christopher/rosetta-code · Datasets at Hugging Face

task_url stringlengths 30 116	task_name stringlengths 2 86	task_description stringlengths 0 14.4k	language_url stringlengths 2 53	language_name stringlengths 1 52	code stringlengths 0 61.9k
http://rosettacode.org/wiki/Loops/Infinite	Loops/Infinite	Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#MUMPS	MUMPS	FOR WRITE "SPAM",!
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Microsoft_Small_Basic	Microsoft Small Basic	i = 1024 While i > 0 TextWindow.WriteLine(i) i = Math.Floor(i / 2) EndWhile
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#min	min	1024 :n (n 0 >) (n puts 2 div @n) while
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#MiniScript	MiniScript	for i in range(10, 0) print i end for
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#.D0.9C.D0.9A-61.2F52	МК-61/52	1 0 П0 ИП0 L0 03 С/П
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.	#Icon_and_Unicon	Icon and Unicon	procedure main() i := 0 repeat { write(i +:= 1) if i % 6 = 0 then break } end
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.	#J	J	,. ([^:(0=6\|])>:)^:a: 0
http://rosettacode.org/wiki/Loops/For	Loops/For	“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * * ** *** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.	#EDSAC_order_code	EDSAC order code	[ Loops ===== A program for the EDSAC Demonstrates nested loops and printer output Works with Initial Orders 2 ] T56K [ set load point ] GK [ set theta ] O21@ [ figure shift ] [ 1 ] T24@ [ a = 0 ] A19@ [ a = i ] [ 3 ] T20@ [ j = a; a = 0 ] O22@ [ write character ] A20@ [ a = j ] S17@ [ a -= 1 ] U20@ [ j = a ] E3@ [ if a>=0 go to 3 ] O23@ [ write line feed ] T24@ [ a = 0 ] A19@ [ a = i ] A17@ [ a += 1 ] U19@ [ i = a ] S18@ [ a -= 5 ] G1@ [ if a<0 go to 1 ] ZF [ halt ] [ 17 ] P0D [ const: 1 ] [ 18 ] P2D [ const: 5 ] [ 19 ] P0F [ var: i ] [ 20 ] P0F [ var: j ] [ 21 ] #F [ figure shift ] [ 22 ] ZF [ '+' character ] [ 23 ] &F [ line feed ] [ 24 ] P0F [ used to clear a ] EZPF [ begin execution ]
http://rosettacode.org/wiki/Loops/For_with_a_specified_step	Loops/For with a specified step	Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Icon_and_Unicon	Icon and Unicon	every 1 to 10 by 2 # the simplest case that satisfies the task, step by 2 every 1 to 10 # no to, step is by 1 by default every EXPR1 to EXPR2 by EXPR3 do EXPR4 # general case - EXPRn can be complete expressions including other generators such as to-by, every's do is optional steps := [2,3,5,7] # a list every i := 1 to 100 by !steps # . more complex, several passes with each step in the list steps, also we might want to know what value we are at every L[1 to 100 by 2] # as a list index every i := 1 to 100 by (k := !steps) # . need () otherwise := generates an error every 1 to 5 to 10 # simple case of combined to-by - 1,..,10, 2,..10, ..., 5,..,10 every 1 to 15 by 2 to 5 # combined to-by every (1 to 15 by 2) to 5 # . made explicit every writes( (TO_BY_EXPR) \| "\n", " " ) # if you want to see how any of these work
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Prolog	Prolog	example :- between(1,10,Val), write(Val), Val<10, write(', '), fail. example.
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#PureBasic	PureBasic	x=1 Repeat Print(Str(x)) x+1 If x>10: Break: EndIf Print(", ") ForEver
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously	Loop over multiple arrays simultaneously	Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#360_Assembly	360 Assembly	* Loop over multiple arrays simultaneously 09/03/2017 LOOPSIM CSECT USING LOOPSIM,R12 base register LR R12,R15 LA R6,1 i=1 LA R7,3 counter=3 LOOP LR R1,R6 i SLA R1,1 *2 LH R2,R-2(R1) r(i) XDECO R2,PG edit r(i) LA R1,S-1(R6) @s(i) MVC PG+3(1),0(R1) output s(i) LA R1,Q-1(R6) @q(i) MVC PG+7(1),0(R1) output q(i) XPRNT PG,80 print s(i),q(i),r(i) LA R6,1(R6) i++ BCT R7,LOOP decrement and loop BR R14 exit S DC C'a',C'b',C'c' Q DC C'A',C'B',C'C' R DC H'1',H'2',H'3' PG DC CL80' ' buffer YREGS END LOOPSIM
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges	#360_Assembly	360 Assembly	* Loops Break 15/02/2017 LOOPBREA CSECT USING LOOPBREA,R13 base register B 72(R15) skip savearea DC 17F'0' savearea STM R14,R12,12(R13) prolog ST R13,4(R15) " <- ST R15,8(R13) " -> LR R13,R15 " addressability LOOP MVC PG,=CL80' ' clean buffer LA R8,PG ipg=0 BAL R14,RANDINT call randint C R6,=F'10' if k=10 then leave BE ENDLOOP <-- loop break BAL R14,RANDINT call randint XPRNT PG,L'PG print buffer B LOOP loop forever ENDLOOP XPRNT PG,L'PG print buffer L R13,4(0,R13) epilog LM R14,R12,12(R13) " restore XR R15,R15 " rc=0 BR R14 exit RANDINT L R5,RANDSEED randint M R4,=F'397204091' " D R4,=X'7FFFFFFF' " ST R4,RANDSEED " LR R5,R4 " SR R4,R4 " D R4,=F'20' " LR R6,R4 k=randint(20) XDECO R6,XDEC edit k MVC 0(4,R8),XDEC+8 output k LA R8,4(R8) ipg=ipg+4 BR R14 return RANDSEED DC F'39710831' seed PG DS CL80 buffer XDEC DS CL12 YREGS END LOOPBREA
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges	#6502_Assembly	6502 Assembly	LoopBreakSub: PHA ;push accumulator onto stack BreakLoop: JSR GenerateRandomNum ;routine not implemented ;generates random number and puts in memory location RandomNumber LDA RandomNumber JSR DisplayAccumulator ;routine not implemented CMP #10 BEQ Break JSR GenerateRandomNum LDA RandomNumber JSR DisplayAccumulator JMP BreakLoop Break: PLA ;restore accumulator from stack RTS ;return from subroutine
http://rosettacode.org/wiki/Longest_common_subsequence	Longest common subsequence	Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the mn coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(mn) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(mn) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(mn log m) time in the worst case, as the number of matches grows to O(mn). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(ns + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet	#11l	11l	F lcs(a, b) V lengths = [[0] * (b.len+1)] * (a.len+1) L(x) a V i = L.index L(y) b V j = L.index I x == y lengths[i + 1][j + 1] = lengths[i][j] + 1 E lengths[i + 1][j + 1] = max(lengths[i + 1][j], lengths[i][j + 1]) V result = ‘’ V j = b.len L(i) 1..a.len I lengths[i][j] != lengths[i - 1][j] result ‘’= a[i - 1] R result print(lcs(‘1234’, ‘1224533324’)) print(lcs(‘thisisatest’, ‘testing123testing’))
http://rosettacode.org/wiki/Look-and-say_sequence	Look-and-say sequence	The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.	#11l	11l	F lookandsay(=number) V result = ‘’ V repeat = number[0] number = number[1..]‘ ’ V times = 1 L(actual) number I actual != repeat result ‘’= String(times)‘’repeat times = 1 repeat = actual E times++ R result V num = ‘1’ L 10 print(num) num = lookandsay(num)
http://rosettacode.org/wiki/Longest_string_challenge	Longest string challenge	Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.	#BBC_BASIC	BBC BASIC	DIM buffer% 65535 bufptr% = buffer% longest$ = " " ON ERROR PRINT $$buffer%; : END REPEAT READ A$ IF FNcmp(A$, longest$) THEN IF FNcmp(longest$, A$) ELSE bufptr% = buffer% longest$ = A$ $bufptr% = A$ WHILE ?bufptr% bufptr% = FNinc(bufptr%) ENDWHILE ?bufptr% = 10 bufptr% = FNinc(bufptr%) ENDIF UNTIL FALSE : REM Loops until 'Out of data' error END DATA a, bb, ccc, ddd, ee, f, ggg DEF FNcmp(a$, b$) : REM Returns LEN(a$)>=LEN(b$) [if b$<>""] LEFT$(a$, 65535) = b$ = INSTR(a$, b$) DEF FNinc(i%) : REM Returns i%+1 FOR i% = i% TO i% : NEXT = i%
http://rosettacode.org/wiki/Longest_string_challenge	Longest string challenge	Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.	#C	C	#include <stdio.h> #include <string.h> int cmp(const char p, const char q) { while (p && q) p = &p[1], q = &q[1]; return p; } int main() { char line[65536]; char buf[1000000] = {0}; char last = buf; char next = buf; while (gets(line)) { strcat(line, "\n"); if (cmp(last, line)) continue; if (cmp(line, last)) next = buf; last = next; strcpy(next, line); while (next) next = &next[1]; } printf("%s", buf); return 0; }
http://rosettacode.org/wiki/Longest_increasing_subsequence	Longest increasing subsequence	Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.	#C.2B.2B	C++	#include <vector> #include <list> #include <algorithm> #include <iostream> template <typename T> struct Node { T value; Node* prev_node; }; template <typename Container> Container lis(const Container& values) { using E = typename Container::value_type; using NodePtr = Node<E>; using ConstNodePtr = const NodePtr; std::vector<NodePtr> pileTops; std::vector<Node<E>> nodes(values.size()); // sort into piles auto cur_node = std::begin(nodes); for (auto cur_value = std::begin(values); cur_value != std::end(values); ++cur_value, ++cur_node) { auto node = &cur_node; node->value = cur_value; // lower_bound returns the first element that is not less than 'node->value' auto lb = std::lower_bound(pileTops.begin(), pileTops.end(), node, [](ConstNodePtr& node1, ConstNodePtr& node2) -> bool { return node1->value < node2->value; }); if (lb != pileTops.begin()) node->prev_node = std::prev(lb); if (lb == pileTops.end()) pileTops.push_back(node); else lb = node; } // extract LIS from piles // note that LIS length is equal to the number of piles Container result(pileTops.size()); auto r = std::rbegin(result); for (NodePtr node = pileTops.back(); node != nullptr; node = node->prev_node, ++r) r = node->value; return result; } template <typename Container> void show_lis(const Container& values) { auto&& result = lis(values); for (auto& r : result) { std::cout << r << ' '; } std::cout << std::endl; } int main() { show_lis(std::list<int> { 3, 2, 6, 4, 5, 1 }); show_lis(std::vector<int> { 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 }); }
http://rosettacode.org/wiki/Loops/Continue	Loops/Continue	Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Arturo	Arturo	loop 1..10 'i [ prints i if 0 = i%5 [ print "" continue ] prints ", " ]
http://rosettacode.org/wiki/Loops/Continue	Loops/Continue	Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Asymptote	Asymptote	for(int i = 1; i <= 10; ++i) { write(i, suffix=none); if(i % 5 == 0) { write(""); continue; } else { write(", ", suffix=none); } }
http://rosettacode.org/wiki/Longest_common_substring	Longest common substring	Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction	#Arturo	Arturo	lcs: function [a,b][ lengths: map 0..size a => [map 0..size b => 0] greatestLength: 0 result: "" loop.with:'i a 'x [ loop.with:'j b 'y [ if x=y [ if? or? i=0 j=0 -> lengths\[i]\[j]: 0 else -> lengths\[i]\[j]: 1 + lengths\[i-1]\[j-1] if greatestLength < lengths\[i]\[j] [ greatestLength: lengths\[i]\[j] result: slice a (i-greatestLength)+1 i ] ] ] ] return result ] print lcs "thisisatest", "testing123testing"
http://rosettacode.org/wiki/Loops/Nested	Loops/Nested	Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#PicoLisp	PicoLisp	(for Lst (make (do 10 (link (make (do 10 (link (rand 1 20))))))) (T (for N Lst (printsp N) (T (= N 20) T) ) ) )
http://rosettacode.org/wiki/Loops/Foreach	Loops/Foreach	Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Ruby	Ruby	for i in collection do puts i end
http://rosettacode.org/wiki/Loops/Foreach	Loops/Foreach	Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Rust	Rust	let collection = vec![1,2,3,4,5]; for elem in collection { println!("{}", elem); }
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers	Luhn test of credit card numbers	The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks SEDOL ISIN	#min	min	((dup 10 <) 'quote (((10 mod) (10 div)) cleave) 'cons linrec) :digits ((0 0) dip (pop 'succ dip over even?) partition ((pop pop) dip) dip) :evens/odds ((2 * digits sum) map sum) :evens-sum (digits evens/odds ('evens-sum 'sum) => spread + 10 mod 0 ==) :luhn? (49927398716 49927398717 1234567812345678 1234567812345670) (dup print! " " print! luhn? puts!) foreach
http://rosettacode.org/wiki/Loops/Infinite	Loops/Infinite	Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Nanoquery	Nanoquery	while true println "SPAM" end
http://rosettacode.org/wiki/Loops/Infinite	Loops/Infinite	Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Nemerle	Nemerle	while (true) WriteLine("SPAM");
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#MiniScript	MiniScript	i = 1024 while i > 0 print i i = floor(i/2) end while
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#MIRC_Scripting_Language	MIRC Scripting Language	alias while_loop { var %n = 10 while (%n >= 0) { echo -a Countdown: %n dec %n } }
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Modula-2	Modula-2	MODULE Downward; IMPORT InOut; VAR i: INTEGER; BEGIN FOR i := 10 TO 0 BY -1 DO InOut.WriteInt(i, 2); InOut.WriteLn END END Downward.
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.	#Java	Java	int val = 0; do{ val++; System.out.println(val); }while(val % 6 != 0);
http://rosettacode.org/wiki/Loops/For	Loops/For	“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * * ** *** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.	#EGL	EGL	str string; for ( i int to 5 ) str = ""; for ( j int to i ) str += "*"; end SysLib.writeStdout(str); end
http://rosettacode.org/wiki/Loops/For_with_a_specified_step	Loops/For with a specified step	Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Io	Io	for(i,2,8,2, write(i,", ") ) write("who do we appreciate?")
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Python	Python	print ( ', '.join(str(i+1) for i in range(10)) )
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Quackery	Quackery	10 times [ i^ 1+ echo i 0 = iff conclude done say ", " ]
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously	Loop over multiple arrays simultaneously	Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#8080_Assembly	8080 Assembly	org 100h lxi b,0 ; Let (B)C be the array index outer: lxi d,As ; Use DE to walk the array-of-arrays inner: xchg ; Swap DE and HL (array-of-array pointer into HL) mov e,m ; Load low byte of array pointer into E inx h mov d,m ; Load high byte of array pointer into D inx h xchg ; Array base in HL, array-of-array pointer in DE mov a,h ; Is HL 0? ora l jz azero ; If so, we are done. dad b ; Otherwise, add index to array base mov a,m ; Get current item (BC'th item of HL) call chout ; Output jmp inner ; Next array azero: mvi a,13 ; Print newline call chout mvi a,10 call chout inr c ; Increment index (we're only using the low byte) mvi a,Alen ; Is it equal to the length? cmp c jnz outer ; If not, get next item from all the arrays. ret ;;; Print character in A, saving all registers. ;;; This code uses CP/M to do it. chout: push psw ; CP/M destroys all registers push b ; Push them all to the stack push d push h mvi c,2 ; 2 = print character syscall mov e,a call 5 pop h ; Restore registers pop d pop b pop psw ret ;;; Arrays A1: db 'a','b','c' A2: db 'A','B','C' A3: db '1','2','3' Alen: equ $-A3 ;;; Zero-terminated array-of-arrays As: dw A1,A2,A3,0
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges	#AArch64_Assembly	AArch64 Assembly	/* ARM assembly AARCH64 Raspberry PI 3B / / program loopbreak64.s / /*****************************************/ / Constantes file / /*****************************************/ / for this file see task include a file in language AArch64 assembly/ .include "../includeConstantesARM64.inc" /*******************************/ / Initialized data / /******************************/ .data szMessEndLoop: .asciz "loop break with value : \n" szMessResult: .asciz "Resultat = @ \n" // message result .align 4 qGraine: .quad 12345678 /******************************/ / UnInitialized data / /******************************/ .bss sZoneConv: .skip 24 /******************************/ / code section / /******************************/ .text .global main main: // entry of program 1: // begin loop mov x4,20 2: mov x0,19 bl genereraleas // generate number cmp x0,10 // compar value beq 3f // break if equal ldr x1,qAdrsZoneConv // display value bl conversion10 // call function with 2 parameter (x0,x1) ldr x0,qAdrszMessResult ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at third @ character bl affichageMess // display message final subs x4,x4,1 // decrement counter bgt 2b // loop if greather b 1b // begin loop one 3: mov x2,x0 // save value ldr x0,qAdrszMessEndLoop bl affichageMess // display message mov x0,x2 ldr x1,qAdrsZoneConv bl conversion10 // call function with 2 parameter (x0,x1) ldr x0,qAdrszMessResult ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at third @ character bl affichageMess // display message 100: // standard end of the program mov x0,0 // return code mov x8,EXIT // request to exit program svc 0 // perform the system call qAdrsZoneConv: .quad sZoneConv qAdrszMessResult: .quad szMessResult qAdrszMessEndLoop: .quad szMessEndLoop /************************************************/ / Generation random number / /*************************************************/ / x0 contains limit / genereraleas: stp x1,lr,[sp,-16]! // save registers stp x2,x3,[sp,-16]! // save registers ldr x3,qAdrqGraine // load graine ldr x2,[x3] lsr x1,x2,17 // see xorshift on wikipedia eor x2,x2,x1 lsl x1,x2,31 eor x2,x2,x1 lsr x1,x2,8 eor x1,x2,x1 str x1,[x3] // save graine for the next call udiv x1,x2,x0 // divide by value maxi msub x0,x1,x0,x2 // résult = remainder 100: // end function ldp x2,x3,[sp],16 // restaur 2 registers ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30 /*****************************************************************/ qAdrqGraine: .quad qGraine /*****************************************************/ / File Include fonctions / /******************************************************/ / for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc"
http://rosettacode.org/wiki/Longest_common_subsequence	Longest common subsequence	Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the mn coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(mn) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(mn) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(mn log m) time in the worst case, as the number of matches grows to O(mn). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(ns + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet	#Ada	Ada	with Ada.Text_IO; use Ada.Text_IO; procedure Test_LCS is function LCS (A, B : String) return String is begin if A'Length = 0 or else B'Length = 0 then return ""; elsif A (A'Last) = B (B'Last) then return LCS (A (A'First..A'Last - 1), B (B'First..B'Last - 1)) & A (A'Last); else declare X : String renames LCS (A, B (B'First..B'Last - 1)); Y : String renames LCS (A (A'First..A'Last - 1), B); begin if X'Length > Y'Length then return X; else return Y; end if; end; end if; end LCS; begin Put_Line (LCS ("thisisatest", "testing123testing")); end Test_LCS;
http://rosettacode.org/wiki/Look-and-say_sequence	Look-and-say sequence	The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.	#8080_Assembly	8080 Assembly	bdos: equ 5 ; CP/M calls puts: equ 9 nmemb: equ 15 ; Change this to print more or fewer members org 100h ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Generate and output members of the sequence mvi b,nmemb ; Counter outloop: push b ; Preserve counter across calls mvi c,puts ; Output current member lxi d,memb call bdos ; And newline mvi c,puts lxi d,newline call bdos lxi h,memb ; Generate next member call looksay pop b ; Restore counter dcr b ; Done yet? jnz outloop rst 0 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Given a $-terminated string under HL, representing ;; a member of the look and say sequence, generate ;; the next one in place (ish). The memory after the ;; string is assumed to be free. looksay: push h ; Save start of string on stack mov d,h ; And in DE mov e,l mvi a,'$' ; Find end of string findend: cmp m inx h jnz findend xchg ; HL=string, DE=destination push d ; Save start of new string on stack lookchar: mvi b,0 ; Zero counter lookloop: mov a,m ; Get current character inr b ; Compare next character inx h cmp m ; While it is the same, keep going jz lookloop mov c,a ; Keep character mvi a,'0' ; There are B amount of these characters add b stax d ; Store the amount inx d ; And in the next location mov a,c ; Store the character stax d inx d mvi a,'$' ; Are we done? cmp m jnz lookchar ; If not, do next character stax d ; If yes, terminate new string ;; Free up memory by copying the new string to where the old ;; string began. pop d ; Start of new string pop h ; Start of old string copyloop: ldax d ; Get char from new string mov m,a ; Store char where old string was cpi '$' ; are we done yet? inx d inx h jnz copyloop ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; newline: db 13,10,'$' ;; This is where the string will be stored. memb: db '1$' ; First item ; Due to how CP/M loads programs, the memory after here ; is free until we hit the stack.
http://rosettacode.org/wiki/Longest_string_challenge	Longest string challenge	Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.	#C.2B.2B	C++	#include <iostream> #include <string.h> int main() { std::string longLine, longestLines, newLine; while (std::cin >> newLine) { auto isNewLineShorter = longLine.c_str(); auto isLongLineShorter = newLine.c_str(); while (isNewLineShorter && isLongLineShorter) { // This determines which string is longer without using a built // in string length function. The loop will stop at the 0 at the // end of the shortest string. isNewLineShorter = &isNewLineShorter[1]; isLongLineShorter = &isLongLineShorter[1]; } if(isNewLineShorter) continue; // other lines were longer, do nothing if(isLongLineShorter) { // the new string is the longest so far longLine = newLine; longestLines = newLine; } else { // the new string is the same lenth as the previous longest longestLines+=newLine; } longestLines+="\n"; // append a new line between the strings } std::cout << "\nLongest string:\n" << longestLines; }
http://rosettacode.org/wiki/Longest_increasing_subsequence	Longest increasing subsequence	Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.	#Clojure	Clojure	(defn place [piles card] (let [[les gts] (->> piles (split-with #(<= (ffirst %) card))) newelem (cons card (->> les last first)) modpile (cons newelem (first gts))] (concat les (cons modpile (rest gts))))) (defn a-longest [cards] (let [piles (reduce place '() cards)] (->> piles last first reverse))) (println (a-longest [3 2 6 4 5 1])) (println (a-longest [0 8 4 12 2 10 6 14 1 9 5 13 3 11 7 15]))
http://rosettacode.org/wiki/Loops/Continue	Loops/Continue	Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#AutoHotkey	AutoHotkey	Loop, 10 { Delimiter := (A_Index = 5) \|\| (A_Index = 10) ? "`n":", " Index .= A_Index . Delimiter } MsgBox %Index%
http://rosettacode.org/wiki/Longest_common_substring	Longest common substring	Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction	#AutoHotkey	AutoHotkey	LCS(a, b){ x := i := 1 while StrLen(x) Loop % StrLen(a) IfInString, b, % x := SubStr(a, i:=StrLen(x)=1 ? i+1 : i, n:=StrLen(a)+1-A_Index) res := StrLen(res) > StrLen(x) ? res : x return res }
http://rosettacode.org/wiki/Loops/Nested	Loops/Nested	Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Pike	Pike	int main() { // enumerate() normally returns a linearly enumerated array, but // allows for the forth argument to specify a function that will // be called and return the value that should be in each cell. We // create an anonymous function (lambda) that just returns a // random value. array a = ({}); for(int i=0; i<20; i++) a += ({ enumerate( 20, 1, 1, lambda(){return random(20)+1;} ) }); // We could use for() and a[x][y] indexing, but foreach is just // shorter and easier to use even if the 2D-array becomes less // obvious. mynestedloops: foreach(a, array inner_a) { foreach(inner_a, int value) { write(value +" "); if(value == 20) break mynestedloops; } } write("\n"); }
http://rosettacode.org/wiki/Loops/Nested	Loops/Nested	Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#PL.2FI	PL/I	declare x(20,20) fixed; /* 16 August 2010. / x = random()20 + 1; loops: do i = 1 to hbound(x,1); do j = 1 to hbound(x,2); put (x(i,j)); if x(i,j) = 20 then leave loops; end; if x(i,j) = 20 then leave; end;
http://rosettacode.org/wiki/Loops/Foreach	Loops/Foreach	Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Salmon	Salmon	iterate (x; ["Red", "Green", "Blue"]) x!;
http://rosettacode.org/wiki/Loops/Foreach	Loops/Foreach	Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#SAS	SAS	/* Initialize an array with integers 1 to 10, and print their sum / data _null_; array a a1-a10; n=1; do over a; a=n; n=n+1; end; s=sum(of a{}); put s; run;
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers	Luhn test of credit card numbers	The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks SEDOL ISIN	#MiniScript	MiniScript	isValid = function(s) sum = 0 odd = true for i in range(s.len-1) d = val(s[i]) sum = sum + d * (2 - odd) if not odd and d > 4 then sum = sum - 9 odd = not odd end for return sum % 10 == 0 end function test = function(s) if isValid(s) then print s + ": valid" else print s + ": invalid" end function test "49927398716" test "49927398717" test "1234567812345678" test "1234567812345670"
http://rosettacode.org/wiki/Loops/Infinite	Loops/Infinite	Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#NetRexx	NetRexx	/* NetRexx */ options replace format comments java crossref savelog symbols nobinary say say 'Loops/Infinite' loop label spam forever say 'SPAM' end spam
http://rosettacode.org/wiki/Loops/Infinite	Loops/Infinite	Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#NewLISP	NewLISP	(while (println "SPAM"))
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#MIXAL	MIXAL	****************************************** * X = M / N WHILE X > 0 * STORE EACH X IN NUMERIC ARRAY * PRINT ARRAY ******************************************* M EQU 1024 N EQU 2 LPR EQU 18 BUF0 EQU 100 MSG EQU 2000 LENGTH EQU 500 ORIG 3000 START IOC 0(LPR) ENTX M CALC STX BUF0,1 DIV =N= SRAX 5 INC1 1 JXP CALC ST1 LENGTH PRINT LDA BUF0,2 CHAR STX MSG OUT MSG(LPR) INC2 1 CMP2 LENGTH JNE PRINT HLT END START
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#.D0.9C.D0.9A-61.2F52	МК-61/52	1 0 2 4 П0 ИП0 /-/ x<0 15 ИП0 2 / П0 БП 05 С/П
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Modula-3	Modula-3	FOR i := 10 TO 0 BY -1 DO IO.PutInt(i); END;
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#MUMPS	MUMPS	LOOPDOWN NEW I FOR I=10:-1:1 WRITE I WRITE:I'=1 ", " KILL I QUIT
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.	#JavaScript	JavaScript	var val = 0; do { print(++val); } while (val % 6);
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.	#jq	jq	# Perform the action, then check the condition, etc def do_while( action; condition ): def w: action \| if (condition \| not) then empty else ., w end; w;
http://rosettacode.org/wiki/Loops/For	Loops/For	“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * * ** *** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.	#Ela	Ela	open monad io loop m n \| n < m = do loop' n 0 putStrLn "" loop m (n + 1) \| else = do return () where loop' m n \| n <= m = do putStr "*" loop' m (n + 1) \| else = do return () _ = loop 10 1 ::: IO
http://rosettacode.org/wiki/Loops/For_with_a_specified_step	Loops/For with a specified step	Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#J	J	' who do we appreciate?' ,~ ": 2 * >: i.4 2 4 6 8 who do we appreciate?
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#R	R	paste(1:10, collapse=", ")
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Racket	Racket	#lang racket (for ((i (in-range 1 15))) (display i) #:break (= 10 i) (display ", "))
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously	Loop over multiple arrays simultaneously	Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#8086_Assembly	8086 Assembly	cpu 8086 bits 16 org 100h section .text mov ah,2 ; Tell MS-DOS to print characters xor si,si ; Clear first index register (holds _i_) outer: mov di,As ; Put array-of-arrays in second index register mov cx,Aslen ; Put length in counter register inner: mov bx,[di] ; Load array pointer into BX (address) register mov dl,[bx+si] ; Get SI'th element from array int 21h ; Print character inc di ; Go to next array (pointers are 2 bytes wide) inc di loop inner ; For each array mov dl,13 ; Print newline int 21h mov dl,10 int 21h inc si ; Increment index register cmp si,Alen ; If it is still lower than the array length jb outer ; Print the next items ret section .data ;;; Arrays A1: db 'a','b','c' A2: db 'A','B','C' A3: db '1','2','3' Alen: equ $-A3 ; Length of arrays (elements are bytes) ;;; Array of arrays As: dw A1,A2,A3 Aslen: equ ($-As)/2 ; Length of array of arrays (in words)
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges	#Action.21	Action!	PROC Main() BYTE v PrintE("Before loop") DO v=Rand(20) PrintBE(v) IF v=10 THEN EXIT FI OD PrintE("After loop") RETURN
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges	#Ada	Ada	with Ada.Text_IO; use Ada.Text_IO; with Ada.Numerics.Discrete_Random; procedure Test_Loop_Break is type Value_Type is range 0..19; package Random_Values is new Ada.Numerics.Discrete_Random (Value_Type); use Random_Values; Dice : Generator; A, B : Value_Type; begin loop A := Random (Dice); Put_Line (Value_Type'Image (A)); exit when A = 10; B := Random (Dice); Put_Line (Value_Type'Image (B)); end loop; end Test_Loop_Break;
http://rosettacode.org/wiki/Longest_common_subsequence	Longest common subsequence	Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the mn coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(mn) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(mn) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(mn log m) time in the worst case, as the number of matches grows to O(mn). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(ns + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet	#ALGOL_68	ALGOL 68	main:( PROC lcs = (STRING a, b)STRING: BEGIN IF UPB a = 0 OR UPB b = 0 THEN "" ELIF a [UPB a] = b [UPB b] THEN lcs (a [:UPB a - 1], b [:UPB b - 1]) + a [UPB a] ELSE STRING x = lcs (a, b [:UPB b - 1]); STRING y = lcs (a [:UPB a - 1], b); IF UPB x > UPB y THEN x ELSE y FI FI END # lcs #; print((lcs ("thisisatest", "testing123testing"), new line)) )
http://rosettacode.org/wiki/Look-and-say_sequence	Look-and-say sequence	The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.	#8086_Assembly	8086 Assembly	bits 16 cpu 8086 puts: equ 9h ; MS/DOS system call to print a string nmemb: equ 15 ; Change this to print more or fewer members section .text org 100h mov cx,nmemb ; CX = how many members to print outloop: mov dx,memb ; Print current member mov ah,puts int 21h mov dx,newline ; Print newline int 21h mov di,memb ; Generate next member call looksay loop outloop ; Decrease CX, and loop until zero. ret ; Go back to DOS. ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; Given a look and say string in ES:DI, generate the next ;;; one in place. Assumption: DS = ES. looksay: push cx ; Keep the counter register mov si,di ; Store pointer to string begin in SI mov bx,di ; And another in BX mov al,'$' ; Find the end of the string xor cx,cx ; Max. 65535 tries dec cx repne scasb ; The 8086 has dedicated string search mov dx,di ; Store copy of start of new str in DX ;;; Process one character .procchar: mov al,'0' ; Set counter to ASCII 0 mov ah,[bx] ; Get current character of string cmp ah,'$' ; Done? je .done .samechar: inc bx ; Increment pointer inc al ; Increment counter cmp ah,[bx] ; Still the same character? je .samechar ; If yes, test next character mov [di],ax ; Store counter and character inc di ; Move ahead two characters inc di jmp .procchar ; Do next character ;;; Copy new string into old location .done: mov byte [di],'$' ; Terminate the string mov cx,di ; Calculate how many bytes to copy sub cx,dx ; end + 1 - start, so one too few here shr cx,1 ; Divide by 2 = words inc cx ; Compensate for the missing +1 mov di,dx ; Pointer to begin of new string xchg si,di ; Set SI = new string and DI = old rep movsw ; Copy 16 bits at a time pop cx ; Restore counter register ret section .data newline: db 13,10,'$' ; Newline to print in between members memb: db '1$' ; This is where the current member is stored
http://rosettacode.org/wiki/Longest_string_challenge	Longest string challenge	Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.	#Clojure	Clojure	ns longest-string (:gen-class)) (defn longer [a b] " if a is longer, it returns the characters in a after length b characters have been removed otherwise it returns nil " (if (or (empty? a) (empty? b)) (not-empty a) (recur (rest a) (rest b)))) (defn get-input [] " Gets the data from standard input as a lazy-sequence of lines (i.e. reads lines as needed by caller Input is terminated by a zero length line (i.e. line with just <CR> " (let [line (read-line)] (if (> (count line) 0) (lazy-seq (cons line (get-input))) nil))) (defn process [] " Returns list of longest lines " (first ; takes lines from [lines longest] (reduce (fn [[lines longest] x] (cond (longer x longest) [x x] ; new longer line (not (longer longest x)) [(str lines "\n" x) longest] ; append x to previous longest :else [lines longest])) ; keep previous lines & longest ["" ""] (get-input)))) (println "Input text:") (println "Output:\n" (process))
http://rosettacode.org/wiki/Longest_increasing_subsequence	Longest increasing subsequence	Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.	#Common_Lisp	Common Lisp	(defun longest-increasing-subseq (list) (let ((subseqs nil)) (dolist (item list) (let ((longest-so-far (longest-list-in-lists (remove-if-not #'(lambda (l) (> item (car l))) subseqs)))) (push (cons item longest-so-far) subseqs))) (reverse (longest-list-in-lists subseqs)))) (defun longest-list-in-lists (lists) (let ((longest nil) (longest-len 0)) (dolist (list lists) (let ((len (length list))) (when (> len longest-len) (setf longest list longest-len len)))) longest)) (dolist (l (list (list 3 2 6 4 5 1) (list 0 8 4 12 2 10 6 14 1 9 5 13 3 11 7 15))) (format t "~A~%" (longest-increasing-subseq l))))
http://rosettacode.org/wiki/Loops/Continue	Loops/Continue	Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#AWK	AWK	BEGIN { for(i=1; i <= 10; i++) { printf("%d", i) if ( i % 5 == 0 ) { print continue } printf(", ") } }
http://rosettacode.org/wiki/Loops/Continue	Loops/Continue	Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#BASIC	BASIC	10 FOR I = 1 TO 10 20 PRINT I; 30 IF I - INT (I / 5) * 5 = 0 THEN PRINT : GOTO 50"CONTINUE 40 PRINT ", "; 50 NEXT
http://rosettacode.org/wiki/Longest_common_substring	Longest common substring	Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction	#BaCon	BaCon	FUNCTION Common_Sub$(haystack$, needle$) WHILE LEN(needle$) FOR x = LEN(needle$) DOWNTO 1 IF INSTR(haystack$, LEFT$(needle$, x)) THEN RETURN LEFT$(needle$, x) NEXT needle$ = MID$(needle$, 2) WEND EXIT ENDFUNC PRINT Common_Sub$("thisisatest", "testing123testing")
http://rosettacode.org/wiki/Longest_common_substring	Longest common substring	Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction	#BASIC256	BASIC256	function LCS(a, b) if length(a) = 0 or length(b) = 0 then return "" while length(b) for j = length(b) to 1 step -1 if instr(a, left(b, j)) then return left(b, j) next j b = mid$(b, 2) end while end function print LCS("thisisatest", "testing123testing") end
http://rosettacode.org/wiki/Loops/Nested	Loops/Nested	Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#PureBasic	PureBasic	; Creating and filling array Dim Value(10, 5) For a = 0 To 10 For b = 0 To 5 Value(a, b) = Random(19) + 1 Next Next ; iterating trough array For a = 0 To 10 For b = 0 To 5 Debug Value(a, b) If Value(a, b) = 20 ; 2 indicates, that there are two nested lopps to break out Break 2 EndIf Next Next
http://rosettacode.org/wiki/Loops/Foreach	Loops/Foreach	Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Sather	Sather	class MAIN is main is num:ARRAY{INT} := \|1, 5, 4, 3, 10\|; loop -- the iterator elt! behaves like a "foreach", -- yielding the next element of the array at each iteration #OUT + num.elt! + "\n"; end; end; end;
http://rosettacode.org/wiki/Loops/Foreach	Loops/Foreach	Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Scala	Scala	val collection = Array(1, 2, 3, 4) collection.foreach(println)
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers	Luhn test of credit card numbers	The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks SEDOL ISIN	#MUMPS	MUMPS	LUHN(C) NEW ODD,EVEN,S SET S=$REVERSE(C) SET ODD=0 FOR I=1:2:$LENGTH(S) SET ODD=ODD+$EXTRACT(S,I) SET EVEN=0 FOR I=2:2:$LENGTH(S) SET T=$EXTRACT(S,I)*2 SET EVEN=EVEN+$SELECT(T<=9:T,T>9:$EXTRACT(T,1)+$EXTRACT(T,2)) QUIT '((ODD+EVEN)#10)
http://rosettacode.org/wiki/Loops/Infinite	Loops/Infinite	Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Nim	Nim	while true: echo "SPAM"
http://rosettacode.org/wiki/Loops/Infinite	Loops/Infinite	Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#NS-HUBASIC	NS-HUBASIC	10 FOR I=0 TO 1 STEP 0 20 PRINT "SPAM" 30 NEXT
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Modula-2	Modula-2	MODULE DivBy2; IMPORT InOut; VAR i: INTEGER; BEGIN i := 1024; WHILE i > 0 DO InOut.WriteInt(i, 4); InOut.WriteLn; i := i DIV 2 END END DivBy2.
http://rosettacode.org/wiki/Loops/While	Loops/While	Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Modula-3	Modula-3	PROCEDURE DivBy2() = VAR i: INTEGER := 1024; BEGIN WHILE i > 0 DO IO.PutInt(i); IO.Put("\n"); i := i DIV 2; END; END DivBy2;
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Nemerle	Nemerle	for (i = 10; i >= 0; i--) {WriteLine($"$i")}
http://rosettacode.org/wiki/Loops/Downward_for	Loops/Downward for	Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#NetRexx	NetRexx	/* NetRexx */ options replace format comments java crossref savelog symbols nobinary say say 'Loops/Downward for' loop i_ = 10 to 0 by -1 say i_.right(2) end i_
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.	#Julia	Julia	julia> i = 0 0 julia> while true println(i) i += 1 i % 6 == 0 && break end 0 1 2 3 4 5
http://rosettacode.org/wiki/Loops/Do-while	Loops/Do-while	Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.	#Kotlin	Kotlin	// version 1.0.6 fun main(args: Array<String>) { var value = 0 do { println(++value) } while (value % 6 != 0) }
http://rosettacode.org/wiki/Loops/For	Loops/For	“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * * ** *** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.	#Elena	Elena	import extensions; public program() { for(int i := 0, i < 5, i += 1) { for(int j := 0, j <= i, j += 1) { console.write:"*" }; console.writeLine() } }
http://rosettacode.org/wiki/Loops/For_with_a_specified_step	Loops/For with a specified step	Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Java	Java	for(int i = 2; i <= 8;i += 2){ System.out.print(i + ", "); } System.out.println("who do we appreciate?");
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Raku	Raku	for 1 .. 10 { .print; last when 10; print ', '; } print "\n";
http://rosettacode.org/wiki/Loops/N_plus_one_half	Loops/N plus one half	Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#REBOL	REBOL	rebol [ Title: "Loop Plus Half" URL: http://rosettacode.org/wiki/Loop/n_plus_one_half ] repeat i 10 [ prin i if 10 = i [break] prin ", " ] print ""
http://rosettacode.org/wiki/Long_year	Long year	Most years have 52 weeks, some have 53, according to ISO8601. Task Write a function which determines if a given year is long (53 weeks) or not, and demonstrate it.	#11l	11l	F is_long_year(year) F p(year) R (year + (year I/ 4) - (year I/ 100) + (year I/ 400)) % 7 R p(year) == 4 \| p(year - 1) == 3 L(year) 2000..2100 I is_long_year(year) print(year, end' ‘ ’)
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously	Loop over multiple arrays simultaneously	Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#ACL2	ACL2	(defun print-lists (xs ys zs) (if (or (endp xs) (endp ys) (endp zs)) nil (progn$ (cw (first xs)) (cw "~x0~x1~%" (first ys) (first zs)) (print-lists (rest xs) (rest ys) (rest zs))))) (print-lists '("a" "b" "c") '(A B C) '(1 2 3))
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges	#Aime	Aime	integer main(void) { integer a, b; while (1) { a = drand(19); o_integer(a); o_byte('\n'); if (a == 10) { break; } b = drand(19); o_integer(b); o_byte('\n'); } return 0; }
http://rosettacode.org/wiki/Loops/Break	Loops/Break	Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges	#ALGOL_60	ALGOL 60	'BEGIN' 'COMMENT' Loops/Break - ALGOL60 - 18/06/2018; 'INTEGER' SEED; 'INTEGER' 'PROCEDURE' RANDOM(N); 'VALUE' N; 'INTEGER' N; 'BEGIN' SEED:=(SEED19157+12347) '/' 21647; RANDOM:=SEED-(SEED '/' N)N+1 'END' RANDOM; 'INTEGER' I,J,K; SYSACT(1,6,120);SYSACT(1,8,60);SYSACT(1,12,1);'COMMENT' open print; SEED:=31567; J:=0; 'FOR' I:=1, I+1 'WHILE' I 'LESS' 100 'DO' 'BEGIN' J:=J+1; K:=RANDOM(20); OUTINTEGER(1,K); 'IF' J=8 'THEN' 'BEGIN' SYSACT(1,14,1); 'COMMENT' skip line; J:=0 'END'; 'IF' K=10 'THEN' 'GOTO' LAB 'END'; LAB: SYSACT(1,14,1); 'COMMENT' skip line; 'END'
http://rosettacode.org/wiki/Longest_common_subsequence	Longest common subsequence	Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the mn coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(mn) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(mn) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(mn log m) time in the worst case, as the number of matches grows to O(mn). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(ns + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet	#APL	APL	lcs←{ ⎕IO←0 betterof←{⊃(</+/¨⍺ ⍵)⌽⍺ ⍵} ⍝ better of 2 selections cmbn←{↑,⊃∘.,/(⊂⊂⍬),⍵} ⍝ combine lists rr←{∧/↑>/1 ¯1↓[1]¨⊂⍵} ⍝ rising rows hmrr←{∨/(rr ⍵)∧∧/⍵=⌈\⍵} ⍝ has monotonically rising rows rnbc←{{⍵/⍳⍴⍵}¨↓[0]×⍵} ⍝ row numbers by column valid←hmrr∘cmbn∘rnbc ⍝ any valid solutions? a w←(</⊃∘⍴¨⍺ ⍵)⌽⍺ ⍵ ⍝ longest first matches←a∘.=w aps←{⍵[;⍒+⌿⍵]}∘{(⍵/2)⊤⍳2*⍵} ⍝ all possible subsequences swps←{⍵/⍨∧⌿~(~∨⌿⍺)⌿⍵} ⍝ subsequences with possible solns sstt←matches swps aps⊃⍴w ⍝ subsequences to try w/⍨{ ⍺←0⍴⍨⊃⍴⍵ ⍝ initial selection (+/⍺)≥+/⍵[;0]:⍺ ⍝ no scope to improve this←⍺ betterof{⍵×valid ⍵/matches}⍵[;0] ⍝ try to improve 1=1⊃⍴⍵:this ⍝ nothing left to try this ∇ 1↓[1]⍵ ⍝ keep looking }sstt }
http://rosettacode.org/wiki/Look-and-say_sequence	Look-and-say sequence	The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.	#Action.21	Action!	BYTE FUNC GetLength(CHAR ARRAY s BYTE pos) CHAR c BYTE len c=s(pos) len=1 DO pos==+1 IF pos<=s(0) AND s(pos)=c THEN len==+1 ELSE EXIT FI OD RETURN (len) PROC Append(CHAR ARRAY text,suffix) BYTE POINTER srcPtr,dstPtr BYTE len len=suffix(0) IF text(0)+len>255 THEN len=255-text(0) FI IF len THEN srcPtr=suffix+1 dstPtr=text+text(0)+1 MoveBlock(dstPtr,srcPtr,len) text(0)==+suffix(0) FI RETURN PROC LookAndSay(CHAR ARRAY in,out) BYTE pos,len CHAR ARRAY tmp(5) pos=1 len=0 out(0)=0 WHILE pos<=in(0) DO len=GetLength(in,pos) StrB(len,tmp) Append(out,tmp) out(0)==+1 out(out(0))=in(pos) pos==+len OD RETURN PROC Main() CHAR ARRAY s1(256),s2(256) BYTE i SCopy(s1,"1") PrintE(s1) FOR i=1 TO 11 DO IF (i&1)=0 THEN LookAndSay(s2,s1) PrintE(s1) ELSE LookAndSay(s1,s2) PrintE(s2) FI OD RETURN
http://rosettacode.org/wiki/Longest_string_challenge	Longest string challenge	Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.	#D	D	import std.stdio, std.array; /// Return a.length - b.length if positive, 0 otherwise. int longer(string a, string b) { while (!a.empty && !b.empty) a.popFront(), b.popFront(); return a.length; } void main() { string longest, lines; foreach (string line; stdin.lines()) if (longer(line, longest)) lines = longest = line; else if (!longer(longest, line)) lines ~= line; writeln(lines); }
http://rosettacode.org/wiki/Longest_increasing_subsequence	Longest increasing subsequence	Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.	#D	D	import std.stdio, std.algorithm, power_set2; T[] lis(T)(T[] items) pure nothrow { //return items.powerSet.filter!isSorted.max!q{ a.length }; return items .powerSet .filter!isSorted .minPos!q{ a.length > b.length } .front; } void main() { [3, 2, 6, 4, 5, 1].lis.writeln; [0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15].lis.writeln; }
http://rosettacode.org/wiki/Loops/Continue	Loops/Continue	Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#bc	bc	for (i = 1; i <= 10; i++) { print i if (i % 5) { print ", " continue } print "\n" } quit
http://rosettacode.org/wiki/Longest_common_substring	Longest common substring	Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction	#Bracmat	Bracmat	( lcs = X a b x L . !arg:(?a.?b) & 0:?L & :?X & ( @( !a : ? ( ?x & @(!x:? [>!L) & @(!b:? !x ?) & @(!x:? [?L:?X) ) (?&~) ) \| !X ) ) & out$(lcs$(thisisatest.testing123testing))
http://rosettacode.org/wiki/Loops/Nested	Loops/Nested	Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Python	Python	from random import randint def do_scan(mat): for row in mat: for item in row: print item, if item == 20: print return print print mat = [[randint(1, 20) for x in xrange(10)] for y in xrange(10)] do_scan(mat)
http://rosettacode.org/wiki/Loops/Foreach	Loops/Foreach	Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges	#Scheme	Scheme	(for-each (lambda (i) (display i) (newline)) the_list)

http://rosettacode.org/wiki/Loops/Infinite

Loops/Infinite

Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#MUMPS

MUMPS

FOR WRITE "SPAM",!

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Microsoft_Small_Basic

Microsoft Small Basic

i = 1024 While i > 0 TextWindow.WriteLine(i) i = Math.Floor(i / 2) EndWhile

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#min

min

1024 :n (n 0 >) (n puts 2 div @n) while

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#MiniScript

MiniScript

for i in range(10, 0) print i end for

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#.D0.9C.D0.9A-61.2F52

МК-61/52

1 0 П0 ИП0 L0 03 С/П

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.

#Icon_and_Unicon

Icon and Unicon

procedure main() i := 0 repeat { write(i +:= 1) if i % 6 = 0 then break } end

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.

#J

J

,. ([^:(0=6|])>:)^:a: 0

http://rosettacode.org/wiki/Loops/For

Loops/For

“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.

#EDSAC_order_code

EDSAC order code

[ Loops ===== A program for the EDSAC Demonstrates nested loops and printer output Works with Initial Orders 2 ] T56K [ set load point ] GK [ set theta ] O21@ [ figure shift ] [ 1 ] T24@ [ a = 0 ] A19@ [ a = i ] [ 3 ] T20@ [ j = a; a = 0 ] O22@ [ write character ] A20@ [ a = j ] S17@ [ a -= 1 ] U20@ [ j = a ] E3@ [ if a>=0 go to 3 ] O23@ [ write line feed ] T24@ [ a = 0 ] A19@ [ a = i ] A17@ [ a += 1 ] U19@ [ i = a ] S18@ [ a -= 5 ] G1@ [ if a<0 go to 1 ] ZF [ halt ] [ 17 ] P0D [ const: 1 ] [ 18 ] P2D [ const: 5 ] [ 19 ] P0F [ var: i ] [ 20 ] P0F [ var: j ] [ 21 ] #F [ figure shift ] [ 22 ] ZF [ '+' character ] [ 23 ] &F [ line feed ] [ 24 ] P0F [ used to clear a ] EZPF [ begin execution ]

http://rosettacode.org/wiki/Loops/For_with_a_specified_step

Loops/For with a specified step

Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Icon_and_Unicon

Icon and Unicon

every 1 to 10 by 2 # the simplest case that satisfies the task, step by 2 every 1 to 10 # no to, step is by 1 by default every EXPR1 to EXPR2 by EXPR3 do EXPR4 # general case - EXPRn can be complete expressions including other generators such as to-by, every's do is optional steps := [2,3,5,7] # a list every i := 1 to 100 by !steps # . more complex, several passes with each step in the list steps, also we might want to know what value we are at every L[1 to 100 by 2] # as a list index every i := 1 to 100 by (k := !steps) # . need () otherwise := generates an error every 1 to 5 to 10 # simple case of combined to-by - 1,..,10, 2,..10, ..., 5,..,10 every 1 to 15 by 2 to 5 # combined to-by every (1 to 15 by 2) to 5 # . made explicit every writes( (TO_BY_EXPR) | "\n", " " ) # if you want to see how any of these work

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Prolog

Prolog

example :- between(1,10,Val), write(Val), Val<10, write(', '), fail. example.

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#PureBasic

PureBasic

x=1 Repeat Print(Str(x)) x+1 If x>10: Break: EndIf Print(", ") ForEver

http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously

Loop over multiple arrays simultaneously

Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#360_Assembly

360 Assembly

* Loop over multiple arrays simultaneously 09/03/2017 LOOPSIM CSECT USING LOOPSIM,R12 base register LR R12,R15 LA R6,1 i=1 LA R7,3 counter=3 LOOP LR R1,R6 i SLA R1,1 *2 LH R2,R-2(R1) r(i) XDECO R2,PG edit r(i) LA R1,S-1(R6) @s(i) MVC PG+3(1),0(R1) output s(i) LA R1,Q-1(R6) @q(i) MVC PG+7(1),0(R1) output q(i) XPRNT PG,80 print s(i),q(i),r(i) LA R6,1(R6) i++ BCT R7,LOOP decrement and loop BR R14 exit S DC C'a',C'b',C'c' Q DC C'A',C'B',C'C' R DC H'1',H'2',H'3' PG DC CL80' ' buffer YREGS END LOOPSIM

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges

#360_Assembly

360 Assembly

* Loops Break 15/02/2017 LOOPBREA CSECT USING LOOPBREA,R13 base register B 72(R15) skip savearea DC 17F'0' savearea STM R14,R12,12(R13) prolog ST R13,4(R15) " <- ST R15,8(R13) " -> LR R13,R15 " addressability LOOP MVC PG,=CL80' ' clean buffer LA R8,PG ipg=0 BAL R14,RANDINT call randint C R6,=F'10' if k=10 then leave BE ENDLOOP <-- loop break BAL R14,RANDINT call randint XPRNT PG,L'PG print buffer B LOOP loop forever ENDLOOP XPRNT PG,L'PG print buffer L R13,4(0,R13) epilog LM R14,R12,12(R13) " restore XR R15,R15 " rc=0 BR R14 exit RANDINT L R5,RANDSEED randint M R4,=F'397204091' " D R4,=X'7FFFFFFF' " ST R4,RANDSEED " LR R5,R4 " SR R4,R4 " D R4,=F'20' " LR R6,R4 k=randint(20) XDECO R6,XDEC edit k MVC 0(4,R8),XDEC+8 output k LA R8,4(R8) ipg=ipg+4 BR R14 return RANDSEED DC F'39710831' seed PG DS CL80 buffer XDEC DS CL12 YREGS END LOOPBREA

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges

#6502_Assembly

6502 Assembly

LoopBreakSub: PHA ;push accumulator onto stack BreakLoop: JSR GenerateRandomNum ;routine not implemented ;generates random number and puts in memory location RandomNumber LDA RandomNumber JSR DisplayAccumulator ;routine not implemented CMP #10 BEQ Break JSR GenerateRandomNum LDA RandomNumber JSR DisplayAccumulator JMP BreakLoop Break: PLA ;restore accumulator from stack RTS ;return from subroutine

http://rosettacode.org/wiki/Longest_common_subsequence

Longest common subsequence

Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the m*n coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(m*n) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(m*n) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(m*n log m) time in the worst case, as the number of matches grows to O(m*n). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(n*s + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet

#11l

11l

F lcs(a, b) V lengths = [[0] * (b.len+1)] * (a.len+1) L(x) a V i = L.index L(y) b V j = L.index I x == y lengths[i + 1][j + 1] = lengths[i][j] + 1 E lengths[i + 1][j + 1] = max(lengths[i + 1][j], lengths[i][j + 1]) V result = ‘’ V j = b.len L(i) 1..a.len I lengths[i][j] != lengths[i - 1][j] result ‘’= a[i - 1] R result print(lcs(‘1234’, ‘1224533324’)) print(lcs(‘thisisatest’, ‘testing123testing’))

http://rosettacode.org/wiki/Look-and-say_sequence

Look-and-say sequence

The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.

#11l

11l

F lookandsay(=number) V result = ‘’ V repeat = number[0] number = number[1..]‘ ’ V times = 1 L(actual) number I actual != repeat result ‘’= String(times)‘’repeat times = 1 repeat = actual E times++ R result V num = ‘1’ L 10 print(num) num = lookandsay(num)

http://rosettacode.org/wiki/Longest_string_challenge

Longest string challenge

Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.

#BBC_BASIC

BBC BASIC

DIM buffer% 65535 bufptr% = buffer% longest$ = " " ON ERROR PRINT $$buffer%; : END REPEAT READ A$ IF FNcmp(A$, longest$) THEN IF FNcmp(longest$, A$) ELSE bufptr% = buffer% longest$ = A$ $bufptr% = A$ WHILE ?bufptr% bufptr% = FNinc(bufptr%) ENDWHILE ?bufptr% = 10 bufptr% = FNinc(bufptr%) ENDIF UNTIL FALSE : REM Loops until 'Out of data' error END DATA a, bb, ccc, ddd, ee, f, ggg DEF FNcmp(a$, b$) : REM Returns LEN(a$)>=LEN(b$) [if b$<>""] LEFT$(a$, 65535) = b$ = INSTR(a$, b$) DEF FNinc(i%) : REM Returns i%+1 FOR i% = i% TO i% : NEXT = i%

http://rosettacode.org/wiki/Longest_string_challenge

Longest string challenge

Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.

#C

C

#include <stdio.h> #include <string.h> int cmp(const char *p, const char *q) { while (*p && *q) p = &p[1], q = &q[1]; return *p; } int main() { char line[65536]; char buf[1000000] = {0}; char *last = buf; char *next = buf; while (gets(line)) { strcat(line, "\n"); if (cmp(last, line)) continue; if (cmp(line, last)) next = buf; last = next; strcpy(next, line); while (*next) next = &next[1]; } printf("%s", buf); return 0; }

http://rosettacode.org/wiki/Longest_increasing_subsequence

Longest increasing subsequence

Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.

#C.2B.2B

C++

#include <vector> #include <list> #include <algorithm> #include <iostream> template <typename T> struct Node { T value; Node* prev_node; }; template <typename Container> Container lis(const Container& values) { using E = typename Container::value_type; using NodePtr = Node<E>*; using ConstNodePtr = const NodePtr; std::vector<NodePtr> pileTops; std::vector<Node<E>> nodes(values.size()); // sort into piles auto cur_node = std::begin(nodes); for (auto cur_value = std::begin(values); cur_value != std::end(values); ++cur_value, ++cur_node) { auto node = &*cur_node; node->value = *cur_value; // lower_bound returns the first element that is not less than 'node->value' auto lb = std::lower_bound(pileTops.begin(), pileTops.end(), node, [](ConstNodePtr& node1, ConstNodePtr& node2) -> bool { return node1->value < node2->value; }); if (lb != pileTops.begin()) node->prev_node = *std::prev(lb); if (lb == pileTops.end()) pileTops.push_back(node); else *lb = node; } // extract LIS from piles // note that LIS length is equal to the number of piles Container result(pileTops.size()); auto r = std::rbegin(result); for (NodePtr node = pileTops.back(); node != nullptr; node = node->prev_node, ++r) *r = node->value; return result; } template <typename Container> void show_lis(const Container& values) { auto&& result = lis(values); for (auto& r : result) { std::cout << r << ' '; } std::cout << std::endl; } int main() { show_lis(std::list<int> { 3, 2, 6, 4, 5, 1 }); show_lis(std::vector<int> { 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 }); }

http://rosettacode.org/wiki/Loops/Continue

Loops/Continue

Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Arturo

Arturo

loop 1..10 'i [ prints i if 0 = i%5 [ print "" continue ] prints ", " ]

http://rosettacode.org/wiki/Loops/Continue

Loops/Continue

Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Asymptote

Asymptote

for(int i = 1; i <= 10; ++i) { write(i, suffix=none); if(i % 5 == 0) { write(""); continue; } else { write(", ", suffix=none); } }

http://rosettacode.org/wiki/Longest_common_substring

Longest common substring

Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction

#Arturo

Arturo

lcs: function [a,b][ lengths: map 0..size a => [map 0..size b => 0] greatestLength: 0 result: "" loop.with:'i a 'x [ loop.with:'j b 'y [ if x=y [ if? or? i=0 j=0 -> lengths\[i]\[j]: 0 else -> lengths\[i]\[j]: 1 + lengths\[i-1]\[j-1] if greatestLength < lengths\[i]\[j] [ greatestLength: lengths\[i]\[j] result: slice a (i-greatestLength)+1 i ] ] ] ] return result ] print lcs "thisisatest", "testing123testing"

http://rosettacode.org/wiki/Loops/Nested

Loops/Nested

Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#PicoLisp

PicoLisp

(for Lst (make (do 10 (link (make (do 10 (link (rand 1 20))))))) (T (for N Lst (printsp N) (T (= N 20) T) ) ) )

http://rosettacode.org/wiki/Loops/Foreach

Loops/Foreach

Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Ruby

Ruby

for i in collection do puts i end

http://rosettacode.org/wiki/Loops/Foreach

Loops/Foreach

Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Rust

Rust

let collection = vec![1,2,3,4,5]; for elem in collection { println!("{}", elem); }

http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers

Luhn test of credit card numbers

The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks SEDOL ISIN

#min

min

((dup 10 <) 'quote (((10 mod) (10 div)) cleave) 'cons linrec) :digits ((0 0) dip (pop 'succ dip over even?) partition ((pop pop) dip) dip) :evens/odds ((2 * digits sum) map sum) :evens-sum (digits evens/odds ('evens-sum 'sum) => spread + 10 mod 0 ==) :luhn? (49927398716 49927398717 1234567812345678 1234567812345670) (dup print! " " print! luhn? puts!) foreach

http://rosettacode.org/wiki/Loops/Infinite

Loops/Infinite

Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Nanoquery

Nanoquery

while true println "SPAM" end

http://rosettacode.org/wiki/Loops/Infinite

Loops/Infinite

Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Nemerle

Nemerle

while (true) WriteLine("SPAM");

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#MiniScript

MiniScript

i = 1024 while i > 0 print i i = floor(i/2) end while

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#MIRC_Scripting_Language

MIRC Scripting Language

alias while_loop { var %n = 10 while (%n >= 0) { echo -a Countdown: %n dec %n } }

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Modula-2

Modula-2

MODULE Downward; IMPORT InOut; VAR i: INTEGER; BEGIN FOR i := 10 TO 0 BY -1 DO InOut.WriteInt(i, 2); InOut.WriteLn END END Downward.

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.

#Java

Java

int val = 0; do{ val++; System.out.println(val); }while(val % 6 != 0);

http://rosettacode.org/wiki/Loops/For

Loops/For

“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.

#EGL

EGL

str string; for ( i int to 5 ) str = ""; for ( j int to i ) str += "*"; end SysLib.writeStdout(str); end

http://rosettacode.org/wiki/Loops/For_with_a_specified_step

Loops/For with a specified step

Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Io

Io

for(i,2,8,2, write(i,", ") ) write("who do we appreciate?")

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Python

Python

print ( ', '.join(str(i+1) for i in range(10)) )

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Quackery

Quackery

10 times [ i^ 1+ echo i 0 = iff conclude done say ", " ]

http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously

Loop over multiple arrays simultaneously

Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#8080_Assembly

8080 Assembly

org 100h lxi b,0 ; Let (B)C be the array index outer: lxi d,As ; Use DE to walk the array-of-arrays inner: xchg ; Swap DE and HL (array-of-array pointer into HL) mov e,m ; Load low byte of array pointer into E inx h mov d,m ; Load high byte of array pointer into D inx h xchg ; Array base in HL, array-of-array pointer in DE mov a,h ; Is HL 0? ora l jz azero ; If so, we are done. dad b ; Otherwise, add index to array base mov a,m ; Get current item (BC'th item of HL) call chout ; Output jmp inner ; Next array azero: mvi a,13 ; Print newline call chout mvi a,10 call chout inr c ; Increment index (we're only using the low byte) mvi a,Alen ; Is it equal to the length? cmp c jnz outer ; If not, get next item from all the arrays. ret ;;; Print character in A, saving all registers. ;;; This code uses CP/M to do it. chout: push psw ; CP/M destroys all registers push b ; Push them all to the stack push d push h mvi c,2 ; 2 = print character syscall mov e,a call 5 pop h ; Restore registers pop d pop b pop psw ret ;;; Arrays A1: db 'a','b','c' A2: db 'A','B','C' A3: db '1','2','3' Alen: equ $-A3 ;;; Zero-terminated array-of-arrays As: dw A1,A2,A3,0

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges

#AArch64_Assembly

AArch64 Assembly

/* ARM assembly AARCH64 Raspberry PI 3B */ /* program loopbreak64.s */ /*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc" /*********************************/ /* Initialized data */ /*********************************/ .data szMessEndLoop: .asciz "loop break with value : \n" szMessResult: .asciz "Resultat = @ \n" // message result .align 4 qGraine: .quad 12345678 /*********************************/ /* UnInitialized data */ /*********************************/ .bss sZoneConv: .skip 24 /*********************************/ /* code section */ /*********************************/ .text .global main main: // entry of program 1: // begin loop mov x4,20 2: mov x0,19 bl genereraleas // generate number cmp x0,10 // compar value beq 3f // break if equal ldr x1,qAdrsZoneConv // display value bl conversion10 // call function with 2 parameter (x0,x1) ldr x0,qAdrszMessResult ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at third @ character bl affichageMess // display message final subs x4,x4,1 // decrement counter bgt 2b // loop if greather b 1b // begin loop one 3: mov x2,x0 // save value ldr x0,qAdrszMessEndLoop bl affichageMess // display message mov x0,x2 ldr x1,qAdrsZoneConv bl conversion10 // call function with 2 parameter (x0,x1) ldr x0,qAdrszMessResult ldr x1,qAdrsZoneConv bl strInsertAtCharInc // insert result at third @ character bl affichageMess // display message 100: // standard end of the program mov x0,0 // return code mov x8,EXIT // request to exit program svc 0 // perform the system call qAdrsZoneConv: .quad sZoneConv qAdrszMessResult: .quad szMessResult qAdrszMessEndLoop: .quad szMessEndLoop /***************************************************/ /* Generation random number */ /***************************************************/ /* x0 contains limit */ genereraleas: stp x1,lr,[sp,-16]! // save registers stp x2,x3,[sp,-16]! // save registers ldr x3,qAdrqGraine // load graine ldr x2,[x3] lsr x1,x2,17 // see xorshift on wikipedia eor x2,x2,x1 lsl x1,x2,31 eor x2,x2,x1 lsr x1,x2,8 eor x1,x2,x1 str x1,[x3] // save graine for the next call udiv x1,x2,x0 // divide by value maxi msub x0,x1,x0,x2 // résult = remainder 100: // end function ldp x2,x3,[sp],16 // restaur 2 registers ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30 /********************************************************************/ qAdrqGraine: .quad qGraine /********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc"

http://rosettacode.org/wiki/Longest_common_subsequence

Longest common subsequence

Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the m*n coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(m*n) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(m*n) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(m*n log m) time in the worst case, as the number of matches grows to O(m*n). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(n*s + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet

#Ada

Ada

with Ada.Text_IO; use Ada.Text_IO; procedure Test_LCS is function LCS (A, B : String) return String is begin if A'Length = 0 or else B'Length = 0 then return ""; elsif A (A'Last) = B (B'Last) then return LCS (A (A'First..A'Last - 1), B (B'First..B'Last - 1)) & A (A'Last); else declare X : String renames LCS (A, B (B'First..B'Last - 1)); Y : String renames LCS (A (A'First..A'Last - 1), B); begin if X'Length > Y'Length then return X; else return Y; end if; end; end if; end LCS; begin Put_Line (LCS ("thisisatest", "testing123testing")); end Test_LCS;

http://rosettacode.org/wiki/Look-and-say_sequence

Look-and-say sequence

The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.

#8080_Assembly

8080 Assembly

bdos: equ 5 ; CP/M calls puts: equ 9 nmemb: equ 15 ; Change this to print more or fewer members org 100h ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Generate and output members of the sequence mvi b,nmemb ; Counter outloop: push b ; Preserve counter across calls mvi c,puts ; Output current member lxi d,memb call bdos ; And newline mvi c,puts lxi d,newline call bdos lxi h,memb ; Generate next member call looksay pop b ; Restore counter dcr b ; Done yet? jnz outloop rst 0 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; Given a $-terminated string under HL, representing ;; a member of the look and say sequence, generate ;; the next one in place (ish). The memory after the ;; string is assumed to be free. looksay: push h ; Save start of string on stack mov d,h ; And in DE mov e,l mvi a,'$' ; Find end of string findend: cmp m inx h jnz findend xchg ; HL=string, DE=destination push d ; Save start of new string on stack lookchar: mvi b,0 ; Zero counter lookloop: mov a,m ; Get current character inr b ; Compare next character inx h cmp m ; While it is the same, keep going jz lookloop mov c,a ; Keep character mvi a,'0' ; There are B amount of these characters add b stax d ; Store the amount inx d ; And in the next location mov a,c ; Store the character stax d inx d mvi a,'$' ; Are we done? cmp m jnz lookchar ; If not, do next character stax d ; If yes, terminate new string ;; Free up memory by copying the new string to where the old ;; string began. pop d ; Start of new string pop h ; Start of old string copyloop: ldax d ; Get char from new string mov m,a ; Store char where old string was cpi '$' ; are we done yet? inx d inx h jnz copyloop ret ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; newline: db 13,10,'$' ;; This is where the string will be stored. memb: db '1$' ; First item ; Due to how CP/M loads programs, the memory after here ; is free until we hit the stack.

http://rosettacode.org/wiki/Longest_string_challenge

Longest string challenge

Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.

#C.2B.2B

C++

#include <iostream> #include <string.h> int main() { std::string longLine, longestLines, newLine; while (std::cin >> newLine) { auto isNewLineShorter = longLine.c_str(); auto isLongLineShorter = newLine.c_str(); while (*isNewLineShorter && *isLongLineShorter) { // This determines which string is longer without using a built // in string length function. The loop will stop at the 0 at the // end of the shortest string. isNewLineShorter = &isNewLineShorter[1]; isLongLineShorter = &isLongLineShorter[1]; } if(*isNewLineShorter) continue; // other lines were longer, do nothing if(*isLongLineShorter) { // the new string is the longest so far longLine = newLine; longestLines = newLine; } else { // the new string is the same lenth as the previous longest longestLines+=newLine; } longestLines+="\n"; // append a new line between the strings } std::cout << "\nLongest string:\n" << longestLines; }

http://rosettacode.org/wiki/Longest_increasing_subsequence

Longest increasing subsequence

Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.

#Clojure

Clojure

(defn place [piles card] (let [[les gts] (->> piles (split-with #(<= (ffirst %) card))) newelem (cons card (->> les last first)) modpile (cons newelem (first gts))] (concat les (cons modpile (rest gts))))) (defn a-longest [cards] (let [piles (reduce place '() cards)] (->> piles last first reverse))) (println (a-longest [3 2 6 4 5 1])) (println (a-longest [0 8 4 12 2 10 6 14 1 9 5 13 3 11 7 15]))

http://rosettacode.org/wiki/Loops/Continue

Loops/Continue

Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#AutoHotkey

AutoHotkey

Loop, 10 { Delimiter := (A_Index = 5) || (A_Index = 10) ? "`n":", " Index .= A_Index . Delimiter } MsgBox %Index%

http://rosettacode.org/wiki/Longest_common_substring

Longest common substring

Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction

#AutoHotkey

AutoHotkey

LCS(a, b){ x := i := 1 while StrLen(x) Loop % StrLen(a) IfInString, b, % x := SubStr(a, i:=StrLen(x)=1 ? i+1 : i, n:=StrLen(a)+1-A_Index) res := StrLen(res) > StrLen(x) ? res : x return res }

http://rosettacode.org/wiki/Loops/Nested

Loops/Nested

Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Pike

Pike

int main() { // enumerate() normally returns a linearly enumerated array, but // allows for the forth argument to specify a function that will // be called and return the value that should be in each cell. We // create an anonymous function (lambda) that just returns a // random value. array a = ({}); for(int i=0; i<20; i++) a += ({ enumerate( 20, 1, 1, lambda(){return random(20)+1;} ) }); // We could use for() and a[x][y] indexing, but foreach is just // shorter and easier to use even if the 2D-array becomes less // obvious. mynestedloops: foreach(a, array inner_a) { foreach(inner_a, int value) { write(value +" "); if(value == 20) break mynestedloops; } } write("\n"); }

http://rosettacode.org/wiki/Loops/Nested

Loops/Nested

Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#PL.2FI

PL/I

declare x(20,20) fixed; /* 16 August 2010. */ x = random()*20 + 1; loops: do i = 1 to hbound(x,1); do j = 1 to hbound(x,2); put (x(i,j)); if x(i,j) = 20 then leave loops; end; if x(i,j) = 20 then leave; end;

http://rosettacode.org/wiki/Loops/Foreach

Loops/Foreach

Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Salmon

Salmon

iterate (x; ["Red", "Green", "Blue"]) x!;

http://rosettacode.org/wiki/Loops/Foreach

Loops/Foreach

Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#SAS

SAS

/* Initialize an array with integers 1 to 10, and print their sum */ data _null_; array a a1-a10; n=1; do over a; a=n; n=n+1; end; s=sum(of a{*}); put s; run;

http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers

Luhn test of credit card numbers

The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks SEDOL ISIN

#MiniScript

MiniScript

isValid = function(s) sum = 0 odd = true for i in range(s.len-1) d = val(s[i]) sum = sum + d * (2 - odd) if not odd and d > 4 then sum = sum - 9 odd = not odd end for return sum % 10 == 0 end function test = function(s) if isValid(s) then print s + ": valid" else print s + ": invalid" end function test "49927398716" test "49927398717" test "1234567812345678" test "1234567812345670"

http://rosettacode.org/wiki/Loops/Infinite

Loops/Infinite

Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#NetRexx

NetRexx

/* NetRexx */ options replace format comments java crossref savelog symbols nobinary say say 'Loops/Infinite' loop label spam forever say 'SPAM' end spam

http://rosettacode.org/wiki/Loops/Infinite

Loops/Infinite

Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#NewLISP

NewLISP

(while (println "SPAM"))

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#MIXAL

MIXAL

****************************************** * X = M / N WHILE X > 0 * STORE EACH X IN NUMERIC ARRAY * PRINT ARRAY ******************************************* M EQU 1024 N EQU 2 LPR EQU 18 BUF0 EQU 100 MSG EQU 2000 LENGTH EQU 500 ORIG 3000 START IOC 0(LPR) ENTX M CALC STX BUF0,1 DIV =N= SRAX 5 INC1 1 JXP CALC ST1 LENGTH PRINT LDA BUF0,2 CHAR STX MSG OUT MSG(LPR) INC2 1 CMP2 LENGTH JNE PRINT HLT END START

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#.D0.9C.D0.9A-61.2F52

МК-61/52

1 0 2 4 П0 ИП0 /-/ x<0 15 ИП0 2 / П0 БП 05 С/П

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Modula-3

Modula-3

FOR i := 10 TO 0 BY -1 DO IO.PutInt(i); END;

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#MUMPS

MUMPS

LOOPDOWN NEW I FOR I=10:-1:1 WRITE I WRITE:I'=1 ", " KILL I QUIT

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.

#JavaScript

JavaScript

var val = 0; do { print(++val); } while (val % 6);

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.

#jq

jq

# Perform the action, then check the condition, etc def do_while( action; condition ): def w: action | if (condition | not) then empty else ., w end; w;

http://rosettacode.org/wiki/Loops/For

Loops/For

“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.

#Ela

Ela

open monad io loop m n | n < m = do loop' n 0 putStrLn "" loop m (n + 1) | else = do return () where loop' m n | n <= m = do putStr "*" loop' m (n + 1) | else = do return () _ = loop 10 1 ::: IO

http://rosettacode.org/wiki/Loops/For_with_a_specified_step

Loops/For with a specified step

Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#J

J

' who do we appreciate?' ,~ ": 2 * >: i.4 2 4 6 8 who do we appreciate?

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#R

R

paste(1:10, collapse=", ")

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Racket

Racket

#lang racket (for ((i (in-range 1 15))) (display i) #:break (= 10 i) (display ", "))

http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously

Loop over multiple arrays simultaneously

Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#8086_Assembly

8086 Assembly

cpu 8086 bits 16 org 100h section .text mov ah,2 ; Tell MS-DOS to print characters xor si,si ; Clear first index register (holds _i_) outer: mov di,As ; Put array-of-arrays in second index register mov cx,Aslen ; Put length in counter register inner: mov bx,[di] ; Load array pointer into BX (address) register mov dl,[bx+si] ; Get SI'th element from array int 21h ; Print character inc di ; Go to next array (pointers are 2 bytes wide) inc di loop inner ; For each array mov dl,13 ; Print newline int 21h mov dl,10 int 21h inc si ; Increment index register cmp si,Alen ; If it is still lower than the array length jb outer ; Print the next items ret section .data ;;; Arrays A1: db 'a','b','c' A2: db 'A','B','C' A3: db '1','2','3' Alen: equ $-A3 ; Length of arrays (elements are bytes) ;;; Array of arrays As: dw A1,A2,A3 Aslen: equ ($-As)/2 ; Length of array of arrays (in words)

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges

#Action.21

Action!

PROC Main() BYTE v PrintE("Before loop") DO v=Rand(20) PrintBE(v) IF v=10 THEN EXIT FI OD PrintE("After loop") RETURN

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges

#Ada

Ada

with Ada.Text_IO; use Ada.Text_IO; with Ada.Numerics.Discrete_Random; procedure Test_Loop_Break is type Value_Type is range 0..19; package Random_Values is new Ada.Numerics.Discrete_Random (Value_Type); use Random_Values; Dice : Generator; A, B : Value_Type; begin loop A := Random (Dice); Put_Line (Value_Type'Image (A)); exit when A = 10; B := Random (Dice); Put_Line (Value_Type'Image (B)); end loop; end Test_Loop_Break;

http://rosettacode.org/wiki/Longest_common_subsequence

Longest common subsequence

Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the m*n coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(m*n) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(m*n) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(m*n log m) time in the worst case, as the number of matches grows to O(m*n). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(n*s + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet

#ALGOL_68

ALGOL 68

main:( PROC lcs = (STRING a, b)STRING: BEGIN IF UPB a = 0 OR UPB b = 0 THEN "" ELIF a [UPB a] = b [UPB b] THEN lcs (a [:UPB a - 1], b [:UPB b - 1]) + a [UPB a] ELSE STRING x = lcs (a, b [:UPB b - 1]); STRING y = lcs (a [:UPB a - 1], b); IF UPB x > UPB y THEN x ELSE y FI FI END # lcs #; print((lcs ("thisisatest", "testing123testing"), new line)) )

http://rosettacode.org/wiki/Look-and-say_sequence

Look-and-say sequence

The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.

#8086_Assembly

8086 Assembly

bits 16 cpu 8086 puts: equ 9h ; MS/DOS system call to print a string nmemb: equ 15 ; Change this to print more or fewer members section .text org 100h mov cx,nmemb ; CX = how many members to print outloop: mov dx,memb ; Print current member mov ah,puts int 21h mov dx,newline ; Print newline int 21h mov di,memb ; Generate next member call looksay loop outloop ; Decrease CX, and loop until zero. ret ; Go back to DOS. ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; Given a look and say string in ES:DI, generate the next ;;; one in place. Assumption: DS = ES. looksay: push cx ; Keep the counter register mov si,di ; Store pointer to string begin in SI mov bx,di ; And another in BX mov al,'$' ; Find the end of the string xor cx,cx ; Max. 65535 tries dec cx repne scasb ; The 8086 has dedicated string search mov dx,di ; Store copy of start of new str in DX ;;; Process one character .procchar: mov al,'0' ; Set counter to ASCII 0 mov ah,[bx] ; Get current character of string cmp ah,'$' ; Done? je .done .samechar: inc bx ; Increment pointer inc al ; Increment counter cmp ah,[bx] ; Still the same character? je .samechar ; If yes, test next character mov [di],ax ; Store counter and character inc di ; Move ahead two characters inc di jmp .procchar ; Do next character ;;; Copy new string into old location .done: mov byte [di],'$' ; Terminate the string mov cx,di ; Calculate how many bytes to copy sub cx,dx ; end + 1 - start, so one too few here shr cx,1 ; Divide by 2 = words inc cx ; Compensate for the missing +1 mov di,dx ; Pointer to begin of new string xchg si,di ; Set SI = new string and DI = old rep movsw ; Copy 16 bits at a time pop cx ; Restore counter register ret section .data newline: db 13,10,'$' ; Newline to print in between members memb: db '1$' ; This is where the current member is stored

http://rosettacode.org/wiki/Longest_string_challenge

Longest string challenge

Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.

#Clojure

Clojure

ns longest-string (:gen-class)) (defn longer [a b] " if a is longer, it returns the characters in a after length b characters have been removed otherwise it returns nil " (if (or (empty? a) (empty? b)) (not-empty a) (recur (rest a) (rest b)))) (defn get-input [] " Gets the data from standard input as a lazy-sequence of lines (i.e. reads lines as needed by caller Input is terminated by a zero length line (i.e. line with just <CR> " (let [line (read-line)] (if (> (count line) 0) (lazy-seq (cons line (get-input))) nil))) (defn process [] " Returns list of longest lines " (first ; takes lines from [lines longest] (reduce (fn [[lines longest] x] (cond (longer x longest) [x x] ; new longer line (not (longer longest x)) [(str lines "\n" x) longest] ; append x to previous longest :else [lines longest])) ; keep previous lines & longest ["" ""] (get-input)))) (println "Input text:") (println "Output:\n" (process))

http://rosettacode.org/wiki/Longest_increasing_subsequence

Longest increasing subsequence

Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.

#Common_Lisp

Common Lisp

(defun longest-increasing-subseq (list) (let ((subseqs nil)) (dolist (item list) (let ((longest-so-far (longest-list-in-lists (remove-if-not #'(lambda (l) (> item (car l))) subseqs)))) (push (cons item longest-so-far) subseqs))) (reverse (longest-list-in-lists subseqs)))) (defun longest-list-in-lists (lists) (let ((longest nil) (longest-len 0)) (dolist (list lists) (let ((len (length list))) (when (> len longest-len) (setf longest list longest-len len)))) longest)) (dolist (l (list (list 3 2 6 4 5 1) (list 0 8 4 12 2 10 6 14 1 9 5 13 3 11 7 15))) (format t "~A~%" (longest-increasing-subseq l))))

http://rosettacode.org/wiki/Loops/Continue

Loops/Continue

Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#AWK

AWK

BEGIN { for(i=1; i <= 10; i++) { printf("%d", i) if ( i % 5 == 0 ) { print continue } printf(", ") } }

http://rosettacode.org/wiki/Loops/Continue

Loops/Continue

Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#BASIC

BASIC

10 FOR I = 1 TO 10 20 PRINT I; 30 IF I - INT (I / 5) * 5 = 0 THEN PRINT : GOTO 50"CONTINUE 40 PRINT ", "; 50 NEXT

http://rosettacode.org/wiki/Longest_common_substring

Longest common substring

Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction

#BaCon

BaCon

FUNCTION Common_Sub$(haystack$, needle$) WHILE LEN(needle$) FOR x = LEN(needle$) DOWNTO 1 IF INSTR(haystack$, LEFT$(needle$, x)) THEN RETURN LEFT$(needle$, x) NEXT needle$ = MID$(needle$, 2) WEND EXIT ENDFUNC PRINT Common_Sub$("thisisatest", "testing123testing")

http://rosettacode.org/wiki/Longest_common_substring

Longest common substring

Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction

#BASIC256

BASIC256

function LCS(a, b) if length(a) = 0 or length(b) = 0 then return "" while length(b) for j = length(b) to 1 step -1 if instr(a, left(b, j)) then return left(b, j) next j b = mid$(b, 2) end while end function print LCS("thisisatest", "testing123testing") end

http://rosettacode.org/wiki/Loops/Nested

Loops/Nested

Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#PureBasic

PureBasic

; Creating and filling array Dim Value(10, 5) For a = 0 To 10 For b = 0 To 5 Value(a, b) = Random(19) + 1 Next Next ; iterating trough array For a = 0 To 10 For b = 0 To 5 Debug Value(a, b) If Value(a, b) = 20 ; 2 indicates, that there are two nested lopps to break out Break 2 EndIf Next Next

http://rosettacode.org/wiki/Loops/Foreach

Loops/Foreach

Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Sather

Sather

class MAIN is main is num:ARRAY{INT} := |1, 5, 4, 3, 10|; loop -- the iterator elt! behaves like a "foreach", -- yielding the next element of the array at each iteration #OUT + num.elt! + "\n"; end; end; end;

http://rosettacode.org/wiki/Loops/Foreach

Loops/Foreach

Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Scala

Scala

val collection = Array(1, 2, 3, 4) collection.foreach(println)

http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers

Luhn test of credit card numbers

The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits. Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test: Reverse the order of the digits in the number. Take the first, third, ... and every other odd digit in the reversed digits and sum them to form the partial sum s1 Taking the second, fourth ... and every other even digit in the reversed digits: Multiply each digit by two and sum the digits if the answer is greater than nine to form partial sums for the even digits Sum the partial sums of the even digits to form s2 If s1 + s2 ends in zero then the original number is in the form of a valid credit card number as verified by the Luhn test. For example, if the trial number is 49927398716: Reverse the digits: 61789372994 Sum the odd digits: 6 + 7 + 9 + 7 + 9 + 4 = 42 = s1 The even digits: 1, 8, 3, 2, 9 Two times each even digit: 2, 16, 6, 4, 18 Sum the digits of each multiplication: 2, 7, 6, 4, 9 Sum the last: 2 + 7 + 6 + 4 + 9 = 28 = s2 s1 + s2 = 70 which ends in zero which means that 49927398716 passes the Luhn test Task Write a function/method/procedure/subroutine that will validate a number with the Luhn test, and use it to validate the following numbers: 49927398716 49927398717 1234567812345678 1234567812345670 Related tasks SEDOL ISIN

#MUMPS

MUMPS

LUHN(C) NEW ODD,EVEN,S SET S=$REVERSE(C) SET ODD=0 FOR I=1:2:$LENGTH(S) SET ODD=ODD+$EXTRACT(S,I) SET EVEN=0 FOR I=2:2:$LENGTH(S) SET T=$EXTRACT(S,I)*2 SET EVEN=EVEN+$SELECT(T<=9:T,T>9:$EXTRACT(T,1)+$EXTRACT(T,2)) QUIT '((ODD+EVEN)#10)

http://rosettacode.org/wiki/Loops/Infinite

Loops/Infinite

Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Nim

Nim

while true: echo "SPAM"

http://rosettacode.org/wiki/Loops/Infinite

Loops/Infinite

Task Print out SPAM followed by a newline in an infinite loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#NS-HUBASIC

NS-HUBASIC

10 FOR I=0 TO 1 STEP 0 20 PRINT "SPAM" 30 NEXT

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Modula-2

Modula-2

MODULE DivBy2; IMPORT InOut; VAR i: INTEGER; BEGIN i := 1024; WHILE i > 0 DO InOut.WriteInt(i, 4); InOut.WriteLn; i := i DIV 2 END END DivBy2.

http://rosettacode.org/wiki/Loops/While

Loops/While

Task Start an integer value at 1024. Loop while it is greater than zero. Print the value (with a newline) and divide it by two each time through the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreachbas Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Modula-3

Modula-3

PROCEDURE DivBy2() = VAR i: INTEGER := 1024; BEGIN WHILE i > 0 DO IO.PutInt(i); IO.Put("\n"); i := i DIV 2; END; END DivBy2;

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Nemerle

Nemerle

for (i = 10; i >= 0; i--) {WriteLine($"$i")}

http://rosettacode.org/wiki/Loops/Downward_for

Loops/Downward for

Task Write a for loop which writes a countdown from 10 to 0. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#NetRexx

NetRexx

/* NetRexx */ options replace format comments java crossref savelog symbols nobinary say say 'Loops/Downward for' loop i_ = 10 to 0 by -1 say i_.right(2) end i_

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.

#Julia

Julia

julia> i = 0 0 julia> while true println(i) i += 1 i % 6 == 0 && break end 0 1 2 3 4 5

http://rosettacode.org/wiki/Loops/Do-while

Loops/Do-while

Start with a value at 0. Loop while value mod 6 is not equal to 0. Each time through the loop, add 1 to the value then print it. The loop must execute at least once. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference Do while loop Wikipedia.

#Kotlin

Kotlin

// version 1.0.6 fun main(args: Array<String>) { var value = 0 do { println(++value) } while (value % 6 != 0) }

http://rosettacode.org/wiki/Loops/For

Loops/For

“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code. Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers. Task Show how two loops may be nested within each other, with the number of iterations performed by the inner for loop being controlled by the outer for loop. Specifically print out the following pattern by using one for loop nested in another: * ** *** **** ***** Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges Reference For loop Wikipedia.

#Elena

Elena

import extensions; public program() { for(int i := 0, i < 5, i += 1) { for(int j := 0, j <= i, j += 1) { console.write:"*" }; console.writeLine() } }

http://rosettacode.org/wiki/Loops/For_with_a_specified_step

Loops/For with a specified step

Task Demonstrate a for-loop where the step-value is greater than one. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Java

Java

for(int i = 2; i <= 8;i += 2){ System.out.print(i + ", "); } System.out.println("who do we appreciate?");

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Raku

Raku

for 1 .. 10 { .print; last when 10; print ', '; } print "\n";

http://rosettacode.org/wiki/Loops/N_plus_one_half

Loops/N plus one half

Quite often one needs loops which, in the last iteration, execute only part of the loop body. Goal Demonstrate the best way to do this. Task Write a loop which writes the comma-separated list 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 using separate output statements for the number and the comma from within the body of the loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#REBOL

REBOL

rebol [ Title: "Loop Plus Half" URL: http://rosettacode.org/wiki/Loop/n_plus_one_half ] repeat i 10 [ prin i if 10 = i [break] prin ", " ] print ""

http://rosettacode.org/wiki/Long_year

Long year

Most years have 52 weeks, some have 53, according to ISO8601. Task Write a function which determines if a given year is long (53 weeks) or not, and demonstrate it.

#11l

11l

F is_long_year(year) F p(year) R (year + (year I/ 4) - (year I/ 100) + (year I/ 400)) % 7 R p(year) == 4 | p(year - 1) == 3 L(year) 2000..2100 I is_long_year(year) print(year, end' ‘ ’)

http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously

Loop over multiple arrays simultaneously

Task Loop over multiple arrays (or lists or tuples or whatever they're called in your language) and display the i th element of each. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. For this example, loop over the arrays: (a,b,c) (A,B,C) (1,2,3) to produce the output: aA1 bB2 cC3 If possible, also describe what happens when the arrays are of different lengths. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#ACL2

ACL2

(defun print-lists (xs ys zs) (if (or (endp xs) (endp ys) (endp zs)) nil (progn$ (cw (first xs)) (cw "~x0~x1~%" (first ys) (first zs)) (print-lists (rest xs) (rest ys) (rest zs))))) (print-lists '("a" "b" "c") '(A B C) '(1 2 3))

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges

#Aime

Aime

integer main(void) { integer a, b; while (1) { a = drand(19); o_integer(a); o_byte('\n'); if (a == 10) { break; } b = drand(19); o_integer(b); o_byte('\n'); } return 0; }

http://rosettacode.org/wiki/Loops/Break

Loops/Break

Task Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive). If a number is 10, stop the loop after printing it, and do not generate any further numbers. Otherwise, generate and print a second random number before restarting the loop. If the number 10 is never generated as the first number in a loop, loop forever. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges

#ALGOL_60

ALGOL 60

'BEGIN' 'COMMENT' Loops/Break - ALGOL60 - 18/06/2018; 'INTEGER' SEED; 'INTEGER' 'PROCEDURE' RANDOM(N); 'VALUE' N; 'INTEGER' N; 'BEGIN' SEED:=(SEED*19157+12347) '/' 21647; RANDOM:=SEED-(SEED '/' N)*N+1 'END' RANDOM; 'INTEGER' I,J,K; SYSACT(1,6,120);SYSACT(1,8,60);SYSACT(1,12,1);'COMMENT' open print; SEED:=31567; J:=0; 'FOR' I:=1, I+1 'WHILE' I 'LESS' 100 'DO' 'BEGIN' J:=J+1; K:=RANDOM(20); OUTINTEGER(1,K); 'IF' J=8 'THEN' 'BEGIN' SYSACT(1,14,1); 'COMMENT' skip line; J:=0 'END'; 'IF' K=10 'THEN' 'GOTO' LAB 'END'; LAB: SYSACT(1,14,1); 'COMMENT' skip line; 'END'

http://rosettacode.org/wiki/Longest_common_subsequence

Longest common subsequence

Introduction Define a subsequence to be any output string obtained by deleting zero or more symbols from an input string. The Longest Common Subsequence (LCS) is a subsequence of maximum length common to two or more strings. Let A ≡ A[0]… A[m - 1] and B ≡ B[0]… B[n - 1], m < n be strings drawn from an alphabet Σ of size s, containing every distinct symbol in A + B. An ordered pair (i, j) will be referred to as a match if A[i] = B[j], where 0 < i ≤ m and 0 < j ≤ n. Define a non-strict product-order (≤) over ordered pairs, such that (i1, j1) ≤ (i2, j2) ⇔ i1 ≤ i2 and j1 ≤ j2. We define (≥) similarly. We say m1, m2 are comparable if either m1 ≤ m2 or m1 ≥ m2 holds. If i1 < i2 and j2 < j1 (or i2 < i1 and j1 < j2) then neither m1 ≤ m2 nor m1 ≥ m2 are possible; and we say m1, m2 are incomparable. We also define the strict product-order (<) over ordered pairs, such that (i1, j1) < (i2, j2) ⇔ i1 < i2 and j1 < j2. We define (>) similarly. Given a set of matches M, a chain C is a subset of M consisting of at least one element m; and where either m1 < m2 or m1 > m2 for every pair of distinct elements m1 and m2. An antichain D is any subset of M in which every pair of distinct elements m1 and m2 are incomparable. The set M represents a relation over match pairs: M[i, j] ⇔ (i, j) ∈ M. A chain C can be visualized as a curve which strictly increases as it passes through each match pair in the m*n coordinate space. Finding an LCS can be restated as the problem of finding a chain of maximum cardinality p over the set of matches M. According to [Dilworth 1950], this cardinality p equals the minimum number of disjoint antichains into which M can be decomposed. Note that such a decomposition into the minimal number p of disjoint antichains may not be unique. Contours Forward Contours FC[k] of class k are defined inductively, as follows: FC[0] consists of those elements m1 for which there exists no element m2 such that m2 < m1. FC[k] consists of those elements m1 for which there exists no element m2 such that m2 < m1; and where neither m1 nor m2 are contained in FC[l] for any class l < k. Reverse Contours RC[k] of class k are defined similarly. Members of the Meet (∧), or Infimum of a Forward Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 < m1. Members of the Join (∨), or Supremum of a Reverse Contour are referred to as its Dominant Matches: those m1 for which there exists no m2 such that m2 > m1. Where multiple Dominant Matches exist within a Meet (or within a Join, respectively) the Dominant Matches will be incomparable to each other. Background Where the number of symbols appearing in matches is small relative to the length of the input strings, reuse of the symbols increases; and the number of matches will tend towards quadratic, O(m*n) growth. This occurs, for example, in the Bioinformatics application of nucleotide and protein sequencing. The divide-and-conquer approach of [Hirschberg 1975] limits the space required to O(n). However, this approach requires O(m*n) time even in the best case. This quadratic time dependency may become prohibitive, given very long input strings. Thus, heuristics are often favored over optimal Dynamic Programming solutions. In the application of comparing file revisions, records from the input files form a large symbol space; and the number of symbols approaches the length of the LCS. In this case the number of matches reduces to linear, O(n) growth. A binary search optimization due to [Hunt and Szymanski 1977] can be applied to the basic Dynamic Programming approach, resulting in an expected performance of O(n log m). Performance can degrade to O(m*n log m) time in the worst case, as the number of matches grows to O(m*n). Note [Rick 2000] describes a linear-space algorithm with a time bound of O(n*s + p*min(m, n - p)). Legend A, B are input strings of lengths m, n respectively p is the length of the LCS M is the set of match pairs (i, j) such that A[i] = B[j] r is the magnitude of M s is the magnitude of the alphabet Σ of distinct symbols in A + B References [Dilworth 1950] "A decomposition theorem for partially ordered sets" by Robert P. Dilworth, published January 1950, Annals of Mathematics [Volume 51, Number 1, pp. 161-166] [Goeman and Clausen 2002] "A New Practical Linear Space Algorithm for the Longest Common Subsequence Problem" by Heiko Goeman and Michael Clausen, published 2002, Kybernetika [Volume 38, Issue 1, pp. 45-66] [Hirschberg 1975] "A linear space algorithm for computing maximal common subsequences" by Daniel S. Hirschberg, published June 1975 Communications of the ACM [Volume 18, Number 6, pp. 341-343] [Hunt and McIlroy 1976] "An Algorithm for Differential File Comparison" by James W. Hunt and M. Douglas McIlroy, June 1976 Computing Science Technical Report, Bell Laboratories 41 [Hunt and Szymanski 1977] "A Fast Algorithm for Computing Longest Common Subsequences" by James W. Hunt and Thomas G. Szymanski, published May 1977 Communications of the ACM [Volume 20, Number 5, pp. 350-353] [Rick 2000] "Simple and fast linear space computation of longest common subsequences" by Claus Rick, received 17 March 2000, Information Processing Letters, Elsevier Science [Volume 75, pp. 275–281] Examples The sequences "1234" and "1224533324" have an LCS of "1234": 1234 1224533324 For a string example, consider the sequences "thisisatest" and "testing123testing". An LCS would be "tsitest": thisisatest testing123testing In this puzzle, your code only needs to deal with strings. Write a function which returns an LCS of two strings (case-sensitive). You don't need to show multiple LCS's. For more information on this problem please see Wikipedia. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet

#APL

APL

lcs←{ ⎕IO←0 betterof←{⊃(</+/¨⍺ ⍵)⌽⍺ ⍵} ⍝ better of 2 selections cmbn←{↑,⊃∘.,/(⊂⊂⍬),⍵} ⍝ combine lists rr←{∧/↑>/1 ¯1↓[1]¨⊂⍵} ⍝ rising rows hmrr←{∨/(rr ⍵)∧∧/⍵=⌈\⍵} ⍝ has monotonically rising rows rnbc←{{⍵/⍳⍴⍵}¨↓[0]×⍵} ⍝ row numbers by column valid←hmrr∘cmbn∘rnbc ⍝ any valid solutions? a w←(</⊃∘⍴¨⍺ ⍵)⌽⍺ ⍵ ⍝ longest first matches←a∘.=w aps←{⍵[;⍒+⌿⍵]}∘{(⍵/2)⊤⍳2*⍵} ⍝ all possible subsequences swps←{⍵/⍨∧⌿~(~∨⌿⍺)⌿⍵} ⍝ subsequences with possible solns sstt←matches swps aps⊃⍴w ⍝ subsequences to try w/⍨{ ⍺←0⍴⍨⊃⍴⍵ ⍝ initial selection (+/⍺)≥+/⍵[;0]:⍺ ⍝ no scope to improve this←⍺ betterof{⍵×valid ⍵/matches}⍵[;0] ⍝ try to improve 1=1⊃⍴⍵:this ⍝ nothing left to try this ∇ 1↓[1]⍵ ⍝ keep looking }sstt }

http://rosettacode.org/wiki/Look-and-say_sequence

Look-and-say sequence

The Look and say sequence is a recursively defined sequence of numbers studied most notably by John Conway. The look-and-say sequence is also known as the Morris Number Sequence, after cryptographer Robert Morris, and the puzzle What is the next number in the sequence 1, 11, 21, 1211, 111221? is sometimes referred to as the Cuckoo's Egg, from a description of Morris in Clifford Stoll's book The Cuckoo's Egg. Sequence Definition Take a decimal number Look at the number, visually grouping consecutive runs of the same digit. Say the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped. This becomes the next number of the sequence. An example: Starting with the number 1, you have one 1 which produces 11 Starting with 11, you have two 1's. I.E.: 21 Starting with 21, you have one 2, then one 1. I.E.: (12)(11) which becomes 1211 Starting with 1211, you have one 1, one 2, then two 1's. I.E.: (11)(12)(21) which becomes 111221 Task Write a program to generate successive members of the look-and-say sequence. Related tasks Fours is the number of letters in the ... Number names Self-describing numbers Self-referential sequence Spelling of ordinal numbers See also Look-and-Say Numbers (feat John Conway), A Numberphile Video. This task is related to, and an application of, the Run-length encoding task. Sequence A005150 on The On-Line Encyclopedia of Integer Sequences.

#Action.21

Action!

BYTE FUNC GetLength(CHAR ARRAY s BYTE pos) CHAR c BYTE len c=s(pos) len=1 DO pos==+1 IF pos<=s(0) AND s(pos)=c THEN len==+1 ELSE EXIT FI OD RETURN (len) PROC Append(CHAR ARRAY text,suffix) BYTE POINTER srcPtr,dstPtr BYTE len len=suffix(0) IF text(0)+len>255 THEN len=255-text(0) FI IF len THEN srcPtr=suffix+1 dstPtr=text+text(0)+1 MoveBlock(dstPtr,srcPtr,len) text(0)==+suffix(0) FI RETURN PROC LookAndSay(CHAR ARRAY in,out) BYTE pos,len CHAR ARRAY tmp(5) pos=1 len=0 out(0)=0 WHILE pos<=in(0) DO len=GetLength(in,pos) StrB(len,tmp) Append(out,tmp) out(0)==+1 out(out(0))=in(pos) pos==+len OD RETURN PROC Main() CHAR ARRAY s1(256),s2(256) BYTE i SCopy(s1,"1") PrintE(s1) FOR i=1 TO 11 DO IF (i&1)=0 THEN LookAndSay(s2,s1) PrintE(s1) ELSE LookAndSay(s1,s2) PrintE(s2) FI OD RETURN

http://rosettacode.org/wiki/Longest_string_challenge

Longest string challenge

Background This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through the introduction of restrictions. Experience has shown that the original restrictions required some adjustment to bring out the intent of the challenge and make it suitable for Rosetta Code. Basic problem statement Write a program that reads lines from standard input and, upon end of file, writes the longest line to standard output. If there are ties for the longest line, the program writes out all the lines that tie. If there is no input, the program should produce no output. Task Implement a solution to the basic problem that adheres to the spirit of the restrictions (see below). Describe how you circumvented or got around these 'restrictions' and met the 'spirit' of the challenge. Your supporting description may need to describe any challenges to interpreting the restrictions and how you made this interpretation. You should state any assumptions, warnings, or other relevant points. The central idea here is to make the task a bit more interesting by thinking outside of the box and perhaps by showing off the capabilities of your language in a creative way. Because there is potential for considerable variation between solutions, the description is key to helping others see what you've done. This task is likely to encourage a variety of different types of solutions. They should be substantially different approaches. Given the input: a bb ccc ddd ee f ggg the output should be (possibly rearranged): ccc ddd ggg Original list of restrictions No comparison operators may be used. No arithmetic operations, such as addition and subtraction, may be used. The only datatypes you may use are integer and string. In particular, you may not use lists. Do not re-read the input file. Avoid using files as a replacement for lists (this restriction became apparent in the discussion). Intent of restrictions Because of the variety of languages on Rosetta Code and the wide variety of concepts used in them, there needs to be a bit of clarification and guidance here to get to the spirit of the challenge and the intent of the restrictions. The basic problem can be solved very conventionally, but that's boring and pedestrian. The original intent here wasn't to unduly frustrate people with interpreting the restrictions, it was to get people to think outside of their particular box and have a bit of fun doing it. The guiding principle here should be to be creative in demonstrating some of the capabilities of the programming language being used. If you need to bend the restrictions a bit, explain why and try to follow the intent. If you think you've implemented a 'cheat', call out the fragment yourself and ask readers if they can spot why. If you absolutely can't get around one of the restrictions, explain why in your description. Now having said that, the restrictions require some elaboration. In general, the restrictions are meant to avoid the explicit use of these features. "No comparison operators may be used" - At some level there must be some test that allows the solution to get at the length and determine if one string is longer. Comparison operators, in particular any less/greater comparison should be avoided. Representing the length of any string as a number should also be avoided. Various approaches allow for detecting the end of a string. Some of these involve implicitly using equal/not-equal; however, explicitly using equal/not-equal should be acceptable. "No arithmetic operations" - Again, at some level something may have to advance through the string. Often there are ways a language can do this implicitly advance a cursor or pointer without explicitly using a +, - , ++, --, add, subtract, etc. The datatype restrictions are amongst the most difficult to reinterpret. In the language of the original challenge strings are atomic datatypes and structured datatypes like lists are quite distinct and have many different operations that apply to them. This becomes a bit fuzzier with languages with a different programming paradigm. The intent would be to avoid using an easy structure to accumulate the longest strings and spit them out. There will be some natural reinterpretation here. To make this a bit more concrete, here are a couple of specific examples: In C, a string is an array of chars, so using a couple of arrays as strings is in the spirit while using a second array in a non-string like fashion would violate the intent. In APL or J, arrays are the core of the language so ruling them out is unfair. Meeting the spirit will come down to how they are used. Please keep in mind these are just examples and you may hit new territory finding a solution. There will be other cases like these. Explain your reasoning. You may want to open a discussion on the talk page as well. The added "No rereading" restriction is for practical reasons, re-reading stdin should be broken. I haven't outright banned the use of other files but I've discouraged them as it is basically another form of a list. Somewhere there may be a language that just sings when doing file manipulation and where that makes sense; however, for most there should be a way to accomplish without resorting to an externality. At the end of the day for the implementer this should be a bit of fun. As an implementer you represent the expertise in your language, the reader may have no knowledge of your language. For the reader it should give them insight into how people think outside the box in other languages. Comments, especially for non-obvious (to the reader) bits will be extremely helpful. While the implementations may be a bit artificial in the context of this task, the general techniques may be useful elsewhere.

#D

D

import std.stdio, std.array; /// Return a.length - b.length if positive, 0 otherwise. int longer(string a, string b) { while (!a.empty && !b.empty) a.popFront(), b.popFront(); return a.length; } void main() { string longest, lines; foreach (string line; stdin.lines()) if (longer(line, longest)) lines = longest = line; else if (!longer(longest, line)) lines ~= line; writeln(lines); }

http://rosettacode.org/wiki/Longest_increasing_subsequence

Longest increasing subsequence

Calculate and show here a longest increasing subsequence of the list: { 3 , 2 , 6 , 4 , 5 , 1 } {\displaystyle \{3,2,6,4,5,1\}} And of the list: { 0 , 8 , 4 , 12 , 2 , 10 , 6 , 14 , 1 , 9 , 5 , 13 , 3 , 11 , 7 , 15 } {\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}} Note that a list may have more than one subsequence that is of the maximum length. Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet Ref Dynamic Programming #1: Longest Increasing Subsequence on YouTube An efficient solution can be based on Patience sorting.

#D

D

import std.stdio, std.algorithm, power_set2; T[] lis(T)(T[] items) pure nothrow { //return items.powerSet.filter!isSorted.max!q{ a.length }; return items .powerSet .filter!isSorted .minPos!q{ a.length > b.length } .front; } void main() { [3, 2, 6, 4, 5, 1].lis.writeln; [0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15].lis.writeln; }

http://rosettacode.org/wiki/Loops/Continue

Loops/Continue

Task Show the following output using one loop. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 Try to achieve the result by forcing the next iteration within the loop upon a specific condition, if your language allows it. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#bc

bc

for (i = 1; i <= 10; i++) { print i if (i % 5) { print ", " continue } print "\n" } quit

http://rosettacode.org/wiki/Longest_common_substring

Longest common substring

Task Write a function that returns the longest common substring of two strings. Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing". Note that substrings are consecutive characters within a string. This distinguishes them from subsequences, which is any sequence of characters within a string, even if there are extraneous characters in between them. Hence, the longest common subsequence between "thisisatest" and "testing123testing" is "tsitest", whereas the longest common substring is just "test". Other tasks related to string operations: Metrics Array length String length Copy a string Empty string (assignment) Counting Word frequency Letter frequency Jewels and stones I before E except after C Bioinformatics/base count Count occurrences of a substring Count how many vowels and consonants occur in a string Remove/replace XXXX redacted Conjugate a Latin verb Remove vowels from a string String interpolation (included) Strip block comments Strip comments from a string Strip a set of characters from a string Strip whitespace from a string -- top and tail Strip control codes and extended characters from a string Anagrams/Derangements/shuffling Word wheel ABC problem Sattolo cycle Knuth shuffle Ordered words Superpermutation minimisation Textonyms (using a phone text pad) Anagrams Anagrams/Deranged anagrams Permutations/Derangements Find/Search/Determine ABC words Odd words Word ladder Semordnilap Word search Wordiff (game) String matching Tea cup rim text Alternade words Changeable words State name puzzle String comparison Unique characters Unique characters in each string Extract file extension Levenshtein distance Palindrome detection Common list elements Longest common suffix Longest common prefix Compare a list of strings Longest common substring Find common directory path Words from neighbour ones Change e letters to i in words Non-continuous subsequences Longest common subsequence Longest palindromic substrings Longest increasing subsequence Words containing "the" substring Sum of the digits of n is substring of n Determine if a string is numeric Determine if a string is collapsible Determine if a string is squeezable Determine if a string has all unique characters Determine if a string has all the same characters Longest substrings without repeating characters Find words which contains all the vowels Find words which contains most consonants Find words which contains more than 3 vowels Find words which first and last three letters are equals Find words which odd letters are consonants and even letters are vowels or vice_versa Formatting Substring Rep-string Word wrap String case Align columns Literals/String Repeat a string Brace expansion Brace expansion using ranges Reverse a string Phrase reversals Comma quibbling Special characters String concatenation Substring/Top and tail Commatizing numbers Reverse words in a string Suffixation of decimal numbers Long literals, with continuations Numerical and alphabetical suffixes Abbreviations, easy Abbreviations, simple Abbreviations, automatic Song lyrics/poems/Mad Libs/phrases Mad Libs Magic 8-ball 99 Bottles of Beer The Name Game (a song) The Old lady swallowed a fly The Twelve Days of Christmas Tokenize Text between Tokenize a string Word break problem Tokenize a string with escaping Split a character string based on change of character Sequences Show ASCII table De Bruijn sequences Self-referential sequences Generate lower case ASCII alphabet References Generalize Suffix Tree Ukkonen’s Suffix Tree Construction

#Bracmat

Bracmat

( lcs = X a b x L . !arg:(?a.?b) & 0:?L & :?X & ( @( !a : ? ( ?x & @(!x:? [>!L) & @(!b:? !x ?) & @(!x:? [?L:?X) ) (?&~) ) | !X ) ) & out$(lcs$(thisisatest.testing123testing))

http://rosettacode.org/wiki/Loops/Nested

Loops/Nested

Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over [ 1 , … , 20 ] {\displaystyle [1,\ldots ,20]} . The loops iterate rows and columns of the array printing the elements until the value 20 {\displaystyle 20} is met. Specifically, this task also shows how to break out of nested loops. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Python

Python

from random import randint def do_scan(mat): for row in mat: for item in row: print item, if item == 20: print return print print mat = [[randint(1, 20) for x in xrange(10)] for y in xrange(10)] do_scan(mat)

http://rosettacode.org/wiki/Loops/Foreach

Loops/Foreach

Loop through and print each element in a collection in order. Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop. Related tasks Loop over multiple arrays simultaneously Loops/Break Loops/Continue Loops/Do-while Loops/Downward for Loops/For Loops/For with a specified step Loops/Foreach Loops/Increment loop index within loop body Loops/Infinite Loops/N plus one half Loops/Nested Loops/While Loops/with multiple ranges Loops/Wrong ranges

#Scheme

Scheme

(for-each (lambda (i) (display i) (newline)) the_list)