-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathlongest-common-subsequence.html
More file actions
1006 lines (709 loc) · 46.3 KB
/
longest-common-subsequence.html
File metadata and controls
1006 lines (709 loc) · 46.3 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html>
<html lang="en">
<head>
<title>Longest Common Subsequence</title>
<!-- Google tag (gtag.js) -->
<script async="" src="https://www.googletagmanager.com/gtag/js?id=G-HCERBDV76D"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag() { dataLayer.push(arguments); }
gtag('js', new Date());
gtag('config', 'G-HCERBDV76D');
</script>
<meta content="B0487B46A104E90209E8A3BEA24ECA0E" name="msvalidate.01"/>
<meta content="f044b3a12c7918f1" name="yandex-verification"/>
<!--end-->
<meta content="learn about data types, variables, lists, tuples, dictionaries,if else,DSA,loops,user-defined functions, oop, threading and scripting." name="description"/>
<meta content="learnPython" name="author"/>
<meta content="Learn Python for free,learn python for beginners,Core Python,Web frameworks,Multiprocess architecture,Serverside templating language,python tutorials,python4" name="keywords"/>
<meta content="website" property="og:type"/>
<meta content="US-CA" name="”geo.region”"/>
<meta content="353 Jane Stanford Way, Stanford, CA 94305, United States" name="”geo.placename”"/>
<meta content="37.430089898615456;-122.17332683124829" name="”geo.position”"/>
<meta content="37.430089898615456, -122.17332683124829" name="”ICBM”"/>
<link href="https://pythonread.github.io/?m=1" rel="alternate"/>
<link href="/favicon.png" rel="icon"/>
<meta charset="utf-8"/>
<meta content="IE=edge" http-equiv="X-UA-Compatible"/>
<meta content="width=device-width, initial-scale=1.0" name="viewport"/>
<link href="/style1.css" media="all" rel="stylesheet" type="text/css"/>
<link href="/style2.css" media="all" rel="stylesheet" type="text/css"/>
<link href="/style0.css" media="all" rel="stylesheet" type="text/css"/>
<!--<![endif]-->
</head>
<body>
<div class="nav-wrapper">
<div class="container">
<nav>
<div class="logo wave">
<a href="/" id="logo">
Python Tutorial
</a>
</div>
<div class="nav-toggle-icon" id="nav-toggle-icon" onclick="mobileMenu()">
<div class="material-hamburger">
<span>
</span>
<span>
</span>
<span>
</span>
</div>
</div>
<div class="menu-wrapper" id="menu-wrapper">
<div class="nav-indicator">
</div>
<ul class="menus">
<li>
<a class="wave" href="/">
Home
</a>
</li>
<li>
<a class="wave" href="/projects.html">
Projects
</a>
</li>
<li>
<a class="wave" href="/free-course.html" target="_blank">
Free Course
</a>
</li>
<li>
<a class="wave" href="/dsa.html">
DSA
</a>
</li>
</ul>
</div>
</nav>
</div>
</div>
<div class="contents contents--neg" style="margin-top: 60px">
<div class="container">
<div class="row">
<div class="col-sm-12">
<div class="d-flex">
<div class="left-bar d-none d-lg-block">
<div class="card-alt mb-10x">
<h3>Page Index</h3>
<div class="list">
<ul>
<li><a href="/dsa.html#data-structure-1" title="Data Structures (I)">Data Structures
(I)</a></li>
<li><a href="/dsa.html#data-structure-2" title="Data Structures (II)">Data Structures
(II)</a></li>
<li><a href="/dsa.html#tree-1" title="Tree based DSA (I)">Tree based DSA (I)</a></li>
<li><a href="/dsa.html#tree-2" title="Tree based DSA (II)">Tree based DSA (II)</a></li>
<li><a href="/dsa.html#graph" title="Graph Data Structures and Algorithm">Graph based
DSA</a></li>
<li><a href="/dsa.html#sorting-searching" title="Sorting and Searching">Sorting and
Searching</a></li>
<li><a href="/dsa.html#greedy-algorithm" title="Greedy Algorithms">Greedy Algorithms</a>
</li>
<li><a href="/dsa.html#dynamic-programming" title="Dynamic Programming">Dynamic
Programming</a></li>
<li><a href="/dsa.html#other-algorithms" title="Other Algorithms">Other Algorithms</a>
</li>
</ul>
</div>
</div>
</div>
<div class="right-bar">
<!--first part end-------------------------------------------->
<iframe width="560" height="315" src="https://www.youtube.com/embed/nfFZdORMtEk" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
<div class="editor-contents">
<h1>Longest Common Subsequence</h1>
<p class="editor-contents__short-description">In this tutorial, you will learn how the longest common subsequence is found. Also, you will find working examples of the longest common subsequence in C, C++, Java and Python.</p>
<div id="node-1572" class="node node-algorithm clearfix" about="/dsa/longest-common-subsequence" typeof="sioc:Item foaf:Document">
<span property="dc:title" content="Longest Common Subsequence" class="rdf-meta element-hidden"></span>
<div class="content">
<p id="definition">The longest common subsequence (LCS) is defined as the longest subsequence that is common to all the given sequences, provided that the elements of the subsequence are not required to occupy consecutive positions within the original sequences.</p>
<p>If <var>S1</var> and <var>S2</var> are the two given sequences then, <var>Z</var> is the common subsequence of <var>S1</var> and <var>S2</var> if <var>Z</var> is a subsequence of both <var>S1</var> and <var>S2</var>. Furthermore, <var>Z</var> must be a <strong>strictly increasing sequence</strong> of the indices of both <var>S1</var> and <var>S2</var>.</p>
<p>In a strictly increasing sequence, the indices of the elements chosen from the original sequences must be in ascending order in <var>Z</var>.</p>
<p>If</p>
<pre>S1 = {B, C, D, A, A, C, D}</pre>
<p>Then, <code>{A, D, B}</code> cannot be a subsequence of <var>S1</var> as the order of the elements is not the same (ie. not strictly increasing sequence).</p>
<hr><p>Let us understand LCS with an example.</p>
<p>If</p>
<pre>S1 = {B, C, D, A, A, C, D}
S2 = {A, C, D, B, A, C}</pre>
<p>Then, common subsequences are <code>{B, C}, {C, D, A, C}, {D, A, C}, {A, A, C}, {A, C}, {C, D},</code> <code>...</code></p>
<p>Among these subsequences, <code>{C, D, A, C}</code> is the longest common subsequence. We are going to find this longest common subsequence using dynamic programming.</p>
<p></p><div class="clearfix"></div><p>Before proceeding further, if you do not already know about dynamic programming, please go through <a href="/dsa/dynamic-programming.html">dynamic programming</a>.</p>
<hr><h2 id="working">Using Dynamic Programming to find the LCS</h2>
<p>Let us take two sequences:</p>
<figure><img alt="Longest Common Subsequence first sequence" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-X.png" title="The first sequence" width="360" height="84"><figcaption>The first sequence</figcaption></figure><figure><img alt="Longest Common Subsequence first sequence" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-Y.png" title="Second Sequence" width="300" height="83"><figcaption>Second Sequence</figcaption></figure><p>The following steps are followed for finding the longest common subsequence.</p>
<ol><li>Create a table of dimension <code>n+1*m+1</code> where n and m are the lengths of <var>X</var> and <var>Y</var> respectively. The first row and the first column are filled with zeros.
<figure><img alt="Longest Common Subsequence initialise table" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-Table-1.png" title="initialise a table" width="278" height="255"><figcaption>Initialise a table</figcaption></figure></li>
<li>Fill each cell of the table using the following logic.</li>
<li>If the character correspoding to the current row and current column are matching, then fill the current cell by adding one to the diagonal element. Point an arrow to the diagonal cell.</li>
<li>Else take the maximum value from the previous column and previous row element for filling the current cell. Point an arrow to the cell with maximum value. If they are equal, point to any of them.
<figure><img alt="Longest Common Subsequence fill the values" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-Table-2.png" title="fill the values" width="278" height="255"><figcaption>Fill the values</figcaption></figure></li>
<li><strong>Step 2</strong> is repeated until the table is filled.
<figure><img alt="Longest Common Subsequence fill all the values" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-Table-3.png" title="fill all the values" width="278" height="255"><figcaption>Fill all the values</figcaption></figure></li>
<li>The value in the last row and the last column is the length of the longest common subsequence.
<figure><img alt="Longest Common Subsequence length" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-Table-4.png" title="the bottom right corner is the length of the LCS" width="278" height="255"><figcaption>The bottom right corner is the length of the LCS</figcaption></figure></li>
<li>In order to find the longest common subsequence, start from the last element and follow the direction of the arrow. The elements corresponding to () symbol form the longest common subsequence.
<figure><img alt="Longest Common Subsequence create a path" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-Table-5.png" title="create a path according to the arrows" width="900" height="330"><figcaption>Create a path according to the arrows</figcaption></figure></li>
</ol><p>Thus, the longest common subsequence is <var>CA</var>.</p>
<figure><img alt="Longest Common Subsequence result" src="//cdn.programiz.com/sites/tutorial2program/files/lcs-LCS.png" title="LCS" width="150" height="81"><figcaption>LCS</figcaption></figure><hr><p><strong>How is a dynamic programming algorithm more efficient than the recursive algorithm while solving an LCS problem?</strong></p>
<p>The method of dynamic programming reduces the number of function calls. It stores the result of each function call so that it can be used in future calls without the need for redundant calls.</p>
<p>In the above dynamic algorithm, the results obtained from each comparison between elements of <var>X</var> and the elements of <var>Y</var> are stored in a table so that they can be used in future computations.</p>
<p>So, the time taken by a dynamic approach is the time taken to fill the table (ie. O(mn)). Whereas, the recursion algorithm has the complexity of <var>2<sup>max(m, n)</sup></var>.</p>
<hr><h2 id="algorithm">Longest Common Subsequence Algorithm</h2>
<pre>X and Y be two given sequences
Initialize a table LCS of dimension X.length * Y.length
X.label = X
Y.label = Y
LCS[0][] = 0
LCS[][0] = 0
Start from LCS[1][1]
Compare X[i] and Y[j]
If X[i] = Y[j]
LCS[i][j] = 1 + LCS[i-1, j-1]
Point an arrow to LCS[i][j]
Else
LCS[i][j] = max(LCS[i-1][j], LCS[i][j-1])
Point an arrow to max(LCS[i-1][j], LCS[i][j-1])</pre>
<hr><h2 id="code">Python, Java and C/C++ Examples</h2>
<div class="tabbed-editor">
<div id="py1" onclick="changepy()" class="tabbed-editor__node tabbed-editor__node--active"><a href="#python-code">Python</a></div>
<div id="java1" onclick="changejava()" class="tabbed-editor__node"><a href="#java-code">Java</a></div>
<div id="c1" onclick="changec()" class="tabbed-editor__node"><a href="#c-code">C</a></div>
<div id="cpp1" onclick="changecpp()" class="tabbed-editor__node"><a href="#cpp-code">C++</a></div>
</div>
<div class="code-editor code-editor--tabbed">
<div class="code-editor__area code-editor__area--active" id="python-code">
<div class="pre-code-wrapper"><div title="Click to copy" class="copy-code-button"></div><pre class="exec" style="max-height: 600px;"><code class="python hljs"><span class="hljs-comment"># The longest common subsequence in Python</span>
<span class="hljs-comment"># Function to find lcs_algo</span>
<span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">lcs_algo</span><span class="hljs-params">(S1, S2, m, n)</span>:</span>
L = [[<span class="hljs-number">0</span> <span class="hljs-keyword">for</span> x <span class="hljs-keyword">in</span> range(n+<span class="hljs-number">1</span>)] <span class="hljs-keyword">for</span> x <span class="hljs-keyword">in</span> range(m+<span class="hljs-number">1</span>)]
<span class="hljs-comment"># Building the mtrix in bottom-up way</span>
<span class="hljs-keyword">for</span> i <span class="hljs-keyword">in</span> range(m+<span class="hljs-number">1</span>):
<span class="hljs-keyword">for</span> j <span class="hljs-keyword">in</span> range(n+<span class="hljs-number">1</span>):
<span class="hljs-keyword">if</span> i == <span class="hljs-number">0</span> <span class="hljs-keyword">or</span> j == <span class="hljs-number">0</span>:
L[i][j] = <span class="hljs-number">0</span>
<span class="hljs-keyword">elif</span> S1[i<span class="hljs-number">-1</span>] == S2[j<span class="hljs-number">-1</span>]:
L[i][j] = L[i<span class="hljs-number">-1</span>][j<span class="hljs-number">-1</span>] + <span class="hljs-number">1</span>
<span class="hljs-keyword">else</span>:
L[i][j] = max(L[i<span class="hljs-number">-1</span>][j], L[i][j<span class="hljs-number">-1</span>])
index = L[m][n]
lcs_algo = [<span class="hljs-string">""</span>] * (index+<span class="hljs-number">1</span>)
lcs_algo[index] = <span class="hljs-string">""</span>
i = m
j = n
<span class="hljs-keyword">while</span> i > <span class="hljs-number">0</span> <span class="hljs-keyword">and</span> j > <span class="hljs-number">0</span>:
<span class="hljs-keyword">if</span> S1[i<span class="hljs-number">-1</span>] == S2[j<span class="hljs-number">-1</span>]:
lcs_algo[index<span class="hljs-number">-1</span>] = S1[i<span class="hljs-number">-1</span>]
i -= <span class="hljs-number">1</span>
j -= <span class="hljs-number">1</span>
index -= <span class="hljs-number">1</span>
<span class="hljs-keyword">elif</span> L[i<span class="hljs-number">-1</span>][j] > L[i][j<span class="hljs-number">-1</span>]:
i -= <span class="hljs-number">1</span>
<span class="hljs-keyword">else</span>:
j -= <span class="hljs-number">1</span>
<span class="hljs-comment"># Printing the sub sequences</span>
<span class="hljs-keyword">print</span>(<span class="hljs-string">"S1 : "</span> + S1 + <span class="hljs-string">"\nS2 : "</span> + S2)
<span class="hljs-keyword">print</span>(<span class="hljs-string">"LCS: "</span> + <span class="hljs-string">""</span>.join(lcs_algo))
S1 = <span class="hljs-string">"ACADB"</span>
S2 = <span class="hljs-string">"CBDA"</span>
m = len(S1)
n = len(S2)
lcs_algo(S1, S2, m, n)</code></pre></div>
</div>
<div class="code-editor__area" id="java-code">
<div class="pre-code-wrapper"><div title="Click to copy" class="copy-code-button"></div><pre class="exec" style="max-height: 600px;"><code class="java hljs"><span class="hljs-comment">// The longest common subsequence in Java</span>
<span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">LCS_ALGO</span> </span>{
<span class="hljs-function"><span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">lcs</span><span class="hljs-params">(String S1, String S2, <span class="hljs-keyword">int</span> m, <span class="hljs-keyword">int</span> n)</span> </span>{
<span class="hljs-keyword">int</span>[][] LCS_table = <span class="hljs-keyword">new</span> <span class="hljs-keyword">int</span>[m + <span class="hljs-number">1</span>][n + <span class="hljs-number">1</span>];
<span class="hljs-comment">// Building the mtrix in bottom-up way</span>
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i <= m; i++) {
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> j = <span class="hljs-number">0</span>; j <= n; j++) {
<span class="hljs-keyword">if</span> (i == <span class="hljs-number">0</span> || j == <span class="hljs-number">0</span>)
LCS_table[i][j] = <span class="hljs-number">0</span>;
<span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (S1.charAt(i - <span class="hljs-number">1</span>) == S2.charAt(j - <span class="hljs-number">1</span>))
LCS_table[i][j] = LCS_table[i - <span class="hljs-number">1</span>][j - <span class="hljs-number">1</span>] + <span class="hljs-number">1</span>;
<span class="hljs-keyword">else</span>
LCS_table[i][j] = Math.max(LCS_table[i - <span class="hljs-number">1</span>][j], LCS_table[i][j - <span class="hljs-number">1</span>]);
}
}
<span class="hljs-keyword">int</span> index = LCS_table[m][n];
<span class="hljs-keyword">int</span> temp = index;
<span class="hljs-keyword">char</span>[] lcs = <span class="hljs-keyword">new</span> <span class="hljs-keyword">char</span>[index + <span class="hljs-number">1</span>];
lcs[index] = <span class="hljs-string">'\0'</span>;
<span class="hljs-keyword">int</span> i = m, j = n;
<span class="hljs-keyword">while</span> (i > <span class="hljs-number">0</span> && j > <span class="hljs-number">0</span>) {
<span class="hljs-keyword">if</span> (S1.charAt(i - <span class="hljs-number">1</span>) == S2.charAt(j - <span class="hljs-number">1</span>)) {
lcs[index - <span class="hljs-number">1</span>] = S1.charAt(i - <span class="hljs-number">1</span>);
i--;
j--;
index--;
}
<span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (LCS_table[i - <span class="hljs-number">1</span>][j] > LCS_table[i][j - <span class="hljs-number">1</span>])
i--;
<span class="hljs-keyword">else</span>
j--;
}
<span class="hljs-comment">// Printing the sub sequences</span>
System.out.print(<span class="hljs-string">"S1 : "</span> + S1 + <span class="hljs-string">"\nS2 : "</span> + S2 + <span class="hljs-string">"\nLCS: "</span>);
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> k = <span class="hljs-number">0</span>; k <= temp; k++)
System.out.print(lcs[k]);
System.out.println(<span class="hljs-string">""</span>);
}
<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">main</span><span class="hljs-params">(String[] args)</span> </span>{
String S1 = <span class="hljs-string">"ACADB"</span>;
String S2 = <span class="hljs-string">"CBDA"</span>;
<span class="hljs-keyword">int</span> m = S1.length();
<span class="hljs-keyword">int</span> n = S2.length();
lcs(S1, S2, m, n);
}
}</code></pre></div>
</div>
<div class="code-editor__area" id="c-code">
<div class="pre-code-wrapper"><div title="Click to copy" class="copy-code-button"></div><pre class="exec" style="max-height: 600px;"><code class="c hljs cpp"><span class="hljs-comment">// The longest common subsequence in C</span>
<span class="hljs-meta">#<span class="hljs-meta-keyword">include</span> <span class="hljs-meta-string"><stdio.h></span></span>
<span class="hljs-meta">#<span class="hljs-meta-keyword">include</span> <span class="hljs-meta-string"><string.h></span></span>
<span class="hljs-keyword">int</span> i, j, m, n, LCS_table[<span class="hljs-number">20</span>][<span class="hljs-number">20</span>];
<span class="hljs-keyword">char</span> S1[<span class="hljs-number">20</span>] = <span class="hljs-string">"ACADB"</span>, S2[<span class="hljs-number">20</span>] = <span class="hljs-string">"CBDA"</span>, b[<span class="hljs-number">20</span>][<span class="hljs-number">20</span>];
<span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">lcsAlgo</span><span class="hljs-params">()</span> </span>{
m = <span class="hljs-built_in">strlen</span>(S1);
n = <span class="hljs-built_in">strlen</span>(S2);
<span class="hljs-comment">// Filling 0's in the matrix</span>
<span class="hljs-keyword">for</span> (i = <span class="hljs-number">0</span>; i <= m; i++)
LCS_table[i][<span class="hljs-number">0</span>] = <span class="hljs-number">0</span>;
<span class="hljs-keyword">for</span> (i = <span class="hljs-number">0</span>; i <= n; i++)
LCS_table[<span class="hljs-number">0</span>][i] = <span class="hljs-number">0</span>;
<span class="hljs-comment">// Building the mtrix in bottom-up way</span>
<span class="hljs-keyword">for</span> (i = <span class="hljs-number">1</span>; i <= m; i++)
<span class="hljs-keyword">for</span> (j = <span class="hljs-number">1</span>; j <= n; j++) {
<span class="hljs-keyword">if</span> (S1[i - <span class="hljs-number">1</span>] == S2[j - <span class="hljs-number">1</span>]) {
LCS_table[i][j] = LCS_table[i - <span class="hljs-number">1</span>][j - <span class="hljs-number">1</span>] + <span class="hljs-number">1</span>;
} <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (LCS_table[i - <span class="hljs-number">1</span>][j] >= LCS_table[i][j - <span class="hljs-number">1</span>]) {
LCS_table[i][j] = LCS_table[i - <span class="hljs-number">1</span>][j];
} <span class="hljs-keyword">else</span> {
LCS_table[i][j] = LCS_table[i][j - <span class="hljs-number">1</span>];
}
}
<span class="hljs-keyword">int</span> index = LCS_table[m][n];
<span class="hljs-keyword">char</span> lcsAlgo[index + <span class="hljs-number">1</span>];
lcsAlgo[index] = <span class="hljs-string">'\0'</span>;
<span class="hljs-keyword">int</span> i = m, j = n;
<span class="hljs-keyword">while</span> (i > <span class="hljs-number">0</span> && j > <span class="hljs-number">0</span>) {
<span class="hljs-keyword">if</span> (S1[i - <span class="hljs-number">1</span>] == S2[j - <span class="hljs-number">1</span>]) {
lcsAlgo[index - <span class="hljs-number">1</span>] = S1[i - <span class="hljs-number">1</span>];
i--;
j--;
index--;
}
<span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (LCS_table[i - <span class="hljs-number">1</span>][j] > LCS_table[i][j - <span class="hljs-number">1</span>])
i--;
<span class="hljs-keyword">else</span>
j--;
}
<span class="hljs-comment">// Printing the sub sequences</span>
<span class="hljs-built_in">printf</span>(<span class="hljs-string">"S1 : %s \nS2 : %s \n"</span>, S1, S2);
<span class="hljs-built_in">printf</span>(<span class="hljs-string">"LCS: %s"</span>, lcsAlgo);
}
<span class="hljs-function"><span class="hljs-keyword">int</span> <span class="hljs-title">main</span><span class="hljs-params">()</span> </span>{
lcsAlgo();
<span class="hljs-built_in">printf</span>(<span class="hljs-string">"\n"</span>);
}</code></pre></div>
</div>
<div class="code-editor__area" id="cpp-code">
<div class="pre-code-wrapper"><div title="Click to copy" class="copy-code-button"></div><pre class="exec" style="max-height: 600px;"><code class="cpp hljs"><span class="hljs-comment">// The longest common subsequence in C++</span>
<span class="hljs-meta">#<span class="hljs-meta-keyword">include</span> <span class="hljs-meta-string"><iostream></span></span>
<span class="hljs-keyword">using</span> <span class="hljs-keyword">namespace</span> <span class="hljs-built_in">std</span>;
<span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">lcsAlgo</span><span class="hljs-params">(<span class="hljs-keyword">char</span> *S1, <span class="hljs-keyword">char</span> *S2, <span class="hljs-keyword">int</span> m, <span class="hljs-keyword">int</span> n)</span> </span>{
<span class="hljs-keyword">int</span> LCS_table[m + <span class="hljs-number">1</span>][n + <span class="hljs-number">1</span>];
<span class="hljs-comment">// Building the mtrix in bottom-up way</span>
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i <= m; i++) {
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> j = <span class="hljs-number">0</span>; j <= n; j++) {
<span class="hljs-keyword">if</span> (i == <span class="hljs-number">0</span> || j == <span class="hljs-number">0</span>)
LCS_table[i][j] = <span class="hljs-number">0</span>;
<span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (S1[i - <span class="hljs-number">1</span>] == S2[j - <span class="hljs-number">1</span>])
LCS_table[i][j] = LCS_table[i - <span class="hljs-number">1</span>][j - <span class="hljs-number">1</span>] + <span class="hljs-number">1</span>;
<span class="hljs-keyword">else</span>
LCS_table[i][j] = max(LCS_table[i - <span class="hljs-number">1</span>][j], LCS_table[i][j - <span class="hljs-number">1</span>]);
}
}
<span class="hljs-keyword">int</span> index = LCS_table[m][n];
<span class="hljs-keyword">char</span> lcsAlgo[index + <span class="hljs-number">1</span>];
lcsAlgo[index] = <span class="hljs-string">'\0'</span>;
<span class="hljs-keyword">int</span> i = m, j = n;
<span class="hljs-keyword">while</span> (i > <span class="hljs-number">0</span> && j > <span class="hljs-number">0</span>) {
<span class="hljs-keyword">if</span> (S1[i - <span class="hljs-number">1</span>] == S2[j - <span class="hljs-number">1</span>]) {
lcsAlgo[index - <span class="hljs-number">1</span>] = S1[i - <span class="hljs-number">1</span>];
i--;
j--;
index--;
}
<span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (LCS_table[i - <span class="hljs-number">1</span>][j] > LCS_table[i][j - <span class="hljs-number">1</span>])
i--;
<span class="hljs-keyword">else</span>
j--;
}
<span class="hljs-comment">// Printing the sub sequences</span>
<span class="hljs-built_in">cout</span> << <span class="hljs-string">"S1 : "</span> << S1 << <span class="hljs-string">"\nS2 : "</span> << S2 << <span class="hljs-string">"\nLCS: "</span> << lcsAlgo << <span class="hljs-string">"\n"</span>;
}
<span class="hljs-function"><span class="hljs-keyword">int</span> <span class="hljs-title">main</span><span class="hljs-params">()</span> </span>{
<span class="hljs-keyword">char</span> S1[] = <span class="hljs-string">"ACADB"</span>;
<span class="hljs-keyword">char</span> S2[] = <span class="hljs-string">"CBDA"</span>;
<span class="hljs-keyword">int</span> m = <span class="hljs-built_in">strlen</span>(S1);
<span class="hljs-keyword">int</span> n = <span class="hljs-built_in">strlen</span>(S2);
lcsAlgo(S1, S2, m, n);
}</code></pre></div>
</div>
</div>
<hr><h2 id="application">Longest Common Subsequence Applications</h2>
<ol><li>in compressing genome resequencing data</li>
<li>to authenticate users within their mobile phone through in-air signatures</li>
</ol></div>
</div>
<div class="tutorial-toc"><div class="tutorial-toc__inner"><h3 class="tutorial-toc__title">Table of Contents
<button class="btn btn--clear align-items-center">
<svg class="programiz-icon"><use xlink:href="/sites/all/themes/programiz/assets/feather-sprite.svg#x"></use></svg></button></h3><div class="tutorial-toc__links"><ul><li><a href="#definition">Definition</a></li>
<li><a href="#working">Using Dynamic Programming to find the LCS</a></li>
<li><a href="#algorithm">Longest Common Subsequence Algorithm</a></li>
<li><a href="#code">Python, Java and C/C++ Examples</a></li>
<li><a href="#application">Longest Common Subsequence Applications</a></li>
</ul></div></div></div> </div>
<!--second------------------------------------------->
<div>
<ul>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/stack.html">
Stack</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/queue.html">
Queue</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/types-of-queue.html">
Types of Queue</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/circular-queue.html">
Circular Queue</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/priority-queue.html">
Priority Queue</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/deque.html">
Deque</a></button>
<br/>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/linked-list.html">
Linked List</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/linked-list-operations.html">
Linked List Operations</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/linked-list-types.html">
Types of Linked List</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/hash-table.html">
Hash Table</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/heap-data-structure.html">
Heap Data Structure</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/fibonacci-heap.html">
Fibonacci Heap</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/decrease-key-and-delete-node-from-a-fibonacci-heap.html">
Decrease Key and Delete node from Fibonacci Heap</a></button>
<br>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/trees.html">
Tree Data Structure</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/tree-traversal.html">
Tree Traversal</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/binary-tree.html">
Binary Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/full-binary-tree.html">
Full Binary Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/perfect-binary-tree.html">
Perfect Binary Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/complete-binary-tree.html">
Complete Binary Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/balanced-binary-tree.html">
Balanced Binary Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/binary-search-tree.html">
Binary Search Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/avl-tree.html">
AVL Tree</a></button>
<br>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/b-tree.html">
B Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/insertion-into-a-b-tree.html">
Insertion into B-tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/deletion-from-a-b-tree.html">
Deletion from B-tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/b-plus-tree.html">
B+ Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/insertion-on-a-b-plus-tree.html">
Insertion on a B+ Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/deletion-from-a-b-plus-tree.html">
Deletion from a B+ Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/red-black-tree.html">
Red Black Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/insertion-in-a-red-black-tree.html">
Insertion in Red Black Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/deletion-from-a-red-black-tree.html">
Deletion from Red Black Tree</a></button>
<br>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/graph.html">
Graph Data Structure</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/spanning-tree-and-minimum-spanning-tree.html">
Spanning Tree</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/strongly-connected-components.html">
Strongly Connected Components</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/graph-adjacency-matrix.html">
Adjacency Matrix</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/graph-adjacency-list.html">
Adjacency List</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/graph-dfs.html">
DFS Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/graph-bfs.html">
Breadth-first Search</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/bellman-ford-algorithm.html">
Bellman Ford's Algorithm</a></button>
<br>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/bubble-sort.html">
Bubble Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/selection-sort.html">
Selection Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/insertion-sort.html">
Insertion Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/merge-sort.html">
Merge Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/quick-sort.html">
Quick Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/counting-sort.html">
Counting Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/radix-sort.html">
Radix Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/bucket-sort.html">
Bucket Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/heap-sort.html">
Heap Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/shell-sort.html">
Shell Sort</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/linear-search.html">
Linear Search</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/binary-search.html">
Binary Search</a></button>
<br>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/greedy-algorithm.html">
Greedy Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/ford-fulkerson-algorithm.html">
Ford-Fulkerson Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/dijkstra-algorithm.html">
Dijkstra's Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/kruskal-algorithm.html">
Kruskal's Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/prim-algorithm.html">
Prim's Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/huffman-coding.html">
Huffman Code</a></button>
<br>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/dynamic-programming.html">
Dynamic Programming</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/floyd-warshall-algorithm.html">
Floyd Warshall Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/longest-common-subsequence.html">
Longest Common Subsequence</a></button>
<br>
<br/>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/backtracking-algorithm.html">
Backtracking Algorithm</a></button>
<button style="padding:5px; margin-bottom:2px"><a href="
/dsa/rabin-karp-algorithm.html">
Rabin-Karp Algorithm</a></button>
<br>
<br/>
<h2>Free Courses on YouTube</h2>
<br/>
<img height="35px" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT9Spnddn1UerjXEbcWQUPhfDHLL9rppkmUp1x4JRPKsdTwmX0kI26Rd0-2qKlwGAAnbgiPz7dZMm5Rv5Fd1QLhkQC6n3ob13ug1bTYtizkDpk2B0LxRiA8QUIjeTmfu6vZHoKJ7pXUgt73sHoXvSpGWjKQ6ZM01IIbJnXmwzXq4RdNYA4swdULgNy/s16000/youtube-logo.png" width="35px"/>
<button style="padding:5px; margin-bottom:2px"><a href="
https://www.youtube.com/watch?v=IbSXF7eT-AU&list=PLR_5PTwg_uAQw40OhdvAwN4NvzWv0xOZ2">
Python Full Course Playlist</a></button>
<br/>
<img height="35px" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT9Spnddn1UerjXEbcWQUPhfDHLL9rppkmUp1x4JRPKsdTwmX0kI26Rd0-2qKlwGAAnbgiPz7dZMm5Rv5Fd1QLhkQC6n3ob13ug1bTYtizkDpk2B0LxRiA8QUIjeTmfu6vZHoKJ7pXUgt73sHoXvSpGWjKQ6ZM01IIbJnXmwzXq4RdNYA4swdULgNy/s16000/youtube-logo.png" width="35px"/>
<button style="padding:5px; margin-bottom:2px"><a href="https://www.youtube.com/watch?v=UEl6wB90Gs8">
105 STL Algorithms in Less Than an Hour</a></button>
<br/>
<img height="35px" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT9Spnddn1UerjXEbcWQUPhfDHLL9rppkmUp1x4JRPKsdTwmX0kI26Rd0-2qKlwGAAnbgiPz7dZMm5Rv5Fd1QLhkQC6n3ob13ug1bTYtizkDpk2B0LxRiA8QUIjeTmfu6vZHoKJ7pXUgt73sHoXvSpGWjKQ6ZM01IIbJnXmwzXq4RdNYA4swdULgNy/s16000/youtube-logo.png" width="35px"/>
<button style="padding:5px; margin-bottom:2px"><a href="https://www.youtube.com/watch?v=zZXTgN7L1UU&list=PLR_5PTwg_uAS6C1cSMjU6oVhOcCX8Zu_4">
C++ STL Playlist</a></button>
<br/>
<img height="35px" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT9Spnddn1UerjXEbcWQUPhfDHLL9rppkmUp1x4JRPKsdTwmX0kI26Rd0-2qKlwGAAnbgiPz7dZMm5Rv5Fd1QLhkQC6n3ob13ug1bTYtizkDpk2B0LxRiA8QUIjeTmfu6vZHoKJ7pXUgt73sHoXvSpGWjKQ6ZM01IIbJnXmwzXq4RdNYA4swdULgNy/s16000/youtube-logo.png" width="35px"/>
<button style="padding:5px; margin-bottom:2px"><a href="https://youtu.be/ty9756v3kc8">
Learn Node.js </a></button>
<br/>
<img height="35px" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT9Spnddn1UerjXEbcWQUPhfDHLL9rppkmUp1x4JRPKsdTwmX0kI26Rd0-2qKlwGAAnbgiPz7dZMm5Rv5Fd1QLhkQC6n3ob13ug1bTYtizkDpk2B0LxRiA8QUIjeTmfu6vZHoKJ7pXUgt73sHoXvSpGWjKQ6ZM01IIbJnXmwzXq4RdNYA4swdULgNy/s16000/youtube-logo.png" width="35px"/>
<button style="padding:5px; margin-bottom:2px"><a href="https://youtu.be/exrIpdS3Crc">
Learn Data Science Full course</a></button>
<br/>
<img height="35px" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT9Spnddn1UerjXEbcWQUPhfDHLL9rppkmUp1x4JRPKsdTwmX0kI26Rd0-2qKlwGAAnbgiPz7dZMm5Rv5Fd1QLhkQC6n3ob13ug1bTYtizkDpk2B0LxRiA8QUIjeTmfu6vZHoKJ7pXUgt73sHoXvSpGWjKQ6ZM01IIbJnXmwzXq4RdNYA4swdULgNy/s16000/youtube-logo.png" width="35px"/>
<button style="padding:5px; margin-bottom:2px"><a href="https://youtu.be/Q8tDO2uSk5U">
Learn Computer Networking Full course</a></button>
<br/>
</br></br></br></br></br></br></br></br></ul>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<footer class="afooter" style="margin-left:20px">
<p>
<a href="/cookie-policy.html">Cookie policy</a> |
<a href="/privacy-policy.html">Privacy policy</a> |
<a href="/terms-of-use.html">Terms of use</a> |
<a href="/disclaimer.html">Disclaimer</a> |
<a href="/about-us.html">About Us</a>
</p>
<p>
© 2023 <a href="https://pythonread.github.io">https://pythonread.github.io</a>
</p>
</footer>
<script type="text/javascript">
document.addEventListener('DOMContentLoaded', function () { htmlTableOfContents() }); function htmlTableOfContents(documentRef) { var documentRef = documentRef || document; var toc = documentRef.getElementById("toc"); var headings = [].slice.call(documentRef.body.querySelectorAll('h2, h3')); headings.forEach(function (heading, index) { var ref = "toc" + index; if (heading.hasAttribute("id")) { ref = heading.getAttribute("id") } else { heading.setAttribute("id", ref) } var link = documentRef.createElement("a"); link.setAttribute("href", "#" + ref); link.textContent = heading.textContent; var div = documentRef.createElement("div"); div.setAttribute("class", heading.tagName.toLowerCase()); div.appendChild(link); toc.appendChild(div) }) } try { module.exports = htmlTableOfContents } catch (e) { } function isScrolledIntoView(el) { var rect = el.getBoundingClientRect(); var elemTop = rect.top; var elemBottom = rect.bottom; var isVisible = (elemTop >= -10) && (elemBottom <= (window.innerHeight)); return isVisible } function highlightMenu() { var headers = document.querySelectorAll("h2, h3"); for (var i = 0; i < headers.length; i += 1) { if (isScrolledIntoView(headers[i])) { var childDivs = document.getElementById('toc').getElementsByTagName('div'); var c = childDivs[i].classList; c.add("active"); for (var j = 0; j < i; j += 1) { var c = childDivs[j].classList; c.remove("active") } for (var j = i + 1; j < childDivs.length; j += 1) { var c = childDivs[j].classList; c.remove("active") } break } } } function highlightMenuLastItem() { var childDivs = document.getElementById('toc').getElementsByTagName('div'); for (var j = 0; j < childDivs.length - 1; j += 1) { var c = childDivs[j].classList; c.remove("active") } var c = childDivs[childDivs.length - 1].classList; c.add("active") } window.addEventListener("click", function (event) { highlightMenu() }); window.onscroll = function (e) { highlightMenu(); if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight) { highlightMenuLastItem() } }; function mobileMenu() { var classes = document.getElementById('nav-toggle-icon').classList; if (classes.contains("active")) { classes.remove("active") } else { classes.add("active") } var classes = document.getElementById('menu-wrapper').classList; if (classes.contains("active")) { classes.remove("active") } else { classes.add("active") } }
</script>
<script type="text/javascript">
function changepy(){
document.getElementById('py1').className = 'tabbed-editor__node tabbed-editor__node--active';
document.getElementById('java1').className = 'tabbed-editor__node';
document.getElementById('c1').className = 'tabbed-editor__node';
document.getElementById('cpp1').className = 'tabbed-editor__node';
document.getElementById('python-code').className = 'code-editor__area code-editor__area--active';
document.getElementById('java-code').className = 'code-editor__area';
document.getElementById('c-code').className = 'code-editor__area';
document.getElementById('cpp-code').className = 'code-editor__area';
}
function changecpp(){
document.getElementById('py1').className = 'tabbed-editor__node';
document.getElementById('java1').className = 'tabbed-editor__node';
document.getElementById('c1').className = 'tabbed-editor__node';
document.getElementById('cpp1').className = 'tabbed-editor__node tabbed-editor__node--active';
document.getElementById('python-code').className = 'code-editor__area';
document.getElementById('java-code').className = 'code-editor__area';
document.getElementById('c-code').className = 'code-editor__area';
document.getElementById('cpp-code').className = 'code-editor__area code-editor__area--active';
}
function changejava(){
document.getElementById('py1').className = 'tabbed-editor__node';
document.getElementById('java1').className = 'tabbed-editor__node tabbed-editor__node--active';
document.getElementById('c1').className = 'tabbed-editor__node';
document.getElementById('cpp1').className = 'tabbed-editor__node';
document.getElementById('python-code').className = 'code-editor__area';
document.getElementById('java-code').className = 'code-editor__area code-editor__area--active';
document.getElementById('c-code').className = 'code-editor__area';
document.getElementById('cpp-code').className = 'code-editor__area';
}
function changec(){
document.getElementById('py1').className = 'tabbed-editor__node';
document.getElementById('java1').className = 'tabbed-editor__node';
document.getElementById('c1').className = 'tabbed-editor__node tabbed-editor__node--active';
document.getElementById('cpp1').className = 'tabbed-editor__node';
document.getElementById('python-code').className = 'code-editor__area';
document.getElementById('java-code').className = 'code-editor__area';
document.getElementById('c-code').className = 'code-editor__area code-editor__area--active';
document.getElementById('cpp-code').className = 'code-editor__area';
}
</script>
<!-- Code injected by live-server -->
<script>
// <![CDATA[ <-- For SVG support
if ('WebSocket' in window) {
(function () {
function refreshCSS() {
var sheets = [].slice.call(document.getElementsByTagName("link"));
var head = document.getElementsByTagName("head")[0];
for (var i = 0; i < sheets.length; ++i) {
var elem = sheets[i];
var parent = elem.parentElement || head;
parent.removeChild(elem);
var rel = elem.rel;
if (elem.href && typeof rel != "string" || rel.length == 0 || rel.toLowerCase() == "stylesheet") {
var url = elem.href.replace(/(&|\?)_cacheOverride=\d+/, '');
elem.href = url + (url.indexOf('?') >= 0 ? '&' : '?') + '_cacheOverride=' + (new Date().valueOf());
}
parent.appendChild(elem);
}
}
var protocol = window.location.protocol === 'http:' ? 'ws://' : 'wss://';
var address = protocol + window.location.host + window.location.pathname + '/ws';
var socket = new WebSocket(address);
socket.onmessage = function (msg) {
if (msg.data == 'reload') window.location.reload();
else if (msg.data == 'refreshcss') refreshCSS();
};
if (sessionStorage && !sessionStorage.getItem('IsThisFirstTime_Log_From_LiveServer')) {
console.log('Live reload enabled.');
sessionStorage.setItem('IsThisFirstTime_Log_From_LiveServer', true);
}
})();
}
else {