1
00:00:07,260 --> 00:00:10,050
[Powered by Google Translate] Fl-ipprogrammar, aħna ta 'spiss jeħtieġu li jirrappreżentaw listi ta' valuri,

2
00:00:10,050 --> 00:00:12,840
bħall-ismijiet ta 'studenti fit-taqsima

3
00:00:12,840 --> 00:00:15,100
jew punteġġi tagħhom fuq l-kwizz aktar tard.

4
00:00:15,100 --> 00:00:17,430
>> Fil-lingwa C, iddikjarat arrays jista 'jintuża

5
00:00:17,430 --> 00:00:19,160
biex jaħżnu listi.

6
00:00:19,160 --> 00:00:21,200
Huwa faċli li jiġu numerati l-elementi ta 'lista

7
00:00:21,200 --> 00:00:23,390
maħżuna fil-firxa, u jekk ikollok bżonn l-aċċess

8
00:00:23,390 --> 00:00:25,050
jew timmodifika l-element lista ith

9
00:00:25,050 --> 00:00:27,570
għal xi indiċi arbitrarja I,

10
00:00:27,570 --> 00:00:29,910
li jista 'jsir fil-ħin kostanti,

11
00:00:29,910 --> 00:00:31,660
iżda arrays jkollu żvantaġġi, wisq.

12
00:00:31,660 --> 00:00:33,850
>> Meta aħna jiddikjaraw lilhom, aħna qed meħtieġ li jgħidu

13
00:00:33,850 --> 00:00:35,900
bil-quddiem kemm hu kbir huma,

14
00:00:35,900 --> 00:00:38,160
jiġifieri, kemm elementi jistgħu jaħżnu

15
00:00:38,160 --> 00:00:40,780
u kemm hu kbir dawn l-elementi huma, li huwa determinat mill-tip tagħhom.

16
00:00:40,780 --> 00:00:45,450
Per eżempju, int arr (10)

17
00:00:45,450 --> 00:00:48,220
jista 'jaħżen 10 punti

18
00:00:48,220 --> 00:00:50,200
li huma d-daqs ta 'int.

19
00:00:50,200 --> 00:00:52,590
>> Aħna ma jistax ibiddel id-daqs firxa wara l dikjarazzjoni.

20
00:00:52,590 --> 00:00:55,290
Irridu jagħmlu firxa ġdida jekk irridu li jaħżen l-elementi aktar.

21
00:00:55,290 --> 00:00:57,410
Ir-raġuni din il-limitazzjoni teżisti hija li tagħna

22
00:00:57,410 --> 00:00:59,040
Programm taħżen l-firxa sħiħa

23
00:00:59,040 --> 00:01:02,310
bħala blokki kontigwi ta 'memorja.

24
00:01:02,310 --> 00:01:04,500
Say dan huwa l-buffer fejn aħna maħżuna fil firxa tagħna.

25
00:01:04,500 --> 00:01:06,910
Jista 'jkun hemm fatturi oħra

26
00:01:06,910 --> 00:01:08,310
tinsab dritt li jmiss għall-firxa

27
00:01:08,310 --> 00:01:10,060
fil-memorja, hekk aħna ma tistax

28
00:01:10,060 --> 00:01:12,060
biss tagħmel l-array akbar.

29
00:01:12,060 --> 00:01:15,700
>> Kultant aħna tixtieq għall-kummerċ tal-firxa tal-veloċità mgħaġġel aċċess għad-data

30
00:01:15,700 --> 00:01:17,650
għal flessibilità ftit aktar.

31
00:01:17,650 --> 00:01:20,380
Ikteb il-lista marbuta, struttura oħra tad-data bażika

32
00:01:20,380 --> 00:01:22,360
inti tista 'ma tkun kif familjari magħhom.

33
00:01:22,360 --> 00:01:24,200
Fuq livell għoli,

34
00:01:24,200 --> 00:01:26,840
lista marbuta jaħżen data f'sekwenza ta 'punti ta' konġunzjoni

35
00:01:26,840 --> 00:01:29,280
li huma konnessi ma 'xulxin b'rabtiet,

36
00:01:29,280 --> 00:01:31,760
għalhekk "lista marbuta." l-isem

37
00:01:31,760 --> 00:01:33,840
Kif aħna ser tara, din id-differenza fid-disinn

38
00:01:33,840 --> 00:01:35,500
twassal għal vantaġġi differenti u l-iżvantaġġi

39
00:01:35,500 --> 00:01:37,000
minn firxa.

40
00:01:37,000 --> 00:01:39,840
>> Hawn xi kodiċi C għal lista sempliċi ħafna marbuta tan-numri interi.

41
00:01:39,840 --> 00:01:42,190
Tista 'tara li għandna rappreżentati' kull node

42
00:01:42,190 --> 00:01:45,520
fil-lista bħala Struct li fih 2 affarijiet,

43
00:01:45,520 --> 00:01:47,280
integer biex jaħżnu imsejħa "val"

44
00:01:47,280 --> 00:01:50,460
u link għall-node li jmiss fil-lista

45
00:01:50,460 --> 00:01:52,990
li aħna jirrappreżentaw bħala indikatur imsejjaħ "jmiss."

46
00:01:54,120 --> 00:01:56,780
Dan il-mod, nistgħu track-lista sħiħa

47
00:01:56,780 --> 00:01:58,790
biss bi pointer waħda lill-node 1,

48
00:01:58,790 --> 00:02:01,270
u allura nistgħu isegwu l-pointers li jmiss

49
00:02:01,270 --> 00:02:03,130
għall-node 2,

50
00:02:03,130 --> 00:02:05,280
għall-node 3,

51
00:02:05,280 --> 00:02:07,000
għall-node 4,

52
00:02:07,000 --> 00:02:09,889
u l-bqija, sakemm aħna jiksbu l-aħħar tal-lista.

53
00:02:10,520 --> 00:02:12,210
>> Inti jista 'jkun kapaċi li tara 1 vantaġġ dan għandu

54
00:02:12,210 --> 00:02:14,490
fuq l-istruttura firxa statiku - b'lista marbuta,

55
00:02:14,490 --> 00:02:16,450
ma kellniex bżonn blokki kbar ta 'memorja għal kollox.

56
00:02:17,400 --> 00:02:20,530
Il-node 1 tal-lista jistgħu jgħixu f'dan il-post fil-memorja,

57
00:02:20,530 --> 00:02:23,160
u l-node 2 tista 'tkun it-triq kollha hawn fuq.

58
00:02:23,160 --> 00:02:25,780
Nistgħu jiksbu l-lymph ebda kwistjoni fejn fil-memorja huma,

59
00:02:25,780 --> 00:02:28,890
għaliex jibda mill-node 1, pointer li jmiss kull node tal

60
00:02:28,890 --> 00:02:31,700
tgħidilna preċiżament fejn għandhom imorru jmiss.

61
00:02:31,700 --> 00:02:33,670
>> Barra minn hekk, aħna ma jkollhom jgħidu bil-quddiem

62
00:02:33,670 --> 00:02:36,740
kemm hu kbir lista marbuta se jkun il-mod kif nagħmlu ma 'arrays statiċi,

63
00:02:36,740 --> 00:02:39,060
peress li aħna jistgħu ikompli jżid nodes għal lista

64
00:02:39,060 --> 00:02:42,600
sakemm hemm l-ispazju x'imkien fil-memorja għal punti strateġiċi ġodda.

65
00:02:42,600 --> 00:02:45,370
Għalhekk, listi marbuta huma faċli biex resize dinamiku.

66
00:02:45,370 --> 00:02:47,950
Say, aktar tard fil-programm għandna bżonn li jżidu punti ta 'konġunzjoni aktar

67
00:02:47,950 --> 00:02:49,350
fil-lista tagħna.

68
00:02:49,350 --> 00:02:51,480
Biex daħħal node ġdid fil-lista tagħna fuq il-fly,

69
00:02:51,480 --> 00:02:53,740
kollha għandna nagħmlu huwa jalloka memorja għal dik node,

70
00:02:53,740 --> 00:02:55,630
plop fil-valur tad-data,

71
00:02:55,630 --> 00:02:59,070
u imbagħad qiegħdu fejn irridu billi jaġġusta l-pointers xierqa.

72
00:02:59,070 --> 00:03:02,310
>> Per eżempju, jekk ridna li tqiegħed node fl bejn

73
00:03:02,310 --> 00:03:04,020
il-lymph 2 u 3 tal-lista,

74
00:03:04,020 --> 00:03:06,800
 aħna ma jkollhom jiċċaqalqu l-lymph 2 jew 3 fil-livelli kollha.

75
00:03:06,800 --> 00:03:09,190
Say aħna qed tiddaħħal din node aħmar.

76
00:03:09,190 --> 00:03:12,890
Kollha għandna d jkollhom biex tagħmel huwa stabbilit pointer li jmiss tal-node ġdid

77
00:03:12,890 --> 00:03:14,870
għall-punt għall-node 3

78
00:03:14,870 --> 00:03:18,580
u mbagħad rewire pointer li jmiss tal-node 2 ta

79
00:03:18,580 --> 00:03:20,980
għall-punt għall node ġdid tagħna.

80
00:03:22,340 --> 00:03:24,370
Allura, nistgħu resize listi tagħna fuq il-fly

81
00:03:24,370 --> 00:03:26,090
peress kompjuter tagħna ma tibbaża ruħha fuq indiċjar,

82
00:03:26,090 --> 00:03:28,990
iżda pjuttost fuq jgħaqqdu jużaw indikaturi taħżen lilhom.

83
00:03:29,120 --> 00:03:31,600
>> Listi Madankollu, żvantaġġ ta marbutin

84
00:03:31,600 --> 00:03:33,370
huwa li, b'differenza firxa statiku,

85
00:03:33,370 --> 00:03:36,690
il-kompjuter tista 'mhux biss jaqbżu l-nofs tal-lista.

86
00:03:38,040 --> 00:03:40,780
Peress li l-kompjuter għandu li jżuru kull node fil-lista marbuta

87
00:03:40,780 --> 00:03:42,330
biex jiksbu l-waħda li jmiss,

88
00:03:42,330 --> 00:03:44,770
li għaddej biex jieħdu aktar żmien biex isibu node partikolari

89
00:03:44,770 --> 00:03:46,400
milli kieku fil-firxa.

90
00:03:46,400 --> 00:03:48,660
Biex travers il-lista sħiħa jieħu ż-żmien proporzjonali

91
00:03:48,660 --> 00:03:50,580
it-tul tal-lista,

92
00:03:50,580 --> 00:03:54,630
jew O (n) fil-notazzjoni asintotiku.

93
00:03:54,630 --> 00:03:56,510
Fuq medja, jilħaq kwalunkwe node

94
00:03:56,510 --> 00:03:58,800
wkoll jieħu ż-żmien proporzjonali għall n.

95
00:03:58,800 --> 00:04:00,700
>> Issa, ejja attwalment tikteb xi kodiċi

96
00:04:00,700 --> 00:04:02,000
li jaħdem ma 'listi marbuta.

97
00:04:02,000 --> 00:04:04,220
Ejja ngħidu li rridu lista marbuta tan-numri interi.

98
00:04:04,220 --> 00:04:06,140
Nistgħu jirrappreżentaw node fil-lista tagħna għal darb'oħra

99
00:04:06,140 --> 00:04:08,340
bħala Struct ma '2 oqsma,

100
00:04:08,340 --> 00:04:10,750
valur integer imsejħa "val"

101
00:04:10,750 --> 00:04:13,490
u werrej li jmiss għall-node li jmiss tal-lista.

102
00:04:13,490 --> 00:04:15,660
Ukoll, jidher sempliċi biżżejjed.

103
00:04:15,660 --> 00:04:17,220
>> Ejja ngħidu li rridu jiktbu funzjoni

104
00:04:17,220 --> 00:04:19,329
li traverses-lista u prints l-

105
00:04:19,329 --> 00:04:22,150
valur maħżuna fil-node aħħar tal-lista.

106
00:04:22,150 --> 00:04:24,850
Ukoll, li jfisser li għandna bzonn biex travers l-lymph fil-lista

107
00:04:24,850 --> 00:04:27,310
biex issib l-aħħar wieħed, iżda peress li aħna mhux qed jiżdiedu

108
00:04:27,310 --> 00:04:29,250
jew tħassir xejn, aħna ma trid tibdel

109
00:04:29,250 --> 00:04:32,210
l-istruttura interna ta 'l-indikaturi li jmiss fil-lista.

110
00:04:32,210 --> 00:04:34,790
>> Allura, aħna ser bżonn pointer speċifikament għall traversal

111
00:04:34,790 --> 00:04:36,940
li aħna ser sejħa "crawler".

112
00:04:36,940 --> 00:04:38,870
Hija se jitkaxkru permezz l-elementi kollha tal-lista

113
00:04:38,870 --> 00:04:41,190
billi jsegwu l-katina ta 'indikaturi li jmiss.

114
00:04:41,190 --> 00:04:43,750
Kollha għandna maħżuna hija pointer għall-node 1,

115
00:04:43,750 --> 00:04:45,730
jew "kap" tal-lista.

116
00:04:45,730 --> 00:04:47,370
Kap jindika l-node 1.

117
00:04:47,370 --> 00:04:49,120
Huwa ta 'tip pointer-to-node.

118
00:04:49,120 --> 00:04:51,280
>> Biex tikseb l-attwali 1 node fil-lista,

119
00:04:51,280 --> 00:04:53,250
irridu dereference dan il-werrej,

120
00:04:53,250 --> 00:04:55,100
iżda qabel ma nistgħu dereference dan, għandna bżonn li jiċċekkja

121
00:04:55,100 --> 00:04:57,180
jekk l-pointer huwa null 1.

122
00:04:57,180 --> 00:04:59,190
Jekk huwa null, il-lista tkun vojta,

123
00:04:59,190 --> 00:05:01,320
u għandna jistampa messaġġ li, minħabba li l-lista tkun vojta,

124
00:05:01,320 --> 00:05:03,250
m'hemm l-ebda node aħħar.

125
00:05:03,250 --> 00:05:05,190
Imma, ejja ngħidu l-lista ma tkunx vojta.

126
00:05:05,190 --> 00:05:08,340
Jekk mhuwiex, allura għandna jitkaxkru permezz tal-lista kollha

127
00:05:08,340 --> 00:05:10,440
sakemm aħna jiksbu l-node aħħar tal-lista,

128
00:05:10,440 --> 00:05:13,030
u kif nistgħu tgħid jekk aħna qed tħares lejn il-node aħħar fil-lista?

129
00:05:13,670 --> 00:05:16,660
>> Ukoll, jekk pointer jmiss node huwa null,

130
00:05:16,660 --> 00:05:18,320
nafu aħna fl-aħħar

131
00:05:18,320 --> 00:05:22,390
peress li l-pointer li jmiss aħħar ma jkollha ebda node li jmiss fil-lista għall-punt li.

132
00:05:22,390 --> 00:05:26,590
Huwa prattika tajba li dejjem iżommu pointer li jmiss tal-node li għaddiet initialized għall null

133
00:05:26,590 --> 00:05:30,800
li jkollha proprjetà standardizzat li allerti magħna meta aħna ve laħqu t-tmiem tal-lista.

134
00:05:30,800 --> 00:05:33,510
>> Għalhekk, jekk tkaxkir → jmiss huwa null,

135
00:05:34,120 --> 00:05:38,270
ftakar li l-sintassi vleġġa huwa shortcut għal dereferencing

136
00:05:38,270 --> 00:05:40,010
pointer għal Struct, allura aċċess

137
00:05:40,010 --> 00:05:42,510
qasam li jmiss tagħha ekwivalenti għal skomdi:

138
00:05:42,510 --> 00:05:48,750
(* Crawler). Jmiss.

139
00:05:49,820 --> 00:05:51,260
Ladarba aħna ħadthom misjuba-node aħħar,

140
00:05:51,260 --> 00:05:53,830
irridu li jistampaw crawler → val,

141
00:05:53,830 --> 00:05:55,000
il-valur fil-node attwali

142
00:05:55,000 --> 00:05:57,130
li nafu huwa l-aħħar wieħed.

143
00:05:57,130 --> 00:05:59,740
Inkella, jekk aħna mhux qed għadhom fl-node aħħar fil-lista,

144
00:05:59,740 --> 00:06:02,340
għandna biex jimxu fuq il-node li jmiss fil-lista

145
00:06:02,340 --> 00:06:04,750
u ċċekkja jekk dan huwa l-aħħar wieħed.

146
00:06:04,750 --> 00:06:07,010
Biex tagħmel dan, aħna biss sett pointer tkaxkir tagħna

147
00:06:07,010 --> 00:06:09,840
għall-punt għall-valur li jmiss tal-node attwali,

148
00:06:09,840 --> 00:06:11,680
jiġifieri, il-node li jmiss fil-lista.

149
00:06:11,680 --> 00:06:13,030
Dan isir billi jiġu

150
00:06:13,030 --> 00:06:15,280
crawler = crawler → jmiss.

151
00:06:16,050 --> 00:06:18,960
Imbagħad aħna irrepeti dan il-proċess, bil-linja per eżempju,

152
00:06:18,960 --> 00:06:20,960
sakemm insibu l-node aħħar.

153
00:06:20,960 --> 00:06:23,150
Għalhekk, per eżempju, jekk tkaxkir kien tipponta lejn ras,

154
00:06:24,050 --> 00:06:27,710
aħna waqqafna tkaxkir għall-punt li crawler → jmiss,

155
00:06:27,710 --> 00:06:30,960
li huwa l-istess bħall-qasam li jmiss tal-node 1.

156
00:06:30,960 --> 00:06:33,620
Allura, issa tkaxkir tagħna hija li tipponta lejn l-node 2,

157
00:06:33,620 --> 00:06:35,480
u, għal darb'oħra, aħna irrepeti dan bil-linja,

158
00:06:37,220 --> 00:06:40,610
sakemm aħna ħadthom sabet il-node aħħar, jiġifieri,

159
00:06:40,610 --> 00:06:43,640
fejn pointer li jmiss tal-node huwa tipponta lejn null.

160
00:06:43,640 --> 00:06:45,070
U hemm aħna għandna hija,

161
00:06:45,070 --> 00:06:47,620
aħna ħadthom sabet il-node aħħar fil-lista, u għall-istampar valur tagħha,

162
00:06:47,620 --> 00:06:50,800
aħna biss użu tkaxkir → val.

163
00:06:50,800 --> 00:06:53,130
>> Traversat mhuwiex daqshekk ħżiena, iżda xi ngħidu dwar ddaħħal?

164
00:06:53,130 --> 00:06:56,290
Tikri say irridu li daħħal numru sħiħ fil-pożizzjoni 4

165
00:06:56,290 --> 00:06:58,040
f'lista numru sħiħ.

166
00:06:58,040 --> 00:07:01,280
Dan huwa bejn il-lymph attwali 3 u 4.

167
00:07:01,280 --> 00:07:03,760
Għal darb'oħra, irridu travers il-lista biss biex

168
00:07:03,760 --> 00:07:06,520
jiksbu l-element 3, l-waħda aħna qed tiddaħħal wara.

169
00:07:06,520 --> 00:07:09,300
Allura, aħna joħolqu pointer tkaxkir darb'oħra biex travers il-lista,

170
00:07:09,300 --> 00:07:11,400
jiċċekkjaw jekk pointer ewlieni tagħna huwa null,

171
00:07:11,400 --> 00:07:14,810
u jekk mhuwiex, punt tkaxkir pointer tagħna fil-node ras.

172
00:07:16,880 --> 00:07:18,060
Allura, aħna qed fil-element 1.

173
00:07:18,060 --> 00:07:21,020
Irridu jimxu 'l quddiem 2 elementi aktar qabel ma nistgħu daħħal,

174
00:07:21,020 --> 00:07:23,390
hekk aħna jistgħu jużaw għal loop

175
00:07:23,390 --> 00:07:26,430
i int = 1; i <3; i + +

176
00:07:26,430 --> 00:07:28,590
u f'kull iterazzjoni tal-linja,

177
00:07:28,590 --> 00:07:31,540
javvanzaw pointer tkaxkir tagħna 'l quddiem sa l-1 node

178
00:07:31,540 --> 00:07:34,570
billi tiċċekkja jekk il-qasam li jmiss l-node attwali huwa null,

179
00:07:34,570 --> 00:07:37,550
u jekk mhuwiex, jimxu pointer crawler tagħna għall-node li jmiss

180
00:07:37,550 --> 00:07:41,810
billi dan ikun iffissat ugwali għall pointer li jmiss tal-node kurrenti.

181
00:07:41,810 --> 00:07:45,210
Għalhekk, peress loop għall tagħna jgħid li tagħmel dan

182
00:07:45,210 --> 00:07:47,550
darbtejn,

183
00:07:49,610 --> 00:07:51,190
aħna ħadthom laħqu l-node 3,

184
00:07:51,190 --> 00:07:53,110
u ladarba pointer tkaxkir tagħna tkun laħqet l-node wara

185
00:07:53,110 --> 00:07:55,270
li aħna tixtieq li daħħal numru sħiħ ġdid tagħna,

186
00:07:55,270 --> 00:07:57,050
kif nistgħu attwalment jagħmlu l-inserzjoni?

187
00:07:57,050 --> 00:07:59,440
>> Ukoll, integer ġdida tagħna għandu jiddaħħal fil-lista

188
00:07:59,440 --> 00:08:01,250
bħala parti mill-Struct tagħha node stess,

189
00:08:01,250 --> 00:08:03,140
peress li dan huwa verament sekwenza ta 'punti ta' konġunzjoni.

190
00:08:03,140 --> 00:08:05,690
Allura, ejja tagħmel pointer ġdid biex node

191
00:08:05,690 --> 00:08:08,910
imsejħa "new_node,"

192
00:08:08,910 --> 00:08:11,800
u stabbilit lill-punt li memorja li aħna issa jallokaw

193
00:08:11,800 --> 00:08:14,270
dwar il-munzell għall-node innifsu,

194
00:08:14,270 --> 00:08:16,000
u kemm memorja għandna bżonn li jiġu allokati?

195
00:08:16,000 --> 00:08:18,250
Ukoll, id-daqs ta 'nodu,

196
00:08:20,450 --> 00:08:23,410
u rridu li jistabbilixxu kamp val tagħha lill-eqreb numru sħiħ li aħna rridu li daħħal.

197
00:08:23,410 --> 00:08:25,590
Ejja ngħidu, 6.

198
00:08:25,590 --> 00:08:27,710
Issa, il-node fih valur sħiħ tagħna.

199
00:08:27,710 --> 00:08:30,650
Huwa wkoll prattika tajba li initialize qasam li jmiss tal-node ġdid

200
00:08:30,650 --> 00:08:33,690
għall-punt għall null,

201
00:08:33,690 --> 00:08:35,080
iżda issa liema?

202
00:08:35,080 --> 00:08:37,179
>> Irridu jibdlu l-istruttura interna tal-lista

203
00:08:37,179 --> 00:08:40,409
u l-pointers li jmiss li jinsabu fil-lista eżistenti tal-

204
00:08:40,409 --> 00:08:42,950
Lymph 3 u 4.

205
00:08:42,950 --> 00:08:46,560
Peress li l-indikaturi li ġejjin jiddetermina l-ordni tal-lista,

206
00:08:46,560 --> 00:08:48,650
u peress li aħna qed tiddaħħal node ġdid tagħna

207
00:08:48,650 --> 00:08:50,510
id-dritt fis-nofs tal-lista,

208
00:08:50,510 --> 00:08:52,010
tista 'tkun daqsxejn delikata.

209
00:08:52,010 --> 00:08:54,250
Dan għaliex, ftakar, kompjuter tagħna

210
00:08:54,250 --> 00:08:56,250
biss jaf il-post ta 'punti ta' konġunzjoni fil-lista

211
00:08:56,250 --> 00:09:00,400
minħabba l-pointers jmiss maħżuna fil-lymph preċedenti.

212
00:09:00,400 --> 00:09:03,940
Għalhekk, jekk aħna qatt mitlufa rekord ta 'xi wieħed minn dawn il-lokalitajiet,

213
00:09:03,940 --> 00:09:06,860
jgħidu billi tbiddel wieħed mill-pointers li jmiss fil-lista tagħna,

214
00:09:06,860 --> 00:09:09,880
per eżempju, ngħidu aħna mibdula

215
00:09:09,880 --> 00:09:12,920
qasam li jmiss tal-node 3 ta

216
00:09:12,920 --> 00:09:15,610
għall-punt li xi node hawn fuq.

217
00:09:15,610 --> 00:09:17,920
Aħna tixtieq tkun minn xortih, għax aħna se le

218
00:09:17,920 --> 00:09:20,940
jkollu ebda idea fejn isibu l-bqija tal-lista,

219
00:09:20,940 --> 00:09:23,070
u li ovvjament tassew ħżiena.

220
00:09:23,070 --> 00:09:25,080
Allura, irridu nkunu verament attenta dwar l-ordni

221
00:09:25,080 --> 00:09:28,360
li aħna jimmanipulaw pointers jmiss tagħna waqt l-inseriment.

222
00:09:28,360 --> 00:09:30,540
>> Allura, biex tissimplifika dan, ejja ngħidu li

223
00:09:30,540 --> 00:09:32,220
1 4 nodi tagħna

224
00:09:32,220 --> 00:09:36,200
huma msejħa A, B, Ċ, u D, bil-vleġeġ jirrappreżentaw il-katina ta 'pointers

225
00:09:36,200 --> 00:09:38,070
li jgħaqqdu l-lymph.

226
00:09:38,070 --> 00:09:40,050
Għalhekk, għandna bżonn li jiddaħħal node ġdid tagħna

227
00:09:40,050 --> 00:09:42,070
fl bejn lymph C u D.

228
00:09:42,070 --> 00:09:45,060
Huwa kritiku li tagħmel dan fl-ordni dritt, u jien ser nuruk għaliex.

229
00:09:45,060 --> 00:09:47,500
>> Ejja nħarsu lejn l-mod żbaljat biex tagħmel l-ewwel.

230
00:09:47,500 --> 00:09:49,490
Ħej, nafu l-node ġdid għandu jasal dritt wara Ċ,

231
00:09:49,490 --> 00:09:51,910
hekk ejja stabbiliti pointer jmiss Ċ

232
00:09:51,910 --> 00:09:54,700
għall-punt għall new_node.

233
00:09:56,530 --> 00:09:59,180
Kull dritt, jidher okay, aħna biss għandhom finitura up issa mill

234
00:09:59,180 --> 00:10:01,580
jagħmlu l-punt l-node ġdid pointer li jmiss D,

235
00:10:01,580 --> 00:10:03,250
iżda stenna, kif nistgħu nagħmlu dan?

236
00:10:03,250 --> 00:10:05,170
L-unika ħaġa li tista 'tgħidilna fejn D kien,

237
00:10:05,170 --> 00:10:07,630
kien il-pointer li jmiss qabel maħżuna fis-C,

238
00:10:07,630 --> 00:10:09,870
imma aħna biss rewrote li werrej

239
00:10:09,870 --> 00:10:11,170
għall-punt għall-node ġdid,

240
00:10:11,170 --> 00:10:14,230
hekk aħna m'għadx għandhom ebda ħjiel fejn D tkun fil-memorja,

241
00:10:14,230 --> 00:10:17,020
u aħna tilfu l-bqija tal-lista.

242
00:10:17,020 --> 00:10:19,000
Mhux tajba fil-livelli kollha.

243
00:10:19,000 --> 00:10:21,090
>> Allura, kif nistgħu nagħmlu dan id-dritt?

244
00:10:22,360 --> 00:10:25,090
L-ewwel, il-punt pointer li jmiss tal-node ġdid fiż D.

245
00:10:26,170 --> 00:10:28,990
Issa, pointers kemm il-ġdid node taċ u s Ċ jmiss

246
00:10:28,990 --> 00:10:30,660
huma tipponta lejn il-node istess, D,

247
00:10:30,660 --> 00:10:32,290
iżda li l-multa.

248
00:10:32,290 --> 00:10:35,680
Issa nistgħu punt pointer li jmiss C fiż-node ġdid.

249
00:10:37,450 --> 00:10:39,670
Allura, aħna ghamilt dan mingħajr ma jitilfu xi data.

250
00:10:39,670 --> 00:10:42,280
Fil kodiċi, C hija l-node kurrenti

251
00:10:42,280 --> 00:10:45,540
li l-tkaxkir pointer traversal hija li tipponta lejn,

252
00:10:45,540 --> 00:10:50,400
u D huwa rappreżentat mill-node indikat mill-qasam li jmiss tal-node attwali,

253
00:10:50,400 --> 00:10:52,600
jew crawler → jmiss.

254
00:10:52,600 --> 00:10:55,460
Allura, aħna l-ewwel stabbiliti pointer li jmiss tal-node ġdid

255
00:10:55,460 --> 00:10:57,370
għall-punt li crawler → jmiss,

256
00:10:57,370 --> 00:11:00,880
Bl-istess mod għidna pointer jmiss new_node s suppost

257
00:11:00,880 --> 00:11:02,780
punt sa D fl-illustrazzjoni.

258
00:11:02,780 --> 00:11:04,540
Imbagħad, nistgħu stabbilit pointer li jmiss tal-node attwali

259
00:11:04,540 --> 00:11:06,330
għall node ġdid tagħna,

260
00:11:06,330 --> 00:11:10,980
biss kif aħna kellhom jistennew għall-punt Ċ ta 'new_node fit-tfassil.

261
00:11:10,980 --> 00:11:12,250
Issa kollox huwa fl-ordni, u aħna ma jitilfu

262
00:11:12,250 --> 00:11:14,490
kont ta 'xi data, u konna kapaċi biss

263
00:11:14,490 --> 00:11:16,200
stick node ġdid tagħna fin-nofs tal-lista

264
00:11:16,200 --> 00:11:19,330
mingħajr bini mill-ġdid il-ħaġa sħiħa jew saħansitra ċaqliq xi elementi

265
00:11:19,330 --> 00:11:22,490
il-mod aħna kien ikollha ma 'firxa ta' tul fiss.

266
00:11:22,490 --> 00:11:26,020
>> Allura, listi linked huma bażiċi, iżda importanti, dinamika struttura tad-data

267
00:11:26,020 --> 00:11:29,080
li għandhom kemm vantaġġi u żvantaġġi

268
00:11:29,080 --> 00:11:31,260
meta mqabbla ma 'arrays u strutturi oħra ta' data,

269
00:11:31,260 --> 00:11:33,350
u kif huwa spiss il-każ fix-xjenza tal-kompjuter,

270
00:11:33,350 --> 00:11:35,640
huwa importanti li tkun taf meta jużaw kull għodda,

271
00:11:35,640 --> 00:11:37,960
sabiex inti tista 'pick-għodda dritt għall-impjieg id-dritt.

272
00:11:37,960 --> 00:11:40,060
>> Għal aktar prattika, ipprova miktub funzjonijiet li

273
00:11:40,060 --> 00:11:42,080
tħassar lymph minn lista marbuta -

274
00:11:42,080 --> 00:11:44,050
ftakar li tkun attenta dwar l-ordni li fiha inti rranġati mill-ġdid

275
00:11:44,050 --> 00:11:47,430
pointers jmiss tiegħek sabiex jiżguraw li inti ma titlef chunk tal-lista tiegħek -

276
00:11:47,430 --> 00:11:50,200
jew funzjoni biex jingħaddu l-għoqiedi fil-lista marbuta,

277
00:11:50,200 --> 00:11:53,280
jew waħda gost, biex jinqaleb l-ordni ta 'kollha tal-lymph fil-lista marbuta.

278
00:11:53,280 --> 00:11:56,090
>> Jisimni Jackson Steinkamp, ​​dan huwa CS50.