1 00:00:00,000 --> 00:00:11,100 2 00:00:11,100 --> 00:00:12,300 >> SPEAKER 1: ħej kulħadd! 3 00:00:12,300 --> 00:00:13,890 Merħba lura għat-taqsima. 4 00:00:13,890 --> 00:00:17,480 Ferħan li tara tant minnkom kemm hawn, u kulħadd li s jaraw online. 5 00:00:17,480 --> 00:00:18,760 6 00:00:18,760 --> 00:00:20,920 Allura, bħas-soltu welcome back. 7 00:00:20,920 --> 00:00:24,360 Nispera li intom kollha kellhom sabiħ weekend, sħiħ ta 'mistrieħ, rilassament. 8 00:00:24,360 --> 00:00:26,026 Hija kienet sabiħa bieraħ. 9 00:00:26,026 --> 00:00:27,525 So, I hope inti tgawdi l-barra. 10 00:00:27,525 --> 00:00:28,840 11 00:00:28,840 --> 00:00:30,610 >> Allura l-ewwel koppja ta 'avviżi. 12 00:00:30,610 --> 00:00:31,920 13 00:00:31,920 --> 00:00:32,700 Gradazzjoni. 14 00:00:32,700 --> 00:00:37,350 Allura, ħafna minnkom għandu gotten email mill me dwar Pset Scratch tiegħek, 15 00:00:37,350 --> 00:00:39,920 kif ukoll gradazzjoni għall Pset 1. 16 00:00:39,920 --> 00:00:41,000 17 00:00:41,000 --> 00:00:42,220 Allura, affarijiet biss ftit. 18 00:00:42,220 --> 00:00:45,150 Ikunu żguri li jużaw check50 fil style50. 19 00:00:45,150 --> 00:00:47,250 Dawn huma intenzjonati li jkunu riżorsi għall inti guys, 20 00:00:47,250 --> 00:00:50,660 biex taċċerta ruħek li qed jkollna punti kemm inti tista ' 21 00:00:50,660 --> 00:00:52,390 mingħajr ma inutilment jitilfu minnhom. 22 00:00:52,390 --> 00:00:54,407 Allura, affarijiet simili istil huma importanti ħafna. 23 00:00:54,407 --> 00:00:55,740 Aħna ser jieħdu off għal dan. 24 00:00:55,740 --> 00:00:58,115 Xi wħud minnkom jista 'jkollok diġà ndunat li minn Pset tiegħek. 25 00:00:58,115 --> 00:00:58,920 26 00:00:58,920 --> 00:01:01,450 U check50 huwa biss mod verament faċli biex tagħmel żgur 27 00:01:01,450 --> 00:01:05,050 li aħna qed attwalment jirritornaw liema jeħtieġ li jiġi rritornat lill-utent, 28 00:01:05,050 --> 00:01:06,690 u li kollox ta 'ħidma kif suppost. 29 00:01:06,690 --> 00:01:08,690 30 00:01:08,690 --> 00:01:12,040 >> Fuq it-tieni nota, kun żgur tiegħek uploading affarijiet għall-folder korretta. 31 00:01:12,040 --> 00:01:14,470 Hija tagħmel il-ħajja tiegħi biss ftit aktar diffiċli 32 00:01:14,470 --> 00:01:18,836 jekk inti upload Pset 2 fis Pset 1 għaliex meta I affarijiet download, 33 00:01:18,836 --> 00:01:20,085 dawn ma download b'mod korrett. 34 00:01:20,085 --> 00:01:21,690 35 00:01:21,690 --> 00:01:24,560 U naf huwa wonky ftit f'sistema biex jidraw, 36 00:01:24,560 --> 00:01:26,950 imma biss tkun super bir-reqqa, jekk biss għalija, 37 00:01:26,950 --> 00:01:30,080 b'tali mod li meta int jkollna emails fil like 02:00 u jien gradazzjoni. 38 00:01:30,080 --> 00:01:33,710 Jekk ma jikkawżax I jkollha tħares kollha madwar għall Pset tiegħek. 39 00:01:33,710 --> 00:01:34,440 Kessaħ. 40 00:01:34,440 --> 00:01:37,270 >> Naf huwa kmieni, imma I totalment ltqajna meħuda off guard 41 00:01:37,270 --> 00:01:40,800 minn esej li dovut din il-ġimgħa, li professuri tiegħi kienu biss nixtieq, oh yeah. 42 00:01:40,800 --> 00:01:42,550 Ftakar, inti għandek essay dovut nhar il-Ġimgħa. 43 00:01:42,550 --> 00:01:45,780 So, I know-ebda waħda jħobb biex jaħsbu dwar midterms, 44 00:01:45,780 --> 00:01:50,620 iżda l-ewwel kwizz tiegħek huwa fuq 15 Ottubru, li ottubru qed jibda din il-ġimgħa. 45 00:01:50,620 --> 00:01:53,290 Allura, jista 'jkun qabel milli suppost mistenni hija kollha. 46 00:01:53,290 --> 00:01:57,510 Hekk li int mhux mibrum off guard meta Nsemmi taqsima ġimgħa d-dieħla li oh, 47 00:01:57,510 --> 00:02:00,560 kwizz ġimgħa d-dieħla tiegħek, ħsibt I d jagħtuk ftit aktar 48 00:02:00,560 --> 00:02:01,500 ta 'kapijiet up issa. 49 00:02:01,500 --> 00:02:02,970 50 00:02:02,970 --> 00:02:04,660 >> Allura, il-problema tiegħek sett, numru tlieta. 51 00:02:04,660 --> 00:02:07,070 Kif in-nies qrajt l- spec out ta 'kurżità? 52 00:02:07,070 --> 00:02:08,560 53 00:02:08,560 --> 00:02:09,199 OK. 54 00:02:09,199 --> 00:02:10,229 Aħna ltqajna koppja. 55 00:02:10,229 --> 00:02:12,320 Tip ta 'isfel mill-aħħar ġimgħa iżda li OK. 56 00:02:12,320 --> 00:02:13,650 Naf li kien barra sbieħ. 57 00:02:13,650 --> 00:02:15,120 58 00:02:15,120 --> 00:02:16,660 Hekk Break Out. 59 00:02:16,660 --> 00:02:21,010 Żgur wara ikollok jsir illum taqra spec tiegħek mill-inqas 60 00:02:21,010 --> 00:02:25,240 ipprova bħal tniżżil kodiċi distribuzzjoni u t-tmexxija 61 00:02:25,240 --> 00:02:27,430 bħall-ewwel inizjali ħaġa li jgħidlek biex. 62 00:02:27,430 --> 00:02:28,681 63 00:02:28,681 --> 00:02:32,590 Għaliex aħna qed jużaw kodiċi ta 'distribuzzjoni u librerija 64 00:02:32,590 --> 00:02:36,790 li konna biss qed using-- --It biss it-tieni darba aħna ghamilt dan Pset, 65 00:02:36,790 --> 00:02:38,650 affarijiet crazy jista 'jiġri mal-appliance tiegħek, 66 00:02:38,650 --> 00:02:41,370 u inti tixtieq li ssib li out issa versus aktar tard. 67 00:02:41,370 --> 00:02:45,570 >> Għaliex jekk huwa lejl il-Ħamis jew huwa Erbgħa bil-lejl u għal xi raġuni 68 00:02:45,570 --> 00:02:48,912 appliance tiegħek biss ma tixtieq li tmexxi bl-librerija 69 00:02:48,912 --> 00:02:50,620 jew mad-distribuzzjoni kodiċi, li l-mezzi 70 00:02:50,620 --> 00:02:52,309 inti ma tista 'anki jibdew jagħmlu l-kodifikazzjoni. 71 00:02:52,309 --> 00:02:54,100 Għaliex inti ma tistax tiċċekkja biex tara jekk din taħdem. 72 00:02:54,100 --> 00:02:55,975 Ma gonna tiegħek tkun kapaċi biex tara jekk jikkompila. 73 00:02:55,975 --> 00:03:00,500 Inti tixtieq li tieħu kura ta 'dawk fil-bidu il-ġimgħa, meta inti xorta tista 'email me 74 00:03:00,500 --> 00:03:03,100 jew wieħed mill-TFS oħra, u nistgħu jiksbu dawk iffissati. 75 00:03:03,100 --> 00:03:05,410 Għaliex dawk huma kwistjonijiet li huma ser tieqaf 76 00:03:05,410 --> 00:03:07,120 milli tagħmel kwalunkwe progress reali. 77 00:03:07,120 --> 00:03:10,055 Mhuwiex simili bug wieħed, li inti tista 'biss tip ta' skip fuq. 78 00:03:10,055 --> 00:03:10,712 79 00:03:10,712 --> 00:03:13,420 Jekk int wara kwistjonijiet mal tiegħek appliance jew kodiċi ta 'distribuzzjoni, 80 00:03:13,420 --> 00:03:16,211 int verament tixtieq li tikseb li jittieħdu kura ta 'mill-aktar. 81 00:03:16,211 --> 00:03:20,410 Għalhekk anki jekk int ma gonna attwalment tibda kodifikazzjoni, tniżżel il distribuzzjoni 82 00:03:20,410 --> 00:03:24,040 kodiċi, aqra l-spec, kun żgur kollox ta 'ħidma hemmhekk. 83 00:03:24,040 --> 00:03:25,134 OK? 84 00:03:25,134 --> 00:03:27,675 Jekk inti tista 'biss tagħmel dan, I wegħda ħajja tiegħek se jkun aktar faċli. 85 00:03:27,675 --> 00:03:28,800 86 00:03:28,800 --> 00:03:31,410 U hekk int probabbilment se biex tagħmel dan id-dritt issa dritt? 87 00:03:31,410 --> 00:03:32,100 OK. 88 00:03:32,100 --> 00:03:33,950 Allura, xi mistoqsijiet hemmhekk? 89 00:03:33,950 --> 00:03:35,850 Kwalunkwe affarijiet loġistiċi? 90 00:03:35,850 --> 00:03:36,910 Kulħadd huwa tajjeb? 91 00:03:36,910 --> 00:03:38,270 OK. 92 00:03:38,270 --> 00:03:41,700 >> Ċaħda ta 'responsabbiltà għal dawk ta' inti fil-kamra u online. 93 00:03:41,700 --> 00:03:45,437 Jien ser tkun qed tipprova li jaqilbu bejn PowerPoint fil-appliance 94 00:03:45,437 --> 00:03:47,270 għaliex aħna qed tmur li tkun qiegħda tagħmel xi kodifikazzjoni 95 00:03:47,270 --> 00:03:53,630 illum mid-domanda popolari ta 'l-anonimu poll suġġeriment I bagħtet aħħar ġimgħa. 96 00:03:53,630 --> 00:03:55,480 Allura, aħna se tkun qiegħda tagħmel xi kodifikazzjoni. 97 00:03:55,480 --> 00:03:57,800 Allura, jekk inti guys tixtieq ukoll li fire up apparat tiegħek, 98 00:03:57,800 --> 00:04:02,910 u inti għandek ltqajna email mill me, ma fajl kampjun. 99 00:04:02,910 --> 00:04:04,310 Nitolbok li tħossok liberu li tagħmel dan. 100 00:04:04,310 --> 00:04:07,340 >> Allura, aħna qed tmur biex jitkellmu dwar GDB, li huwa debugger. 101 00:04:07,340 --> 00:04:09,970 Li għaddej biex jgħinek tip ta 'figura fejn 102 00:04:09,970 --> 00:04:11,860 affarijiet sejrin ħażin fil-kodiċi tiegħek. 103 00:04:11,860 --> 00:04:15,370 Huwa tassew biss mod biex inti pass permezz kodiċi tiegħek kif jiġri, 104 00:04:15,370 --> 00:04:19,100 u jkun kapaċi li jistampa varjabbli jew tara x'inhu verament jiġri 105 00:04:19,100 --> 00:04:22,980 taħt il-barnuża versi programm tiegħek biss running, huwa simili faulting, 106 00:04:22,980 --> 00:04:25,030 u int simili, l-ebda idea dak li ġara biss hawn. 107 00:04:25,030 --> 00:04:26,730 I do not know liema linja hija naqset bi. 108 00:04:26,730 --> 00:04:29,040 I do not know fejn marret ħażin. 109 00:04:29,040 --> 00:04:31,280 Allura, GDB se jgħinuk ma 'dak. 110 00:04:31,280 --> 00:04:35,240 Ukoll, jekk inti tiddeċiedi li tkompli iva, u jieħdu 61, 111 00:04:35,240 --> 00:04:38,430 dan se verament, verament tkun tiegħek aqwa ħabib, jikkawżaw I jista 'jgħidlek 112 00:04:38,430 --> 00:04:40,840 għaliex jien għaddejjin dik il-klassi. 113 00:04:40,840 --> 00:04:43,620 >> Aħna qed tmur biex tħares lejn binarju tfittxija, li jekk inti guys tiftakar 114 00:04:43,620 --> 00:04:47,540 l-eżempju ktieb tat-telefon kbir spettaklu mill-klassi. 115 00:04:47,540 --> 00:04:50,620 Aħna ser tkun implimentattivi li, u mixi permezz ta 'dak ftit aktar, 116 00:04:50,620 --> 00:04:54,650 u allura aħna qed tmur permezz ta 'erba xorta differenti, li huma Bubble, 117 00:04:54,650 --> 00:04:56,285 Għażla, Inserzjoni, u Jingħaqdu. 118 00:04:56,285 --> 00:04:57,830 119 00:04:57,830 --> 00:04:58,330 Kessaħ. 120 00:04:58,330 --> 00:05:00,390 Allura, GDB kif semmejt, huwa debugger. 121 00:05:00,390 --> 00:05:01,400 122 00:05:01,400 --> 00:05:09,370 U dawn huma tip ta 'l-big affarijiet, il-funzjonijiet kbar jew l-ordnijiet 123 00:05:09,370 --> 00:05:13,240 li tuża ġewwa GDB, u jien se jimxu inti permezz demo ta 'dan fit-tieni. 124 00:05:13,240 --> 00:05:15,360 >> Allura, dan mhux biss ser jibqgħu astratt. 125 00:05:15,360 --> 00:05:18,000 I ser jippruvaw u jagħmilha bħala konkreti kemm possibbli għalik guys. 126 00:05:18,000 --> 00:05:19,870 Allura, break. 127 00:05:19,870 --> 00:05:22,200 Hija ser jkun jew pawża bħal, xi numru, li 128 00:05:22,200 --> 00:05:26,900 jirrappreżenta linja fil-programm tiegħek, jew inti tista 'isem funzjoni. 129 00:05:26,900 --> 00:05:30,150 Allura, jekk inti tgħidli break prinċipali, se tieqaf fil prinċipali, 130 00:05:30,150 --> 00:05:32,400 u let inti timxi permezz dik il-funzjoni. 131 00:05:32,400 --> 00:05:36,350 >> Bl-istess mod, jekk għandek xi esterna funzjoni bħal Swap jew Cube, 132 00:05:36,350 --> 00:05:38,450 li ħarisna lejn ġimgħa li għaddiet. 133 00:05:38,450 --> 00:05:41,780 Jekk tgħid break wieħed minn dawk, kull meta program tiegħek hits li, 134 00:05:41,780 --> 00:05:44,290 inneħħu stenna għalik biex għid x'għandek tagħmel. 135 00:05:44,290 --> 00:05:47,860 Qabel se biss tesegwixxi sabiex inti tista 'effettivament pass ġewwa l-funzjoni 136 00:05:47,860 --> 00:05:49,020 u ara x'inhu għaddej. 137 00:05:49,020 --> 00:05:50,370 138 00:05:50,370 --> 00:05:53,515 Allura, Sussegwentement, ftit skips fuq il- linja li jmiss, tmur fuq il-funzjonijiet. 139 00:05:53,515 --> 00:05:54,730 140 00:05:54,730 --> 00:05:55,560 Pass. 141 00:05:55,560 --> 00:05:56,810 Dawn huma kollha astratt ftit. 142 00:05:56,810 --> 00:06:00,530 Allura, jien biss ser jimxu permezz tagħhom, iżda inti ser tara minnhom fl-użu fit-tieni. 143 00:06:00,530 --> 00:06:01,810 >> Pass lejn funzjoni. 144 00:06:01,810 --> 00:06:04,170 So I kif kien qal, bħal ma Swap, ikun 145 00:06:04,170 --> 00:06:07,110 jippermettu li inti fil-fatt kif jekk int bħal fiżikament titjib ġewwa, 146 00:06:07,110 --> 00:06:10,990 inti tista mess ma 'dawk varjabbli, print out dak li huma, tara x'inhu għaddej. 147 00:06:10,990 --> 00:06:12,140 148 00:06:12,140 --> 00:06:14,830 Lista se litteralment biss print l-kodiċi tal-madwar. 149 00:06:14,830 --> 00:06:17,570 Allura, jekk inti tip ta tinsa fejn inti fil-programm tiegħek, 150 00:06:17,570 --> 00:06:19,880 jew int mintix x'inhu għaddej madwaru, 151 00:06:19,880 --> 00:06:23,790 dan se biss jistampa segment ta simili ħames jew sitt linji madwaru. 152 00:06:23,790 --> 00:06:26,080 Allura, inti tista 'tikseb orjentati dwar fejn int. 153 00:06:26,080 --> 00:06:27,230 154 00:06:27,230 --> 00:06:28,650 >> Stampa xi varjabbli. 155 00:06:28,650 --> 00:06:34,590 Għalhekk, jekk inti għandek l-muftieħ simili fil Caesar, li aħna ser tħares lejn. 156 00:06:34,590 --> 00:06:36,220 Tista 'tgħid Stampa Key fi kwalunkwe punt. 157 00:06:36,220 --> 00:06:40,070 Hija ser jgħidlek dak il-valur huwa tant li, forsi x'imkien matul it-triq, 158 00:06:40,070 --> 00:06:42,070 inti overwrote prinċipali tiegħek. 159 00:06:42,070 --> 00:06:45,495 Inti tista 'attwalment tgħid li minħabba inti tista 'attwalment josservaw dak il-valur. 160 00:06:45,495 --> 00:06:46,500 161 00:06:46,500 --> 00:06:48,780 >> Fil-lokal, biss prints out varjabbli lokali tiegħek. 162 00:06:48,780 --> 00:06:53,120 Allura, ghaċ int fi loop, u inti biss trid tara simili, oh. 163 00:06:53,120 --> 00:06:54,270 X'inhu I tiegħi? 164 00:06:54,270 --> 00:06:57,020 X'inhu dan il-valur ewlieni li I initialize hawn? 165 00:06:57,020 --> 00:06:58,537 X'inhu l-messaġġ f'dan il-punt? 166 00:06:58,537 --> 00:07:00,370 Hija se biss print kollha ta 'dawk, sabiex inti 167 00:07:00,370 --> 00:07:04,330 ma għandekx individwalment jgħidu, Stampa I. Stampa Message. 168 00:07:04,330 --> 00:07:04,970 Key Stampa. 169 00:07:04,970 --> 00:07:06,190 170 00:07:06,190 --> 00:07:07,700 U mbagħad Display. 171 00:07:07,700 --> 00:07:10,370 Dak li ma huwa kif inti pass permezz tal-programm, 172 00:07:10,370 --> 00:07:13,980 dan ser biss tagħmel ċert li huwa wiri xi varjabbli partikolari 173 00:07:13,980 --> 00:07:14,780 f'kull punt. 174 00:07:14,780 --> 00:07:17,160 Allura li inti also-- --it s tip ta 'shortcut fejn 175 00:07:17,160 --> 00:07:19,530 inti ma għandekx biex iżommu għaddejjin bħal, oh. 176 00:07:19,530 --> 00:07:23,150 Key Stampa jew Stampa I. Hija biss awtomatikament se tagħmel dan għalik. 177 00:07:23,150 --> 00:07:25,959 >> Allura, ma 'dan, aħna qed tmur biex tara kif dan imur. 178 00:07:25,959 --> 00:07:28,000 Jien ser jippruvaw u switch trasferiti għas appliance tiegħi. 179 00:07:28,000 --> 00:07:30,200 180 00:07:30,200 --> 00:07:31,271 Ara jekk I tista 'tagħmel dan. 181 00:07:31,271 --> 00:07:31,770 Kollha. 182 00:07:31,770 --> 00:07:40,970 183 00:07:40,970 --> 00:07:42,370 Aħna biss se jirrifletti dan. 184 00:07:42,370 --> 00:07:44,530 M'hemm xejn crazy fuq laptop tiegħi anyways. 185 00:07:44,530 --> 00:07:49,600 186 00:07:49,600 --> 00:07:50,100 OK. 187 00:07:50,100 --> 00:07:57,030 188 00:07:57,030 --> 00:08:01,054 Dan jeħtieġ li jkun dan wieħed. 189 00:08:01,054 --> 00:08:01,795 Huwa hekk ċkejkna. 190 00:08:01,795 --> 00:08:03,730 191 00:08:03,730 --> 00:08:05,120 Ejja naraw jekk nistgħu nagħmlu dan. 192 00:08:05,120 --> 00:08:09,970 193 00:08:09,970 --> 00:08:10,940 >> OK. 194 00:08:10,940 --> 00:08:15,305 Alice hija ovvjament tissara hawn biss ftit, 195 00:08:15,305 --> 00:08:17,995 iżda aħna ser ġġibu fil momento. 196 00:08:17,995 --> 00:08:20,810 197 00:08:20,810 --> 00:08:22,020 OK. 198 00:08:22,020 --> 00:08:25,900 Aħna biss ser iżżid dan. 199 00:08:25,900 --> 00:08:28,770 200 00:08:28,770 --> 00:08:29,380 OK. 201 00:08:29,380 --> 00:08:31,679 Jistgħu kulħadd tip ta 'tara li? 202 00:08:31,679 --> 00:08:32,470 Forsi ftit? 203 00:08:32,470 --> 00:08:33,594 Naf huwa ftit żgħira. 204 00:08:33,594 --> 00:08:34,570 205 00:08:34,570 --> 00:08:37,530 Inti ma tistax pjuttost figura kif jagħmlu dan akbar. 206 00:08:37,530 --> 00:08:38,350 Jekk xi ħadd jaf. 207 00:08:38,350 --> 00:08:40,309 Ħadd ma jaf kif jagħmlu dan akbar? 208 00:08:40,309 --> 00:08:40,932 OK. 209 00:08:40,932 --> 00:08:42,140 Aħna qed tmur biex roll magħha. 210 00:08:42,140 --> 00:08:45,801 Ma jimpurtax anyways għaliex huwa biss dak l-kodiċi li inti guys għandhom 211 00:08:45,801 --> 00:08:46,300 jkollhom. 212 00:08:46,300 --> 00:08:48,310 >> X'hemm aktar importanti huwa l-terminal hawnhekk. 213 00:08:48,310 --> 00:08:52,840 214 00:08:52,840 --> 00:08:58,690 U aħna għandna hawnhekk Għaliex huwa tant żgħar? 215 00:08:58,690 --> 00:09:02,325 216 00:09:02,325 --> 00:09:02,825 Settings. 217 00:09:02,825 --> 00:09:07,920 218 00:09:07,920 --> 00:09:08,420 Oh. 219 00:09:08,420 --> 00:09:09,500 Ike veru. 220 00:09:09,500 --> 00:09:10,880 Kif jgħid dan? 221 00:09:10,880 --> 00:09:11,770 Minn hemmhekk. 222 00:09:11,770 --> 00:09:19,370 223 00:09:19,370 --> 00:09:21,810 Hija li aħjar għal kulħadd? 224 00:09:21,810 --> 00:09:22,525 OK ,. 225 00:09:22,525 --> 00:09:23,025 Kessaħ. 226 00:09:23,025 --> 00:09:25,830 227 00:09:25,830 --> 00:09:28,220 >> Inti taf meta int fil-CS diffikultajiet tekniċi klassi 228 00:09:28,220 --> 00:09:32,971 huma tip ta 'parti mill the-- Allura, ejja ċar dan. 229 00:09:32,971 --> 00:09:33,470 OK. 230 00:09:33,470 --> 00:09:38,060 Allura, dritt hawn fit-taqsima, li kellna hawn. 231 00:09:38,060 --> 00:09:40,830 Caesar huwa fajl eżekutibbli. 232 00:09:40,830 --> 00:09:41,800 So I għamilha. 233 00:09:41,800 --> 00:09:46,370 Allura, ħaġa waħda li tirrealizza ma GDB huwa li taħdem biss fuq fajls eżekutibbli. 234 00:09:46,370 --> 00:09:48,040 Allura, inti ma tista 'taħdem fuq dotsy. 235 00:09:48,040 --> 00:09:50,532 Inti għandek tagħmel attwalment żgur li kodiċi tiegħek jikkompila, 236 00:09:50,532 --> 00:09:51,865 u li jkun jista 'effettivament jitmexxew. 237 00:09:51,865 --> 00:09:52,970 238 00:09:52,970 --> 00:09:56,186 >> Allura, kun żgur li jekk ma jikkompilaw, ġġibu biex jikkompilaw, 239 00:09:56,186 --> 00:09:57,810 sabiex inti tista 'tip ta' run permezz ta 'dan. 240 00:09:57,810 --> 00:10:04,590 Allura, biex tibda GDB, kull ma għandek tagħmel, Gloria tip GDB, u mbagħad biss l- 241 00:10:04,590 --> 00:10:06,250 fajl li inti tixtieq. 242 00:10:06,250 --> 00:10:08,240 Jien dejjem misspell Caesar. 243 00:10:08,240 --> 00:10:11,730 Iżda inti tixtieq li tagħmel ċert peress li huwa eżekutibbli, 244 00:10:11,730 --> 00:10:14,210 ti tal dot flash hekk li ifisser li inti qed tmur 245 00:10:14,210 --> 00:10:19,240 jiddekorri CSI int ser tesegwixxi dan fajls jew mal-debugger. 246 00:10:19,240 --> 00:10:19,910 OK. 247 00:10:19,910 --> 00:10:22,885 Allura, inti tagħmel dan, inti tikseb dan it-tip ta 'gibberish. 248 00:10:22,885 --> 00:10:24,250 249 00:10:24,250 --> 00:10:25,750 Huwa biss l-affarijiet kollha dwar debugger. 250 00:10:25,750 --> 00:10:28,200 Inti ma verament ikollhom tinkwieta dwar dan id-dritt issa. 251 00:10:28,200 --> 00:10:31,460 U kif tara, aħna għandna dan parens miftuħa, PGD, parens qrib, 252 00:10:31,460 --> 00:10:34,690 u biss tip ta 'qisu linja tal-kmand tagħna, id-dritt? 253 00:10:34,690 --> 00:10:37,010 >> Allura, dak li rridu do-- --So, L-ewwel ħaġa 254 00:10:37,010 --> 00:10:39,570 huwa irridu jagħżlu post li din tinqasam. 255 00:10:39,570 --> 00:10:42,332 Allura, hemm bug wieħed f'dan il-programm Caesar 256 00:10:42,332 --> 00:10:44,290 li nintroduċi, li aħna qed tmur biex issir taf. 257 00:10:44,290 --> 00:10:45,330 258 00:10:45,330 --> 00:10:56,350 Hija Dak li dan huwa li tieħu l-input Barfoo fil tappijiet kollha, u għal xi raġuni 259 00:10:56,350 --> 00:11:01,950 dan ma jbiddilx A. Hija biss tħalli waħdu, Huwa kollox korretti, 260 00:11:01,950 --> 00:11:03,980 iżda t-tieni ittra A tibqa 'mhux mibdula. 261 00:11:03,980 --> 00:11:07,120 Allura, aħna qed tmur biex jippruvaw u figura għaliex dan huwa. 262 00:11:07,120 --> 00:11:10,440 Allura, l-ewwel ħaġa li għandek tipikament trid tagħmel kull meta inti tibda fuq GDB 263 00:11:10,440 --> 00:11:12,010 huwa insemmu fejn li din tinqasam. 264 00:11:12,010 --> 00:11:14,956 >> Allura Caesar huwa programm pretty qasir. 265 00:11:14,956 --> 00:11:16,330 Aħna biss għandhom funzjoni waħda, id-dritt? 266 00:11:16,330 --> 00:11:18,520 Dak li kien il-funzjoni tagħna fl Caesar? 267 00:11:18,520 --> 00:11:19,590 268 00:11:19,590 --> 00:11:24,350 Hemm wieħed biss funzjoni, id-dritt Main? 269 00:11:24,350 --> 00:11:26,490 Main hija funzjoni għall-programmi kollha tiegħek. 270 00:11:26,490 --> 00:11:29,230 Jekk inti ma kellhiex Main, I jista jkun ftit inkwetat dritt issa, 271 00:11:29,230 --> 00:11:31,000 imma nispera li intom kollha kellhom Main fil hemmhekk. 272 00:11:31,000 --> 00:11:34,150 Allura, dak li nistgħu nagħmlu huwa li nistgħu biss break Main, biss bħal dik. 273 00:11:34,150 --> 00:11:35,190 Allura, huwa jgħid, OK. 274 00:11:35,190 --> 00:11:37,430 Waqqafna wieħed breakpoint tagħna hemmhekk. 275 00:11:37,430 --> 00:11:42,870 >> Allura, issa l-ħaġa li tiftakar huwa Caesar jieħu kmand wieħed argument linja dritt 276 00:11:42,870 --> 00:11:45,150 u aħna ma għamlu dan għadu kullimkien. 277 00:11:45,150 --> 00:11:47,560 Allura, dak li għandek tagħmel huwa meta inti fil-fatt tmur run 278 00:11:47,560 --> 00:11:51,540 il-programm, kwalunkwe programm li int li jibda fil GDB li jeħtieġ linja ta 'kmand 279 00:11:51,540 --> 00:11:55,010 argumenti, int ser input meta inti l-ewwel tibda taħdem dan. 280 00:11:55,010 --> 00:11:59,280 Allura, f'dan il-każ, nagħmlu Mexxi ma 'ċavetta ta' tlieta. 281 00:11:59,280 --> 00:12:00,770 282 00:12:00,770 --> 00:12:02,040 U fil-fatt se tibda. 283 00:12:02,040 --> 00:12:08,480 >> Allura, jekk inti tara hawn, aħna għandna Jekk RC mhuwiex ugwali għal 2. 284 00:12:08,480 --> 00:12:12,210 Hekk jekk inti guys kollha għandhom dan il-fajl li I bagħtet up 285 00:12:12,210 --> 00:12:15,100 tkun taf tara li dan huwa bħall- ewwel linja funzjoni prinċipali tagħna, id-dritt? 286 00:12:15,100 --> 00:12:17,890 Huwa verifika biex tara jekk ikollna in-numru korrett ta 'argumenti. 287 00:12:17,890 --> 00:12:20,620 Allura, jekk int mintix jekk RC hija korretta, 288 00:12:20,620 --> 00:12:23,250 inti tista 'tagħmel xi ħaġa bħad Stampa RC. 289 00:12:23,250 --> 00:12:24,380 290 00:12:24,380 --> 00:12:28,640 RC huwa tnejn, li huwa dak li aħna mistennija, id-dritt? 291 00:12:28,640 --> 00:12:32,010 >> Allura, nistgħu mmorru Sussegwentement, u tkompli permezz. 292 00:12:32,010 --> 00:12:33,200 Allura, aħna għandna xi ċavetta hemmhekk. 293 00:12:33,200 --> 00:12:34,260 294 00:12:34,260 --> 00:12:37,090 U nistgħu jistampaw ewlieni tagħna tagħmel ċert li l-korretta. 295 00:12:37,090 --> 00:12:38,380 296 00:12:38,380 --> 00:12:39,500 Interessanti. 297 00:12:39,500 --> 00:12:41,210 Mhux pjuttost dak li aħna mistennija. 298 00:12:41,210 --> 00:12:44,810 Allura, ħaġa waħda li tirrealizza ma GDB wkoll, huwa 299 00:12:44,810 --> 00:12:49,000 li mhuwiex sakemm inti fil-fatt hit Sussegwentement, li l-linja li inti biss raw 300 00:12:49,000 --> 00:12:50,720 huwa attwalment eżegwita. 301 00:12:50,720 --> 00:12:53,870 Allura, f'dan il-każ Key ma ġiex assenjat s'issa. 302 00:12:53,870 --> 00:12:57,050 Allura, Key hija xi valur żibel li tara fuq il-qiegħ hemmhekk. 303 00:12:57,050 --> 00:13:03,680 Negattiv $ 120-- --It ta 'biljun u xi ħaġa affarijiet fard dritt? 304 00:13:03,680 --> 00:13:05,340 Mhuwiex l-Key li aħna mistennija. 305 00:13:05,340 --> 00:13:10,720 Imma jekk aħna hit Sussegwentement, u allura aħna jippruvaw u Stampa ewlieni, huwa tlieta. 306 00:13:10,720 --> 00:13:11,710 >> Kulħadd tara li? 307 00:13:11,710 --> 00:13:13,780 Allura, jekk ikollok xi ħaġa li int tixtieq, stenna. 308 00:13:13,780 --> 00:13:15,540 Dan huwa kompletament ħażin, u jien ma nafx 309 00:13:15,540 --> 00:13:20,150 kif dan jiġri minħabba kollha nixtieq tagħmel hu li tassenja numru, varjabbli, 310 00:13:20,150 --> 00:13:22,900 jippruvaw laqtu Sussegwentement, ipprova istampar mill-ġdid, u ara jekk li x-xogħlijiet. 311 00:13:22,900 --> 00:13:27,830 Għaliex dan huwa biss ser jesegwixxu u attwalment tassenja xi ħaġa wara li inti 312 00:13:27,830 --> 00:13:29,340 hit jmiss. 313 00:13:29,340 --> 00:13:30,336 Jagħmel sens għal kulħadd? 314 00:13:30,336 --> 00:13:30,836 Uh huh? 315 00:13:30,836 --> 00:13:33,220 >> SPEAKER 2: Meta inti każwali numri dak ma jfisser? 316 00:13:33,220 --> 00:13:34,790 >> SPEAKER 1: Huwa biss bl-addoċċ. 317 00:13:34,790 --> 00:13:35,710 Huwa biss żibel. 318 00:13:35,710 --> 00:13:38,320 Huwa biss xi ħaġa li tiegħek kompjuter se saltwarjament tassenja. 319 00:13:38,320 --> 00:13:39,721 320 00:13:39,721 --> 00:13:40,220 Kessaħ. 321 00:13:40,220 --> 00:13:45,760 Allura, issa nistgħu jimxu permezz, u għalhekk issa għandna din GetString test sempliċi. 322 00:13:45,760 --> 00:13:48,600 Allura, let me biss jintroduċu liema se jiġri meta aħna hit li jmiss hawn. 323 00:13:48,600 --> 00:13:51,320 GDB tagħna tip ta tisparixxi, id-dritt? 324 00:13:51,320 --> 00:13:55,720 Dak għax GetString issa qed jesegwixxi, id-dritt? 325 00:13:55,720 --> 00:14:01,460 Allura, meta rajna test sempliċi ugwali GetString, parens miftuħa u parens, 326 00:14:01,460 --> 00:14:04,380 u aħna hit Sussegwentement, li għandha attwalment esegwiti issa. 327 00:14:04,380 --> 00:14:06,580 Allura, huwa stennija għal ahna xi ħaġa input. 328 00:14:06,580 --> 00:14:13,560 >> Allura, aħna qed tmur biex input ikel tagħna li huwa dak huwa jonqos kif I qallek 329 00:14:13,560 --> 00:14:18,020 u li biss jgħid li huwa lest eżekuzzjoni, li l-magħluqa 330 00:14:18,020 --> 00:14:19,980 bracket ifisser li huwa joħorġu barra minn dak loop. 331 00:14:19,980 --> 00:14:21,170 332 00:14:21,170 --> 00:14:25,420 Allura, nistgħu hit Sussegwentement, u issa, kif jien żgur li int kollha familjari minn Caesar, 333 00:14:25,420 --> 00:14:27,260 dan huwa, x'hemm din il-linja se jagħmlu. 334 00:14:27,260 --> 00:14:32,030 Huwa għal Int I ikun egwali għal 0, N ugwali Strlen, test sempliċi, u mbagħad 335 00:14:32,030 --> 00:14:33,960 I hija inqas minn n, I, plus, plus. 336 00:14:33,960 --> 00:14:35,210 X'inhu dan loop se jagħmlu? 337 00:14:35,210 --> 00:14:37,900 338 00:14:37,900 --> 00:14:39,160 Iftaħ il-messaġġ tiegħek. 339 00:14:39,160 --> 00:14:39,770 Kessaħ. 340 00:14:39,770 --> 00:14:41,330 Allura, ejja tibda tagħmel dan. 341 00:14:41,330 --> 00:14:47,210 >> Allura, jekk din il-kundizzjoni jaqblu, għall-ewwel waħda tagħna? 342 00:14:47,210 --> 00:14:52,250 Jekk huwa B, huwa test sempliċi I. Aħna tista 'tikseb informazzjoni dwar lokal tagħna. 343 00:14:52,250 --> 00:14:53,610 344 00:14:53,610 --> 00:14:57,970 So, I huwa żero, u jekk sitta, li nistennew, u ewlenin tagħna huwa tlieta. 345 00:14:57,970 --> 00:14:59,227 Kollha li jagħmel sens, id-dritt? 346 00:14:59,227 --> 00:15:01,310 Dawn in-numri huma kollha eżattament dak li għandu jkun. 347 00:15:01,310 --> 00:15:02,590 348 00:15:02,590 --> 00:15:03,870 Allura, HUM? 349 00:15:03,870 --> 00:15:05,620 SPEAKER 3: Għandi każwali numri għal mini. 350 00:15:05,620 --> 00:15:09,156 351 00:15:09,156 --> 00:15:12,030 SPEAKER 1: Well, nistgħu check-- --we tista 'chat dwar dan fit-tieni. 352 00:15:12,030 --> 00:15:14,110 353 00:15:14,110 --> 00:15:15,750 Imma inti għandek tkun jkollna dan. 354 00:15:15,750 --> 00:15:17,700 355 00:15:17,700 --> 00:15:20,130 Allura, jekk għandna kapital B għall-ewwel waħda tagħna, 356 00:15:20,130 --> 00:15:22,080 din il-kondizzjoni għandha qabda, id-dritt? 357 00:15:22,080 --> 00:15:27,120 Allura, jekk aħna hit Sussegwentement, naraw li din Jekk attwalment tesegwixxi. 358 00:15:27,120 --> 00:15:29,220 Għaliex jekk int wara flimkien fil-kodiċi tiegħek, 359 00:15:29,220 --> 00:15:33,460 din il-linja hawn, fejn test sempliċi I huwa mibdul ma 'dan aritmetika, 360 00:15:33,460 --> 00:15:35,720 tesegwixxi biss jekk il Jekk kundizzjoni huwa dritt korretta? 361 00:15:35,720 --> 00:15:36,905 362 00:15:36,905 --> 00:15:40,240 >> GDB huwa biss se nuruk affarijiet li huma attwalment esekuzzjoni. 363 00:15:40,240 --> 00:15:45,140 Mela jekk din il-kundizzjoni Jekk ma kinitx sodisfatta, huwa biss se skip sa l-linja li jmiss. 364 00:15:45,140 --> 00:15:46,540 OK? 365 00:15:46,540 --> 00:15:48,510 Allura, aħna għandna dan. 366 00:15:48,510 --> 00:15:51,171 Dan bracket ifisser li huwa magħluq ta 'dak loop issa. 367 00:15:51,171 --> 00:15:52,420 Allura, li għaddej biex jerġa 'jibda. 368 00:15:52,420 --> 00:15:54,760 369 00:15:54,760 --> 00:15:56,280 Eżatt bħal dik. 370 00:15:56,280 --> 00:15:59,120 Allura, li nistgħu jiksbu info dwar lokal tagħna hawn, 371 00:15:59,120 --> 00:16:02,575 u naraw li l-ewwel tagħna ittra inbidlet, id-dritt? 372 00:16:02,575 --> 00:16:05,150 Huwa issa E, kif għandu jkun. 373 00:16:05,150 --> 00:16:07,360 Allura, nistgħu tkompli fuq. 374 00:16:07,360 --> 00:16:08,500 >> U aħna għandna dan il-kontroll. 375 00:16:08,500 --> 00:16:09,916 U dan il-kontroll għandhom jaħdmu, right? 376 00:16:09,916 --> 00:16:12,570 Huwa A. Għandu jinbidlu tliet ittri quddiem. 377 00:16:12,570 --> 00:16:14,320 378 00:16:14,320 --> 00:16:16,530 Imma jekk tinnota, aħna nikseb xi ħaġa differenti. 379 00:16:16,530 --> 00:16:17,580 380 00:16:17,580 --> 00:16:22,860 Allura f'dan il-każ up here, maqbuda dan, u għalhekk din il-linja eżegwit, 381 00:16:22,860 --> 00:16:28,620 li modifikata tagħna B. Iżda, f'dan il-każ hawnhekk, 382 00:16:28,620 --> 00:16:32,860 aħna għandna li hija biss skipped dan, u marru għall-[? L siff. ?] 383 00:16:32,860 --> 00:16:34,660 Allura xi ħaġa għaddej fuq hemmhekk. 384 00:16:34,660 --> 00:16:37,780 Dak thats tghidlek huwa li, nafu li dan għandu qabda hawnhekk, 385 00:16:37,780 --> 00:16:39,200 iżda mhux. 386 00:16:39,200 --> 00:16:42,210 Jista 'xi ħadd tara dak tagħna problema hija f'dik il-linja? 387 00:16:42,210 --> 00:16:45,380 388 00:16:45,380 --> 00:16:46,969 Hija ħaġa ħafna minuta. 389 00:16:46,969 --> 00:16:48,510 U inti tista 'wkoll tħares lejn kodiċi tiegħek. 390 00:16:48,510 --> 00:16:49,980 391 00:16:49,980 --> 00:16:54,940 Huwa line-- wkoll tinsa liema linja huwa fil there-- imma hija fil-[inaudible]. 392 00:16:54,940 --> 00:16:55,480 Iva? 393 00:16:55,480 --> 00:16:58,639 >> SPEAKER 4: Hu l fuq l-akbar minn paġna jekk inti taqraha fil-ktieb. 394 00:16:58,639 --> 00:16:59,430 SPEAKER 1: Eżattament. 395 00:16:59,430 --> 00:17:02,620 Allura, l-debugger ma setax jgħid inti, iżda l-debugger 396 00:17:02,620 --> 00:17:05,880 jistgħu jiksbu inti isfel ma 'linja li inti taf ma tkunx qed taħdem. 397 00:17:05,880 --> 00:17:09,319 U xi kultant, meta speċjalment aktar tard fil-semestru, meta 398 00:17:09,319 --> 00:17:12,910 int jittrattaw mitt, a mitt ftit linji tal-kodiċi, u inti 399 00:17:12,910 --> 00:17:16,190 ma nafx fejn huwa fin-nuqqas, dan huwa mod tajjeb ħafna biex jagħmlu dan. 400 00:17:16,190 --> 00:17:17,900 401 00:17:17,900 --> 00:17:18,989 Allura, sibna bug tagħna. 402 00:17:18,989 --> 00:17:21,530 Inti tista 'tiffissa lilha fil-fajl tiegħek, u allura inti tista 'tmexxi dan mill-ġdid, 403 00:17:21,530 --> 00:17:23,029 u kollox se taħdem perfettament. 404 00:17:23,029 --> 00:17:24,970 405 00:17:24,970 --> 00:17:30,590 U l-akbar ħaġa hija dan jista 'jidher simili, OK. 406 00:17:30,590 --> 00:17:31,090 Yeah. 407 00:17:31,090 --> 00:17:31,370 Kessaħ. 408 00:17:31,370 --> 00:17:32,744 Inti taf dak li qed tfittex. 409 00:17:32,744 --> 00:17:34,910 Allura, inti kienu jafu x'għandhom jagħmlu. 410 00:17:34,910 --> 00:17:39,021 >> GDB jista 'jkun utli super għaliex inti jista jistampa dawn kollha affarijiet li inti 411 00:17:39,021 --> 00:17:39,520 kieku ma. 412 00:17:39,520 --> 00:17:41,160 Huwa ħafna aktar utli minn printf. 413 00:17:41,160 --> 00:17:43,440 Kemm inti tuża bħal dikjarazzjonijiet printf 414 00:17:43,440 --> 00:17:46,200 biex insemmu fejn bug kien, id-dritt? 415 00:17:46,200 --> 00:17:48,450 Allura, ma 'dan, inti ma għandhom iżommu tmur lura, 416 00:17:48,450 --> 00:17:51,139 u simili kummentar fil Printf, jew jikkummentaw out, 417 00:17:51,139 --> 00:17:52,930 u ċifra barra dak inti għandek tkun l-istampar. 418 00:17:52,930 --> 00:17:55,670 Dan fil-fatt biss tippermetti li inti pass permezz, jistampa affarijiet 419 00:17:55,670 --> 00:18:00,000 kif int għaddejjin, hekk, inti tista ' josservaw kif dawn jinbidlu fil-ħin reali, 420 00:18:00,000 --> 00:18:02,190 kif program tiegħek tkun qed taħdem. 421 00:18:02,190 --> 00:18:04,390 >> U ma tieħu ftit daqsxejn ta 'jkollna użati biex. 422 00:18:04,390 --> 00:18:07,850 I jirrakkomanda ħafna biss tip li tkun ftit frustrat magħha 423 00:18:07,850 --> 00:18:08,930 għal dritt issa. 424 00:18:08,930 --> 00:18:13,450 Jekk inti tqatta siegħa fuq il- ġimgħa d-dieħla tagħlim kif tuża GDB, 425 00:18:13,450 --> 00:18:16,140 inti se jiffrankaw yourself tant żmien aktar tard. 426 00:18:16,140 --> 00:18:18,750 U litteralment. we tell dan nies kull sena, 427 00:18:18,750 --> 00:18:23,890 u I tiftakar meta I ħa l- klassi, I kien simili, I se tkun multa. 428 00:18:23,890 --> 00:18:24,700 No 429 00:18:24,700 --> 00:18:27,030 Pset 6 daħal fuq u I kien bħal, jien gonna jitgħallmu 430 00:18:27,030 --> 00:18:29,500 kif tuża GDB minħabba I ma jafu x'inhu għaddej hawn. 431 00:18:29,500 --> 00:18:32,940 >> Mela jekk inti tieħu l-ħin hekk użu fuq programmi iżgħar 432 00:18:32,940 --> 00:18:35,697 li int ser tkun jaħdmu fuq, bħal xogħol 433 00:18:35,697 --> 00:18:37,530 permezz xi ħaġa bħal Visionare, bħal dan. 434 00:18:37,530 --> 00:18:38,800 435 00:18:38,800 --> 00:18:42,850 Jew jekk inti tixtieq prattika żejda, jien ċert I tista 'toħroġ bi programmi Buggy, 436 00:18:42,850 --> 00:18:45,300 għalik biex debug jekk inti tixtieq. 437 00:18:45,300 --> 00:18:49,300 >> Imma jekk inti biss tieħu ftit ħin biex tikseb użati biex dan, biss play madwar magħha, 438 00:18:49,300 --> 00:18:50,550 se int verament sservi tajjeb. 439 00:18:50,550 --> 00:18:52,591 U huwa verament wieħed mill dawk l-affarijiet li inti biss 440 00:18:52,591 --> 00:18:57,340 jkollhom biex jippruvaw, u tikseb idejk maħmuġin ma ', qabel ma int verament tifhem dan. 441 00:18:57,340 --> 00:19:02,090 I really mifhum biss darba I kellha affarijiet debug magħha, 442 00:19:02,090 --> 00:19:08,170 u huwa ħafna nicer li jkollhom idea ta ' kif debug mill-aktar. 443 00:19:08,170 --> 00:19:08,850 OK. 444 00:19:08,850 --> 00:19:09,625 Kessaħ. 445 00:19:09,625 --> 00:19:12,960 Naf li tip simili kors tiġrifa fil GDB, 446 00:19:12,960 --> 00:19:16,400 u jien se definittivament taħdem fuq jkollna dawn biex tħares ħin li jmiss akbar. 447 00:19:16,400 --> 00:19:17,590 448 00:19:17,590 --> 00:19:18,280 Kessaħ. 449 00:19:18,280 --> 00:19:20,390 >> Allura, jekk immorru lura għall PowerPoint tagħna. 450 00:19:20,390 --> 00:19:27,194 451 00:19:27,194 --> 00:19:28,110 Huwa dan se jaħdem? 452 00:19:28,110 --> 00:19:29,711 453 00:19:29,711 --> 00:19:30,210 AWH. 454 00:19:30,210 --> 00:19:31,101 Iva. 455 00:19:31,101 --> 00:19:31,600 OK. 456 00:19:31,600 --> 00:19:35,480 Allura, jekk inti qatt bżonn xi wieħed dawk darb'oħra, hemm il-lista. 457 00:19:35,480 --> 00:19:37,160 458 00:19:37,160 --> 00:19:40,830 Allura Binarju Fittex, li kulħadd jiftakar l-ispettaklu kbir ta 'David 459 00:19:40,830 --> 00:19:42,259 ripping phone kotba fil nofs. 460 00:19:42,259 --> 00:19:44,050 I ma verament tikseb l- kotba tat-telefon aktar, 461 00:19:44,050 --> 00:19:46,530 għaliex bħal fejn do inti tikseb kotba tat-telefon dawn il-jiem? 462 00:19:46,530 --> 00:19:48,220 I verament ma nafx. 463 00:19:48,220 --> 00:19:49,840 464 00:19:49,840 --> 00:19:50,590 Il Fittex Binarju. 465 00:19:50,590 --> 00:19:52,464 Hawn xi ħadd ftakar kif Binarju Fittex xogħlijiet? 466 00:19:52,464 --> 00:19:54,380 467 00:19:54,380 --> 00:19:55,220 Kulħadd fil-livelli kollha? 468 00:19:55,220 --> 00:19:56,325 Yeah? 469 00:19:56,325 --> 00:19:58,283 SPEAKER 5: Inti taf meta inti tħares lejn li nofshom 470 00:19:58,283 --> 00:20:01,146 ikun fi, Ibbażat fuq dan, u jeħles mill-nofs l-ieħor. 471 00:20:01,146 --> 00:20:01,896 >> SPEAKER 1 Eżattament. 472 00:20:01,896 --> 00:20:06,290 Allura, Binarju Fittex, huwa tip ta 'a-- --we simili li hija sejħa jaqsam u jirbħu. 473 00:20:06,290 --> 00:20:09,170 Allura, dak li inti ser tagħmel hu inti ser tħares fin-nofs, 474 00:20:09,170 --> 00:20:11,990 u tkun taf tara jekk logħbiet dak li qed tfittex. 475 00:20:11,990 --> 00:20:15,420 U jekk ma jiġrix dan, allura inti tipprova insemmu, huwa se jitħalla 476 00:20:15,420 --> 00:20:16,450 nofs jew il-nofs tal-lemin. 477 00:20:16,450 --> 00:20:19,325 Allura, dan jista 'jkun jekk inti qed tfittex fuq xi ħaġa thats alphabetized, 478 00:20:19,325 --> 00:20:20,720 tara, oh. 479 00:20:20,720 --> 00:20:22,750 Does Allison jiġi qabel M? 480 00:20:22,750 --> 00:20:23,250 Iva. 481 00:20:23,250 --> 00:20:25,030 Allura, aħna qed tmur biex tħares lejn l-ewwel nofs. 482 00:20:25,030 --> 00:20:26,450 >> Jew jista 'jkun simili bin-numri. 483 00:20:26,450 --> 00:20:28,830 Kwalunkwe ħaġa li inti tista ' iqabblu, dan jistgħu jiġu magħżula. 484 00:20:28,830 --> 00:20:29,920 485 00:20:29,920 --> 00:20:31,260 Inti tista 'tuża tfittxija binarja fuq. 486 00:20:31,260 --> 00:20:32,340 487 00:20:32,340 --> 00:20:37,455 Allura, xi ħadd ftakar dan grafika jew dak li din hija? 488 00:20:37,455 --> 00:20:39,520 Huwa Kumplessità Asymptotic. 489 00:20:39,520 --> 00:20:42,830 Allura, din il-graff biss tiddeskrivi kemm hija 490 00:20:42,830 --> 00:20:46,230 tieħdok biex isolvu problema bħala inti jiżdied in-numru ta 'affarijiet 491 00:20:46,230 --> 00:20:47,090 li inti qed tuża. 492 00:20:47,090 --> 00:20:51,260 >> Allura, aħna għandna N, li huwa żmien lineari. 493 00:20:51,260 --> 00:20:54,560 Jekk N fuq tnejn, li hija ftit aħjar, xorta tikber super fast. 494 00:20:54,560 --> 00:20:58,360 U allura aħna għandna Login, li hija dak li aħna nikkunsidraw Binarju Search. 495 00:20:58,360 --> 00:21:03,630 Jekk aħna Avviż, kif l-problema tiegħek gets ħafna u ħafna akbar, 496 00:21:03,630 --> 00:21:06,600 il-ħin li tieħu inti issolviha ma verament jżidu li ħafna. 497 00:21:06,600 --> 00:21:09,010 Huwa simili komparabbli hawn fil-bidu. 498 00:21:09,010 --> 00:21:10,060 Int simili, OK. 499 00:21:10,060 --> 00:21:13,000 Xejn hawn ma verament kwistjoni li wieħed nużaw, 500 00:21:13,000 --> 00:21:16,220 imma inti toħroġ lil miljun, biljun. 501 00:21:16,220 --> 00:21:20,010 Inti qed tipprova ssib some-- --you're jippruvaw isibu labra fil haystack. 502 00:21:20,010 --> 00:21:21,550 >> Naħseb li inti tixtieq din il-problema. 503 00:21:21,550 --> 00:21:25,850 Inti tixtieq din il-kumplessità, mhux lineari għaliex għal kull ma għandek 504 00:21:25,850 --> 00:21:30,049 taf gonna tiegħek tkun tiftix permezz kull labra individwali, ħaġa tal ħuxlief, 505 00:21:30,049 --> 00:21:31,340 tipprova tfittex għal labra tiegħek. 506 00:21:31,340 --> 00:21:34,730 U li mhux wisq gost fl-opinjoni tiegħi. 507 00:21:34,730 --> 00:21:35,500 I simili fast. 508 00:21:35,500 --> 00:21:36,620 I simili effiċjenti. 509 00:21:36,620 --> 00:21:40,450 U l-istudenti kif hardworking inti guys huma, inti taf taħdem aktar intelliġenti, 510 00:21:40,450 --> 00:21:43,010 mhux aktar diffiċli ħaġa tip, kif inti jista 'jagħmel sa dawn algoritmi. 511 00:21:43,010 --> 00:21:45,110 512 00:21:45,110 --> 00:21:47,910 >> Allura, aħna qed tmur biex jimxu permezz biss eżempju malajr. 513 00:21:47,910 --> 00:21:51,090 Naħseb li inti guys għandu jkollhom idejn fuq Binarju Fittex, 514 00:21:51,090 --> 00:21:54,352 iżda fil-każ ħadd huwa ftit fuzzy, tixtieq li din tissaħħaħ, 515 00:21:54,352 --> 00:21:56,310 aħna qed tmur biex jmorru biss permezz ta 'eżempju hawn. 516 00:21:56,310 --> 00:21:59,490 Allura, aħna qed tfittex jekk l-array fih sebgħa. 517 00:21:59,490 --> 00:22:00,540 518 00:22:00,540 --> 00:22:06,010 >> Allura, l-ewwel ħaġa li għandna nagħmlu huwa ħarsa fin-nofs, id-dritt? 519 00:22:06,010 --> 00:22:09,340 U wkoll int se tkun kodifikazzjoni Binarju Fittex fi ftit tieni. 520 00:22:09,340 --> 00:22:11,310 Allura, li għaddej biex tkun divertenti. 521 00:22:11,310 --> 00:22:13,710 Allura aħna tfittex fil- arrays ftit nofs 3. 522 00:22:13,710 --> 00:22:15,501 Does 3 ugwali 7? 523 00:22:15,501 --> 00:22:16,000 Ma. 524 00:22:16,000 --> 00:22:18,670 525 00:22:18,670 --> 00:22:19,550 Huwa sitta. 526 00:22:19,550 --> 00:22:21,480 Allura, huwa inqas minn jew akbar minn seba? 527 00:22:21,480 --> 00:22:23,080 528 00:22:23,080 --> 00:22:23,960 Inqas minn. 529 00:22:23,960 --> 00:22:24,570 Iva. 530 00:22:24,570 --> 00:22:25,170 Guys xogħol sbieħ. 531 00:22:25,170 --> 00:22:25,569 532 00:22:25,569 --> 00:22:27,360 Inħoss I simili I għandhom jkollhom kandju minħabba I 533 00:22:27,360 --> 00:22:29,460 tixtieq li tarmi it out fil-tarzni. 534 00:22:29,460 --> 00:22:30,270 Huwa dak li jiena ser tagħmel ġimgħa d-dieħla. 535 00:22:30,270 --> 00:22:31,436 Hija se jżommok guys qawwija. 536 00:22:31,436 --> 00:22:32,560 537 00:22:32,560 --> 00:22:34,690 >> Allura, aħna armih li ewwel nofs, id-dritt? 538 00:22:34,690 --> 00:22:35,670 kien inqas minn. 539 00:22:35,670 --> 00:22:39,325 nafu li kollox fuq dik in-naħa tax-xellug 540 00:22:39,325 --> 00:22:41,700 se tkun inqas minn dak aħna qed fil-fatt tfittex. 541 00:22:41,700 --> 00:22:43,491 Allura, hemm ebda bżonn li tagħti attenzjoni għalih. 542 00:22:43,491 --> 00:22:45,120 Just tinsieh. 543 00:22:45,120 --> 00:22:48,720 Allura, issa irridu nħarsu lejn in-naħa tagħna tal-lemin, u nħarsu lejn l-nofs hemmhekk, 544 00:22:48,720 --> 00:22:50,510 u issa huwa disgħa. 545 00:22:50,510 --> 00:22:55,510 Allura, 9 is-- --Everyone? 546 00:22:55,510 --> 00:22:57,470 Akbar minn dak li aħna qed tfittex, id-dritt? 547 00:22:57,470 --> 00:22:59,860 Allura, aħna qed tmur biex tarmi bogħod kollox lejn il-lemin. 548 00:22:59,860 --> 00:23:00,970 549 00:23:00,970 --> 00:23:01,940 Bħal dik. 550 00:23:01,940 --> 00:23:03,700 Issa, kollox aħna qed xellug ma huwa wieħed. 551 00:23:03,700 --> 00:23:07,760 Allura aħna jiċċekkjaw, huwa dan wieħed dak aħna qed tfittex? huwa. 552 00:23:07,760 --> 00:23:08,970 Sibna dak li ridna. 553 00:23:08,970 --> 00:23:10,440 554 00:23:10,440 --> 00:23:11,690 Allura aħna qed isir. 555 00:23:11,690 --> 00:23:12,550 Bilinear Search. 556 00:23:12,550 --> 00:23:15,740 >> U jekk tinnota, aħna kellhom seba inputs hemmhekk. 557 00:23:15,740 --> 00:23:24,320 Hija biss ħadet us bħal tliet darbiet, imma jekk int tagħmel bħal biljun, 558 00:23:24,320 --> 00:23:28,190 inti guys taf kif ħafna passi li kieku jieħu jekk kellna erba 'biljun affarijiet? 559 00:23:28,190 --> 00:23:29,940 560 00:23:29,940 --> 00:23:30,455 Kwalunkwe guesses? 561 00:23:30,455 --> 00:23:32,286 562 00:23:32,286 --> 00:23:33,960 Huwa 32. 563 00:23:33,960 --> 00:23:37,110 32 passi biex isibu xi ħaġa fil-erba 'biljun 564 00:23:37,110 --> 00:23:39,650 element array minħabba setgħat ta 'tnejn. 565 00:23:39,650 --> 00:23:43,550 Allura tnejn huwa sa 32, huwa li erba 'biljun. 566 00:23:43,550 --> 00:23:50,430 >> Kif so pretty crazy int xorta ġewwa bħal numru pjuttost żgħir ta 'passi 567 00:23:50,430 --> 00:23:52,650 biex isibu xi ħaġa fil erba 'biljun elementi. 568 00:23:52,650 --> 00:23:55,730 Allura fuq din in-nota, aħna qed jmorru għall-kodiċi dan 569 00:23:55,730 --> 00:23:58,950 Allura inti guys tista 'attwalment tip ta 'tara kif dan xogħlijiet. 570 00:23:58,950 --> 00:24:01,520 Kull dritt, sabiex inti guys tista 'kodiċi. 571 00:24:01,520 --> 00:24:04,100 Jien ser tavżak guys jitkellmu għal ftit. 572 00:24:04,100 --> 00:24:07,970 Jsiru jafu nies ta 'madwarek, li hija dak li xi ħadd ried mill-aħħar taqsima. 573 00:24:07,970 --> 00:24:10,280 >> Allura isiru jafu l-poplu madwar inti. 574 00:24:10,280 --> 00:24:11,305 Jitkellmu għal ftit. 575 00:24:11,305 --> 00:24:12,580 576 00:24:12,580 --> 00:24:15,730 U kollha nixtieq minn int guys dritt issa huwa biss 577 00:24:15,730 --> 00:24:17,575 tipprova toħloq kontorn ta pseudocode. 578 00:24:17,575 --> 00:24:18,075 OK? 579 00:24:18,075 --> 00:24:20,825 580 00:24:20,825 --> 00:24:21,325 Whoa. 581 00:24:21,325 --> 00:24:23,320 582 00:24:23,320 --> 00:24:29,520 All I trid mill inti guys huwa int biss se timla f'dan il-każ waqt. 583 00:24:29,520 --> 00:24:32,170 So I waqqfu dawn ta 'fuq u limiti baxxi li 584 00:24:32,170 --> 00:24:35,250 jirrappreżentaw il-bidu u t-tmiem ta 'firxa tagħna. 585 00:24:35,250 --> 00:24:40,440 U inti ser attwalment loop permezz ta 'u figura 586 00:24:40,440 --> 00:24:42,470 dak li aħna qed tagħmel fi ħdan dan loop waqt. 587 00:24:42,470 --> 00:24:45,810 >> Hekk jekk inti tista 'figura out-- Għandi ħjiel there-- liema huma l-każijiet 588 00:24:45,810 --> 00:24:46,640 li għandna hawnhekk? 589 00:24:46,640 --> 00:24:48,100 590 00:24:48,100 --> 00:24:51,560 Mela jekk inti tixtieq li insemmu l- każijiet, aħna se pseudocode dawk 591 00:24:51,560 --> 00:24:53,350 u allura aħna ser attwalment kodiċi lilhom. 592 00:24:53,350 --> 00:24:55,330 U li għaddej biex tkun, I think, nisperaw inneħħu 593 00:24:55,330 --> 00:24:56,788 jkun ftit aktar faċli milli għandek tistenna. 594 00:24:56,788 --> 00:24:57,554 595 00:24:57,554 --> 00:25:00,220 Għaliex dan m'huwiex kodiċi ħafna, attwalment, li huwa verament jibred. 596 00:25:00,220 --> 00:25:34,110 597 00:25:34,110 --> 00:25:35,018 >> Mm-hm? 598 00:25:35,018 --> 00:25:35,893 >> STUDENT: [inaudible]? 599 00:25:35,893 --> 00:25:36,984 600 00:25:36,984 --> 00:25:37,650 Istruttur: Iva. 601 00:25:37,650 --> 00:25:38,595 Kien hemm xi ħaġa li ssib fil-nofs. 602 00:25:38,595 --> 00:25:39,552 >> STUDENT: Allura nistgħu nużaw dak. 603 00:25:39,552 --> 00:25:39,770 OK. 604 00:25:39,770 --> 00:25:40,603 >> Istruttur: Perfect. 605 00:25:40,603 --> 00:25:42,950 Allura li l-ewwel ħaġa li għandna bżonn tagħmel. 606 00:25:42,950 --> 00:25:44,330 Allura ssib-nofs. 607 00:25:44,330 --> 00:25:45,415 608 00:25:45,415 --> 00:25:45,915 Kbira. 609 00:25:45,915 --> 00:25:47,770 610 00:25:47,770 --> 00:25:55,010 Allura inti għandek idea ta 'kif nistgħu attwalment issib l-nofs bil-kodiċi? 611 00:25:55,010 --> 00:25:55,980 >> STUDENT: Yeah. 612 00:25:55,980 --> 00:25:57,000 n aktar minn 2? 613 00:25:57,000 --> 00:25:58,500 614 00:25:58,500 --> 00:25:59,500 Istruttur: Allura n aktar minn 2. 615 00:25:59,500 --> 00:26:05,170 Allura ħaġa waħda hija li tiftakar li limiti ta 'fuq u t'isfel tiegħek bidla. 616 00:26:05,170 --> 00:26:08,110 Inżommu constricting l-parti mill-firxa aħna qed tfittex għal. 617 00:26:08,110 --> 00:26:11,970 Allura n aktar minn 2 se taħdem biss għall-ewwel ħaġa li għandna nagħmlu. 618 00:26:11,970 --> 00:26:17,810 Allura tieħu fuq u t'isfel kont, kif tista nikbru li element tan-nofs? 619 00:26:17,810 --> 00:26:20,640 Għaliex irridu-nofs bejn fuq u t'isfel, id-dritt? 620 00:26:20,640 --> 00:26:21,730 621 00:26:21,730 --> 00:26:22,494 Mm-hm? 622 00:26:22,494 --> 00:26:23,369 >> STUDENT: [inaudible]. 623 00:26:23,369 --> 00:26:26,170 624 00:26:26,170 --> 00:26:28,080 >> Istruttur: Allura aħna għandna xi nofs. 625 00:26:28,080 --> 00:26:32,730 U dan ser ikun ta 'fuq plus t'isfel fuq 2. 626 00:26:32,730 --> 00:26:34,740 627 00:26:34,740 --> 00:26:35,690 Biża. 628 00:26:35,690 --> 00:26:36,570 Hemm immorru. 629 00:26:36,570 --> 00:26:37,280 Wieħed linja stabbiliti. 630 00:26:37,280 --> 00:26:38,560 Inti guys fuq tiegħek mod. 631 00:26:38,560 --> 00:26:41,400 Allura issa li għandna tagħna nofs, dak li rridu nagħmlu? 632 00:26:41,400 --> 00:26:45,050 633 00:26:45,050 --> 00:26:45,900 Just b'mod ġenerali. 634 00:26:45,900 --> 00:26:47,734 Inti ma għandekx kodiċi lilha. 635 00:26:47,734 --> 00:26:48,335 Iva. 636 00:26:48,335 --> 00:26:49,210 STUDENT: [inaudible]? 637 00:26:49,210 --> 00:27:00,310 638 00:27:00,310 --> 00:27:10,310 Istruttur: Allura huwa plus għax int konstatazzjoni tal-medja bejn it-tnejn 639 00:27:10,310 --> 00:27:10,810 minnhom. 640 00:27:10,810 --> 00:27:11,890 641 00:27:11,890 --> 00:27:17,370 Mela jekk inti taħseb minnhom bħala tip ta 'żieda fil mill-ġnub, 642 00:27:17,370 --> 00:27:21,640 taħseb dwarha bħala inti approċċ l-nofs, inti tixtieq bħal dik. 643 00:27:21,640 --> 00:27:27,150 Mela jekk inti kienu fuq kull naħa tal- tan-nofs, u għandna simili 5 u 7. 644 00:27:27,150 --> 00:27:31,440 Meta inti żid lilhom flimkien inti nikseb 12, inti iddividi 2, huwa 6. 645 00:27:31,440 --> 00:27:33,726 >> Xi kultant huwa diffiċli li jispjega għaliex li x-xogħlijiet, 646 00:27:33,726 --> 00:27:35,600 imma jekk inti taħdem permezz eżempju kultant, 647 00:27:35,600 --> 00:27:37,962 dan ser jgħinek insemmu jekk għandu jkun plus jew minus. 648 00:27:37,962 --> 00:27:38,846 Iva. 649 00:27:38,846 --> 00:27:40,830 >> STUDENT: [inaudible] eżattament fin-nofs 650 00:27:40,830 --> 00:27:43,950 jekk kellhom każ fejn hemm ħafna ta 'numri iżgħar 651 00:27:43,950 --> 00:27:45,860 u bħal wieħed numru kbir? 652 00:27:45,860 --> 00:27:49,750 >> Istruttur: Allura kull ma għandek bżonn huwa l-nofs tal-firxa. 653 00:27:49,750 --> 00:27:53,010 Mela jekk kellek mazz ta 'numri żgħar u mbagħad numru wieħed verament kbir 654 00:27:53,010 --> 00:27:54,799 fl-aħħar, ma jimpurtax. 655 00:27:54,799 --> 00:27:56,840 Dak kollu li huwa importanti huwa li dawn qed magħżula, inti biss 656 00:27:56,840 --> 00:27:59,339 tixtieq li tħares lejn l-nofs ta ' l-array għax int xorta 657 00:27:59,339 --> 00:28:00,700 tiflil problema tiegħek nofs. 658 00:28:00,700 --> 00:28:03,020 659 00:28:03,020 --> 00:28:03,680 Kessaħ. 660 00:28:03,680 --> 00:28:06,430 Allura issa li aħna għandna l- nofs, dak li nagħmlu jmiss? 661 00:28:06,430 --> 00:28:07,150 >> STUDENT: Qabbel. 662 00:28:07,150 --> 00:28:08,150 Istruttur: Il jqabblu. 663 00:28:08,150 --> 00:28:11,670 Allura jqabblu nofs biex value_wanted. 664 00:28:11,670 --> 00:28:14,300 665 00:28:14,300 --> 00:28:15,160 Kessaħ. 666 00:28:15,160 --> 00:28:17,950 Allura inti tara up here għandna dan il-valur irridu up here. 667 00:28:17,950 --> 00:28:22,012 668 00:28:22,012 --> 00:28:23,095 Ftakar li dan huwa firxa. 669 00:28:23,095 --> 00:28:24,100 670 00:28:24,100 --> 00:28:26,970 Hekk nofs tirreferi għall-indiċi. 671 00:28:26,970 --> 00:28:29,785 Allura rridu nagħmlu valuri ta 'nofs. 672 00:28:29,785 --> 00:28:32,380 673 00:28:32,380 --> 00:28:35,650 Tinsiex jekk inti tixtieq li jqabblu, ugwali doppja. 674 00:28:35,650 --> 00:28:38,250 You do wieħed ugwali int biss se jassenja mill-ġdid, 675 00:28:38,250 --> 00:28:41,090 u mbagħad, ovvjament, huwa se jkun il-valur li trid. 676 00:28:41,090 --> 00:28:42,300 Allura ma tagħmel dan. 677 00:28:42,300 --> 00:28:44,350 >> Allura aħna qed tmur biex tara jekk il-valuri fil-nofs 678 00:28:44,350 --> 00:28:46,460 huwa ugwali għall-valur li rridu. 679 00:28:46,460 --> 00:28:47,749 680 00:28:47,749 --> 00:28:48,790 Tinsiex braces tiegħek. 681 00:28:48,790 --> 00:28:50,520 682 00:28:50,520 --> 00:28:52,235 Dropbox għandhom imorru. 683 00:28:52,235 --> 00:28:54,140 684 00:28:54,140 --> 00:28:56,200 Allura x'nistgħu nagħmlu f'dan il-każ? 685 00:28:56,200 --> 00:28:59,360 Jekk huwa dak li rridu li jirritornaw? 686 00:28:59,360 --> 00:29:01,510 687 00:29:01,510 --> 00:29:02,626 Aħna qed nipprova ngħid. 688 00:29:02,626 --> 00:29:03,440 >> STUDENT: Stampa off. 689 00:29:03,440 --> 00:29:05,314 >> Istruttur: Well, aħna ma jridux li jistampaw off. 690 00:29:05,314 --> 00:29:08,220 Allura dan huwa BOOL hawn, hekk aħna jridu jirritornaw vera jew falza. 691 00:29:08,220 --> 00:29:12,280 Aħna qed tgħid, huwa dan in-numru l [? RRA? ?] Mela jekk huwa, 692 00:29:12,280 --> 00:29:13,788 aħna biss ritorn veru. 693 00:29:13,788 --> 00:29:16,780 694 00:29:16,780 --> 00:29:17,760 Jekk I jistgħu jfissru veru. 695 00:29:17,760 --> 00:29:18,830 696 00:29:18,830 --> 00:29:20,805 >> STUDENT: Għaliex ma inti tirritorna żero? 697 00:29:20,805 --> 00:29:22,930 Istruttur: Allura inti tista ritorn żero jekk int riedu. 698 00:29:22,930 --> 00:29:26,780 Iżda f'dan il-każ għaliex funzjoni tagħna jirritorna BOOL, 699 00:29:26,780 --> 00:29:28,962 għandna bżonn li jirritornaw jew vera jew falza. 700 00:29:28,962 --> 00:29:30,920 STUDENT: Meta int qal espressjoni Boolean, 701 00:29:30,920 --> 00:29:33,450 inti tista 'tistabbilixxi lilha ugwali għal falza? 702 00:29:33,450 --> 00:29:39,860 Bħal jekk irrid ngħid, jekk din il-kundizzjoni ma tiġix sodisfatta, bħal huwa fuq ugwali falza. 703 00:29:39,860 --> 00:29:42,332 Se tifhem jekk inti biss tpoġġi falza fuq in-naħa l-oħra? 704 00:29:42,332 --> 00:29:43,040 Istruttur: Yeah. 705 00:29:43,040 --> 00:29:44,820 Mela attwalment jekk int qatt tagħmel xi ħaġa 706 00:29:44,820 --> 00:29:49,600 bħall hija ta 'fuq jew t'isfel, li jirritorna veru jew falza 707 00:29:49,600 --> 00:29:53,850 u huwa stil attwalment ħażina li jiġifieri ugwali ugwali vera jew partijiet ugwali 708 00:29:53,850 --> 00:29:54,840 ugwali falza. 709 00:29:54,840 --> 00:30:00,210 Inti tixtieq li tuża dik riżultat kif ruħu bħala check tiegħek. 710 00:30:00,210 --> 00:30:04,720 711 00:30:04,720 --> 00:30:05,860 Mhux dak li ridt. 712 00:30:05,860 --> 00:30:08,150 713 00:30:08,150 --> 00:30:09,240 Dan huwa dak li ridt. 714 00:30:09,240 --> 00:30:13,205 Hekk fil-każ ta 'int tistaqsi dwar xi ħaġa bħal tiffranka dan fil ċ. 715 00:30:13,205 --> 00:30:16,320 716 00:30:16,320 --> 00:30:25,150 >> Hekk jekk ikollna int prinċipali (vojt) u xi ħaġa bħal din. 717 00:30:25,150 --> 00:30:31,922 U inti għandek jekk huwa ta 'fuq ta 'xi kontribut u int 718 00:30:31,922 --> 00:30:33,630 tistaqsi jekk inti tista 'tagħmel xi ħaġa bħal din? 719 00:30:33,630 --> 00:30:35,010 720 00:30:35,010 --> 00:30:35,679 Dritt? 721 00:30:35,679 --> 00:30:37,470 STUDENT: I ​​kien qed jipprova biex tagħmel dan [inaudible]. 722 00:30:37,470 --> 00:30:38,450 Għaliex jekk it's-- 723 00:30:38,450 --> 00:30:39,200 Istruttur: Dritt. 724 00:30:39,200 --> 00:30:41,197 Allura inti tixtieq li dan ikun falz, id-dritt? 725 00:30:41,197 --> 00:30:41,780 STUDENT: Yeah. 726 00:30:41,780 --> 00:30:45,960 Istruttur: Allura f'dan il-każ inti tixtieq li tesegwixxi jekk mhuwiex veru. 727 00:30:45,960 --> 00:30:50,510 Allura l-ħaġa jibred li inti tagħmel hemm dan. 728 00:30:50,510 --> 00:30:52,900 729 00:30:52,900 --> 00:30:55,650 Mela ftakar exclamation punt jiċħad l-affarijiet? 730 00:30:55,650 --> 00:30:58,270 Hija tgħid [inaudible] ifisser mhux. 731 00:30:58,270 --> 00:31:03,590 Mela jekk inħarsu lejn biss din il-parti hawn, youd 732 00:31:03,590 --> 00:31:05,740 jgħidu li jevalwa li falza kif inti tixtieq li. 733 00:31:05,740 --> 00:31:06,790 734 00:31:06,790 --> 00:31:09,880 Mhuwiex falz huwa veru li ifisser dan ikun tesegwixxi. 735 00:31:09,880 --> 00:31:11,037 Ma li jagħmel sens? 736 00:31:11,037 --> 00:31:11,620 STUDENT: Yeah. 737 00:31:11,620 --> 00:31:12,453 Istruttur: biża. 738 00:31:12,453 --> 00:31:13,800 739 00:31:13,800 --> 00:31:14,300 OK. 740 00:31:14,300 --> 00:31:16,330 Allura nistgħu biss ritorn veru f'dan il-każ. 741 00:31:16,330 --> 00:31:20,357 Allura issa għandna tnejn l-oħra każijiet f'dan il-każ. 742 00:31:20,357 --> 00:31:21,565 Liema huma żewġ każijiet l-oħra tagħna? 743 00:31:21,565 --> 00:31:31,610 744 00:31:31,610 --> 00:31:32,900 Ejja biss tagħmel dan il-mod. 745 00:31:32,900 --> 00:31:40,660 Mela ejja nibdew mal-ieħor jekk il-valuri fil-nofs 746 00:31:40,660 --> 00:31:43,230 huwa inqas mill-valur li rridu. 747 00:31:43,230 --> 00:31:47,200 748 00:31:47,200 --> 00:31:52,020 Allura valur tagħna fin-nofs huwa inqas mill-valur li aħna qed tfittex. 749 00:31:52,020 --> 00:31:53,765 750 00:31:53,765 --> 00:31:56,720 >> Allura liema marbuta do you think irridu li taġġorna? 751 00:31:56,720 --> 00:31:57,870 752 00:31:57,870 --> 00:31:58,780 Fuq jew t'isfel? 753 00:31:58,780 --> 00:32:01,440 754 00:32:01,440 --> 00:32:01,940 Upper? 755 00:32:01,940 --> 00:32:03,230 756 00:32:03,230 --> 00:32:06,470 Allura liema naħa tal-firxa huma aħna se tkun tħares lejn? 757 00:32:06,470 --> 00:32:07,500 >> STUDENT: L-inqas. 758 00:32:07,500 --> 00:32:09,750 >> Istruttur: Aħna ser nieħdu tkun tħares lejn ix-xellug. 759 00:32:09,750 --> 00:32:11,120 Mela inkella jekk il-valur ftit huwa inqas. 760 00:32:11,120 --> 00:32:14,730 Allura valur tan-nofs tiegħek hawn huwa inqas minn dak li rridu. 761 00:32:14,730 --> 00:32:17,202 Allura aħna tixtieq li tieħu l- lemin ta 'firxa tagħna. 762 00:32:17,202 --> 00:32:18,910 Allura aħna qed tmur biex taġġorna inferjuri tagħna. 763 00:32:18,910 --> 00:32:20,210 764 00:32:20,210 --> 00:32:23,020 Allura aħna ser jassenja mill-ġdid aktar baxx tagħna. 765 00:32:23,020 --> 00:32:25,221 U x'taħseb aktar baxx għandu jkun? 766 00:32:25,221 --> 00:32:26,304 STUDENT: Il-valur tan-nofs? 767 00:32:26,304 --> 00:32:27,446 768 00:32:27,446 --> 00:32:28,820 Istruttur: Allura l-value-- nofs 769 00:32:28,820 --> 00:32:30,136 STUDENT: Plus 1. 770 00:32:30,136 --> 00:32:31,010 Istruttur: --plus 1. 771 00:32:31,010 --> 00:32:32,300 772 00:32:32,300 --> 00:32:34,380 Jista 'xi ħadd tell me għaliex għandna li flimkien ma '1? 773 00:32:34,380 --> 00:32:35,730 >> STUDENT: [? Ebda valur?] huwa aktar ugwali għal dan. 774 00:32:35,730 --> 00:32:36,120 >> Istruttur: Dritt. 775 00:32:36,120 --> 00:32:38,661 Għaliex aħna diġà jafu li valur tan-nofs tagħna ma tkunx ugwali għal 776 00:32:38,661 --> 00:32:42,750 dan u rridu li teskludiha minn tfittxijiet kollha sussegwenti. 777 00:32:42,750 --> 00:32:46,360 Jekk inti tinsa li flimkien ma '1, dan se bħal loop indefinittivament. 778 00:32:46,360 --> 00:32:49,620 U inti taf biss tkun maqbuda fi loop infinita u allura inti ser segfault 779 00:32:49,620 --> 00:32:50,370 u l-affarijiet imorru ħażin. 780 00:32:50,370 --> 00:32:54,780 Hekk dejjem kun żgur li int mhux inkluż il-valur li inti biss 781 00:32:54,780 --> 00:32:55,380 ħares lejn. 782 00:32:55,380 --> 00:32:58,530 Allura aħna jieħdu ħsieb ta 'li bil plus 1. 783 00:32:58,530 --> 00:33:04,840 >> Allura issa għandna l-aħħar kondizzjoni tagħna li jiena dejjem għall-finijiet tas-sigurtà 784 00:33:04,840 --> 00:33:12,664 tista 'tiċċekkja hawn, inkella jekk il-valur fil l-nofs huwa akbar mill-valur 785 00:33:12,664 --> 00:33:13,163 irridu. 786 00:33:13,163 --> 00:33:16,260 787 00:33:16,260 --> 00:33:20,230 Dan ifisser li aħna rridu l-nofs tax-xellug. 788 00:33:20,230 --> 00:33:21,350 789 00:33:21,350 --> 00:33:23,260 Allura liema waħda huma aħna se taġġorna? 790 00:33:23,260 --> 00:33:23,760 Upper. 791 00:33:23,760 --> 00:33:25,470 792 00:33:25,470 --> 00:33:26,970 U dak li huwa dan wieħed se ugwali? 793 00:33:26,970 --> 00:33:31,630 794 00:33:31,630 --> 00:33:33,690 Nofs minus 1 għaliex, naturalment, irridu 795 00:33:33,690 --> 00:33:38,370 biex tiżgura li aħna mhux qed tħares lejn dak il-valur tan-nofs mill-ġdid. 796 00:33:38,370 --> 00:33:41,830 797 00:33:41,830 --> 00:33:45,110 U allura aħna għandna hija. 798 00:33:45,110 --> 00:33:45,610 Thats it. 799 00:33:45,610 --> 00:33:46,820 Li kollox tfittxija binarja huwa. 800 00:33:46,820 --> 00:33:48,190 Huwa mhux ħażin, id-dritt? 801 00:33:48,190 --> 00:33:51,590 Huwa simili 10 linji ta ' kodiċi bi spazju abjad. 802 00:33:51,590 --> 00:33:57,510 Allura qawwija ħafna, utli ħafna, inti se tkun qed tuża din f'waħda mill psets aktar tard tiegħek. 803 00:33:57,510 --> 00:33:59,360 Forsi mhux dan wieħed, iżda iktar tard. 804 00:33:59,360 --> 00:34:00,670 Allura jitgħallmu. 805 00:34:00,670 --> 00:34:01,510 Imħabba tiegħu. 806 00:34:01,510 --> 00:34:02,980 Hija se jikkurak ukoll. 807 00:34:02,980 --> 00:34:05,370 Allura ħadd ma jkollu xi mistoqsijiet dwar tfittxija binarja? 808 00:34:05,370 --> 00:34:06,196 Iva. 809 00:34:06,196 --> 00:34:09,840 >> STUDENT: Ma jimpurtax jekk n tiegħek huwa saħansitra jew fard? 810 00:34:09,840 --> 00:34:10,750 >> Istruttur: No 811 00:34:10,750 --> 00:34:18,150 Għaliex aħna mitfugħa lill-nofs bħala l int, se biss truncate dan. 812 00:34:18,150 --> 00:34:21,600 Għalhekk se jibqgħu integer u se eventwalment sort permezz kollox. 813 00:34:21,600 --> 00:34:23,909 Allura inti ma għandekx għalfejn tinkwieta dwar dan. 814 00:34:23,909 --> 00:34:24,580 Kulħadd tajba? 815 00:34:24,580 --> 00:34:25,659 816 00:34:25,659 --> 00:34:26,850 Biża. 817 00:34:26,850 --> 00:34:27,919 Kessaħ. 818 00:34:27,919 --> 00:34:30,836 Allura, inti guys sibt dan. 819 00:34:30,836 --> 00:34:33,380 820 00:34:33,380 --> 00:34:33,880 Wirja. 821 00:34:33,880 --> 00:34:35,719 822 00:34:35,719 --> 00:34:43,270 Allura kif aħna kienu jitkellem dwar, I know David imsemmi runtimes kumplessità. 823 00:34:43,270 --> 00:34:44,420 824 00:34:44,420 --> 00:34:50,340 >> Hekk fil-każ aħjar, huwa biss waħda, li aħna sejħa ta 'żmien kostanti. 825 00:34:50,340 --> 00:34:51,909 Jista 'xi ħadd tell me għaliex dan jista' jkun? 826 00:34:51,909 --> 00:34:52,969 827 00:34:52,969 --> 00:34:55,800 Liema tip ta 'xenarju li jinvolvi? 828 00:34:55,800 --> 00:34:58,260 829 00:34:58,260 --> 00:34:58,760 Mm-hm. 830 00:34:58,760 --> 00:34:59,926 >> STUDENT: [inaudible] first-- 831 00:34:59,926 --> 00:35:00,789 832 00:35:00,789 --> 00:35:03,830 Istruttur: Allura-nofs huwa l- ewwel element li aħna jaslu għal, id-dritt? 833 00:35:03,830 --> 00:35:08,167 Dan jew firxa ta 'wieħed jew ikun x'ikun aħna qed tfittex għal ftit 834 00:35:08,167 --> 00:35:09,750 jiġri li jkun smack dab fin-nofs. 835 00:35:09,750 --> 00:35:11,190 836 00:35:11,190 --> 00:35:13,380 Allura dak il-każ l-almu tagħna. 837 00:35:13,380 --> 00:35:17,540 Ikollok fis-problemi reali, probabbilment mhux ser tilħaq [inaudible] li spiss. 838 00:35:17,540 --> 00:35:18,667 839 00:35:18,667 --> 00:35:19,750 What about agħar każ tagħna? 840 00:35:19,750 --> 00:35:21,270 Agħar każ tagħna huwa log n. 841 00:35:21,270 --> 00:35:25,360 U li għandha x'taqsam ma 'l-sħiħ setgħat ta 'żewġ ħaġa li I tkellem dwar. 842 00:35:25,360 --> 00:35:30,930 >> Allura fl-agħar każ li jista 'jfisser li kellna biex CHOP l-array isfel 843 00:35:30,930 --> 00:35:33,270 sakemm kien element ta 'wieħed. 844 00:35:33,270 --> 00:35:34,810 845 00:35:34,810 --> 00:35:38,930 Hekk kellna biex CHOP l-isfel fil-nofs kemm drabi aħna possibilment jistgħu. 846 00:35:38,930 --> 00:35:41,430 C'est pourquoi huwa log n għax inti biss iżommu diviż bi tnejn. 847 00:35:41,430 --> 00:35:42,890 848 00:35:42,890 --> 00:35:45,830 Allura suppożizzjonijiet, affarijiet inti jeħtieġ li tkun taf jekk int qatt 849 00:35:45,830 --> 00:35:48,050 ser tuża tfittxija binarja. 850 00:35:48,050 --> 00:35:50,680 Elementi tiegħek għandhom jiġu magħżula. 851 00:35:50,680 --> 00:35:53,890 Huma għandhom jiġu magħżula minħabba dak l-uniku mod inti 852 00:35:53,890 --> 00:35:57,060 tista 'tkun taf jekk inti kapaċi li tarmi l-nofs ta 'dan. 853 00:35:57,060 --> 00:36:00,260 >> Jekk kellek dan il-borża jumbled ta 'numri u inti qed tgħid, 854 00:36:00,260 --> 00:36:05,380 OK, jien ser jiċċekkja l-nofs numru u n-numru jien infittxu 855 00:36:05,380 --> 00:36:08,510 huwa inqas minn dak, jien biss se biex arbitrarjament tarmi out nofs. 856 00:36:08,510 --> 00:36:11,130 Inti ma tkunx taf jekk tiegħek numri li nofs l-ieħor. 857 00:36:11,130 --> 00:36:12,655 Lista tiegħek għandha tkun magħżula. 858 00:36:12,655 --> 00:36:14,030 859 00:36:14,030 --> 00:36:16,560 Kif ukoll, dan jista 'jkun jimxu 'l quddiem ftit, 860 00:36:16,560 --> 00:36:18,360 iżda inti għandek bżonn li jkollhom aċċess bl-addoċċ. 861 00:36:18,360 --> 00:36:21,940 Inti jeħtieġ li tkun kapaċi biss tmur f'dak l-element tan-nofs. 862 00:36:21,940 --> 00:36:25,110 Jekk għandek travers permezz xi ħaġa 863 00:36:25,110 --> 00:36:28,630 jew din tieħdok passi addizzjonali biex jiksbu għal dak l-element tan-nofs, 864 00:36:28,630 --> 00:36:31,750 mhuwiex log n jibqgħalu għaliex int żżid aktar xogħol fis dan. 865 00:36:31,750 --> 00:36:34,800 U dan se jagħmel ftit aktar sens fil-ġimgħatejn, 866 00:36:34,800 --> 00:36:37,950 imma I biss tip ta 'riedu prefazju, jagħtuk guys idea ta 'x'hemm 867 00:36:37,950 --> 00:36:38,999 li ġejjin. 868 00:36:38,999 --> 00:36:40,790 Iżda dawk huma ż-żewġ suppożizzjonijiet importanti 869 00:36:40,790 --> 00:36:44,804 li għandek bżonn għal lista binarja. 870 00:36:44,804 --> 00:36:45,720 Kun ċert li huwa magħżula. 871 00:36:45,720 --> 00:36:47,920 Dik hija l-waħda kbira għal inti guys dritt issa. 872 00:36:47,920 --> 00:36:52,170 U fuq li aħna tista 'tmur fil il-bqija ta 'tipi tagħna. 873 00:36:52,170 --> 00:36:56,444 Allura erba bużżieqa sorts--, inserzjoni, selezzjoni, u jingħaqdu. 874 00:36:56,444 --> 00:36:57,485 Huma qed kull tip ta 'kessaħ. 875 00:36:57,485 --> 00:37:02,860 Jekk inti guys jiddeċiedu li jieħdu CS 124, inti ser jitgħallmu dwar kull xorta ta 'xorta. 876 00:37:02,860 --> 00:37:07,575 U jekk int fan XKCD, hemm huwa dwar komiks verament jibred 877 00:37:07,575 --> 00:37:11,530 bħal xorta verament ineffettivi, li jiena jirrakkomanda ħafna li inti tmur biex tħares lejn. 878 00:37:11,530 --> 00:37:16,170 Waħda minnhom hija simili sort paniku, li huwa simili, oh no, ritorn firxa każwali. 879 00:37:16,170 --> 00:37:16,991 Sistema għeluq. 880 00:37:16,991 --> 00:37:17,490 Leave. 881 00:37:17,490 --> 00:37:19,070 882 00:37:19,070 --> 00:37:21,500 Allura Humer geeky huwa dejjem tajjeb. 883 00:37:21,500 --> 00:37:22,620 884 00:37:22,620 --> 00:37:25,750 >> Sabiex ħadd ma tiftakar tip ta 'prodotti simili biss idea ġenerali 885 00:37:25,750 --> 00:37:27,810 ta 'kif sort bużżieqa xogħlijiet. 886 00:37:27,810 --> 00:37:31,130 887 00:37:31,130 --> 00:37:32,155 Tiftakar? 888 00:37:32,155 --> 00:37:32,755 >> STUDENT: Yeah. 889 00:37:32,755 --> 00:37:33,970 >> Istruttur: Mur għaliha. 890 00:37:33,970 --> 00:37:38,980 >> STUDENT: Allura inti qed tmur permezz u jekk huwa akbar, allura inti tpartit it-tnejn. 891 00:37:38,980 --> 00:37:39,820 >> Istruttur: Mm-hm. 892 00:37:39,820 --> 00:37:40,564 Eżattament. 893 00:37:40,564 --> 00:37:41,730 Allura inti biss jtenni permezz. 894 00:37:41,730 --> 00:37:43,050 Inti tiċċekkja żewġ numri. 895 00:37:43,050 --> 00:37:46,510 Jekk il-wieħed qabel hija akbar minn dak wara, 896 00:37:46,510 --> 00:37:50,230 inti biss tpartit lilhom b'tali mod li fil- dan il-mod kollha tal-numri ogħla 897 00:37:50,230 --> 00:37:54,990 bużżieqa up lejn l-aħħar tal-lista u il-numri baxxi bużżieqa isfel. 898 00:37:54,990 --> 00:37:59,355 >> Did hu nuruk guys l-jibred ħoss effett issortjar video? 899 00:37:59,355 --> 00:38:00,480 Huwa tip ta 'kessaħ. 900 00:38:00,480 --> 00:38:01,510 901 00:38:01,510 --> 00:38:05,200 Allura kif Robert biss qal, l-algoritmu li inti biss pass permezz tal-lista, 902 00:38:05,200 --> 00:38:07,930 iskambji tal-valuri biswit jekk dawn mhux qed fl-ordni. 903 00:38:07,930 --> 00:38:10,975 U mbagħad biss iżommu tirrepeti sakemm inti ma tagħmel xi swaps. 904 00:38:10,975 --> 00:38:11,990 905 00:38:11,990 --> 00:38:12,740 Allura mhux ħażin, right? 906 00:38:12,740 --> 00:38:14,080 907 00:38:14,080 --> 00:38:16,319 Allura aħna biss ikollhom eżempju quick hawn. 908 00:38:16,319 --> 00:38:18,360 Allura dan se sort minnhom axxendenti ordni. 909 00:38:18,360 --> 00:38:19,470 910 00:38:19,470 --> 00:38:23,470 Allura meta aħna jgħaddu l-ewwel ħin, irridu nħarsu permezz tmienja 911 00:38:23,470 --> 00:38:26,880 u sitta huma ovvjament mhux sabiex, aħna tpartit minnhom. 912 00:38:26,880 --> 00:38:27,985 >> Allura tħares lejn dak li jmiss. 913 00:38:27,985 --> 00:38:29,430 Tmienja u erbgħa mhux fl-ordni. 914 00:38:29,430 --> 00:38:30,450 Tpartit minnhom. 915 00:38:30,450 --> 00:38:32,530 U mbagħad tmienja u tnejn, tpartit minnhom. 916 00:38:32,530 --> 00:38:33,470 Hemm immorru. 917 00:38:33,470 --> 00:38:39,519 Allura wara l-ewwel pass tiegħek, inti jafu li l-akbar numru tiegħek 918 00:38:39,519 --> 00:38:41,810 se tkun it-triq kollha fil-quċċata għaliex huwa biss 919 00:38:41,810 --> 00:38:44,210 se jiġu kostantement akbar minn kull ħaġa oħra 920 00:38:44,210 --> 00:38:46,810 u huwa biss se bużżieqa up-triq kollha sa l-aħħar hemmhekk. 921 00:38:46,810 --> 00:38:48,226 Does li jagħmel sens għal kulħadd? 922 00:38:48,226 --> 00:38:48,560 923 00:38:48,560 --> 00:38:49,060 Kessaħ. 924 00:38:49,060 --> 00:38:51,310 925 00:38:51,310 --> 00:38:53,920 >> Hekk allura aħna nħarsu lejn it-tieni pass tagħna. 926 00:38:53,920 --> 00:38:54,980 Sitta u erbgħa, swiċċ. 927 00:38:54,980 --> 00:38:55,920 Sitta u tnejn, swiċċ. 928 00:38:55,920 --> 00:38:58,700 U issa għandna ftit affarijiet fl-ordni. 929 00:38:58,700 --> 00:39:02,240 Allura għal kull pass li aħna jagħmlu permezz lista tagħna kollu, 930 00:39:02,240 --> 00:39:06,320 nafu li bħal li ħafna numri fl-aħħar se jkunu ġew magħżula. 931 00:39:06,320 --> 00:39:07,690 932 00:39:07,690 --> 00:39:09,610 Allura nagħmlu terz pass, li hija tpartit wieħed. 933 00:39:09,610 --> 00:39:10,860 934 00:39:10,860 --> 00:39:15,910 U mbagħad fuq raba tagħna jgħaddu, aħna għandna żero slots. 935 00:39:15,910 --> 00:39:18,570 U hekk aħna nafu li tagħna array jkunu ġew magħżula. 936 00:39:18,570 --> 00:39:20,900 >> U li huwa l-big ħaġa ma sort bużżieqa. 937 00:39:20,900 --> 00:39:23,720 Aħna nafu li meta aħna ikollhom żero tpartit, li 938 00:39:23,720 --> 00:39:26,497 ifisser li kollox hija fl-ordni kompluta. 939 00:39:26,497 --> 00:39:27,580 Huwa tip ta 'kif aħna jiċċekkjaw. 940 00:39:27,580 --> 00:39:28,740 941 00:39:28,740 --> 00:39:36,480 Allura aħna wkoll se kodiċi bużżieqa sort li huwa wkoll mhux ħażin. 942 00:39:36,480 --> 00:39:38,120 Xejn minn dawn huma ħżiena. 943 00:39:38,120 --> 00:39:40,210 I jafu li jistgħu jidhru ftit scary. 944 00:39:40,210 --> 00:39:42,124 I know I meta ħa il-klassi, anki meta I 945 00:39:42,124 --> 00:39:44,290 kien tagħlim l-klassi għal l-ewwel darba aħħar sena, 946 00:39:44,290 --> 00:39:46,165 I kien simili, kif nista 'nagħmlu dan? 947 00:39:46,165 --> 00:39:48,540 Jagħmel sens fit-teorija, iżda kif nistgħu fil-fatt jagħmlu dan? 948 00:39:48,540 --> 00:39:51,420 Liema hu għaliex I wkoll jixtiequ li jimxu permezz kodiċi miegħek guys hawn. 949 00:39:51,420 --> 00:39:54,915 So I jkollhom pseudocode għalik guys din id-darba. 950 00:39:54,915 --> 00:39:55,950 951 00:39:55,950 --> 00:39:58,970 Hekk biss jżomm dan f'moħħu kif aħna qed dwar li transizzjoni fuq. 952 00:39:58,970 --> 00:40:04,210 Allura aħna għandna xi counter li iżomm rekord ta 'swaps tagħna, 953 00:40:04,210 --> 00:40:08,370 għaliex għandna bżonn tagħmel ċert li aħna qed tiċċekkja li. 954 00:40:08,370 --> 00:40:11,830 U aħna jtenni l-array kollu kif aħna biss għamlet ma 'dan l-eżempju. 955 00:40:11,830 --> 00:40:12,900 956 00:40:12,900 --> 00:40:17,325 Jekk l-element qabel hija akbar minn l-element wara fejn aħna qed fil, 957 00:40:17,325 --> 00:40:20,760 aħna tpartit lilhom u aħna inkrement tagħna kontro għaliex hekk kif aħna tpartit, 958 00:40:20,760 --> 00:40:23,850 irridu let kontro tagħna jafu li. 959 00:40:23,850 --> 00:40:26,247 Kwalunkwe mistoqsijiet hemm? 960 00:40:26,247 --> 00:40:27,580 Xi ħaġa jidher umoristiċi hawn fuq. 961 00:40:27,580 --> 00:40:29,225 962 00:40:29,225 --> 00:40:32,350 STUDENT: Do tissettja l-counter għal żero kull darba li inti tmur permezz tal-linja? 963 00:40:32,350 --> 00:40:34,339 Ma inti żżomm għaddej lura għal żero kull darba? 964 00:40:34,339 --> 00:40:35,505 Istruttur: Mhux bilfors. 965 00:40:35,505 --> 00:40:39,710 Allura dak li jiġri huwa immorru permezz ta 'hawn. 966 00:40:39,710 --> 00:40:43,830 Allura tagħmel waqt, ftakar, dan se tesegwixxi darba mingħajr dubju. 967 00:40:43,830 --> 00:40:46,480 Allura li għaddej biex tiffissa l- counter ugwali għal żero, 968 00:40:46,480 --> 00:40:48,070 allura li għaddej biex jtenni permezz. 969 00:40:48,070 --> 00:40:50,590 Kif itenni permezz, din se taġġorna counter. 970 00:40:50,590 --> 00:40:51,870 971 00:40:51,870 --> 00:40:56,900 Kif aġġornamenti counter, meta dan isir, meta huwa laħqu t-tmiem ta 'l-array, 972 00:40:56,900 --> 00:41:00,830 jekk il-lista tagħna ma tkunx ġiet magħżula, kontro se jkunu ġew aġġornati. 973 00:41:00,830 --> 00:41:01,840 974 00:41:01,840 --> 00:41:07,150 >> Mela allura din il-kontrolli l-kundizzjoni u jgħid, OK, huwa kontro akbar minn żero. 975 00:41:07,150 --> 00:41:09,290 Jekk huwa, jagħmlu mill-ġdid. 976 00:41:09,290 --> 00:41:14,340 Inti tixtieq li reset hekk li meta inti jgħaddu, kontro huwa ugwali għal żero. 977 00:41:14,340 --> 00:41:18,240 Jekk inti tmur permezz ta 'issortjati firxa, xejn bidliet, 978 00:41:18,240 --> 00:41:21,355 dan ma jirnexxix, u int jirritorna l-lista magħżula. 979 00:41:21,355 --> 00:41:23,104 980 00:41:23,104 --> 00:41:24,020 Does li jagħmel sens? 981 00:41:24,020 --> 00:41:24,940 982 00:41:24,940 --> 00:41:26,356 STUDENT: Jista fi ftit. 983 00:41:26,356 --> 00:41:27,147 Istruttur: OK. 984 00:41:27,147 --> 00:41:28,980 Jekk hemm xi ieħor kwistjoni li taqa up. 985 00:41:28,980 --> 00:41:30,180 986 00:41:30,180 --> 00:41:30,680 Iva. 987 00:41:30,680 --> 00:41:33,760 >> STUDENT: Liema kieku l-funzjoni jkun għall-iskambji l-elementi? 988 00:41:33,760 --> 00:41:36,900 >> Istruttur: Allura nistgħu ngħidu jikteb li jekk aħna qed tmur biex dritt issa. 989 00:41:36,900 --> 00:41:37,801 990 00:41:37,801 --> 00:41:38,300 Kessaħ. 991 00:41:38,300 --> 00:41:42,155 Allura fuq din in-nota, Alison va li jaqilbu lura għall-appliance. 992 00:41:42,155 --> 00:41:43,080 Li għaddej biex tkun divertenti. 993 00:41:43,080 --> 00:41:45,170 994 00:41:45,170 --> 00:41:47,390 U aħna għandna sbieħ tagħna bubble ħaġa sort hawn. 995 00:41:47,390 --> 00:41:50,800 So I diġà għamlu ċikliżmu permezz tal-firxa. 996 00:41:50,800 --> 00:41:53,030 Għandna swaps tagħna li huma ugwali għal żero. 997 00:41:53,030 --> 00:41:54,480 998 00:41:54,480 --> 00:41:58,440 Hekk irridu li tpartit biswit Elementi jekk dawn qed out of order. 999 00:41:58,440 --> 00:42:03,020 Allura l-ewwel ħaġa li għandna bżonn li do huwa jtenni permezz firxa tagħna. 1000 00:42:03,020 --> 00:42:04,500 1001 00:42:04,500 --> 00:42:08,260 >> Allura kif taħseb nistgħu jtenni permezz firxa tagħna? 1002 00:42:08,260 --> 00:42:09,720 1003 00:42:09,720 --> 00:42:13,990 Għandna għall ui ikun egwali għal 0. 1004 00:42:13,990 --> 00:42:16,950 1005 00:42:16,950 --> 00:42:22,454 Aħna tixtieq li i tkun inqas minn n minus 1 minus k. 1006 00:42:22,454 --> 00:42:23,870 U jien ser jispjegaw li fit-tieni. 1007 00:42:23,870 --> 00:42:26,280 1008 00:42:26,280 --> 00:42:32,830 Allura dan huwa ottimizzazzjoni hawnhekk fejn, tiftakar kif I qal wara kull pass 1009 00:42:32,830 --> 00:42:36,655 permezz tal-firxa aħna jafu li kwalunkwe s on-- 1010 00:42:36,655 --> 00:42:43,590 1011 00:42:43,590 --> 00:42:46,295 >> Allura wara pass wieħed we taf li dan huwa magħżul. 1012 00:42:46,295 --> 00:42:47,370 1013 00:42:47,370 --> 00:42:50,060 Wara żewġ passes nafu li dan kollu huwa magħżul. 1014 00:42:50,060 --> 00:42:52,750 Wara tliet passes aħna jafu li s magħżula. 1015 00:42:52,750 --> 00:42:55,620 Allura l-mod jien mtennija permezz tal-firxa hawn, 1016 00:42:55,620 --> 00:43:01,090 huwa Hi tagħmel żgur li jmorru biss permezz ta 'dak li nafu hu mhux magħżul. 1017 00:43:01,090 --> 00:43:01,644 OK? 1018 00:43:01,644 --> 00:43:02,810 Li jinsab biss l-ottimizzazzjoni. 1019 00:43:02,810 --> 00:43:04,430 1020 00:43:04,430 --> 00:43:08,210 Inti tista 'tikteb it naively biss mtennija permezz kollox, 1021 00:43:08,210 --> 00:43:09,970 hija kienet ser ħu itwal. 1022 00:43:09,970 --> 00:43:12,470 Ma 'dan erba loop huwa biss ottimizzazzjoni sbieħ 1023 00:43:12,470 --> 00:43:18,460 għaliex aħna nafu li wara kull sħiħa iterazzjoni permezz tal-firxa hawn, 1024 00:43:18,460 --> 00:43:24,050 bħal kull linja sħiħa hawn, nafu li wieħed aktar ta 'dawn l-elementi 1025 00:43:24,050 --> 00:43:25,760 se jiġu magħżula fl-aħħar. 1026 00:43:25,760 --> 00:43:28,294 >> Allura aħna ma jkollhomx għalfejn tinkwieta dwar dawk. 1027 00:43:28,294 --> 00:43:29,710 Does li jagħmel sens għal kulħadd? 1028 00:43:29,710 --> 00:43:30,950 Li jibred trick ftit? 1029 00:43:30,950 --> 00:43:32,060 1030 00:43:32,060 --> 00:43:37,270 Allura f'dak il-każ, jekk aħna qed jiġu mtennija permezz, 1031 00:43:37,270 --> 00:43:50,590 nafu li aħna rridu li jiċċekkjaw jekk firxa nu n plus 1 huma fl-ordni. 1032 00:43:50,590 --> 00:43:52,640 1033 00:43:52,640 --> 00:43:53,559 OK. 1034 00:43:53,559 --> 00:43:54,600 Allura hawnhekk-pseudocode. 1035 00:43:54,600 --> 00:43:57,540 Aħna rridu li jiċċekkjaw jekk array n u n plus 1 huma fl-ordni. 1036 00:43:57,540 --> 00:43:59,520 Allura dak li jista għandna hemmhekk? 1037 00:43:59,520 --> 00:44:01,090 1038 00:44:01,090 --> 00:44:03,120 Huwa ser jkun hemm xi kondizzjonali. 1039 00:44:03,120 --> 00:44:04,220 Se jkun jekk. 1040 00:44:04,220 --> 00:44:07,066 >> STUDENT: Jekk array n huwa inqas minn firxa n plus 1. 1041 00:44:07,066 --> 00:44:07,816 Istruttur: Mm-hm. 1042 00:44:07,816 --> 00:44:09,000 1043 00:44:09,000 --> 00:44:10,699 Ukoll, inqas minn jew akbar minn. 1044 00:44:10,699 --> 00:44:11,615 STUDENT: Akbar minn. 1045 00:44:11,615 --> 00:44:15,850 1046 00:44:15,850 --> 00:44:17,620 Imbagħad irridu li tpartit lilhom. 1047 00:44:17,620 --> 00:44:18,570 Eżattament. 1048 00:44:18,570 --> 00:44:23,570 Allura issa nikbru fil x'inhu l- mekkaniżmu għall iskambji għalihom? 1049 00:44:23,570 --> 00:44:24,840 1050 00:44:24,840 --> 00:44:28,137 Allura aħna marru permezz ta 'dan fil-qosor, tip ta 'funzjoni tpartit ġimgħa li għaddiet. 1051 00:44:28,137 --> 00:44:29,595 Hawn xi ħadd ftakar kif maħduma? 1052 00:44:29,595 --> 00:44:32,300 1053 00:44:32,300 --> 00:44:34,950 Allura ma nistgħux biss assenjati mill-ġdid, id-dritt? 1054 00:44:34,950 --> 00:44:36,640 Minħabba li wieħed minnhom se jintilfu. 1055 00:44:36,640 --> 00:44:41,696 Jekk għidna A hija ugwali għal B u mbagħad B hija ugwali għal A, kollha f'daqqa tnejn minnhom 1056 00:44:41,696 --> 00:44:43,150 huma biss ugwali għal B. 1057 00:44:43,150 --> 00:44:45,720 >> Allura dak li għandna nagħmlu hija aħna jkollhom varjabbli temporanja li l- 1058 00:44:45,720 --> 00:44:49,055 ser ikollhom wieħed mid filwaqt tagħna aħna qed fil-proċess ta 'iskambji. 1059 00:44:49,055 --> 00:44:50,200 1060 00:44:50,200 --> 00:44:56,464 Allura dak li għandna huwa aħna ser ikollhom xi int temperatura hija ugwali to-- inti tista 'tassenja dan 1061 00:44:56,464 --> 00:44:59,130 għal liema waħda tixtieq, biss aċċerta ruħek li żżomm rekord ta 'it-- 1062 00:44:59,130 --> 00:45:01,840 hekk f'dan il-każ, jien ser tassenja lill array n plus 1. 1063 00:45:01,840 --> 00:45:03,360 1064 00:45:03,360 --> 00:45:07,674 Allura li għaddej biex iżommu kwalunkwe valur huwa f'dan it-tieni blokk 1065 00:45:07,674 --> 00:45:08,590 li aħna qed tħares lejn. 1066 00:45:08,590 --> 00:45:09,700 1067 00:45:09,700 --> 00:45:13,240 >> U allura nistgħu nagħmlu huwa nistgħu mmorru quddiem u firxa jassenja mill-ġdid n plus 1, 1068 00:45:13,240 --> 00:45:14,990 għaliex aħna nafu li aħna jkollhom dak il-valur maħżun. 1069 00:45:14,990 --> 00:45:16,645 1070 00:45:16,645 --> 00:45:19,270 Din hija wkoll waħda mill-kbar things-- I do not know jekk kwalunkwe inti 1071 00:45:19,270 --> 00:45:23,780 kienu kwistjonijiet fejn jekk inti jaqilbu tnejn linji ta 'kodiċi f'daqqa affarijiet maħduma. 1072 00:45:23,780 --> 00:45:25,880 Ordni huwa importanti ħafna fil CS. 1073 00:45:25,880 --> 00:45:29,450 Sabiex tagħmel żgur li int dijagramma affarijiet out jekk possibbli 1074 00:45:29,450 --> 00:45:31,230 dwar dak li qed jiġri attwalment. 1075 00:45:31,230 --> 00:45:34,256 Allura issa aħna qed tmur biex jassenja mill-ġdid array n plus 1, 1076 00:45:34,256 --> 00:45:36,005 għaliex aħna nafu li aħna jkollhom dak il-valur maħżun. 1077 00:45:36,005 --> 00:45:37,090 1078 00:45:37,090 --> 00:45:41,560 >> U nistgħu tassenja li biex array n jew f'dan il-każ firxa i. 1079 00:45:41,560 --> 00:45:50,540 1080 00:45:50,540 --> 00:45:51,465 Varjabbli wisq. 1081 00:45:51,465 --> 00:45:54,230 1082 00:45:54,230 --> 00:45:55,470 OK. 1083 00:45:55,470 --> 00:46:01,500 Firxa Allura issa konna assenjati i plus 1 sa ugwali x'hemm firxa i. 1084 00:46:01,500 --> 00:46:08,240 U issa nistgħu mmorru lura u tassenja firxa i għal dak? 1085 00:46:08,240 --> 00:46:10,680 1086 00:46:10,680 --> 00:46:11,180 Xi ħadd? 1087 00:46:11,180 --> 00:46:13,490 1088 00:46:13,490 --> 00:46:14,010 >> STUDENT: 10. 1089 00:46:14,010 --> 00:46:14,680 >> Istruttur: 10. 1090 00:46:14,680 --> 00:46:15,180 Eżattament. 1091 00:46:15,180 --> 00:46:16,930 1092 00:46:16,930 --> 00:46:18,640 U l-aħħar ħaġa waħda. 1093 00:46:18,640 --> 00:46:21,840 Jekk aħna għandna skambjat issa, dak li għandna bżonn tagħmel? 1094 00:46:21,840 --> 00:46:23,740 X'hemm-ħaġa waħda li għaddej biex tgħidilna 1095 00:46:23,740 --> 00:46:27,542 jekk aħna qatt tittermina dan il-programm? 1096 00:46:27,542 --> 00:46:29,250 Liema tgħidilna li aħna jkollhom lista magħżula? 1097 00:46:29,250 --> 00:46:31,560 1098 00:46:31,560 --> 00:46:33,750 Jekk aħna ma jwettqu l-ebda tpartit, id-dritt? 1099 00:46:33,750 --> 00:46:36,900 Jekk Swaps hija ugwali għal żero fl-aħħar ta 'dan. 1100 00:46:36,900 --> 00:46:42,975 Allura kull meta inti twettaq tpartit, kif aħna biss ma hawn, irridu li taġġorna swaps. 1101 00:46:42,975 --> 00:46:45,002 1102 00:46:45,002 --> 00:46:47,210 U naf kien hemm mistoqsija preċedenti dwar tista 'inti 1103 00:46:47,210 --> 00:46:49,689 jużaw żero jew wieħed minflok ta 'vera jew falza. 1104 00:46:49,689 --> 00:46:50,980 U dak hu li dan ma hawn. 1105 00:46:50,980 --> 00:46:52,750 Allura dan jgħid jekk mhux swaps. 1106 00:46:52,750 --> 00:47:01,310 Hekk jekk swaps huwa żero, li is-- jien dejjem nikseb veritajiet tiegħi u falses tiegħi mħallta up. 1107 00:47:01,310 --> 00:47:03,960 Aħna rridu magħna biex tevalwa li veru u mhuwiex. 1108 00:47:03,960 --> 00:47:07,680 1109 00:47:07,680 --> 00:47:09,630 Mela jekk huwa żero, allura huwa falz. 1110 00:47:09,630 --> 00:47:12,560 Jekk inti jċaħħdu dan bil- [? bang?] isir veru. 1111 00:47:12,560 --> 00:47:13,975 Mela allura din il-linja tesegwixxi. 1112 00:47:13,975 --> 00:47:15,060 1113 00:47:15,060 --> 00:47:17,370 >> Veritajiet u foloz u żerijiet u dawk nikseb crazy. 1114 00:47:17,370 --> 00:47:20,690 Just jekk inti bil-mod timxi permezz ta 'dan hija ser tagħmel sens. 1115 00:47:20,690 --> 00:47:23,320 Imma dak hu dan ftit daqsxejn ta 'kodiċi hawn ma. 1116 00:47:23,320 --> 00:47:26,490 Allura dan kontrolli biex tara li aħna għamlu xi swaps. 1117 00:47:26,490 --> 00:47:30,054 Mela jekk huwa xi ħaġa minbarra żero, li għaddej biex tkun falza 1118 00:47:30,054 --> 00:47:31,970 u l-ħaġa sħiħa hija ser tesegwixxi darb'oħra. 1119 00:47:31,970 --> 00:47:33,150 1120 00:47:33,150 --> 00:47:33,650 Kessaħ? 1121 00:47:33,650 --> 00:47:34,660 1122 00:47:34,660 --> 00:47:36,000 >> STUDENT: X'tagħmel break tagħmel? 1123 00:47:36,000 --> 00:47:38,990 >> Istruttur: Break biss pawżi inti out tal-linja. 1124 00:47:38,990 --> 00:47:41,570 Allura f'dan il-każ kieku bħad tmiem il-programm 1125 00:47:41,570 --> 00:47:43,828 u inti biss jkollhom lista magħżula tiegħek. 1126 00:47:43,828 --> 00:47:44,536 STUDENT: Amazing. 1127 00:47:44,536 --> 00:47:48,094 1128 00:47:48,094 --> 00:47:49,010 Istruttur: Jien sorry? 1129 00:47:49,010 --> 00:47:52,110 STUDENT: Għaliex qabel we użati bil-miktub 1 fuq miktub żero 1130 00:47:52,110 --> 00:47:54,170 biex tippreżenta li jekk li se jaħdmu jew le. 1131 00:47:54,170 --> 00:47:54,878 >> Istruttur: Yeah. 1132 00:47:54,878 --> 00:47:56,410 Allura inti tista 'ritorn żero jew 1. 1133 00:47:56,410 --> 00:47:58,950 F'dan il-każ, għaliex aħna mhux qed attwalment tagħmel xejn mal-funzjoni, 1134 00:47:58,950 --> 00:48:00,150 aħna biss jixtiequ li jinkiser. 1135 00:48:00,150 --> 00:48:02,680 Aħna ma verament kura dwar dan. 1136 00:48:02,680 --> 00:48:06,960 Brejk hija wkoll tajba jekk huwa użat għall-breaking out 1137 00:48:06,960 --> 00:48:10,710 ta 'erba' linji jew kundizzjonijiet li inti ma tixtieq li żżomm eżekuzzjoni. 1138 00:48:10,710 --> 00:48:12,110 Hija biss jieħu inti out minnhom. 1139 00:48:12,110 --> 00:48:13,587 1140 00:48:13,587 --> 00:48:14,795 Huwa daqsxejn ta 'ħaġa influwenzata. 1141 00:48:14,795 --> 00:48:16,737 1142 00:48:16,737 --> 00:48:18,445 Inħoss bħal hemm lott ta 'waving idejn, 1143 00:48:18,445 --> 00:48:19,740 bħal inti ser jitgħallmu dwar dan dalwaqt. 1144 00:48:19,740 --> 00:48:20,955 >> Imma inti ser jitgħallmu dwar dan dalwaqt. 1145 00:48:20,955 --> 00:48:21,500 I wegħda. 1146 00:48:21,500 --> 00:48:22,670 1147 00:48:22,670 --> 00:48:23,170 OK. 1148 00:48:23,170 --> 00:48:24,840 Allura ma kulħadd nikseb sort bużżieqa? 1149 00:48:24,840 --> 00:48:25,550 Mhux wisq ħażina. 1150 00:48:25,550 --> 00:48:31,910 Jtenni permezz, affarijiet tpartit bl-użu ta ' temperatura varjabbli, u aħna qed kollha stabbiliti hemmhekk? 1151 00:48:31,910 --> 00:48:32,960 Kessaħ. 1152 00:48:32,960 --> 00:48:34,080 Biża. 1153 00:48:34,080 --> 00:48:34,807 OK. 1154 00:48:34,807 --> 00:48:35,765 Lura għall-PowerPoint. 1155 00:48:35,765 --> 00:48:38,140 1156 00:48:38,140 --> 00:48:40,130 Kwalunkwe mistoqsijiet b'mod ġenerali dwar dawn s'issa? 1157 00:48:40,130 --> 00:48:41,200 1158 00:48:41,200 --> 00:48:41,700 Kessaħ. 1159 00:48:41,700 --> 00:48:43,110 1160 00:48:43,110 --> 00:48:43,695 Mm-hm. 1161 00:48:43,695 --> 00:48:45,279 >> STUDENT: [inaudible] int prinċipali normalment. 1162 00:48:45,279 --> 00:48:46,695 Do inti trid li jkollha li għal dan? 1163 00:48:46,695 --> 00:48:48,400 1164 00:48:48,400 --> 00:48:53,550 >> Istruttur: Allura konna biss tfittex biss fil-algoritmu issortjar attwali. 1165 00:48:53,550 --> 00:48:54,559 1166 00:48:54,559 --> 00:48:56,350 Jekk kellek dan fi bħal programm akbar, 1167 00:48:56,350 --> 00:48:57,891 inti jkollha x'imkien prinċipali int. 1168 00:48:57,891 --> 00:49:00,070 1169 00:49:00,070 --> 00:49:02,880 Jiddependi fuq fejn inti jużaw dan algoritmu, 1170 00:49:02,880 --> 00:49:05,860 hija tiddetermina x'inhu jkun mibgħut lura minnha. 1171 00:49:05,860 --> 00:49:09,960 Iżda għall-każ tagħna, aħna qed strettament tħares lejn kif ma dan fil-fatt 1172 00:49:09,960 --> 00:49:11,300 jtenni permezz ta 'firxa. 1173 00:49:11,300 --> 00:49:12,570 Allura aħna ma tinkwieta dwar dan. 1174 00:49:12,570 --> 00:49:14,150 1175 00:49:14,150 --> 00:49:19,830 >> Allura konna nitkellmu dwar l-aħjar każ u xenarji każ agħar għal tfittxija binarja. 1176 00:49:19,830 --> 00:49:22,470 Allura huwa wkoll importanti li jagħmlu li għal kull tip tagħna. 1177 00:49:22,470 --> 00:49:24,200 1178 00:49:24,200 --> 00:49:27,560 Allura dak li taħseb hija l-agħar każ runtime ta sort bużżieqa? 1179 00:49:27,560 --> 00:49:29,560 1180 00:49:29,560 --> 00:49:30,700 Inti guys tiftakar? 1181 00:49:30,700 --> 00:49:31,784 >> STUDENT: N minus 1. 1182 00:49:31,784 --> 00:49:32,700 Istruttur: N minus 1. 1183 00:49:32,700 --> 00:49:35,070 Allura dan ifisser li hemm n minus 1 paraguni. 1184 00:49:35,070 --> 00:49:40,060 Allura ħaġa waħda li tirrealizza hija li fuq l-ewwel iterazzjoni, 1185 00:49:40,060 --> 00:49:43,360 aħna jgħaddu, inqabblu dawn two-- b'tali mod li għamilhom 1. 1186 00:49:43,360 --> 00:49:46,685 Dawn tnejn, tlieta, erbgħa. 1187 00:49:46,685 --> 00:49:48,070 1188 00:49:48,070 --> 00:49:55,050 Allura wara iterazzjoni waħda we diġà jkollhom erba paraguni. 1189 00:49:55,050 --> 00:49:58,230 Meta jien jitkellem dwar runtime u n. 1190 00:49:58,230 --> 00:50:04,680 N jirrappreżenta n-numru ta 'tqabbil bħala funzjoni ta 'kif ħafna elementi 1191 00:50:04,680 --> 00:50:05,570 għandna. 1192 00:50:05,570 --> 00:50:06,430 OK? 1193 00:50:06,430 --> 00:50:08,860 >> Allura aħna jgħaddu, għandna erba. 1194 00:50:08,860 --> 00:50:11,780 Il-ħin li jmiss inti taf aħna ma għandek tieħu kura ta 'dan. 1195 00:50:11,780 --> 00:50:15,140 Inqabblu dawn iż-żewġ, dawn iż-żewġ, dawn iż-żewġ, 1196 00:50:15,140 --> 00:50:20,050 u jekk aħna ma kellhiex dak ottimizzazzjoni bl-erba 'linja li I kiteb, 1197 00:50:20,050 --> 00:50:22,750 inti tkun tqabbel fil hawn anyways. 1198 00:50:22,750 --> 00:50:26,170 Allura inti jkollha jgħaddi mill-firxa 1199 00:50:26,170 --> 00:50:34,380 u jagħmlu paraguni n n żminijiet, għaliex kull darba aħna 1200 00:50:34,380 --> 00:50:36,670 run permezz ta 'dan aħna xorta ħaġa waħda. 1201 00:50:36,670 --> 00:50:38,300 1202 00:50:38,300 --> 00:50:41,475 >> U kull darba we run permezz l-array, aħna jagħmlu paraguni n. 1203 00:50:41,475 --> 00:50:42,920 1204 00:50:42,920 --> 00:50:46,330 Allura runtime tagħna għal dan huwa attwalment n kwadrat, li 1205 00:50:46,330 --> 00:50:48,400 hija ħafna agħar fl tagħna log aħħar minħabba li 1206 00:50:48,400 --> 00:50:51,965 tfisser jekk kellna erba biljun elementi, huwa 1207 00:50:51,965 --> 00:50:55,260 se tieħu lilna erba 'biljun kwadrat minflok 32. 1208 00:50:55,260 --> 00:51:01,240 Hekk mhux l-aħjar runtime, iżda għal xi affarijiet, 1209 00:51:01,240 --> 00:51:04,610 inti taf, jekk int fi ċertu firxa ta 'elementi 1210 00:51:04,610 --> 00:51:06,540 sort bużżieqa tista 'tkun multa għall-użu. 1211 00:51:06,540 --> 00:51:07,530 >> OK. 1212 00:51:07,530 --> 00:51:12,290 Allura issa dak li huwa l-każ runtime aħjar? 1213 00:51:12,290 --> 00:51:14,357 1214 00:51:14,357 --> 00:51:14,940 STUDENT: Zero? 1215 00:51:14,940 --> 00:51:16,420 Jew 1? 1216 00:51:16,420 --> 00:51:18,140 >> Istruttur: Allura 1 kieku jkun paragun wieħed. 1217 00:51:18,140 --> 00:51:19,114 Dritt. 1218 00:51:19,114 --> 00:51:20,002 >> STUDENT: N minus 1? 1219 00:51:20,002 --> 00:51:21,380 1220 00:51:21,380 --> 00:51:22,320 >> Istruttur: Allura, yeah. 1221 00:51:22,320 --> 00:51:22,990 Allura n minus 1. 1222 00:51:22,990 --> 00:51:26,510 Kull meta għandek kunċett bħal n minus 1, għandna t-tendenza li biss qatra off 1223 00:51:26,510 --> 00:51:31,680 u aħna biss jgħidu n għax għandek li tqabbel kull wieħed these-- kull par. 1224 00:51:31,680 --> 00:51:36,470 Għalhekk ikun n minus 1, li aħna aħna'd biss jgħidu huwa ta 'madwar n. 1225 00:51:36,470 --> 00:51:39,280 Meta inti qed jittrattaw ma runtime, kollox huwa fl tapprossima. 1226 00:51:39,280 --> 00:51:43,860 Sakemm l-esponent huwa korretta, int pretty tajba. 1227 00:51:43,860 --> 00:51:45,700 >> Thats kif aħna jittrattaw dan. 1228 00:51:45,700 --> 00:51:47,410 1229 00:51:47,410 --> 00:51:51,780 Hekk li l-aħjar każ huwa n, li ifisser li l-lista hija diġà riżolta, 1230 00:51:51,780 --> 00:51:54,320 u kollha għandna nagħmlu hija mmexxija permezz u jivverifikaw li huwa magħżula. 1231 00:51:54,320 --> 00:51:56,110 1232 00:51:56,110 --> 00:51:56,855 Kessaħ. 1233 00:51:56,855 --> 00:51:57,355 Kull dritt. 1234 00:51:57,355 --> 00:51:58,980 1235 00:51:58,980 --> 00:52:01,920 Allura kif tara hawn, aħna biss għandhom xi graffs aktar. 1236 00:52:01,920 --> 00:52:02,660 Allura n kwadrat. 1237 00:52:02,660 --> 00:52:03,780 1238 00:52:03,780 --> 00:52:05,120 Gost. 1239 00:52:05,120 --> 00:52:09,730 Ħafna agħar milli n kif naraw, u ħafna, ħafna agħar minn log 2n. 1240 00:52:09,730 --> 00:52:12,060 U allura inti wkoll tikseb fis zkuk log. 1241 00:52:12,060 --> 00:52:18,020 U inti tieħu 124, ikollok fis bħal log star, li huwa simili crazy. 1242 00:52:18,020 --> 00:52:20,172 Hekk jekk int interessat, Lookup star log. 1243 00:52:20,172 --> 00:52:20,880 Huwa tip ta 'gost. 1244 00:52:20,880 --> 00:52:22,800 1245 00:52:22,800 --> 00:52:24,220 Allura aħna għandna din it-tabella kbira. 1246 00:52:24,220 --> 00:52:25,360 1247 00:52:25,360 --> 00:52:28,720 Just a kapijiet up, dan ta ' chart wunderbare li jkollhom 1248 00:52:28,720 --> 00:52:31,350 għal nofs it-terminu tiegħek għaliex aħna twil biex nitolbuk dawn thins. 1249 00:52:31,350 --> 00:52:36,090 Hekk biss kapijiet up, jkollhom dan fuq tiegħek nofs it-terminu fuq folja iqarrqu sbieħ tiegħek 1250 00:52:36,090 --> 00:52:36,616 hemmhekk. 1251 00:52:36,616 --> 00:52:37,990 Allura aħna biss ħares lejn sort bużżieqa. 1252 00:52:37,990 --> 00:52:39,510 1253 00:52:39,510 --> 00:52:42,370 Agħar każ, n kwadrat, aħjar każ, n. 1254 00:52:42,370 --> 00:52:43,367 1255 00:52:43,367 --> 00:52:44,950 U aħna qed tmur biex tħares lejn l-oħrajn. 1256 00:52:44,950 --> 00:52:47,940 >> U kif tistgħu taraw, l-uniku wieħed li verament ma ukoll 1257 00:52:47,940 --> 00:52:50,910 huwa tip jingħaqdu, li aħna ser jsibu rwieħhom għaliex. 1258 00:52:50,910 --> 00:52:52,690 1259 00:52:52,690 --> 00:52:55,215 Allura aħna qed tmur biex tmur fil- li jmiss minn tip wieħed ta 'għażla here--. 1260 00:52:55,215 --> 00:52:56,360 1261 00:52:56,360 --> 00:52:58,420 Hawn xi ħadd ftakar kif għażla ħadem sort? 1262 00:52:58,420 --> 00:53:05,200 1263 00:53:05,200 --> 00:53:05,700 Mur għaliha. 1264 00:53:05,700 --> 00:53:08,210 >> STUDENT: Bażikament jgħaddu ordni u joħolqu lista ġdida. 1265 00:53:08,210 --> 00:53:11,001 U hekk kif int tqegħid elementi fil, tpoġġihom fil-post it-tajjeb 1266 00:53:11,001 --> 00:53:11,750 fil-lista l-ġdida. 1267 00:53:11,750 --> 00:53:14,040 >> Istruttur: Allura li ħsejjes aktar simili sort inserzjoni. 1268 00:53:14,040 --> 00:53:15,040 Imma int verament qrib. 1269 00:53:15,040 --> 00:53:15,915 Huma qed simili ħafna. 1270 00:53:15,915 --> 00:53:17,440 Anke I tikseb minnhom mħallta up kultant. 1271 00:53:17,440 --> 00:53:18,981 Qabel din is-sezzjoni I kien simili, stenna. 1272 00:53:18,981 --> 00:53:20,130 1273 00:53:20,130 --> 00:53:20,630 OK. 1274 00:53:20,630 --> 00:53:24,141 Allura dak li trid tagħmel huwa sort għażla, 1275 00:53:24,141 --> 00:53:25,890 il-mod inti tista 'taħseb dwar dan u l-mod 1276 00:53:25,890 --> 00:53:30,140 I jagħmlu ċert I ipprova ma tikseb minnhom mħallta up, huwa tmur permezz 1277 00:53:30,140 --> 00:53:33,280 u huwa jagħżel l- iżgħar numru u 1278 00:53:33,280 --> 00:53:36,070 ipoġġi li fil-bidu tal-lista tiegħek. 1279 00:53:36,070 --> 00:53:37,730 Hija tpartit ma 'dik l-ewwel post. 1280 00:53:37,730 --> 00:53:42,600 1281 00:53:42,600 --> 00:53:45,370 Huma għandhom attwalment eżempju għalija. 1282 00:53:45,370 --> 00:53:46,540 Biża. 1283 00:53:46,540 --> 00:53:50,130 Allura biss mod biex jaħsbu ta 'għażla it-- sort, tagħżel l-iżgħar valur. 1284 00:53:50,130 --> 00:53:51,940 U aħna qed tmur biex run permezz ta 'eżempju 1285 00:53:51,940 --> 00:53:55,320 li naħseb se jgħinu għaliex Naħseb visuals dejjem tgħin. 1286 00:53:55,320 --> 00:53:58,510 Allura aħna tibda ma 'xi ħaġa li huwa kompletament mhux magħżul. 1287 00:53:58,510 --> 00:54:00,730 Red se jkun mhux magħżula, aħdar se jiġu magħżula. 1288 00:54:00,730 --> 00:54:02,190 Dan kollu jagħmel sens fit-tieni. 1289 00:54:02,190 --> 00:54:08,950 >> Allura aħna jgħaddu u aħna jtenni mill-bidu sat-tmiem. 1290 00:54:08,950 --> 00:54:12,320 U aħna ngħidu, OK, 2 hija iżgħar numru tagħna. 1291 00:54:12,320 --> 00:54:15,680 Allura aħna qed tmur biex tieħu 2 u aħna qed tmur li jġorrhom lejn il-quddiem tal-firxa tagħna 1292 00:54:15,680 --> 00:54:17,734 għaliex dan huwa l- iżgħar numru għandna. 1293 00:54:17,734 --> 00:54:19,150 Allura dak hu li din qed tagħmel hawn. 1294 00:54:19,150 --> 00:54:20,820 Huwa biss se tpartit dawn iż-żewġ. 1295 00:54:20,820 --> 00:54:21,850 1296 00:54:21,850 --> 00:54:25,450 Allura issa għandna magħżula parti u parti mhux magħżul. 1297 00:54:25,450 --> 00:54:27,810 U x'hemm tajjeb li niftakru dwar sort għażla 1298 00:54:27,810 --> 00:54:30,690 hija aħna qed biss għażla mill-parti mhux magħżul. 1299 00:54:30,690 --> 00:54:32,220 1300 00:54:32,220 --> 00:54:34,527 >> Il-parti magħżul inti biss leave waħdu. 1301 00:54:34,527 --> 00:54:35,660 Mm-hm? 1302 00:54:35,660 --> 00:54:38,452 >> STUDENT: Kif ma taf liema hu l-iżgħar mingħajr tqabbilha 1303 00:54:38,452 --> 00:54:39,868 għal kull valur ieħor fil-firxa. 1304 00:54:39,868 --> 00:54:41,250 Istruttur: Hija ma din titqabbel. 1305 00:54:41,250 --> 00:54:42,041 Aħna simili skipped dan. 1306 00:54:42,041 --> 00:54:43,850 Dan huwa biss ġenerali globali. 1307 00:54:43,850 --> 00:54:44,831 Yeah. 1308 00:54:44,831 --> 00:54:47,205 Meta aħna tikteb l-kodiċi jien żgur li int ser tkun aktar sodisfatti. 1309 00:54:47,205 --> 00:54:48,696 1310 00:54:48,696 --> 00:54:53,030 Imma int taħżen din l-ewwel element bħala l-iżgħar. 1311 00:54:53,030 --> 00:54:56,110 Tqabbel u int jgħidu, OK, huwa iżgħar? 1312 00:54:56,110 --> 00:54:56,660 Iva. 1313 00:54:56,660 --> 00:54:57,460 Żomm dan. 1314 00:54:57,460 --> 00:54:58,640 Hawnhekk huwa iżgħar? 1315 00:54:58,640 --> 00:54:59,660 No? 1316 00:54:59,660 --> 00:55:02,510 >> Dan huwa l-iżgħar tiegħek, jassenja mill-ġdid lill-valur tiegħek. 1317 00:55:02,510 --> 00:55:06,340 U tkun taf tkun ferm kuntenti meta aħna jgħaddu mill-kodiċi. 1318 00:55:06,340 --> 00:55:07,510 1319 00:55:07,510 --> 00:55:13,970 Allura aħna jgħaddu, aħna tpartit, hekk allura aħna nħarsu lejn dan il-porzjon mhux magħżul. 1320 00:55:13,970 --> 00:55:15,810 Allura aħna qed tmur biex jagħżlu tlieta out. 1321 00:55:15,810 --> 00:55:18,890 Aħna qed tmur biex tqiegħed lilha fuq mill l-aħħar tal-porzjon magħżul tagħna. 1322 00:55:18,890 --> 00:55:20,267 1323 00:55:20,267 --> 00:55:23,100 U aħna qed biss jmorru biex iżommu tagħmel li, tagħmel dan, u tagħmel dan. 1324 00:55:23,100 --> 00:55:24,130 1325 00:55:24,130 --> 00:55:27,420 Allura dan huwa tip tagħna ta pseudocode hawn. 1326 00:55:27,420 --> 00:55:29,470 1327 00:55:29,470 --> 00:55:31,380 Aħna ser kodiċi it up here fit-tieni. 1328 00:55:31,380 --> 00:55:34,140 1329 00:55:34,140 --> 00:55:37,270 Iżda biss xi ħaġa li jimxu permezz ta 'fuq livell għoli. 1330 00:55:37,270 --> 00:55:40,275 Inti qed tmur biex jmorru minn i ugwali 0 sa n minus 2. 1331 00:55:40,275 --> 00:55:41,570 1332 00:55:41,570 --> 00:55:43,530 C'est ottimizzazzjoni ieħor. 1333 00:55:43,530 --> 00:55:45,020 Tinkwetax wisq dwar dan. 1334 00:55:45,020 --> 00:55:46,620 Allura kif inti kienu jgħidu. 1335 00:55:46,620 --> 00:55:49,660 1336 00:55:49,660 --> 00:55:54,406 Kif Jacob kien qal, kif do we iżommu rekord ta 'dak minimu tagħna huwa? 1337 00:55:54,406 --> 00:55:55,030 Kif inkunu nafu? 1338 00:55:55,030 --> 00:55:57,060 Aħna jkollu jqabbel kollox fil-lista tagħna. 1339 00:55:57,060 --> 00:55:59,600 >> Allura minimu ugwali i. 1340 00:55:59,600 --> 00:56:03,870 Huwa biss qal f'dan il-każ l-indiċi tal-valur minimu tagħna. 1341 00:56:03,870 --> 00:56:07,660 Mela allura li għaddej biex jtenni permezz u jmur minn j ugwali i plus 1. 1342 00:56:07,660 --> 00:56:11,420 Allura aħna diġà jafu li li l-ewwel element tagħna. 1343 00:56:11,420 --> 00:56:13,240 Ma kellniex bżonn li din titqabbel ma innifsu. 1344 00:56:13,240 --> 00:56:16,970 Allura nibdew jitqabbel mal-li jmiss waħda li hija għaliex huwa i plus 1 sa n 1345 00:56:16,970 --> 00:56:20,110 minus 1, li hija l- aħħar tal-firxa hemmhekk. 1346 00:56:20,110 --> 00:56:25,090 U aħna qal jekk firxa fi j huwa inqas minn firxa min, 1347 00:56:25,090 --> 00:56:29,200 allura aħna jassenja mill-ġdid fejn indiċijiet minimi tagħna huwa. 1348 00:56:29,200 --> 00:56:37,470 >> U jekk min mhuwiex ugwali għal i, kif fil fejn konna lura fuq hawn. 1349 00:56:37,470 --> 00:56:38,950 1350 00:56:38,950 --> 00:56:41,790 Allura simili meta aħna ewwel għamlet dan wieħed. 1351 00:56:41,790 --> 00:56:49,310 F'dan il-każ, ikun jibdew fil żero, ikun jispiċċaw tnejn. 1352 00:56:49,310 --> 00:56:53,010 Allura min kieku ma ugwali i fl-aħħar. 1353 00:56:53,010 --> 00:56:55,720 Li tikri minna nafu li għandna bżonn li tpartit lilhom. 1354 00:56:55,720 --> 00:56:57,420 1355 00:56:57,420 --> 00:57:00,470 Inħoss bħal eżempju konkret se jgħin ħafna aktar minn dan. 1356 00:57:00,470 --> 00:57:04,970 So I ser kodiċi dan up miegħek guys dritt issa u naħseb li ser tkun aħjar. 1357 00:57:04,970 --> 00:57:07,380 1358 00:57:07,380 --> 00:57:11,350 >> Xorta għandhom tendenza li jaħdmu dak il-mod f'dik huwa spiss aħjar biss biex tara minnhom. 1359 00:57:11,350 --> 00:57:12,780 1360 00:57:12,780 --> 00:57:17,280 Allura dak li rridu nagħmlu huwa aħna l-ewwel trid l-iżgħar 1361 00:57:17,280 --> 00:57:19,890 element fil-pożizzjoni tagħha fil-firxa. 1362 00:57:19,890 --> 00:57:21,280 Eżattament dak Jacob kien qal. 1363 00:57:21,280 --> 00:57:23,090 Ikollok bżonn taħżen li b'xi mod. 1364 00:57:23,090 --> 00:57:25,900 Allura aħna qed tmur biex tibda hawn mtennija tul l-arranġament. 1365 00:57:25,900 --> 00:57:28,970 Aħna qed tmur biex ngħid huwa tagħna ewwel wieħed biss biex tibda bil. 1366 00:57:28,970 --> 00:57:38,308 Allura aħna ser ikollhom int iżgħar hija ugwali għal firxa fil i. 1367 00:57:38,308 --> 00:57:40,500 1368 00:57:40,500 --> 00:57:45,050 >> Allura ħaġa waħda li l-avviż, kull żmien dan loop tesegwixxi, 1369 00:57:45,050 --> 00:57:48,550 aħna qed jibdew pass ulterjuri flimkien. 1370 00:57:48,550 --> 00:57:54,780 1371 00:57:54,780 --> 00:57:57,440 Meta nibdew inħarsu lejn dan wieħed. 1372 00:57:57,440 --> 00:58:00,840 Il-ħin li jmiss aħna jtenni permezz, aħna qed jibdew minn dan wieħed 1373 00:58:00,840 --> 00:58:02,680 u assenjazzjoni tiegħu iżgħar valur tagħna. 1374 00:58:02,680 --> 00:58:10,450 Allura huwa simili ħafna għall tip bużżieqa fejn nafu li wara pass wieħed, 1375 00:58:10,450 --> 00:58:11,700 dan l-aħħar element huwa magħżul. 1376 00:58:11,700 --> 00:58:12,810 1377 00:58:12,810 --> 00:58:15,120 Bil sort għażla, huwa biss l-oppost. 1378 00:58:15,120 --> 00:58:18,950 >> F'kull pass, aħna nafu li l-ewwel wieħed huwa magħżul. 1379 00:58:18,950 --> 00:58:21,360 Wara t-tieni pass, il- tieni waħda se jiġu magħżula. 1380 00:58:21,360 --> 00:58:26,470 U kif inti raw mal-eżempji slide, porzjon magħżula tagħna biss tkompli tikber. 1381 00:58:26,470 --> 00:58:34,020 Allura billi tistabbilixxi iżgħar wieħed tagħna biex arrays i, kollha li qed jagħmel 1382 00:58:34,020 --> 00:58:37,340 huwa constricting liema aħna qed tħares lejn sabiex 1383 00:58:37,340 --> 00:58:40,164 biex jimminimizzaw in-numru ta 'paraguni nagħmlu. 1384 00:58:40,164 --> 00:58:41,770 Ma li jagħmel sens għal kulħadd? 1385 00:58:41,770 --> 00:58:42,920 1386 00:58:42,920 --> 00:58:46,380 Għandek bżonn lili biex imexxu permezz ta 'dak għal darb'oħra bil-mod jew fi kliem differenti? 1387 00:58:46,380 --> 00:58:47,180 Ninsab kuntenta li. 1388 00:58:47,180 --> 00:58:48,095 1389 00:58:48,095 --> 00:58:48,595 OK. 1390 00:58:48,595 --> 00:58:50,060 1391 00:58:50,060 --> 00:58:55,540 >> Allura aħna qed ħażna tal- valur f'dan il-punt, 1392 00:58:55,540 --> 00:58:57,840 imma aħna wkoll tixtieq li taħżen l-indiċi. 1393 00:58:57,840 --> 00:59:01,010 Allura aħna qed tmur biex jaħżnu l- pożizzjoni tal-iżgħar 1394 00:59:01,010 --> 00:59:02,770 wieħed, li huwa biss se tkun i. 1395 00:59:02,770 --> 00:59:04,357 1396 00:59:04,357 --> 00:59:05,440 Allura issa Jacob huwa sodisfatt. 1397 00:59:05,440 --> 00:59:06,870 Għandna affarijiet maħżuna. 1398 00:59:06,870 --> 00:59:08,240 1399 00:59:08,240 --> 00:59:11,870 U issa għandna bżonn li tfittex permezz il-parti mhux magħżul mill-firxa. 1400 00:59:11,870 --> 00:59:18,170 Allura f'dan il-każ dan Ikun mhux magħżul tagħna. 1401 00:59:18,170 --> 00:59:20,980 1402 00:59:20,980 --> 00:59:22,462 Dan huwa i. 1403 00:59:22,462 --> 00:59:25,430 1404 00:59:25,430 --> 00:59:26,210 OK. 1405 00:59:26,210 --> 00:59:30,040 >> Allura dak li aħna qed tmur biex tagħmel se tkun għal loop. 1406 00:59:30,040 --> 00:59:32,066 Kull meta għandek bżonn biex jtenni permezz ta 'firxa, 1407 00:59:32,066 --> 00:59:33,440 moħħok tista 'tmur għall għal loop. 1408 00:59:33,440 --> 00:59:34,760 1409 00:59:34,760 --> 00:59:38,090 Allura għal xi int k equals-- dak li aħna naħsbu 1410 00:59:38,090 --> 00:59:39,700 k se indaqs biex tibda bil? 1411 00:59:39,700 --> 00:59:41,580 1412 00:59:41,580 --> 00:59:44,766 Dan huwa dak li aħna waqqafna bħala iżgħar tagħna valur u rridu li din titqabbel. 1413 00:59:44,766 --> 00:59:47,090 What do rridu li din titqabbel ma? 1414 00:59:47,090 --> 00:59:48,730 Li għaddej biex jkun dan wieħed li jmiss, id-dritt? 1415 00:59:48,730 --> 00:59:53,200 Hekk irridu k li għandu initialized biex i flimkien ma '1 biex tibda. 1416 00:59:53,200 --> 00:59:55,350 1417 00:59:55,350 --> 01:00:02,800 >> U rridu k f'dan il-każ aħna diġà qies maħżuna up here, 1418 01:00:02,800 --> 01:00:03,930 hekk nistgħu biss tuża daqs. 1419 01:00:03,930 --> 01:00:06,240 Daqs huwa l-daqs tal-array. 1420 01:00:06,240 --> 01:00:09,620 U aħna biss jixtiequ taġġorna k minn wieħed kull darba. 1421 01:00:09,620 --> 01:00:17,410 1422 01:00:17,410 --> 01:00:17,910 Kessaħ. 1423 01:00:17,910 --> 01:00:19,650 1424 01:00:19,650 --> 01:00:23,430 Allura issa għandna bżonn li ssib l-element iżgħar hawn. 1425 01:00:23,430 --> 01:00:24,470 1426 01:00:24,470 --> 01:00:31,380 Hekk jekk aħna jtenni permezz, aħna irrid ngħid, jekk array fi k 1427 01:00:31,380 --> 01:00:37,080 huwa inqas minn iżgħar value-- tagħna dan huwa fejn aħna qed attwalment 1428 01:00:37,080 --> 01:00:42,950 iżżomm rekord ta 'x'hemm l-iżgħar here-- 1429 01:00:42,950 --> 01:00:47,740 allura irridu jassenja mill-ġdid dak iżgħar valur tagħna huwa. 1430 01:00:47,740 --> 01:00:50,645 >> Dan ifisser li, oh, aħna qed mtennija permezz ta 'hawn. 1431 01:00:50,645 --> 01:00:51,699 1432 01:00:51,699 --> 01:00:53,740 Tkun xi valur huwa hawnhekk huwa mhux ħaġa iżgħar tagħna. 1433 01:00:53,740 --> 01:00:54,448 Aħna ma jriduhom. 1434 01:00:54,448 --> 01:00:56,100 Aħna rridu li jassenja mill-ġdid. 1435 01:00:56,100 --> 01:01:02,050 Mela jekk aħna qed jassenjaw mill-ġdid huwa, liema do inti taħseb li tista 'tkun f'dan il-kodiċi hawn? 1436 01:01:02,050 --> 01:01:04,160 Aħna rridu li jassenja mill-ġdid iżgħar u l-pożizzjoni. 1437 01:01:04,160 --> 01:01:05,740 1438 01:01:05,740 --> 01:01:07,010 Allura dak li huwa l-iżgħar issa? 1439 01:01:07,010 --> 01:01:08,422 1440 01:01:08,422 --> 01:01:09,130 STUDENT: Array k. 1441 01:01:09,130 --> 01:01:09,963 Istruttur: Array k. 1442 01:01:09,963 --> 01:01:13,480 1443 01:01:13,480 --> 01:01:15,956 U dak li huwa f'pożizzjoni issa? 1444 01:01:15,956 --> 01:01:20,940 1445 01:01:20,940 --> 01:01:23,000 X'hemm l-indiċi ta ' iżgħar valur tagħna? 1446 01:01:23,000 --> 01:01:24,030 1447 01:01:24,030 --> 01:01:24,530 Huwa biss k. 1448 01:01:24,530 --> 01:01:25,690 1449 01:01:25,690 --> 01:01:27,790 Allura firxa k, k, huma jaqblu. 1450 01:01:27,790 --> 01:01:31,670 1451 01:01:31,670 --> 01:01:33,120 Hekk ridna li jassenja mill-ġdid dik. 1452 01:01:33,120 --> 01:01:34,390 1453 01:01:34,390 --> 01:01:39,950 U allura wara sibna iżgħar tagħna, hekk fl-aħħar ta dan għall loop 1454 01:01:39,950 --> 01:01:45,100 hawn sibna dak iżgħar tagħna valur huwa, hekk aħna biss tpartit. 1455 01:01:45,100 --> 01:01:47,100 1456 01:01:47,100 --> 01:01:50,816 F'dan il-każ, bħal ngħidu tagħna iżgħar valur huwa hawnhekk. 1457 01:01:50,816 --> 01:01:51,940 Dan huwa l-iżgħar valur tagħna. 1458 01:01:51,940 --> 01:01:57,690 >> Aħna biss trid li tpartit hawnhekk, li hija dak dik il-funzjoni tpartit fil-qiegħ 1459 01:01:57,690 --> 01:02:01,270 ma, li aħna biss kiteb up flimkien koppja minuti ilu. 1460 01:02:01,270 --> 01:02:02,775 Għalhekk għandha tfittex familjari. 1461 01:02:02,775 --> 01:02:04,320 1462 01:02:04,320 --> 01:02:08,030 U allura biss se jtenni permezz sakemm jilħaq it-triq kollha 1463 01:02:08,030 --> 01:02:13,100 sa l-aħħar, li jfisser li inti ikollhom elementi żero li mhumiex magħżulin 1464 01:02:13,100 --> 01:02:14,800 u kull ħaġa oħra tkun ġiet magħżula. 1465 01:02:14,800 --> 01:02:16,216 1466 01:02:16,216 --> 01:02:16,715 Jagħmel sens? 1467 01:02:16,715 --> 01:02:18,010 1468 01:02:18,010 --> 01:02:19,280 A ftit aktar konkret? 1469 01:02:19,280 --> 01:02:19,990 L-għajnuna kodiċi? 1470 01:02:19,990 --> 01:02:21,720 1471 01:02:21,720 --> 01:02:26,410 >> STUDENT: Għal daqs, int qatt ma verament jiddefinixxu jew jibdlu, 1472 01:02:26,410 --> 01:02:27,340 kif ma taf? 1473 01:02:27,340 --> 01:02:32,380 >> Istruttur: Allura ħaġa waħda li Avviż up hawnhekk huwa daqs int. 1474 01:02:32,380 --> 01:02:35,680 Allura aħna qed tgħid f'dan it-tip sort-- hija funzjoni f'dan case-- huwa 1475 01:02:35,680 --> 01:02:40,770 sort għażla, huwa għadda fil mal-funzjoni. 1476 01:02:40,770 --> 01:02:43,460 Mela jekk ma kienx għadda fil, inti se tagħmel xi ħaġa 1477 01:02:43,460 --> 01:02:47,840 bħall mat-tul tal-firxa jew inti se jtenni permezz 1478 01:02:47,840 --> 01:02:49,390 biex isibu l-tul. 1479 01:02:49,390 --> 01:02:52,680 Iżda għaliex dan huwa għadda fil, nistgħu tagħmel użu minnha biss. 1480 01:02:52,680 --> 01:02:55,720 Inti biss wieħed jassumi li l-utent ħadt daqs valida li 1481 01:02:55,720 --> 01:02:57,698 attwalment tirrappreżenta daqs ta 'firxa tiegħek. 1482 01:02:57,698 --> 01:02:59,461 1483 01:02:59,461 --> 01:02:59,960 Kessaħ? 1484 01:02:59,960 --> 01:03:01,610 1485 01:03:01,610 --> 01:03:05,870 >> Jekk inti guys jkollhom xi problemi ma 'dawn jew tixtieq aktar prattika kodifikazzjoni xorta 1486 01:03:05,870 --> 01:03:08,050 fuq tiegħek, inti għandek mur study.cs50. 1487 01:03:08,050 --> 01:03:11,560 1488 01:03:11,560 --> 01:03:12,670 Huwa għodda. 1489 01:03:12,670 --> 01:03:15,040 Huma għandhom kontrollur li inti tista 'attwalment tikteb. 1490 01:03:15,040 --> 01:03:16,180 Huma jagħmlu pseudocode. 1491 01:03:16,180 --> 01:03:19,310 Huma għandhom aktar videos u slides inklużi dawk I użu hawn. 1492 01:03:19,310 --> 01:03:23,150 Mela jekk int xorta tħossok ftit fuzzy, ipprova li minn. 1493 01:03:23,150 --> 01:03:25,670 Bħal dejjem, come tkellem lili, wisq. 1494 01:03:25,670 --> 01:03:26,320 Mistoqsija? 1495 01:03:26,320 --> 01:03:28,611 >> STUDENT: Inti tgħid l- Daqs huwa definit preċedentement? 1496 01:03:28,611 --> 01:03:29,234 1497 01:03:29,234 --> 01:03:29,900 Istruttur: Iva. 1498 01:03:29,900 --> 01:03:35,570 Id-daqs jiġi qabel definit up hawn fid-dikjarazzjoni funzjoni. 1499 01:03:35,570 --> 01:03:39,060 Allura inti jassumi li huwa kien għadda fi mill-utent, u għall-finijiet ta 'sempliċità, 1500 01:03:39,060 --> 01:03:41,896 aħna qed tmur li wieħed jassumi li l- utent tawna l-daqs korrett. 1501 01:03:41,896 --> 01:03:43,240 Kessaħ. 1502 01:03:43,240 --> 01:03:44,390 Allura dak it-tip ta 'għażla. 1503 01:03:44,390 --> 01:03:45,590 1504 01:03:45,590 --> 01:03:47,640 Guys, I know aħna qed jitgħallmu ħafna llum. 1505 01:03:47,640 --> 01:03:49,710 Huwa data dens għal taqsima. 1506 01:03:49,710 --> 01:03:51,880 1507 01:03:51,880 --> 01:03:57,340 Allura ma 'dan, aħna ser biex tmur sort inserzjoni. 1508 01:03:57,340 --> 01:04:01,550 1509 01:04:01,550 --> 01:04:02,510 >> OK. 1510 01:04:02,510 --> 01:04:06,100 Allura qabel li għandna nagħmlu analiżi runtime tagħna hawn. 1511 01:04:06,100 --> 01:04:10,190 Hekk fil-każ aħjar, mogħti peress I wera li inti 1512 01:04:10,190 --> 01:04:11,960 -tabella I diġà tip ta 'tatha bogħod. 1513 01:04:11,960 --> 01:04:15,430 Iżda każ runtime aħjar, dak li aħna naħsbu? 1514 01:04:15,430 --> 01:04:17,310 1515 01:04:17,310 --> 01:04:18,130 Kollox magħżula. 1516 01:04:18,130 --> 01:04:21,040 1517 01:04:21,040 --> 01:04:22,070 N kwadru. 1518 01:04:22,070 --> 01:04:24,780 Kull min ikollu spjegazzjoni għal għaliex taħseb? 1519 01:04:24,780 --> 01:04:29,060 1520 01:04:29,060 --> 01:04:30,519 >> STUDENT: Inti jitqabblu through-- 1521 01:04:30,519 --> 01:04:31,268 Istruttur: Dritt. 1522 01:04:31,268 --> 01:04:32,540 Inti jitqabblu permezz. 1523 01:04:32,540 --> 01:04:35,630 F'kull iterazzjoni, anki jekk aħna qed decrementing dan billi wieħed, 1524 01:04:35,630 --> 01:04:38,950 int xorta tiftix permezz kollox biex isibu l-iżgħar waħda. 1525 01:04:38,950 --> 01:04:42,390 Għalhekk anki jekk iżgħar valur tiegħek huwa hawn fil-bidu, 1526 01:04:42,390 --> 01:04:44,710 int xorta tqabbilha kontra kull ħaġa oħra 1527 01:04:44,710 --> 01:04:46,550 biex tagħmel ċert li huwa l-ħaġa iżgħar. 1528 01:04:46,550 --> 01:04:49,820 Allura inti ser jispiċċaw taħdem permezz madwar n kwadrat żminijiet. 1529 01:04:49,820 --> 01:04:51,090 1530 01:04:51,090 --> 01:04:51,590 Kull dritt. 1531 01:04:51,590 --> 01:04:52,785 U x'inhu l-agħar każ? 1532 01:04:52,785 --> 01:04:54,350 1533 01:04:54,350 --> 01:04:57,980 Wkoll n kwadrat għaliex inti qed tmur li tkun qiegħda tagħmel l-istess proċedura. 1534 01:04:57,980 --> 01:05:01,670 Allura f'dan il-każ, l-għażla sort għandu xi ħaġa 1535 01:05:01,670 --> 01:05:04,010 li aħna wkoll sejħa runtime mistenni. 1536 01:05:04,010 --> 01:05:07,400 Allura fl-oħrajn, aħna biss nafu il-limiti ta 'fuq u t'isfel. 1537 01:05:07,400 --> 01:05:11,180 Skond kif crazy tagħna lista hija jew kif mhux magħżul huwa, 1538 01:05:11,180 --> 01:05:15,350 dawn ivarjaw bejn n jew n kwadrat. 1539 01:05:15,350 --> 01:05:16,550 Ma nafux. 1540 01:05:16,550 --> 01:05:22,820 >> Iżda minħabba sort għażla għandha l-istess agħar u l-aħjar każ, li tgħidilna li 1541 01:05:22,820 --> 01:05:25,880 x'ikun it-tip ta 'input aħna jkollhom, kemm jekk huwa kompletament 1542 01:05:25,880 --> 01:05:29,130 magħżula jew kompletament reverse magħżula, huwa 1543 01:05:29,130 --> 01:05:30,740 ser tieħu l-istess ammont ta 'ħin. 1544 01:05:30,740 --> 01:05:33,760 Allura f'dak il-każ, jekk inti ftakar mit-tabella tagħna, 1545 01:05:33,760 --> 01:05:38,610 hija effettivament kellha valur li dawn iż-żewġ tipi ma jkollhomx, 1546 01:05:38,610 --> 01:05:40,390 li huwa runtime mistenni. 1547 01:05:40,390 --> 01:05:43,350 Allura aħna nafu li kull meta we run sort għażla, 1548 01:05:43,350 --> 01:05:45,380 huwa garantit li run n kwadrat żmien. 1549 01:05:45,380 --> 01:05:46,630 M'hemm l-ebda varjabilità hemmhekk. 1550 01:05:46,630 --> 01:05:47,630 Huwa biss mistenni. 1551 01:05:47,630 --> 01:05:48,820 1552 01:05:48,820 --> 01:05:52,140 U, għal darb'oħra, jekk inti tixtieq titgħallem aktar, tieħu CS 124 fil-Rebbiegħa. 1553 01:05:52,140 --> 01:05:55,370 1554 01:05:55,370 --> 01:05:56,712 Kull dritt. 1555 01:05:56,712 --> 01:05:57,545 Rajna dan wieħed. 1556 01:05:57,545 --> 01:05:58,530 1557 01:05:58,530 --> 01:05:59,030 Kessaħ. 1558 01:05:59,030 --> 01:06:00,930 Sort hekk inserzjoni. 1559 01:06:00,930 --> 01:06:03,330 U jien probabbilment se blaze permezz ta 'dan. 1560 01:06:03,330 --> 01:06:05,440 I mhux se jkollhom inti guys kodiċi dan. 1561 01:06:05,440 --> 01:06:06,580 Aħna ser biss walk permezz tiegħu. 1562 01:06:06,580 --> 01:06:10,500 Allura sort inserzjoni huwa tip ta 'tip simili għal għażla 1563 01:06:10,500 --> 01:06:14,460 f'dak għandna kemm mhux magħżul u magħżula parti mill-firxa. 1564 01:06:14,460 --> 01:06:20,260 >> Imma x'hemm differenti hija li kif aħna jgħaddu waħda waħda, 1565 01:06:20,260 --> 01:06:24,210 aħna biss jieħdu kwalunkwe numru huwa li jmiss fil mhux magħżul tagħna, 1566 01:06:24,210 --> 01:06:28,507 u sort korrettament fis firxa ssortjat tagħna. 1567 01:06:28,507 --> 01:06:30,090 Hija ser tagħmel aktar sens ma 'eżempju. 1568 01:06:30,090 --> 01:06:31,140 1569 01:06:31,140 --> 01:06:35,430 Hekk kollox jibda bħala mhux magħżul, Eżatt bħal ma sort għażla. 1570 01:06:35,430 --> 01:06:38,740 U aħna qed tmur biex dan sort fl axxendenti ordni kif ilna. 1571 01:06:38,740 --> 01:06:40,360 1572 01:06:40,360 --> 01:06:43,340 Allura fuq l-ewwel pass tagħna nieħdu l-ewwel valur 1573 01:06:43,340 --> 01:06:46,700 u aħna ngħidu, OK, inti issa f'lista mill yourself. 1574 01:06:46,700 --> 01:06:49,150 >> Għaliex inti fil-lista minnek, inti huma magħżula. 1575 01:06:49,150 --> 01:06:52,460 Congratulations talli kienet l- ewwel element f'din firxa. 1576 01:06:52,460 --> 01:06:54,800 Int diġà magħżula kollha fuq tiegħek. 1577 01:06:54,800 --> 01:06:58,900 Allura issa għandna magħżula u l-firxa mhux magħżul. 1578 01:06:58,900 --> 01:07:01,760 Allura issa aħna jieħdu l-ewwel. 1579 01:07:01,760 --> 01:07:05,600 X'jiġri bejn hawn u hawnhekk hija li aħna ngħidu, 1580 01:07:05,600 --> 01:07:08,890 OK, aħna qed tmur biex tħares lejn il- ewwel valur tal-firxa mhux magħżul tagħna 1581 01:07:08,890 --> 01:07:13,270 u aħna qed tmur biex input fil tagħha post korretta fil-firxa ssortjat. 1582 01:07:13,270 --> 01:07:21,460 >> Allura dak li nagħmlu huwa nieħdu 5 u ngħidu, OK, 5 huwa akbar minn 3, 1583 01:07:21,460 --> 01:07:24,630 hekk aħna biss daħħal dan id-dritt għad-dritt ta 'dak. 1584 01:07:24,630 --> 01:07:25,130 Aħna qed tajba. 1585 01:07:25,130 --> 01:07:26,200 1586 01:07:26,200 --> 01:07:28,420 Allura mbagħad immorru fuq xi wiehed jmiss tagħna. 1587 01:07:28,420 --> 01:07:29,720 U nieħdu 2. 1588 01:07:29,720 --> 01:07:34,330 Aħna ngħidu, OK, 2 huwa inqas minn 3, hekk aħna nafu li 1589 01:07:34,330 --> 01:07:36,220 jeħtieġ li tkun fil- quddiem tal-lista tagħna issa. 1590 01:07:36,220 --> 01:07:41,800 Allura dak li nagħmlu huwa aħna timbotta 3 u 5 isfel u nimxu 2 f'dak l-ewwel slot. 1591 01:07:41,800 --> 01:07:42,990 1592 01:07:42,990 --> 01:07:45,870 Allura aħna qed biss ddaħħalha fis il-post korretta għandu jkun. 1593 01:07:45,870 --> 01:07:46,960 1594 01:07:46,960 --> 01:07:49,470 >> Allura aħna nħarsu lejn tagħna wieħed li jmiss, u aħna ngħidu 6. 1595 01:07:49,470 --> 01:07:53,620 OK, 6 huwa akbar minn kollox fil-firxa ssortjat tagħna, 1596 01:07:53,620 --> 01:07:56,000 hekk aħna biss tag fuq l-aħħar. 1597 01:07:56,000 --> 01:07:56,960 U allura aħna nħarsu lejn 4. 1598 01:07:56,960 --> 01:07:58,130 1599 01:07:58,130 --> 01:08:03,020 4 huwa inqas minn 6, huwa inqas minn 5 iżda huwa akbar minn 3. 1600 01:08:03,020 --> 01:08:06,270 Allura aħna biss daħħal dan id-dritt fis -nofs bejn 3 u 5. 1601 01:08:06,270 --> 01:08:07,380 1602 01:08:07,380 --> 01:08:10,530 Allura biex jagħmlu dak ftit ftit aktar konkreti, 1603 01:08:10,530 --> 01:08:12,280 hawnhekk huwa tip ta 'l- idea ta 'dak li ġara. 1604 01:08:12,280 --> 01:08:16,430 Allura għal kull element mhux magħżul, aħna ddeterminat fejn fil-porzjon magħżul 1605 01:08:16,430 --> 01:08:17,090 huwa. 1606 01:08:17,090 --> 01:08:20,680 >> Allura jżomm f'moħħu l- magħżula u mhux magħżula, 1607 01:08:20,680 --> 01:08:26,080 għandna biex travers permezz u figura fejn taqbel fil-firxa ssortjat. 1608 01:08:26,080 --> 01:08:31,460 U aħna daħħalha billi ċċaqlaq il- elementi għad-dritt ta l-isfel. 1609 01:08:31,460 --> 01:08:34,910 U allura aħna biss iżommu iterazzjoni permezz sakemm aħna 1610 01:08:34,910 --> 01:08:39,270 jkollhom lista kompletament magħżula fejn mhux magħżul issa huwa żero 1611 01:08:39,270 --> 01:08:41,720 u magħżula jieħu l- intier tal-lista tagħna. 1612 01:08:41,720 --> 01:08:43,146 1613 01:08:43,146 --> 01:08:45,854 Allura, għal darb'oħra, biex tagħmel affarijiet anke aktar konkreti, għandna pseudocode. 1614 01:08:45,854 --> 01:08:47,979 1615 01:08:47,979 --> 01:08:52,410 >> Allura bażikament għall I huwa ugwali għal 0 sa n minus 1, 1616 01:08:52,410 --> 01:08:54,790 li jinsab biss t-tul ta 'firxa tagħna. 1617 01:08:54,790 --> 01:09:00,979 Għandna xi element li huwa ugwali għal l-ewwel firxa jew l-ewwel indiċi. 1618 01:09:00,979 --> 01:09:03,200 Waqqafna j ugwali għal dak. 1619 01:09:03,200 --> 01:09:04,649 1620 01:09:04,649 --> 01:09:09,210 Allura filwaqt li j huwa akbar minn żero u l-array, j minus 1 1621 01:09:09,210 --> 01:09:11,660 huwa akbar mill- element, sabiex dak kollu li qed jagħmel 1622 01:09:11,660 --> 01:09:17,479 qed tagħmel ċert li j tiegħek verament tirrappreżenta 1623 01:09:17,479 --> 01:09:20,010 il-porzjon mhux magħżul mill-firxa. 1624 01:09:20,010 --> 01:09:30,745 >> Allura filwaqt li għad hemm affarijiet biex issolvi u wieħed nieqes j is-- liema 1625 01:09:30,745 --> 01:09:31,840 huwa l-element tagħha? 1626 01:09:31,840 --> 01:09:34,760 J qatt ġie definit hawn. 1627 01:09:34,760 --> 01:09:35,677 Huwa tip ta 'annoying. 1628 01:09:35,677 --> 01:09:36,176 OK. 1629 01:09:36,176 --> 01:09:36,689 Anyways. 1630 01:09:36,689 --> 01:09:39,899 Allura j minus 1, int iċċekkjar l-element quddiemha. 1631 01:09:39,899 --> 01:09:46,460 Inti qed tgħid, OK, huwa l-element qabel kull fejn I am-- ejja 1632 01:09:46,460 --> 01:09:47,540 attwalment tiġbed dan out. 1633 01:09:47,540 --> 01:09:52,580 1634 01:09:52,580 --> 01:09:56,830 Mela ejja ngħidu li dan huwa simili fuq it-tieni pass tagħna. 1635 01:09:56,830 --> 01:09:59,525 Hekk i se jkun ugwali għal 1, li hija hawnhekk. 1636 01:09:59,525 --> 01:10:03,310 1637 01:10:03,310 --> 01:10:06,025 >> Hekk i se tkun ugwali għal 1. 1638 01:10:06,025 --> 01:10:09,510 1639 01:10:09,510 --> 01:10:13,702 Dan ikun 2, 4, 5, 6, 7. 1640 01:10:13,702 --> 01:10:16,060 1641 01:10:16,060 --> 01:10:16,750 Kull dritt. 1642 01:10:16,750 --> 01:10:20,945 Allura element tagħna f'dan il-każ se tkun ugwali għal 4. 1643 01:10:20,945 --> 01:10:22,110 1644 01:10:22,110 --> 01:10:24,946 U aħna għandna xi j thats se jkun ugwali għal 1. 1645 01:10:24,946 --> 01:10:29,770 1646 01:10:29,770 --> 01:10:30,971 Oh, j huwa decrementing. 1647 01:10:30,971 --> 01:10:31,720 Dan huwa dak li hu. 1648 01:10:31,720 --> 01:10:35,680 Allura j hija ugwali għal i, hekk dak li din hija tgħid huwa li kif nimxu 'l quddiem, 1649 01:10:35,680 --> 01:10:37,530 aħna qed biss tagħmel ċert li aħna mhux qed fuq 1650 01:10:37,530 --> 01:10:43,520 indiċjar B'dan il-mod meta aħna qed jippruvaw li daħħal l-affarijiet fil-lista magħżula tagħna. 1651 01:10:43,520 --> 01:10:49,850 >> Allura meta j hija ugwali għal 1 f'dan il-każ u firxa j minus one-- hekk firxa minus j 1 1652 01:10:49,850 --> 01:10:54,610 hija ta '2 f'dan case-- jekk dan huwa akbar mill-element, 1653 01:10:54,610 --> 01:10:57,700 allura dan kollu qed tagħmel qed tiċċaqlaq affarijiet isfel. 1654 01:10:57,700 --> 01:11:04,790 Allura f'dan il-każ, array nieqes j wieħed Ikun firxa żero, li huwa 2. 1655 01:11:04,790 --> 01:11:08,430 2 ma tkunx akbar minn 4, għalhekk dan ma jeżegwixxix. 1656 01:11:08,430 --> 01:11:11,460 Allura l-bidla ma jiċċaqlaqx isfel. 1657 01:11:11,460 --> 01:11:18,790 X'inhu dan ma hawn huwa biss jiċċaqilqu firxa ssortjat tiegħek isfel. 1658 01:11:18,790 --> 01:11:22,340 1659 01:11:22,340 --> 01:11:26,400 F'dan il-każ, fil-fatt, aħna jista do-- ejja jagħmlu dan 3. 1660 01:11:26,400 --> 01:11:28,080 1661 01:11:28,080 --> 01:11:31,970 Hekk jekk aħna qed jimxu permezz ma dan l-eżempju, aħna qed issa hawn. 1662 01:11:31,970 --> 01:11:32,740 Dan huwa magħżul. 1663 01:11:32,740 --> 01:11:34,492 1664 01:11:34,492 --> 01:11:35,200 Dan huwa mhux magħżul. 1665 01:11:35,200 --> 01:11:39,090 1666 01:11:39,090 --> 01:11:39,860 Kessaħ? 1667 01:11:39,860 --> 01:11:46,620 Hekk i huwa ugwali għal 2, hekk element tagħna hija ugwali għal 3. 1668 01:11:46,620 --> 01:11:47,920 1669 01:11:47,920 --> 01:11:52,270 U j tagħna hija ugwali għal 2. 1670 01:11:52,270 --> 01:12:00,620 Allura aħna tfittex permezz u aħna jgħidu, OK, huwa wieħed nieqes firxa j 1671 01:12:00,620 --> 01:12:03,470 akbar mill-element li aħna qed tħares lejn? 1672 01:12:03,470 --> 01:12:05,540 U t-tweġiba hija iva, id-dritt? 1673 01:12:05,540 --> 01:12:11,275 4 huwa akbar minn 3 u j huwa ta '2, tant dan il-kodiċi tesegwixxi. 1674 01:12:11,275 --> 01:12:12,510 1675 01:12:12,510 --> 01:12:18,550 >> Allura issa dak li nagħmlu firxa fi 2, hekk dritt hawn, aħna tpartit minnhom. 1676 01:12:18,550 --> 01:12:25,620 Allura aħna biss jgħidu, OK, array ta '2 issa se jkun ta' 3. 1677 01:12:25,620 --> 01:12:28,130 1678 01:12:28,130 --> 01:12:32,340 U j se ugwali j minus 1, li hija l-1. 1679 01:12:32,340 --> 01:12:34,590 1680 01:12:34,590 --> 01:12:37,200 C'est horrible, iżda inti guys jiksbu l-idea. 1681 01:12:37,200 --> 01:12:38,360 J issa huwa ugwali għal 1. 1682 01:12:38,360 --> 01:12:44,360 U firxa j huwa biss se tkun ugwali għal element tagħna, li kienet ta '4. 1683 01:12:44,360 --> 01:12:45,950 1684 01:12:45,950 --> 01:12:48,570 I mħassra xi ħaġa I ma għandu ikollhom jew xi ħaġa miswrote, 1685 01:12:48,570 --> 01:12:49,910 imma inti guys jiksbu l-idea. 1686 01:12:49,910 --> 01:12:50,640 >> Hija jimxu n. 1687 01:12:50,640 --> 01:12:51,920 1688 01:12:51,920 --> 01:12:57,960 U mbagħad jekk dan kien, ikun loop għal darb'oħra u ngħid, OK, j huwa 1 issa. 1689 01:12:57,960 --> 01:13:00,665 U firxa j minus 1 issa 2 hija. 1690 01:13:00,665 --> 01:13:01,750 1691 01:13:01,750 --> 01:13:03,760 Huwa inqas minn 2 element tagħna? 1692 01:13:03,760 --> 01:13:04,540 No? 1693 01:13:04,540 --> 01:13:07,970 Dan ifisser li aħna stajt mdaħħal dan l-element 1694 01:13:07,970 --> 01:13:10,110 fil-post korretta fil-firxa ssortjat tagħna. 1695 01:13:10,110 --> 01:13:14,400 Imbagħad nistgħu nieħdu dan u aħna ngħidu, OK, array magħżul tagħna huwa hawnhekk. 1696 01:13:14,400 --> 01:13:19,940 U hija kienet ser tieħu dan in-numru 6 u tkun simili, OK, hija ta '6 inqas minn dan in-numru? 1697 01:13:19,940 --> 01:13:20,480 No? 1698 01:13:20,480 --> 01:13:21,080 Kessaħ. 1699 01:13:21,080 --> 01:13:22,680 Aħna qed multa. 1700 01:13:22,680 --> 01:13:23,530 >> Jagħmlu mill-ġdid. 1701 01:13:23,530 --> 01:13:24,740 Ngħidu 7. 1702 01:13:24,740 --> 01:13:29,010 Huwa 7 inqas mill-aħħar ta 'firxa ssortjat tagħna? 1703 01:13:29,010 --> 01:13:29,520 No 1704 01:13:29,520 --> 01:13:30,430 Allura aħna qed multa. 1705 01:13:30,430 --> 01:13:32,760 Għalhekk dan ikun jiġu magħżula. 1706 01:13:32,760 --> 01:13:38,610 Bażikament dan kollu ma huwa Hi tgħid jieħdu 1707 01:13:38,610 --> 01:13:42,060 l-ewwel element ta ' firxa mhux magħżul tiegħek, 1708 01:13:42,060 --> 01:13:46,010 insemmu fejn din tmur fil-firxa ssortjat tiegħek. 1709 01:13:46,010 --> 01:13:48,780 U dan biss jieħu kura ta 'swaps sabiex tagħmel dan. 1710 01:13:48,780 --> 01:13:51,300 Inti bażikament biss iskambji sakemm ikun fil-post dritt. 1711 01:13:51,300 --> 01:13:53,600 1712 01:13:53,600 --> 01:13:56,990 L-immaġni viżwali hija li int jiċċaqalqu kollox stabbiliti billi tagħmel dan. 1713 01:13:56,990 --> 01:13:59,420 >> Allura huwa simili nofs bużżieqa tip esque. 1714 01:13:59,420 --> 01:14:02,280 1715 01:14:02,280 --> 01:14:03,420 Check out istudju 50. 1716 01:14:03,420 --> 01:14:06,000 I jirrakkomanda ħafna jippruvaw għall-kodiċi dan fuq tiegħek stess. 1717 01:14:06,000 --> 01:14:07,220 1718 01:14:07,220 --> 01:14:12,450 Jekk għandek xi kwistjonijiet jew inti tixtieq li tara kodiċi kampjun għal tip inserzjoni, 1719 01:14:12,450 --> 01:14:13,750 jekk jogħġbok let me know. 1720 01:14:13,750 --> 01:14:14,500 Jien dejjem madwar. 1721 01:14:14,500 --> 01:14:16,600 1722 01:14:16,600 --> 01:14:20,200 Allura runtime agħar każ u l-każ runtime aħjar. 1723 01:14:20,200 --> 01:14:30,700 Kif inti Guy raw mit-tabella I diġà wera inti, huwa kemm n kwadrat u n. 1724 01:14:30,700 --> 01:14:35,590 >> Tant tip ta 'għaddej off ta' dak li tkellimna dwar ma xorta preċedenti tagħna, agħar 1725 01:14:35,590 --> 01:14:38,760 każ runtime huwa li jekk huwa kompletament mhux magħżul, 1726 01:14:38,760 --> 01:14:42,530 għandna biex iqabblu kollha ta 'dawn iż-żminijiet n. 1727 01:14:42,530 --> 01:14:47,020 We do lott kollu ta 'paraguni għaliex jekk huwa fl-ordni invers, 1728 01:14:47,020 --> 01:14:50,360 aħna qed tmur biex ngħid, OK, dan huwa l-istess, dan huwa tajjeb, 1729 01:14:50,360 --> 01:14:54,650 u dan wieħed se jkollhom jiġu mqabbla kontra l-ewwel waħda li għandha tiġi mċaqalqa lura. 1730 01:14:54,650 --> 01:14:56,710 U kif nikbru lejn l-aħħar denb, għandna 1731 01:14:56,710 --> 01:14:59,440 biex iqabblu, iqabblu, u qabbel kontra kollox. 1732 01:14:59,440 --> 01:15:03,030 >> Allura huwa jispiċċa jkun madwar n kwadrat. 1733 01:15:03,030 --> 01:15:09,510 Jekk huwa korrett allura inti jgħidu, OK, 2, int tajba. 1734 01:15:09,510 --> 01:15:11,330 3, int imqabbel ma '2. 1735 01:15:11,330 --> 01:15:12,310 Int tajba. 1736 01:15:12,310 --> 01:15:14,150 4, inti biss mqabbla mal-denb. 1737 01:15:14,150 --> 01:15:14,990 Int tajba. 1738 01:15:14,990 --> 01:15:17,140 6, mqabbla mal-denb, int multa. 1739 01:15:17,140 --> 01:15:20,870 Allura għal kull post jekk huwa diġà magħżula, int tagħmel paragun wieħed. 1740 01:15:20,870 --> 01:15:22,320 Allura huwa biss n. 1741 01:15:22,320 --> 01:15:26,840 U għaliex għandna każ runtime aħjar ta n u runtime agħar każ ta 'n 1742 01:15:26,840 --> 01:15:28,680 kwadrat, għandna l-ebda runtime mistenni. 1743 01:15:28,680 --> 01:15:31,290 1744 01:15:31,290 --> 01:15:34,020 >> Hija biss tiddependi fuq il- kaos tal-lista tagħna hemmhekk. 1745 01:15:34,020 --> 01:15:35,860 1746 01:15:35,860 --> 01:15:39,530 U għal darb'oħra, ieħor graff u tabella ieħor. 1747 01:15:39,530 --> 01:15:41,170 Allura differenzi bejn xorta. 1748 01:15:41,170 --> 01:15:44,180 Jien biss ser riħ permezz, I jħossu bħal konna tkellimna estensiv 1749 01:15:44,180 --> 01:15:46,570 dwar kif dawn kull tip tal ivarjaw u torbot flimkien. 1750 01:15:46,570 --> 01:15:50,564 Allura jingħaqdu sort hija l-aħħar waħda I għandhom bore inti guys ma. 1751 01:15:50,564 --> 01:15:52,105 We do jkollhom stampa pretty colorful. 1752 01:15:52,105 --> 01:15:53,860 1753 01:15:53,860 --> 01:15:56,040 Allura jingħaqdu sort huwa algoritmu rikursivi. 1754 01:15:56,040 --> 01:15:59,910 Allura do inti guys taf liema funzjoni jirrikorri hu? 1755 01:15:59,910 --> 01:16:01,550 1756 01:16:01,550 --> 01:16:03,320 >> Kull min jixtiequ li ngħid? 1757 01:16:03,320 --> 01:16:04,739 Inti tixtieq li jippruvaw? 1758 01:16:04,739 --> 01:16:07,280 Allura funzjoni jirrikorri huwa biss funzjoni li s-sejħiet innifsu. 1759 01:16:07,280 --> 01:16:08,570 1760 01:16:08,570 --> 01:16:11,590 Hekk jekk inti guys huma familjari mas-sekwenza Fibonacci, 1761 01:16:11,590 --> 01:16:15,670 thats meqjusa rikursivi għaliex tieħu l-żewġ preċedenti 1762 01:16:15,670 --> 01:16:17,530 u żidhom flimkien biex tikseb wieħed li jmiss tiegħek. 1763 01:16:17,530 --> 01:16:21,440 So rikursivi, I dejjem taħseb ta 'recursion bħala bħal spirali 1764 01:16:21,440 --> 01:16:24,430 hekk int simili jaqaw isfel fis dan. 1765 01:16:24,430 --> 01:16:27,150 Imma huwa biss funzjoni li s-sejħiet innifsu. 1766 01:16:27,150 --> 01:16:32,660 >> U, fil-fatt, verament malajr I inti tista 'turi dak li qisu. 1767 01:16:32,660 --> 01:16:34,260 1768 01:16:34,260 --> 01:16:41,840 Allura rikursivi hawn, jekk inħarsu, dan huwa il-mod rikursivi li qosor fuq firxa. 1769 01:16:41,840 --> 01:16:45,900 1770 01:16:45,900 --> 01:16:47,880 Allura dak kollu li nagħmlu huwa għandna funzjoni somma 1771 01:16:47,880 --> 01:16:52,210 somma li tieħu daqs u l-firxa. 1772 01:16:52,210 --> 01:16:55,210 U jekk tinnota, id-daqs ta 'tnaqqis minn wieħed kull darba. 1773 01:16:55,210 --> 01:17:00,365 U kull ma tagħmel hija jekk x huwa ugwali għal zero-- hekk jekk id-daqs tal-array 1774 01:17:00,365 --> 01:17:02,710 hija ugwali għal zero-- dan jirritorna żero. 1775 01:17:02,710 --> 01:17:10,440 >> Inkella somom din aħħar element tal-firxa, 1776 01:17:10,440 --> 01:17:14,790 u mbagħad jieħu somma ta il-bqija tal-firxa. 1777 01:17:14,790 --> 01:17:17,555 Allura huwa biss jitkissru l-isfel fis-problemi iżgħar u iżgħar. 1778 01:17:17,555 --> 01:17:18,990 1779 01:17:18,990 --> 01:17:21,890 Long storja qasira, recursion, funzjoni li s-sejħiet innifsu. 1780 01:17:21,890 --> 01:17:25,740 Jekk dan huwa kull ma għandek ltqajna barra ta 'dan, dan huwa dak funzjoni jirrikorri hu. 1781 01:17:25,740 --> 01:17:29,870 Jekk inti tieħu 51, inti se tikseb ħafna, ħafna komda mal recursion. 1782 01:17:29,870 --> 01:17:31,110 1783 01:17:31,110 --> 01:17:32,370 Huwa verament jibred. 1784 01:17:32,370 --> 01:17:34,660 Kien jagħmel sens fi simili 03:00 wieħed bil-lejl out. 1785 01:17:34,660 --> 01:17:37,900 U I kien simili, għaliex jiena qatt ma jużaw dan? 1786 01:17:37,900 --> 01:17:39,170 1787 01:17:39,170 --> 01:17:42,430 >> Allura għal tip jingħaqdu, bażikament dak li għaddej biex tagħmel huwa huwa 1788 01:17:42,430 --> 01:17:45,620 se din tinqasam u farrku isfel sakemm huwa biss elementi singoli. 1789 01:17:45,620 --> 01:17:47,570 L-elementi singoli huma faċli biex sort. 1790 01:17:47,570 --> 01:17:48,070 Naraw li. 1791 01:17:48,070 --> 01:17:50,760 Jekk għandek element wieħed, huwa diġà kkunsidrati magħżul. 1792 01:17:50,760 --> 01:17:53,800 Allura fuq input ta 'elementi n, jekk n hija inqas minn 2, 1793 01:17:53,800 --> 01:17:58,120 sempliċiment tirritorna għax li l-mezzi huwa jew 0 jew 1 kif aħna stajt tidher. 1794 01:17:58,120 --> 01:18:00,050 Dawk huma kkunsidrati elementi magħżula. 1795 01:18:00,050 --> 01:18:02,170 >> Inkella jitkisser fil nofs. 1796 01:18:02,170 --> 01:18:06,336 Isolvi l-ewwel nofs, sort-tieni nofs, u mbagħad jingħaqdu flimkien. 1797 01:18:06,336 --> 01:18:07,460 Għaliex huwa msejjaħ sort jingħaqdu. 1798 01:18:07,460 --> 01:18:08,700 1799 01:18:08,700 --> 01:18:12,155 Allura aħna għandna hawnhekk aħna ser sort dawn. 1800 01:18:12,155 --> 01:18:13,410 1801 01:18:13,410 --> 01:18:17,210 Hekk aħna iżommu jkollhom magħhom sakemm id-daqs array huwa 1. 1802 01:18:17,210 --> 01:18:20,790 Allura meta huwa 1, aħna biss ritorn minħabba li din hija firxa magħżula, 1803 01:18:20,790 --> 01:18:23,940 u dan huwa firxa magħżula, u li l- firxa ssortjat, aħna qed kollha magħżula. 1804 01:18:23,940 --> 01:18:25,390 1805 01:18:25,390 --> 01:18:29,420 Mela allura dak li nagħmlu hija aħna tibda jgħaqqadhom flimkien. 1806 01:18:29,420 --> 01:18:31,820 >> Allura l-mod inti tista ' jaħsbu dwar amalgamazzjoni huwa 1807 01:18:31,820 --> 01:18:36,240 inti biss tneħħi l-iżgħar numru ta 'kull wieħed mill-arrays sub 1808 01:18:36,240 --> 01:18:38,330 u biss tehmeż lill-firxa ħarġu. 1809 01:18:38,330 --> 01:18:44,290 Mela jekk inti tfittex hawn, meta jkollna dawn is-settijiet għandna 4, 6, u 1. 1810 01:18:44,290 --> 01:18:47,280 Meta irridu li jingħaqdu dawn, aħna nħarsu lejn dawn l-ewwel tnejn 1811 01:18:47,280 --> 01:18:50,730 u aħna ngħidu, OK, 1 hija iżgħar, din tmur għall-quddiem. 1812 01:18:50,730 --> 01:18:54,330 4 u 6, m'hemm xejn li jqabblu li, biss tag fuq l-aħħar. 1813 01:18:54,330 --> 01:18:58,020 >> Meta aħna jgħaqqdu dawn iż-żewġ, aħna biss jieħdu l-iżgħar waħda minn dawn tnejn, 1814 01:18:58,020 --> 01:18:59,310 hekk huwa 1. 1815 01:18:59,310 --> 01:19:01,690 U issa aħna jieħdu l- iżgħar ta 'dawn iż-żewġ, hekk 2. 1816 01:19:01,690 --> 01:19:03,330 Iżgħar ta 'dawn iż-żewġ, 3. 1817 01:19:03,330 --> 01:19:06,260 Iżgħar ta 'dawn iż-żewġ, 4, 5, 6. 1818 01:19:06,260 --> 01:19:08,630 Allura int biss ġbid off dawn. 1819 01:19:08,630 --> 01:19:11,210 U minħabba li ħadthom ġew magħżula preċedentement, 1820 01:19:11,210 --> 01:19:14,300 inti biss għandek wieħed paragun kull darba li jkun hemm. 1821 01:19:14,300 --> 01:19:19,610 Allura aktar kodiċi hawn, biss rappreżentazzjoni. 1822 01:19:19,610 --> 01:19:24,410 Allura inti tibda fil-nofs u inti sort xellug u l-lemin 1823 01:19:24,410 --> 01:19:26,180 u mbagħad inti biss jingħaqdu dawk. 1824 01:19:26,180 --> 01:19:30,080 >> U aħna ma jkollhomx kodiċi għall jingħaqdu dritt hawn. 1825 01:19:30,080 --> 01:19:34,110 Iżda, għal darb'oħra, jekk inti tmur fuq tistudja 50, dan ser ikun hemm. 1826 01:19:34,110 --> 01:19:36,860 Inkella come tkellem lili jekk int xorta konfuż. 1827 01:19:36,860 --> 01:19:42,340 Allura jibred ħaġa hawnhekk huwa li l-aħjar każ, agħar każ, u runtime mistennija 1828 01:19:42,340 --> 01:19:46,250 huma kollha fil log n, li hija ħafna aħjar minn konna 1829 01:19:46,250 --> 01:19:48,000 dehru għall-bqija ta 'tipi tagħna. 1830 01:19:48,000 --> 01:19:51,840 Rajna n kwadrat u dak li għandna attwalment 1831 01:19:51,840 --> 01:19:54,380 wasalt hawn huwa n log n, li hija kbira. 1832 01:19:54,380 --> 01:19:55,830 >> Ħares lejn kif ħafna aħjar li hu. 1833 01:19:55,830 --> 01:19:56,780 Tali kurva sbieħ. 1834 01:19:56,780 --> 01:19:58,130 1835 01:19:58,130 --> 01:20:00,120 Għalhekk ħafna aktar effiċjenti. 1836 01:20:00,120 --> 01:20:03,510 Jekk inti qatt tista ', l-użu jingħaqdu sort. 1837 01:20:03,510 --> 01:20:04,810 Hija se jiffrankaw il-ħin. 1838 01:20:04,810 --> 01:20:07,670 Mbagħad, kif għidna, jekk int stabbiliti f'dan ir-reġjun t'isfel, 1839 01:20:07,670 --> 01:20:09,480 ma jagħmilx dan ħafna ta 'differenza. 1840 01:20:09,480 --> 01:20:11,360 Ikollok up għal eluf u eluf ta 'inputs, 1841 01:20:11,360 --> 01:20:13,318 inti definittivament tixtieq a algoritmu aktar effiċjenti. 1842 01:20:13,318 --> 01:20:14,730 1843 01:20:14,730 --> 01:20:19,400 U, għal darb'oħra, tabella sabiħ tagħna ta 'kulħadd xorta li inti guys tgħallmu llum. 1844 01:20:19,400 --> 01:20:21,157 >> So I know huwa kien jum dens. 1845 01:20:21,157 --> 01:20:23,490 Dan mhux neċessarjament ser biex jgħinuk bil pset tiegħek. 1846 01:20:23,490 --> 01:20:28,250 Imma I biss jixtiequ jagħmlu dikjarazzjoni ta 'ċaħda dik is-sezzjoni mhix biss dwar psets. 1847 01:20:28,250 --> 01:20:31,240 Dan kollu materjal huwa ġust logħba għall midterms tiegħek. 1848 01:20:31,240 --> 01:20:35,430 U wkoll jekk inti tagħmel tkompli fuq il CS, dawn huma elementi fundamentali verament importanti 1849 01:20:35,430 --> 01:20:37,870 li għandek bżonn tkun taf. 1850 01:20:37,870 --> 01:20:41,700 Allura xi jiem se jkun ftit aktar għajnuna pset, 1851 01:20:41,700 --> 01:20:44,600 iżda xi ġimgħat se jkun ħafna aktar kontenut attwali 1852 01:20:44,600 --> 01:20:46,600 li ma jista 'jidher super utli għalik dritt issa, 1853 01:20:46,600 --> 01:20:51,215 imma I wegħda jekk inti tkompli fuq se jkun ħafna, utli ħafna. 1854 01:20:51,215 --> 01:20:52,560 1855 01:20:52,560 --> 01:20:54,250 >> Allura dak għal sezzjoni. 1856 01:20:54,250 --> 01:20:55,250 L isfel għall-wajer. 1857 01:20:55,250 --> 01:20:56,570 I ma kien fi żmien minuta. 1858 01:20:56,570 --> 01:20:58,262 1859 01:20:58,262 --> 01:20:58,970 Iżda hemm inti tmur. 1860 01:20:58,970 --> 01:21:01,240 U jien se jkollhom donuts jew kandju. 1861 01:21:01,240 --> 01:21:03,464 Huwa xi ħadd allerġiku għal xejn, mill-mod? 1862 01:21:03,464 --> 01:21:05,307 1863 01:21:05,307 --> 01:21:05,890 Bajd u ħalib. 1864 01:21:05,890 --> 01:21:08,120 Allura doughnuts huma no? 1865 01:21:08,120 --> 01:21:09,400 1866 01:21:09,400 --> 01:21:10,160 OK. 1867 01:21:10,160 --> 01:21:10,770 Kull dritt. 1868 01:21:10,770 --> 01:21:12,120 Ebda ċikkulata? 1869 01:21:12,120 --> 01:21:12,620 Starburst. 1870 01:21:12,620 --> 01:21:13,837 1871 01:21:13,837 --> 01:21:14,670 Starbursts huma tajbin. 1872 01:21:14,670 --> 01:21:15,170 OK. 1873 01:21:15,170 --> 01:21:17,045 Aħna qed tmur biex ikollhom Starburst ġimgħa d-dieħla mbagħad. 1874 01:21:17,045 --> 01:21:18,240 Dan huwa dak I ser tingħata. 1875 01:21:18,240 --> 01:21:19,690 Inti guys jkollhom ġimgħa kbira. 1876 01:21:19,690 --> 01:21:20,460 Aqra spec tiegħek. 1877 01:21:20,460 --> 01:21:22,130 >> Let me know jekk għandek xi mistoqsijiet. 1878 01:21:22,130 --> 01:21:25,300 Pset żewġ gradi għandhom ikunu out lilek mill-Ħamis. 1879 01:21:25,300 --> 01:21:28,320 Jekk għandek xi mistoqsijiet dwar kif I gradati xi ħaġa 1880 01:21:28,320 --> 01:21:32,250 jew għaliex I gradati ħaġa li l-mod I ma, jekk jogħġbok email me, come tkellem lili. 1881 01:21:32,250 --> 01:21:34,210 Jien din crazy ftit ġimgħa, iżda I wegħda 1882 01:21:34,210 --> 01:21:36,340 I xorta se jwieġeb fi żmien 24 siegħa. 1883 01:21:36,340 --> 01:21:38,240 Allura jkollhom ġimgħa kbira, kulħadd. 1884 01:21:38,240 --> 01:21:40,090 Xorti tajba fuq pset tiegħek. 1885 01:21:40,090 --> 01:21:41,248