħba wherein-- kif inti tista 'tfakkar mill childhood-- 701 00:33:24,840 --> 00:33:28,040 l-għan kien li bash l- briks li huma atop l-iskrin 702 00:33:28,040 --> 00:33:30,190 hawn, jakkumulaw punteġġ tul it-triq, 703 00:33:30,190 --> 00:33:35,460 u l-implimentazzjoni algoritmi tiegħek stess li magħhom din is-soluzzjoni finalment 704 00:33:35,460 --> 00:33:37,357 ihallik jilagħbu l-logħba. 705 00:33:37,357 --> 00:33:39,440 Sadanittant, aktar tard fil- semestru, ahna naghtuk 706 00:33:39,440 --> 00:33:43,470 dizzjunarju ta '143,091 kliem Ingliż. 707 00:33:43,470 --> 00:33:46,300 U int se tkun sfidata jiktbu program li 708 00:33:46,300 --> 00:33:50,260 jespliċitaw kontrolli, dokumenti, billi tagħbija kliem li ħafna fil-memorja 709 00:33:50,260 --> 00:33:52,300 mod effiċjenti possibbli. 710 00:33:52,300 --> 00:33:54,240 Ġeneralment pitting inti kontra klassi tiegħek 711 00:33:54,240 --> 00:33:56,610 jekk inti opt fis daqsxejn ta ' sfida fil-bord mexxej 712 00:33:56,610 --> 00:34:00,090 biex tara li jistgħu jużaw l-inqas numru sekondi ta 'running time, 713 00:34:00,090 --> 00:34:03,550 u l-inqas numru ta 'megabytes tal-memorja, 714 00:34:03,550 --> 00:34:08,659 u fil-fatt l-irfinar programmi tiegħek li jkun oerhört effiċjenti fir-riżorsi mhux 715 00:34:08,659 --> 00:34:09,820 biss żmien. 716 00:34:09,820 --> 00:34:13,239 >> Sena li għaddiet, wisq, ħarisna lejn il-aħħar tas-semestru fil-programmazzjoni web. 717 00:34:13,239 --> 00:34:16,230 U fil-fatt, aħna ser tagħmel dan mill-ġdid dan sena ma 'settijiet problema multipli, 718 00:34:16,230 --> 00:34:20,290 introduzzjoni li inti l-tekniki u il-mentalità li magħhom inti tista 'tapplika 719 00:34:20,290 --> 00:34:23,489 dawn il-ħiliet ta 'programmazzjoni lil websajts, websajts dinamiku, 720 00:34:23,489 --> 00:34:26,639 websajts li attwalment ssolvi problemi u jġib ruħu differenti 721 00:34:26,639 --> 00:34:30,620 u mhumiex sempliċiment statiku siti b'informazzjoni statika. 722 00:34:30,620 --> 00:34:32,854 >> Il-proġett finali finalment se jiddefinixxu, għalkemm, 723 00:34:32,854 --> 00:34:34,770 l-quċċata tal-kors għall-istudenti, fejn 724 00:34:34,770 --> 00:34:37,228 inti ser jiġi kkontestat li jimplimentaw aktar ħaġa ta 'interess 725 00:34:37,228 --> 00:34:40,590 lilek, sakemm qualche ispirat mill-lezzjonijiet tal-kors tal-. 726 00:34:40,590 --> 00:34:42,930 >> U kif inti raw fil- video fil-bidu, 727 00:34:42,930 --> 00:34:47,340 aħna se tikkonkludi l-semestru mal- CS50 Hackathon, li jekk, familjari, 728 00:34:47,340 --> 00:34:51,420 se jibda fil 07:00 bil-lejl wieħed u jispiċċaw fi 7:00 am l-għada filgħodu. 729 00:34:51,420 --> 00:34:53,614 Madwar 09:00, aħna ser ordni fl-ewwel pranzu. 730 00:34:53,614 --> 00:34:55,489 Madwar 01:00, aħna ser ordni tieni pranzu. 731 00:34:55,489 --> 00:34:57,490 U jekk int xorta wieqfa fil 05:00, aħna 732 00:34:57,490 --> 00:35:00,320 se shuttle bus inti biex IHOP għall-kolazzjon. 733 00:35:00,320 --> 00:35:04,980 >> Il-Fiera CS50, sadanittant, huwa avveniment li 2,000 plus fakultà, studenti, 734 00:35:04,980 --> 00:35:07,850 u l-persunal minn madwar kampus se ġejjin biex tara kisbiet tiegħek 735 00:35:07,850 --> 00:35:10,150 fil-kors u l-finali proġetti u l-kreazzjonijiet 736 00:35:10,150 --> 00:35:14,960 li inti toħloq fuq laptops tiegħek, desktops, jew bozoz forsi anke dawl. 737 00:35:14,960 --> 00:35:17,340 >> Sadanittant, ħinijiet tal-uffiċċju u l-istruttura ta 'appoġġ. 738 00:35:17,340 --> 00:35:20,480 U issa kieku stajt kien aħjar żmien biex iġibu inti kollha up. 739 00:35:20,480 --> 00:35:24,310 >> Uffiċċju siegħa se sseħħ erba iljieli ġimgħa għal sigħat multipli kull lejl 740 00:35:24,310 --> 00:35:27,710 b'ġeneralment 20 sa 30 ta 'l- persunal kors dwar id-dazju f'daqqa 741 00:35:27,710 --> 00:35:31,240 li jagħtuk intima one-on-one-opportunitajiet għal appoġġ 742 00:35:31,240 --> 00:35:33,790 ma 'settijiet problema tal-kors tal-. 743 00:35:33,790 --> 00:35:36,120 Tutoring wisq se jkun disponibbli, partikolarment 744 00:35:36,120 --> 00:35:39,630 għall-istudenti inqas comfortable-- jew DARE ngħid inqas comfortable-- għalihom 745 00:35:39,630 --> 00:35:41,869 ħinijiet tal-uffiċċju mhumiex l- aktar ambjent trawwim 746 00:35:41,869 --> 00:35:43,660 u huma ċertament mhux l-aktar stress-free. 747 00:35:43,660 --> 00:35:47,430 Speċjalment meta l-iskadenzi huma ippressar, aħna se proattiv par inti nfusna 748 00:35:47,430 --> 00:35:51,440 ma 'membru tal-persunal biex jaħdem mar fuq xi skeda regolari bħala bżonnijiet tiegħek 749 00:35:51,440 --> 00:35:53,850 u l-iskeda tagħhom tippermetti. 750 00:35:53,850 --> 00:35:55,260 >> U l-istaff. 751 00:35:55,260 --> 00:36:01,020 Ippermettuli li jintroduċu Davon, Rob, u Gabriel, kapijiet din is-sena. 752 00:36:01,020 --> 00:36:02,370 Jekk inti tixtieq li kull say-- 753 00:36:02,370 --> 00:36:03,349 >> [Applause] 754 00:36:03,349 --> 00:36:03,849 kelma --a. 755 00:36:03,849 --> 00:36:05,328 [Applause] 756 00:36:05,328 --> 00:36:10,270 757 00:36:10,270 --> 00:36:13,220 Davon fuq hawnhekk huwa l- maniġer course, li 758 00:36:13,220 --> 00:36:15,730 ifisser fir-rwol tiegħu full-time hu jgħin bl-eżekuzzjoni 759 00:36:15,730 --> 00:36:18,424 u l-loġistika ta 'CS50. 760 00:36:18,424 --> 00:36:19,340 Davon: Yeah, hi, guys. 761 00:36:19,340 --> 00:36:20,965 Int ser ikollok tara ħafna lili fil ħinijiet tal-uffiċċju. 762 00:36:20,965 --> 00:36:22,110 I ser tkun tagħlim sezzjonijiet. 763 00:36:22,110 --> 00:36:25,150 U jekk inti rimja emails quddiem, I ser probabbilment jiġu tirrispondi. 764 00:36:25,150 --> 00:36:27,670 So I ser tara lottijiet ta 'inti kollha semestru. 765 00:36:27,670 --> 00:36:29,890 U merħba lill CS50. 766 00:36:29,890 --> 00:36:38,330 >> DAVID J. Malan: U issa Gabriel, li innifsu kien biss freshman sena li għaddiet, 767 00:36:38,330 --> 00:36:41,820 iżda għall-aħħar ftit snin għandha ilha topera verżjoni tiegħu stess ta 'CS50 768 00:36:41,820 --> 00:36:44,660 fil-Brażil, li biha hu jitniżżel kollha ta 'content---kors tal- 769 00:36:44,660 --> 00:36:46,890 li qed tiġi kjarament iffilmjati u mqiegħda online-- 770 00:36:46,890 --> 00:36:51,480 sabiex ikun jista 'tittraduċi din li Portugiż u mbagħad jgħallmu aktar minn 100 771 00:36:51,480 --> 00:36:54,610 ta klassi tiegħu fuq l- kors ta 'koppja ta' snin, 772 00:36:54,610 --> 00:36:57,650 tagħlim fil-lingwa nattiva tiegħu kurrikulu tal-kors tal-. 773 00:36:57,650 --> 00:36:58,964 >> GABRIEL: Hello. 774 00:36:58,964 --> 00:37:00,912 >> [Applause] 775 00:37:00,912 --> 00:37:06,669 776 00:37:06,669 --> 00:37:07,710 GABRIEL: Hi, jien Gabriel. 777 00:37:07,710 --> 00:37:09,340 Jien l-kap TF tal-kors. 778 00:37:09,340 --> 00:37:10,780 U nispera li inti ser imħabba CS50. 779 00:37:10,780 --> 00:37:12,830 Dan huwa CS50. 780 00:37:12,830 --> 00:37:14,697 >> DAVID J. Malan: Issa għall Rob. 781 00:37:14,697 --> 00:37:15,780 Oh, inti tixtieq introduzzjoni? 782 00:37:15,780 --> 00:37:16,696 >> ROB: Nru, I do not know. 783 00:37:16,696 --> 00:37:18,225 [Rires] 784 00:37:18,225 --> 00:37:19,475 DAVID J. Malan: U Rob Boden. 785 00:37:19,475 --> 00:37:22,300 [Rires] 786 00:37:22,300 --> 00:37:23,800 ROB: Hi, jien Rob. 787 00:37:23,800 --> 00:37:27,220 Dan huwa ħames sena tiegħi involuti mal-kors. 788 00:37:27,220 --> 00:37:29,220 Kull sena, huwa biss aħjar u l-klassi aħjar, 789 00:37:29,220 --> 00:37:31,550 Allura inti guys huma b'mod ċar se tkun biża '. 790 00:37:31,550 --> 00:37:33,181 Nispera li intom kollha jieħdu pjaċir miegħu. 791 00:37:33,181 --> 00:37:34,430 Jien ser jieħdu pjaċir miegħu. 792 00:37:34,430 --> 00:37:36,670 Allura tara int madwar. 793 00:37:36,670 --> 00:37:38,445 >> DAVID J. Malan: U ħin mhux se jippermetti us-- 794 00:37:38,445 --> 00:37:39,670 >> [Applause] 795 00:37:39,670 --> 00:37:41,661 >> Ħin mhux se jippermettu magħna li tintroduċi kulħadd 796 00:37:41,661 --> 00:37:44,660 fuq il-palk u kollha tal-kollegi tagħhom li huma shopping klassijiet illum. 797 00:37:44,660 --> 00:37:47,390 Imma ippermettuli li jintroduċu Belinda u CS50 Puzzle 798 00:37:47,390 --> 00:37:49,550 Jum, li jistenna dan ġejjin Sibt li 799 00:37:49,550 --> 00:37:51,800 hija l-ewwel ta 'l- avvenimenti fuq skala kbira kors'S. 800 00:37:51,800 --> 00:37:54,300 >> Dan wieħed b'mod partikolari fisser li martell dar il-punt 801 00:37:54,300 --> 00:37:57,580 li x-xjenza tal-kompjuter hija finalment mhux dwar l-ipprogrammar, iżda pjuttost 802 00:37:57,580 --> 00:37:59,280 dwar il-problema jissolvew b'mod aktar ġenerali. 803 00:37:59,280 --> 00:38:01,450 U Puzzle Jum, kif inti ser tara, inti ser iġġib 804 00:38:01,450 --> 00:38:04,207 u klassi tiegħek together-- nittamaw din is-Sibt. 805 00:38:04,207 --> 00:38:04,961 >> Belinda: OK. 806 00:38:04,961 --> 00:38:05,750 Hi, guys. 807 00:38:05,750 --> 00:38:06,740 Allura grazzi. 808 00:38:06,740 --> 00:38:10,120 Allura bħala kaptan illustri tagħna qal, Belinda isem tiegħi. 809 00:38:10,120 --> 00:38:12,100 I am a sophomore fil Quincy House. 810 00:38:12,100 --> 00:38:15,730 >> I, bħad inti guys, ħa Sena l-aħħar CS50, verament iħobb dan. 811 00:38:15,730 --> 00:38:17,960 I jkollhom soft spot għal inti guys fit-tielet filliera. 812 00:38:17,960 --> 00:38:21,384 U jien kburi ngħid, jien issa f'relazzjoni impenjata 813 00:38:21,384 --> 00:38:22,300 ma CS50 [inaudible]. 814 00:38:22,300 --> 00:38:22,799 OK. 815 00:38:22,799 --> 00:38:26,140 Dan kien verżjoni lame tiegħi ta Joke. 816 00:38:26,140 --> 00:38:28,320 >> Xorta waħda, hekk jimxu fuq, biss riedu li jistiednu 817 00:38:28,320 --> 00:38:31,439 inti guys kollha għall-i-lab, jew urtikarja HBs. 818 00:38:31,439 --> 00:38:33,730 Aħna ser jkun li jkollhom Puzzle Jum 12:00-03:00. 819 00:38:33,730 --> 00:38:37,680 U huwa opportunità kbira għalik guys biex jilħqu kollegi CS-ħbieb tiegħek, 820 00:38:37,680 --> 00:38:42,780 isolvu uħud mill-CS puzzles, bħal Captain imsemmi, u wkoll jieklu xi ikel b'xejn, 821 00:38:42,780 --> 00:38:46,910 jaqilgħu xi premjijiet tal-biża, bħal karti rigal, $ 75 kull persuna, 822 00:38:46,910 --> 00:38:48,400 u also-- dak li kien dan? 823 00:38:48,400 --> 00:38:49,540 Wii U jew xi ħaġa? 824 00:38:49,540 --> 00:38:50,333 Wii U? 825 00:38:50,333 --> 00:38:51,040 Iva. 826 00:38:51,040 --> 00:38:52,330 Għal raffle tagħna. 827 00:38:52,330 --> 00:38:52,830 Tal-biża '. 828 00:38:52,830 --> 00:38:54,310 So I ser twaħħal madwar wara klassi. 829 00:38:54,310 --> 00:38:56,770 U jekk inti guys xi mistoqsijiet, let me know. 830 00:38:56,770 --> 00:38:59,980 >> DAVID J. Malan: U tkun taf tara, lil hinn dan hemm xejn li jagħmlu llum. 831 00:38:59,980 --> 00:39:01,920 L-ewwel problema sett se jmorru out Ġimgħa. 832 00:39:01,920 --> 00:39:05,420 Iżda biex iġibu us dar illum, nixtieq li jintroduċu inti speċifikament wieħed aktar 833 00:39:05,420 --> 00:39:09,080 membru tal-persunal, Colton Ogden hawn, li f'idejha huma issa 834 00:39:09,080 --> 00:39:12,250 protetti hawn fuq inti ma dan il-kontrollur MIDI 835 00:39:12,250 --> 00:39:15,170 li martell dar il-punt ulterjuri li x-xjenza tal-kompjuter, wisq, 836 00:39:15,170 --> 00:39:19,130 għandha applikabilità ferm lil hinn inġinerija u ZOKK u x-xjenza tal-kompjuter innifsu, 837 00:39:19,130 --> 00:39:22,890 testendi anke għal dawk oqsma bħall-mużika. 838 00:39:22,890 --> 00:39:30,590 >> Colton għandha ġentilment offered-- ħsibt wieħed minnhom kien se tiffissa l-fokus. 839 00:39:30,590 --> 00:39:34,400 Andrew, jekk nistgħu jsejħu fokus minn hawn għal ftit mument. 840 00:39:34,400 --> 00:39:36,780 >> Dak Colton għamlet bil-quddiem huwa programm 841 00:39:36,780 --> 00:39:40,345 dan il-mezz, dan pad ta 'buttuni li tara isaffru up here, 842 00:39:40,345 --> 00:39:42,470 bħala kontrollur MIDI, li biha kull wieħed minn dawk buttuni 843 00:39:42,470 --> 00:39:47,080 huwa fili għal nota mużikali partikolari jew ħoss, b'mod aktar ġenerali reġistrazzjoni, 844 00:39:47,080 --> 00:39:50,445 b'tali mod li bil-logħob mudelli ta 'dawn buttuni, ħafna bħall-mudelli ta 'bits, 845 00:39:50,445 --> 00:39:52,620 jistgħu jirrappreżentaw oħra kunċetti livell ogħla. 846 00:39:52,620 --> 00:39:56,750 Se hu jkun kapaċi finalment li jqarrbuna dar hawn illum? 847 00:39:56,750 --> 00:39:59,540 Mingħajr aktar dewmien, jekk nistgħu dim-dwal, 848 00:39:59,540 --> 00:40:03,145 u dawwar fuq l-iskrin wara Colton. 849 00:40:03,145 --> 00:40:03,865 >> UDJENZA: Woo! 850 00:40:03,865 --> 00:40:06,090 >> DAVID J. Malan: Dan huwa CS50. 851 00:40:06,090 --> 00:40:10,518 >> [Daqq ta mużika] 852 00:40:10,518 --> 00:42:46,018 853 00:42:46,018 --> 00:42:49,420 >> [Applause] 854 00:42:49,420 --> 00:42:54,766 855 00:42:54,766 --> 00:42:56,450 >> C'est għal CS50. 856 00:42:56,450 --> 00:42:57,950 Aħna se tara int Ġimgħa. 857 00:42:57,950 --> 00:42:59,890 Xi kejk jistenna inti fil-kappellun. 858 00:42:59,890 --> 00:43:04,046 859 00:43:04,046 --> 00:43:08,850 >> [Daqq ta mużika] 860 00:43:08,850 --> 00:45:49,227