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http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#FreeBASIC
FreeBASIC
  redim shared as string Result(-1) 'represent our sets as strings; 'this'll do to illustrate the concept   sub sym( A() as string, B() as string ) dim as integer ai, bi, ri dim as boolean add_it for ai = lbound(A) to ubound(A) add_it = true for bi = lbound(B) to ubound(B) if A(ai) = B(bi) then add_it=false exit for 'if item is common to both lists, don't include it end if next bi if add_it then for ri = 0 to ubound(Result) if A(ai) = Result(ri) then add_it=false exit for 'if item is already in the result, don't include it again end if next ri end if if add_it then redim preserve as string Result(0 to ubound(Result)+1) Result(ubound(Result)) = A(ai) end if   next ai end sub   dim as string A(0 to 3) = {"John", "Bob", "Mary", "Serena"} dim as string B(0 to 4) = {"Jim", "Mary", "John", "Bob", "Jim"} 'contains a double to show code can handle it     sym(A(), B()) sym(B(), A())   for i as uinteger = 0 to ubound(Result) print Result(i) next i  
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#PHP
PHP
  #!/usr/bin/php <?php if ($argc > 1) file_put_contents( 'notes.txt', date('r')."\n\t".implode(' ', array_slice($argv, 1))."\n", FILE_APPEND ); else @readfile('notes.txt');  
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#PicoLisp
PicoLisp
#!/usr/bin/picolisp /usr/lib/picolisp/lib.l   (load "@lib/misc.l") (if (argv) (out "+notes.txt" (prinl (stamp) "^J^I" (glue " " @))) (and (info "notes.txt") (in "notes.txt" (echo))) ) (bye)
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#Racket
Racket
#lang racket (require plot) #;(plot-new-window? #t)   (define ((superellipse a b n) x y) (+ (expt (abs (/ x a)) n) (expt (abs (/ y b)) n)))   (plot (isoline (superellipse 200 200 2.5) 1 -220 220 -220 220))
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#Raku
Raku
constant a = 200; constant b = 200; constant n = 2.5;   # y in terms of x sub y ($x) { sprintf "%d", b * (1 - ($x / a).abs ** n ) ** (1/n) }   # find point pairs for one quadrant my @q = flat map -> \x { x, y(x) }, (0, 1 ... 200);   # Generate an SVG image INIT say qq:to/STOP/; <?xml version="1.0" standalone="no"?> <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"> <svg height="{b*2}" width="{a*2}" version="1.1" xmlns="http://www.w3.org/2000/svg"> STOP END say '</svg>';   .put for pline( @q ), pline( @q «*» ( 1,-1) ), # flip and mirror pline( @q «*» (-1,-1) ), # for the other pline( @q «*» (-1, 1) ); # three quadrants   sub pline (@q) { qq:to/END/; <polyline points="{@q}" style="fill:none; stroke:black; stroke-width:3" transform="translate({a}, {b})" /> END }
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#Sidef
Sidef
var (start=1, end=25) = ARGV.map{.to_i}...   func display (h, start, end) { var i = start for n in [h.grep {|_,v| v.len > 1 }.keys.sort_by{.to_i}[start-1 .. end-1]] { printf("%4d %10d =>\t%s\n", i++, n, h{n}.map{ "%4d³ + %-s" % (.first, "#{.last}³") }.join(",\t")) } }   var taxi = Hash() var taxis = 0 var terminate = 0   for c1 (1..Inf) { if (0<terminate && terminate<c1) { display(taxi, start, end) break } var c = c1**3 for c2 (1..c1) { var this = (c2**3 + c) taxi{this} := [] << [c2, c1] ++taxis if (taxi{this}.len == 2) if (taxis==end && !terminate) { terminate = taxi.grep{|_,v| v.len > 1 }.keys.map{.to_i}.max.root(3) } } }
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#F.23
F#
  // Define units of measure [<Measure>] type k [<Measure>] type f [<Measure>] type c [<Measure>] type r   // Define conversion functions let kelvinToCelsius (t : float<k>) = ((float t) - 273.15) * 1.0<c> let kelvinToFahrenheit (t : float<k>) = (((float t) * 1.8) - 459.67) * 1.0<f> let kelvinToRankine (t : float<k>) = ((float t) * 1.8) * 1.0<r>   // Example code let K = 21.0<k> printfn "%A Kelvin is %A Celsius" K (kelvinToCelsius K) printfn "%A Kelvin is %A Fahrenheit" K (kelvinToFahrenheit K) printfn "%A Kelvin is %A Rankine" K (kelvinToRankine K)  
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Run_BASIC
Run BASIC
testFalse = 0 ' F testDoNotKnow = 1 ' ? testTrue = 2 ' T   print "Short and long names for ternary logic values" for i = testFalse to testTrue print shortName3$(i);" ";longName3$(i) next i print   print "Single parameter functions" print "x";" ";"=x";" ";"not(x)" for i = testFalse to testTrue print shortName3$(i);" ";shortName3$(i);" ";shortName3$(not3(i)) next print   print "Double parameter fuctions" html "<table border=1><TR align=center bgcolor=wheat><TD>x</td><td>y</td><td>x AND y</td><td>x OR y</td><td>x EQ y</td><td>x XOR y</td></tr>" for a = testFalse to testTrue for b = testFalse to testTrue html "<TR align=center><td>" html shortName3$(a); "</td><td>";shortName3$(b); "</td><td>" html shortName3$(and3(a,b));"</td><td>";shortName3$(or3(a,b)); "</td><td>" html shortName3$(eq3(a,b)); "</td><td>";shortName3$(xor3(a,b));"</td></tr>" next next html "</table>" function and3(a,b) and3 = min(a,b) end function   function or3(a,b) or3 = max(a,b) end function   function eq3(a,b) eq3 = testFalse if a = tDontKnow or b = tDontKnow then eq3 = tDontKnow if a = b then eq3 = testTrue end function   function xor3(a,b) xor3 = not3(eq3(a,b)) end function   function not3(b) not3 = 2-b end function   '------------------------------------------------ function shortName3$(i) shortName3$ = word$("F ? T", i+1) end function   function longName3$(i) longName3$ = word$("False,Don't know,True", i+1, ",") end function
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Rust
Rust
use std::{ops, fmt};   #[derive(Copy, Clone, Debug)] enum Trit { True, Maybe, False, }   impl ops::Not for Trit { type Output = Self; fn not(self) -> Self { match self { Trit::True => Trit::False, Trit::Maybe => Trit::Maybe, Trit::False => Trit::True, } } }   impl ops::BitAnd for Trit { type Output = Self; fn bitand(self, other: Self) -> Self { match (self, other) { (Trit::True, Trit::True) => Trit::True, (Trit::False, _) | (_, Trit::False) => Trit::False, _ => Trit::Maybe, } } }   impl ops::BitOr for Trit { type Output = Self; fn bitor(self, other: Self) -> Self { match (self, other) { (Trit::True, _) | (_, Trit::True) => Trit::True, (Trit::False, Trit::False) => Trit::False, _ => Trit::Maybe, } } }   impl Trit { fn imp(self, other: Self) -> Self { match self { Trit::True => other, Trit::Maybe => { if let Trit::True = other { Trit::True } else { Trit::Maybe } } Trit::False => Trit::True, } }   fn eqv(self, other: Self) -> Self { match self { Trit::True => other, Trit::Maybe => Trit::Maybe, Trit::False => !other, } } }   impl fmt::Display for Trit { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!( f, "{}", match self { Trit::True => 'T', Trit::Maybe => 'M', Trit::False => 'F', } ) } }   static TRITS: [Trit; 3] = [Trit::True, Trit::Maybe, Trit::False];   fn main() { println!("not"); println!("-------"); for &t in &TRITS { println!(" {} | {}", t, !t); }   table("and", |a, b| a & b); table("or", |a, b| a | b); table("imp", |a, b| a.imp(b)); table("eqv", |a, b| a.eqv(b)); }   fn table(title: &str, f: impl Fn(Trit, Trit) -> Trit) { println!(); println!("{:3} | T M F", title); println!("-------------"); for &t1 in &TRITS { print!(" {} | ", t1); for &t2 in &TRITS { print!("{} ", f(t1, t2)); } println!(); } }
http://rosettacode.org/wiki/Text_processing/1
Text processing/1
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion. Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another program can be written to parse and transform the original data into a format useful to the other. The term "Data Munging" is often used in programming circles for this task. A request on the comp.lang.awk newsgroup led to a typical data munging task: I have to analyse data files that have the following format: Each row corresponds to 1 day and the field logic is: $1 is the date, followed by 24 value/flag pairs, representing measurements at 01:00, 02:00 ... 24:00 of the respective day. In short: <date> <val1> <flag1> <val2> <flag2> ... <val24> <flag24> Some test data is available at: ... (nolonger available at original location) I have to sum up the values (per day and only valid data, i.e. with flag>0) in order to calculate the mean. That's not too difficult. However, I also need to know what the "maximum data gap" is, i.e. the longest period with successive invalid measurements (i.e values with flag<=0) The data is free to download and use and is of this format: Data is no longer available at that link. Zipped mirror available here (offsite mirror). 1991-03-30 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 1991-03-31 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 20.000 1 20.000 1 20.000 1 35.000 1 50.000 1 60.000 1 40.000 1 30.000 1 30.000 1 30.000 1 25.000 1 20.000 1 20.000 1 20.000 1 20.000 1 20.000 1 35.000 1 1991-03-31 40.000 1 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 1991-04-01 0.000 -2 13.000 1 16.000 1 21.000 1 24.000 1 22.000 1 20.000 1 18.000 1 29.000 1 44.000 1 50.000 1 43.000 1 38.000 1 27.000 1 27.000 1 24.000 1 23.000 1 18.000 1 12.000 1 13.000 1 14.000 1 15.000 1 13.000 1 10.000 1 1991-04-02 8.000 1 9.000 1 11.000 1 12.000 1 12.000 1 12.000 1 27.000 1 26.000 1 27.000 1 33.000 1 32.000 1 31.000 1 29.000 1 31.000 1 25.000 1 25.000 1 24.000 1 21.000 1 17.000 1 14.000 1 15.000 1 12.000 1 12.000 1 10.000 1 1991-04-03 10.000 1 9.000 1 10.000 1 10.000 1 9.000 1 10.000 1 15.000 1 24.000 1 28.000 1 24.000 1 18.000 1 14.000 1 12.000 1 13.000 1 14.000 1 15.000 1 14.000 1 15.000 1 13.000 1 13.000 1 13.000 1 12.000 1 10.000 1 10.000 1 Only a sample of the data showing its format is given above. The full example file may be downloaded here. Structure your program to show statistics for each line of the file, (similar to the original Python, Perl, and AWK examples below), followed by summary statistics for the file. When showing example output just show a few line statistics and the full end summary.
#Wren
Wren
import "io" for File import "/pattern" for Pattern import "/fmt" for Fmt   var p = Pattern.new("+1/s") var fileName = "readings.txt" var lines = File.read(fileName).trimEnd().split("\r\n") var f = "Line: $s Reject: $2d Accept: $2d Line_tot: $8.3f Line_avg: $7.3f" var grandTotal = 0 var readings = 0 var date = "" var run = 0 var maxRun = -1 var finishLine = "" for (line in lines) { var fields = p.splitAll(line) date = fields[0] if (fields.count == 49) { var accept = 0 var total = 0 var i = 1 while (i < fields.count) { if (Num.fromString(fields[i+1]) >= 1) { accept = accept + 1 total = total + Num.fromString(fields[i]) if (run > maxRun) { maxRun = run finishLine = date } run = 0 } else { run = run + 1 } i = i + 2 } grandTotal = grandTotal + total readings = readings + accept Fmt.print(f, date, 24-accept, accept, total, total/accept) } else { Fmt.print("Line: $s does not have 49 fields and has been ignored", date) } }   if (run > maxRun) { maxRun = run finishLine = date } var average = grandTotal / readings Fmt.print("\nFile = $s", fileName) Fmt.print("Total = $0.3f", grandTotal) Fmt.print("Readings = $d", readings) Fmt.print("Average = $0.3f", average) Fmt.print("\nMaximum run of $d consecutive false readings", maxRun) Fmt.print("ends at line starting with date: $s", finishLine)
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#q
q
  days:" "vs"first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth"   gifts:( "Twelve drummers drumming"; "Eleven pipers piping"; "Ten lords a-leaping"; "Nine ladies dancing"; "Eight maids a-milking"; "Seven swans a-swimming"; "Six geese a-laying"; "Five golden rings"; "Four calling birds"; "Three french hens"; "Two turtle doves"; "And a partridge in a pear tree."; "")   verses:stanza 0 1,/:{(reverse x)+2+til each 2+x}til 12 lyric:raze .[;0 2;{"A",5_x}] verses{@[x;0;ssr[;"twelfth";y]]}'days   1 "\n"sv lyric; // print  
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Python
Python
import sys from Queue import Queue from threading import Thread   lines = Queue(1) count = Queue(1)   def read(file): try: for line in file: lines.put(line) finally: lines.put(None) print count.get()   def write(file): n = 0 while 1: line = lines.get() if line is None: break file.write(line) n += 1 count.put(n)   reader = Thread(target=read, args=(open('input.txt'),)) writer = Thread(target=write, args=(sys.stdout,)) reader.start() writer.start() reader.join() writer.join()
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Crystal
Crystal
# current time in system's time zone: Time.local   # current time in UTC Time.utc   # monotonic time (useful for measuring elapsed time) Time.monotonic  
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#D
D
Stdout(Clock.now.span.days / 365).newline;
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#Go
Go
package main   import ( "fmt" "strconv" )   func main() { var maxLen int var seqMaxLen [][]string for n := 1; n < 1e6; n++ { switch s := seq(n); { case len(s) == maxLen: seqMaxLen = append(seqMaxLen, s) case len(s) > maxLen: maxLen = len(s) seqMaxLen = [][]string{s} } } fmt.Println("Max sequence length:", maxLen) fmt.Println("Sequences:", len(seqMaxLen)) for _, seq := range seqMaxLen { fmt.Println("Sequence:") for _, t := range seq { fmt.Println(t) } } }   func seq(n int) []string { s := strconv.Itoa(n) ss := []string{s}   for { dSeq := sortD(s) d := dSeq[0] nd := 1 s = "" for i := 1; ; i++ { if i == len(dSeq) { s = fmt.Sprintf("%s%d%c", s, nd, d) break } if dSeq[i] == d { nd++ } else { s = fmt.Sprintf("%s%d%c", s, nd, d) d = dSeq[i] nd = 1 } } for _, s0 := range ss { if s == s0 { return ss } } ss = append(ss, s) } panic("unreachable") }   func sortD(s string) []rune { r := make([]rune, len(s)) for i, d := range s { j := 0 for ; j < i; j++ { if d > r[j] { copy(r[j+1:], r[j:i]) break } } r[j] = d } return r }
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#PureBasic
PureBasic
Structure point_f x.f y.f EndStructure   Procedure isInside(*p.point_f, *cp1.point_f, *cp2.point_f) If (*cp2\x - *cp1\x) * (*p\y - *cp1\y) > (*cp2\y - *cp1\y) * (*p\x - *cp1\x) ProcedureReturn 1 EndIf EndProcedure   Procedure intersection(*cp1.point_f, *cp2.point_f, *s.point_f, *e.point_f, *newPoint.point_f) Protected.point_f dc, dp Protected.f n1, n2, n3 dc\x = *cp1\x - *cp2\x: dc\y = *cp1\y - *cp2\y dp\x = *s\x - *e\x: dp\y = *s\y - *e\y n1 = *cp1\x * *cp2\y - *cp1\y * *cp2\x n2 = *s\x * *e\y - *s\y * *e\x n3 = 1 / (dc\x * dp\y - dc\y * dp\x) *newPoint\x = (n1 * dp\x - n2 * dc\x) * n3: *newPoint\y = (n1 * dp\y - n2 * dc\y) * n3 EndProcedure   Procedure clip(List vPolygon.point_f(), List vClippedBy.point_f(), List vClippedPolygon.point_f()) Protected.point_f cp1, cp2, s, e, newPoint CopyList(vPolygon(), vClippedPolygon()) If LastElement(vClippedBy()) cp1 = vClippedBy()   NewList vPreClipped.point_f() ForEach vClippedBy() cp2 = vClippedBy() CopyList(vClippedPolygon(), vPreClipped()) ClearList(vClippedPolygon()) If LastElement(vPreClipped()) s = vPreClipped() ForEach vPreClipped() e = vPreClipped() If isInside(e, cp1, cp2) If Not isInside(s, cp1, cp2) intersection(cp1, cp2, s, e, newPoint) AddElement(vClippedPolygon()): vClippedPolygon() = newPoint EndIf AddElement(vClippedPolygon()): vClippedPolygon() = e ElseIf isInside(s, cp1, cp2) intersection(cp1, cp2, s, e, newPoint) AddElement(vClippedPolygon()): vClippedPolygon() = newPoint EndIf s = e Next EndIf cp1 = cp2 Next EndIf EndProcedure   DataSection Data.f 50,150, 200,50, 350,150, 350,300, 250,300, 200,250, 150,350, 100,250, 100,200 ;subjectPolygon's vertices (x,y) Data.f 100,100, 300,100, 300,300, 100,300 ;clipPolygon's vertices (x,y) EndDataSection   NewList subjectPolygon.point_f() For i = 1 To 9 AddElement(subjectPolygon()) Read.f subjectPolygon()\x Read.f subjectPolygon()\y Next   NewList clipPolygon.point_f() For i = 1 To 4 AddElement(clipPolygon()) Read.f clipPolygon()\x Read.f clipPolygon()\y Next   NewList newPolygon.point_f() clip(subjectPolygon(), clipPolygon(), newPolygon()) If OpenConsole() ForEach newPolygon() PrintN("(" + StrF(newPolygon()\x, 2) + ", " + StrF(newPolygon()\y, 2) + ")") Next   Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input() CloseConsole() EndIf
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Frink
Frink
A = new set["John", "Bob", "Mary", "Serena"] B = new set["Jim", "Mary", "John", "Bob"]   println["Symmetric difference: " + symmetricDifference[A,B]] println["A - B  : " + setDifference[A,B]] println["B - A  : " + setDifference[B,A]]
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#GAP
GAP
SymmetricDifference := function(a, b) return Union(Difference(a, b), Difference(b, a)); end;   a := ["John", "Serena", "Bob", "Mary", "Serena"]; b := ["Jim", "Mary", "John", "Jim", "Bob"]; SymmetricDifference(a,b); [ "Jim", "Serena" ]
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#PL.2FI
PL/I
NOTES: procedure (text) options (main); /* 8 April 2014 */ declare text character (100) varying; declare note_file file;   on undefinedfile(note_file) go to file_does_not_exist; open file (note_file) title ('/NOTES.TXT,recsize(100),type(text)'); revert error;   if text = '' then do; on endfile (note_file) stop;   do forever; get file (note_file) edit (text) (L); put skip list (text); end; end; close file (note_file); open file (note_file) output title ('/NOTES.TXT,recsize(100),type(text),append(y)');   put file (note_file) skip list (DATETIME('DDMmmYYYY'), TIME()); put file (note_file) skip list (text); put file (note_file) skip;   put skip list ('Appended ' || text || ' to file');   return;   file_does_not_exist: revert undefinedfile (note_file); close file (note_file); open file (note_file) output title ('/NOTES.TXT,recsize(100),type(text)'); put file (note_file) skip list (DATETIME('DDMmmYYYY'), TIME()); put file (note_file) skip list (text); put file (note_file) skip; put skip list ('The file, NOTES.TXT, has been created'); end NOTES;
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#PowerShell
PowerShell
$notes = "notes.txt" if (($args).length -eq 0) { if(Test-Path $notes) { Get-Content $notes } } else { Get-Date | Add-Content $notes "`t" + $args -join " " | Add-Content $notes }
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#REXX
REXX
/* REXX *************************************************************** * Create a BMP file showing a few super ellipses **********************************************************************/ Parse Version v If pos('Regina',v)>0 Then superegg='superegga.bmp' Else superegg='supereggo.bmp' 'erase' superegg s='424d4600000000000000360000002800000038000000280000000100180000000000'X||, '1000000000000000000000000000000000000000'x z.0=0 black='000000'x white='ffffff'x red ='00ff00'x green='ff0000'x blue ='0000ff'x m=80 n=80 hor=m*8 /* 56 */ ver=n*8 /* 40 */ s=overlay(lend(hor),s,19,4) s=overlay(lend(ver),s,23,4) z.=copies('f747ff'x,3192%3) z.=copies('ffffff'x,8*m) z.0=648 u=320 v=320 Call supegg black,080,080,0.5,u,v Call supegg black,110,110,1 ,u,v Call supegg black,140,140,1.5,u,v Call supegg blue ,170,170,2 ,u,v Call supegg red ,200,200,2.5,u,v Call supegg green,230,230,3 ,u,v Call supegg black,260,260,4 ,u,v Call supegg black,290,290,7 ,u,v Do i=1 To z.0 s=s||z.i End   Call lineout superegg,s Call lineout superegg Exit   supegg: Parse Arg color,a,b,n,u,v Do y=0 To b t=(1-power(y/b,n)) x=a*power(t,1/n) Call point color,format(u+x,4,0),format(v+y,4,0) Call point color,format(u-x,4,0),format(v+y,4,0) Call point color,format(u+x,4,0),format(v-y,4,0) Call point color,format(u-x,4,0),format(v-y,4,0) End Do x=0 To a t=(1-power(x/b,n)) y=a*power(t,1/n) Call point color,format(u+x,4,0),format(v+y,4,0) Call point color,format(u-x,4,0),format(v+y,4,0) Call point color,format(u+x,4,0),format(v-y,4,0) Call point color,format(u-x,4,0),format(v-y,4,0) End Return   lend: Return reverse(d2c(arg(1),4))   point: Procedure Expose z. Call trace 'O' Parse Arg color,x0,y0 --Say x0 y0 Do x=x0-2 To x0+2 Do y=y0-2 To y0+2 z.y=overlay(copies(color,3),z.y,3*x) End End Return   power: Procedure /*********************************************************************** * Return b**x for any x -- with reasonable or specified precision * 920903 Walter Pachl ***********************************************************************/ Parse Arg b,x,prec If prec<9 Then prec=9 Numeric Digits (2*prec) Numeric Fuzz 3 If b=0 Then Return 0 If b<>'' Then x=x*ln(b,prec+2) o=1 u=1 r=1 Do i=1 By 1 ra=r o=o*x u=u*i r=r+(o/u) If r=ra Then Leave End Numeric Digits (prec) Return r+0   ln: Procedure /*********************************************************************** * Return ln(x) -- with specified precision * Three different series are used for the ranges 0 to 0.5 * 0.5 to 1.5 * 1.5 to infinity * 920903 Walter Pachl ***********************************************************************/ Parse Arg x,prec,b If prec='' Then prec=9 Numeric Digits (2*prec) Numeric Fuzz 3 Select When x<=0 Then r='*** invalid argument ***' When x<0.5 Then Do z=(x-1)/(x+1) o=z r=z k=1 Do i=3 By 2 ra=r k=k+1 o=o*z*z r=r+o/i If r=ra Then Leave End r=2*r End When x<1.5 Then Do z=(x-1) o=z r=z k=1 Do i=2 By 1 ra=r k=k+1 o=-o*z r=r+o/i If r=ra Then Leave End End Otherwise /* 1.5<=x */ Do z=(x+1)/(x-1) o=1/z r=o k=1 Do i=3 By 2 ra=r k=k+1 o=o/(z*z) r=r+o/i If r=ra Then Leave End r=2*r End End If b<>'' Then r=r/ln(b) Numeric Digits (prec) Return r+0
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#Swift
Swift
extension Array { func combinations(_ k: Int) -> [[Element]] { return Self._combinations(slice: self[startIndex...], k) }   static func _combinations(slice: Self.SubSequence, _ k: Int) -> [[Element]] { guard k != 1 else { return slice.map({ [$0] }) }   guard k != slice.count else { return [slice.map({ $0 })] }   let chopped = slice[slice.index(after: slice.startIndex)...]   var res = _combinations(slice: chopped, k - 1).map({ [[slice.first!], $0].flatMap({ $0 }) })   res += _combinations(slice: chopped, k)   return res } }   let cubes = (1...).lazy.map({ $0 * $0 * $0 }) let taxis = Array(cubes.prefix(1201)) .combinations(2) .reduce(into: [Int: [[Int]]](), { $0[$1[0] + $1[1], default: []].append($1) })     let res = taxis .lazy .filter({ $0.value.count > 1 }) .sorted(by: { $0.key < $1.key }) .map({ ($0.key, $0.value) }) .prefix(2006)   print("First 25 taxicab numbers:") for taxi in res[..<25] { print(taxi) }   print("\n2000th through 2006th taxicab numbers:") for taxi in res[1999..<2006] { print(taxi) }
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#Tcl
Tcl
package require Tcl 8.6   proc heappush {heapName item} { upvar 1 $heapName heap set idx [lsearch -bisect -index 0 -integer $heap [lindex $item 0]] set heap [linsert $heap [expr {$idx + 1}] $item] } coroutine cubesum apply {{} { yield set h {} set n 1 while true { while {![llength $h] || [lindex $h 0 0] > $n**3} { heappush h [list [expr {$n**3 + 1}] $n 1] incr n } set h [lassign $h item] yield $item lassign $item s x y if {[incr y] < $x} { heappush h [list [expr {$x**3 + $y**3}] $x $y] } } }} coroutine taxis apply {{} { yield set out {{0 0 0}} while true { set s [cubesum] if {[lindex $s 0] == [lindex $out end 0]} { lappend out $s } else { if {[llength $out] > 1} {yield $out} set out [list $s] } } }}   # Put a cache in front for convenience variable taxis {} proc taxi {n} { variable taxis while {$n > [llength $taxis]} {lappend taxis [taxis]} return [lindex $taxis [expr {$n-1}]] }   set 3 "\u00b3" for {set n 1} {$n <= 25} {incr n} { puts ${n}:[join [lmap t [taxi $n] {format " %d = %d$3 + %d$3" {*}$t}] ","] } for {set n 2000} {$n <= 2006} {incr n} { puts ${n}:[join [lmap t [taxi $n] {format " %d = %d$3 + %d$3" {*}$t}] ","] }
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Factor
Factor
USING: combinators formatting kernel math ; IN: rosetta-code.temperature   : k>c ( kelvin -- celsius ) 273.15 - ; : k>r ( kelvin -- rankine ) 9/5 * ; : k>f ( kelvin -- fahrenheit ) k>r 459.67 - ;   : convert ( kelvin -- ) { [ ] [ k>c ] [ k>f ] [ k>r ] } cleave "K  %.2f\nC  %.2f\nF  %.2f\nR  %.2f\n" printf ;   21 convert
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Scala
Scala
sealed trait Trit { self => def nand(that:Trit):Trit=(this,that) match { case (TFalse, _) => TTrue case (_, TFalse) => TTrue case (TMaybe, _) => TMaybe case (_, TMaybe) => TMaybe case _ => TFalse }   def nor(that:Trit):Trit = this.or(that).not() def and(that:Trit):Trit = this.nand(that).not() def or(that:Trit):Trit = this.not().nand(that.not()) def not():Trit = this.nand(this) def imply(that:Trit):Trit = this.nand(that.not()) def equiv(that:Trit):Trit = this.and(that).or(this.nor(that)) } case object TTrue extends Trit case object TMaybe extends Trit case object TFalse extends Trit   object TernaryLogic extends App { val v=List(TTrue, TMaybe, TFalse) println("- NOT -") for(a<-v) println("%6s => %6s".format(a, a.not)) println("\n- AND -") for(a<-v; b<-v) println("%6s : %6s => %6s".format(a, b, a and b)) println("\n- OR -") for(a<-v; b<-v) println("%6s : %6s => %6s".format(a, b, a or b)) println("\n- Imply -") for(a<-v; b<-v) println("%6s : %6s => %6s".format(a, b, a imply b)) println("\n- Equiv -") for(a<-v; b<-v) println("%6s : %6s => %6s".format(a, b, a equiv b)) }
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Quackery
Quackery
[ [ table $ "first" $ "second" $ "third" $ "fourth" $ "fifth" $ "sixth" $ "seventh" $ "eighth" $ "ninth" $ "tenth" $ "eleventh" $ "twelfth" ] do echo$ ] is day ( n --> )   [ [ table $ "A partridge in a pear tree." $ "Two turtle doves and" $ "Three French hens," $ "Four calling birds," $ "Five gold rings," $ "Six geese a-laying," $ "Seven swans a-swimming," $ "Eight maids a-milking," $ "Nine ladies dancing," $ "Ten lords a-leaping," $ "Eleven pipers piping," $ "Twelve drummers drumming," ] do echo$ ] is gift ( n --> )   [ say "On the " dup day say " day of Christmas," cr say "My true love gave to me," cr 1+ times [ i gift cr ] cr ] is verse ( n --> )   [ 12 times [ i^ verse ] ] is song ( --> )   song
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#R
R
  gifts <- c("A partridge in a pear tree.", "Two turtle doves and", "Three french hens", "Four calling birds", "Five golden rings", "Six geese a-laying", "Seven swans a-swimming", "Eight maids a-milking", "Nine ladies dancing", "Ten lords a-leaping", "Eleven pipers piping", "Twelve drummers drumming") days <- c("first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth")   for (i in seq_along(days)) { cat("On the", days[i], "day of Christmas\n") cat("My true love gave to me:\n") cat(paste(gifts[i:1], collapse = "\n"), "\n\n") }
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Racket
Racket
  (define (reader) (for ([line (in-lines (open-input-file "input.txt"))]) (thread-send printer-thread line)) (thread-send printer-thread eof) (printf "Number of lines: ~a\n" (thread-receive)))   (define (printer) (thread-send reader-thread (for/sum ([line (in-producer thread-receive eof)]) (displayln line) 1)))   (define printer-thread (thread printer)) (define reader-thread (thread reader))   (for-each thread-wait (list printer-thread reader-thread))    
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Raku
Raku
sub MAIN ($infile) { $infile.IO.lines ==> printer() ==> my $count; say "printed $count lines"; }   sub printer(*@lines) { my $lines; for @lines { .say; ++$lines; } $lines; }
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#DBL
DBL
XCALL TIME (D6)  ;D6=hhmmss
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#DCL
DCL
$ start_time = f$time() $ wait 0::10 $ end_time = f$time() $ write sys$output "start time was ", start_time $ write sys$output "end time was ", end_time $ write sys$output "delta time is ", f$delta_time( start_time, end_time )
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#Groovy
Groovy
Number.metaClass.getSelfReferentialSequence = { def number = delegate as String; def sequence = []   while (!sequence.contains(number)) { sequence << number def encoded = new StringBuilder() ((number as List).sort().join('').reverse() =~ /(([0-9])\2*)/).each { matcher, text, digit -> encoded.append(text.size()).append(digit) } number = encoded.toString() } sequence }   def maxSeqSize = { List values -> values.inject([seqSize: 0, seeds: []]) { max, n -> if (n % 100000 == 99999) println 'HT' else if (n % 10000 == 9999) print '.' def seqSize = n.selfReferentialSequence.size() switch (seqSize) { case max.seqSize: max.seeds << n case { it < max.seqSize }: return max default: return [seqSize: seqSize, seeds: [n]] } } }
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#Python
Python
  def clip(subjectPolygon, clipPolygon): def inside(p): return(cp2[0]-cp1[0])*(p[1]-cp1[1]) > (cp2[1]-cp1[1])*(p[0]-cp1[0])   def computeIntersection(): dc = [ cp1[0] - cp2[0], cp1[1] - cp2[1] ] dp = [ s[0] - e[0], s[1] - e[1] ] n1 = cp1[0] * cp2[1] - cp1[1] * cp2[0] n2 = s[0] * e[1] - s[1] * e[0] n3 = 1.0 / (dc[0] * dp[1] - dc[1] * dp[0]) return [(n1*dp[0] - n2*dc[0]) * n3, (n1*dp[1] - n2*dc[1]) * n3]   outputList = subjectPolygon cp1 = clipPolygon[-1]   for clipVertex in clipPolygon: cp2 = clipVertex inputList = outputList outputList = [] s = inputList[-1]   for subjectVertex in inputList: e = subjectVertex if inside(e): if not inside(s): outputList.append(computeIntersection()) outputList.append(e) elif inside(s): outputList.append(computeIntersection()) s = e cp1 = cp2 return(outputList)  
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Go
Go
package main   import "fmt"   var a = map[string]bool{"John": true, "Bob": true, "Mary": true, "Serena": true} var b = map[string]bool{"Jim": true, "Mary": true, "John": true, "Bob": true}   func main() { sd := make(map[string]bool) for e := range a { if !b[e] { sd[e] = true } } for e := range b { if !a[e] { sd[e] = true } } fmt.Println(sd) }
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#PureBasic
PureBasic
#FileName="notes.txt" Define argc=CountProgramParameters() If OpenConsole() If argc=0 If ReadFile(0,#FileName) While Eof(0)=0 PrintN(ReadString(0)) ; No new notes, so present the old Wend CloseFile(0) EndIf Else ; e.g. we have some arguments Define d$=FormatDate("%yyyy-%mm-%dd %hh:%ii:%ss",date()) If OpenFile(0,#FileName) Define args$="" While argc args$+" "+ProgramParameter() ; Read all arguments argc-1 Wend FileSeek(0,Lof(0)) ; Go to the end of this file WriteStringN(0,d$+#CRLF$+#TAB$+args$) ; Append date & note CloseFile(0) EndIf EndIf EndIf
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#Scala
Scala
import java.awt._ import java.awt.geom.Path2D import java.util   import javax.swing._ import javax.swing.event.{ChangeEvent, ChangeListener}   object SuperEllipse extends App {   SwingUtilities.invokeLater(() => { new JFrame("Super Ellipse") {   class SuperEllipse extends JPanel with ChangeListener { setPreferredSize(new Dimension(650, 650)) setBackground(Color.white) setFont(new Font("Serif", Font.PLAIN, 18)) private var exp = 2.5   override def paintComponent(gg: Graphics): Unit = { val g = gg.asInstanceOf[Graphics2D]   def drawGrid(g: Graphics2D): Unit = { g.setStroke(new BasicStroke(2)) g.setColor(new Color(0xEEEEEE)) val w = getWidth val h = getHeight val spacing = 25   for (i <- 0 until (w / spacing)) { g.drawLine(0, i * spacing, w, i * spacing) g.drawLine(i * spacing, 0, i * spacing, w) } g.drawLine(0, h - 1, w, h - 1) g.setColor(new Color(0xAAAAAA)) g.drawLine(0, w / 2, w, w / 2) g.drawLine(w / 2, 0, w / 2, w) }   def drawLegend(g: Graphics2D): Unit = { g.setColor(Color.black) g.setFont(getFont) g.drawString("n = " + String.valueOf(exp), getWidth - 150, 45) g.drawString("a = b = 200", getWidth - 150, 75) }   def drawEllipse(g: Graphics2D): Unit = { val a = 200 // calculate first quadrant val points = Array.tabulate(a + 1)(n => math.pow(math.pow(a, exp) - math.pow(n, exp), 1 / exp)) val p = new Path2D.Double   p.moveTo(a, 0) for (n <- a to 0 by -1) p.lineTo(n, -points(n)) // mirror to others for (x <- points.indices) p.lineTo(x, points(x)) for (y <- a to 0 by -1) p.lineTo(-y, points(y)) for (z <- points.indices) p.lineTo(-z, -points(z)) g.translate(getWidth / 2, getHeight / 2) g.setStroke(new BasicStroke(2)) g.setColor(new Color(0x25B0C4DE, true)) g.fill(p) g.setColor(new Color(0xB0C4DE)) // LightSteelBlue g.draw(p) }   super.paintComponent(gg) g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON) g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON) drawGrid(g) drawLegend(g) drawEllipse(g) }   override def stateChanged(e: ChangeEvent): Unit = { val source = e.getSource.asInstanceOf[JSlider] exp = source.getValue / 2.0 repaint() } }   setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE) setResizable(false) val panel = new SuperEllipse add(panel, BorderLayout.CENTER) val exponent = new JSlider(SwingConstants.HORIZONTAL, 1, 9, 5) exponent.addChangeListener(panel) exponent.setBackground(Color.white) exponent.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20)) exponent.setMajorTickSpacing(1) exponent.setPaintLabels(true) val labelTable = new util.Hashtable[Integer, JLabel] for (i <- 1 until 10) labelTable.put(i, new JLabel(String.valueOf(i * 0.5)))   exponent.setLabelTable(labelTable) add(exponent, BorderLayout.SOUTH) pack() setLocationRelativeTo(null) setVisible(true) }   })   }
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#VBA
VBA
Public Type tuple i As Variant j As Variant sum As Variant End Type Public Type tuple3 i1 As Variant j1 As Variant i2 As Variant j2 As Variant i3 As Variant j3 As Variant sum As Variant End Type Sub taxicab_numbers() Dim i As Variant, j As Variant Dim k As Long Const MAX = 2019 Dim p(MAX) As Variant Const bigMAX = (MAX + 1) * (MAX / 2) Dim big(1 To bigMAX) As tuple Const resMAX = 4400 Dim res(1 To resMAX) As tuple3 For i = 1 To MAX p(i) = CDec(i * i * i) 'convert Variant to Decimal Next i 'wich hold numbers upto 10^28 k = 1 For i = 1 To MAX For j = i To MAX big(k).i = CDec(i) big(k).j = CDec(j) big(k).sum = CDec(p(i) + p(j)) k = k + 1 Next j Next i n = 1 Quicksort big, LBound(big), UBound(big) For i = 1 To bigMAX - 1 If big(i).sum = big(i + 1).sum Then res(n).i1 = CStr(big(i).i) res(n).j1 = CStr(big(i).j) res(n).i2 = CStr(big(i + 1).i) res(n).j2 = CStr(big(i + 1).j) If big(i + 1).sum = big(i + 2).sum Then res(n).i3 = CStr(big(i + 2).i) res(n).j3 = CStr(big(i + 2).j) i = i + 1 End If res(n).sum = CStr(big(i).sum) n = n + 1 i = i + 1 End If Next i Debug.Print n - 1; " taxis" For i = 1 To 25 With res(i) Debug.Print String$(4 - Len(CStr(i)), " "); i; Debug.Print String$(11 - Len(.sum), " "); .sum; " = "; Debug.Print String$(4 - Len(.i1), " "); .i1; "^3 +"; Debug.Print String$(4 - Len(.j1), " "); .j1; "^3 = "; Debug.Print String$(4 - Len(.i2), " "); .i2; "^3 +"; Debug.Print String$(4 - Len(.j2), " "); .j2; "^3" End With Next i Debug.Print For i = 2000 To 2006 With res(i) Debug.Print String$(4 - Len(CStr(i)), " "); i; Debug.Print String$(11 - Len(.sum), " "); .sum; " = "; Debug.Print String$(4 - Len(.i1), " "); .i1; "^3 +"; Debug.Print String$(4 - Len(.j1), " "); .j1; "^3 = "; Debug.Print String$(4 - Len(.i2), " "); .i2; "^3 +"; Debug.Print String$(4 - Len(.j2), " "); .j2; "^3" End With   Next i Debug.Print For i = 1 To resMAX If res(i).i3 <> "" Then With res(i) Debug.Print String$(4 - Len(CStr(i)), " "); i; Debug.Print String$(11 - Len(.sum), " "); .sum; " = "; Debug.Print String$(4 - Len(.i1), " "); .i1; "^3 +"; Debug.Print String$(4 - Len(.j1), " "); .j1; "^3 = "; Debug.Print String$(4 - Len(.i2), " "); .i2; "^3 +"; Debug.Print String$(4 - Len(.j2), " "); .j2; "^3"; Debug.Print String$(4 - Len(.i3), " "); .i3; "^3 +"; Debug.Print String$(4 - Len(.j3), " "); .j3; "^3" End With End If Next i End Sub Sub Quicksort(vArray() As tuple, arrLbound As Long, arrUbound As Long) 'https://wellsr.com/vba/2018/excel/vba-quicksort-macro-to-sort-arrays-fast/ 'Sorts a one-dimensional VBA array from smallest to largest 'using a very fast quicksort algorithm variant. 'Adapted to multidimensions/typedef Dim pivotVal As Variant Dim vSwap As tuple Dim tmpLow As Long Dim tmpHi As Long   tmpLow = arrLbound tmpHi = arrUbound pivotVal = vArray((arrLbound + arrUbound) \ 2).sum   While (tmpLow <= tmpHi) 'divide While (vArray(tmpLow).sum < pivotVal And tmpLow < arrUbound) tmpLow = tmpLow + 1 Wend   While (pivotVal < vArray(tmpHi).sum And tmpHi > arrLbound) tmpHi = tmpHi - 1 Wend   If (tmpLow <= tmpHi) Then vSwap.i = vArray(tmpLow).i vSwap.j = vArray(tmpLow).j vSwap.sum = vArray(tmpLow).sum vArray(tmpLow).i = vArray(tmpHi).i vArray(tmpLow).j = vArray(tmpHi).j vArray(tmpLow).sum = vArray(tmpHi).sum vArray(tmpHi).i = vSwap.i vArray(tmpHi).j = vSwap.j vArray(tmpHi).sum = vSwap.sum tmpLow = tmpLow + 1 tmpHi = tmpHi - 1 End If Wend   If (arrLbound < tmpHi) Then Quicksort vArray, arrLbound, tmpHi 'conquer If (tmpLow < arrUbound) Then Quicksort vArray, tmpLow, arrUbound 'conquer End Sub
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#FOCAL
FOCAL
01.10 ASK "TEMPERATURE IN KELVIN", K 01.20 TYPE "K ", %6.02, K, ! 01.30 TYPE "C ", %6.02, K - 273.15, ! 01.40 TYPE "F ", %6.02, K * 1.8 - 459.67, ! 01.50 TYPE "R ", %6.02, K * 1.8, !
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Forth
Forth
: k>°C ( F: kelvin -- celsius ) 273.15e0 f- ; : k>°R ( F: kelvin -- rankine ) 1.8e0 f* ; : °R>°F ( F: rankine -- fahrenheit ) 459.67e0 f- ; : k>°F ( F: kelvin -- fahrenheit ) k>°R °R>°F ; : main argc 1 > if 1 arg >float fdup f. ." K" cr fdup k>°C f. ." °C" cr fdup k>°F f. ." °F" cr fdup k>°R f. ." °R" cr then ;   main bye
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Seed7
Seed7
$ include "seed7_05.s7i";   const type: trit is new enum False, Maybe, True end enum;   # Enum types define comparisons (=, <, >, <=, >=, <>) and # the conversions ord and conv.   const func string: str (in trit: aTrit) is return [] ("False", "Maybe", "True")[succ(ord(aTrit))];   enable_output(trit); # Allow writing trit values   const array trit: tritNot is [] (True, Maybe, False); const array array trit: tritAnd is [] ( [] (False, False, False), [] (False, Maybe, Maybe), [] (False, Maybe, True )); const array array trit: tritOr is [] ( [] (False, Maybe, True ), [] (Maybe, Maybe, True ), [] (True, True, True )); const array array trit: tritXor is [] ( [] (False, Maybe, True ), [] (Maybe, Maybe, Maybe), [] (True, Maybe, False)); const array array trit: tritImplies is [] ( [] (True, True, True ), [] (Maybe, Maybe, True ), [] (False, Maybe, True )); const array array trit: tritEquiv is [] ( [] (True, Maybe, False), [] (Maybe, Maybe, Maybe), [] (False, Maybe, True ));   const func trit: not (in trit: aTrit) is return tritNot[succ(ord(aTrit))];   const func trit: (in trit: aTrit1) and (in trit: aTrit2) is return tritAnd[succ(ord(aTrit1))][succ(ord(aTrit2))];   const func trit: (in trit: aTrit1) and (ref func trit: aTrit2) is func result var trit: res is False; begin if aTrit1 = True then res := aTrit2; elsif aTrit1 = Maybe and aTrit2 <> False then res := Maybe; end if; end func;   const func trit: (in trit: aTrit1) or (in trit: aTrit2) is return tritOr[succ(ord(aTrit1))][succ(ord(aTrit2))];   const func trit: (in trit: aTrit1) or (ref func trit: aTrit2) is func result var trit: res is True; begin if aTrit1 = False then res := aTrit2; elsif aTrit1 = Maybe and aTrit2 <> True then res := Maybe; end if; end func;   $ syntax expr: .().xor.() is -> 15; const func trit: (in trit: aTrit1) xor (in trit: aTrit2) is return tritImplies[succ(ord(aTrit1))][succ(ord(aTrit2))];   const func trit: (in trit: aTrit1) -> (in trit: aTrit2) is return tritImplies[succ(ord(aTrit1))][succ(ord(aTrit2))];   const func trit: (in trit: aTrit1) == (in trit: aTrit2) is return tritEquiv[succ(ord(aTrit1))][succ(ord(aTrit2))];   const func trit: rand (in trit: low, in trit: high) is return trit conv (rand(ord(low), ord(high)));   # Begin of test code   var trit: operand1 is False; var trit: operand2 is False;   const proc: writeTable (ref func trit: tritExpr, in string: name) is func begin writeln; writeln(" " <& name rpad 7 <& " | False Maybe True"); writeln("---------+---------------------"); for operand1 range False to True do write(" " <& operand1 rpad 7 <& " | "); for operand2 range False to True do write(tritExpr rpad 7); end for; writeln; end for; end func;   const proc: main is func begin writeln(" not" rpad 8 <& " | False Maybe True"); writeln("---------+---------------------"); write(" | "); for operand1 range False to True do write(not operand1 rpad 7); end for; writeln; writeTable(operand1 and operand2, "and"); writeTable(operand1 or operand2, "or"); writeTable(operand1 xor operand2, "xor"); writeTable(operand1 -> operand2, "->"); writeTable(operand1 == operand2, "=="); end func;
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Racket
Racket
#lang racket (define (ordinal-text d) (vector-ref (vector "zeroth" "first" "second" "third" "fourth" "fifth" "sixth" "seventh" "eighth" "ninth" "tenth" "eleventh" "twelfth") d))   (define (on-the... day) (printf "On the ~a day of Christmas,~%" (ordinal-text day)) (printf "My True Love gave to me,~%"))   (define (prezzy prezzy-line day) (match prezzy-line [1 (string-append (if (= day 1) "A " "And a")" partridge in a pear tree")] [2 "Two turtle doves"] [3 "Three French hens"] [4 "Four calling birds"] [5 "FIVE GO-OLD RINGS"] [6 "Six geese a-laying"] [7 "Seven swans a-swimming"] [8 "Eight maids a-milking"] [9 "Nine ladies dancing"] [10 "Ten lords a-leaping"] [11 "Eleven pipers piping"] [12 "Twelve drummers drumming"]))   (define (line-end prezzy-line day) (match* (day prezzy-line) [(12 1) "."] [(x 1) ".\n"] [(_ _) ","]))   (for ((day (sequence-map add1 (in-range 12))) #:when (on-the... day) (prezzy-line (in-range day 0 -1))) (printf "~a~a~%" (prezzy prezzy-line day) (line-end prezzy-line day)))
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Raku
Raku
my @days = <first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth>;   my @gifts = lines q:to/END/; And a partridge in a pear tree. Two turtle doves, Three french hens, Four calling birds, Five golden rings, Six geese a-laying, Seven swans a-swimming, Eight maids a-milking, Nine ladies dancing, Ten lords a-leaping, Eleven pipers piping, Twelve drummers drumming, END   sub nth($n) { say "On the @days[$n] day of Christmas, my true love gave to me:" }   nth(0); say @gifts[0].subst('And a','A');   for 1 ... 11 -> $d { say ''; nth($d); say @gifts[$_] for $d ... 0; }
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Raven
Raven
'input.txt' as src_file   class Queue   new list as items condition as ready   define item_put items push ready notify   define item_get items empty if ready wait items shift   Queue as lines Queue as count   thread reader "file://r:%(src_file)s" open each lines.item_put NULL lines.item_put count.item_get "reader: %d\n" print   thread writer 0 repeat lines.item_get dup while "writer: %s" print 1+ drop count.item_put   reader as r writer as w
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Ruby
Ruby
count = 0 IO.foreach("input.txt") { |line| print line; count += 1 } puts "Printed #{count} lines."
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Delphi
Delphi
lblDateTime.Caption := FormatDateTime('dd mmmm yyyy hh:mm:ss', Now);
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#DWScript
DWScript
PrintLn(FormatDateTime('dd mmmm yyyy hh:mm:ss', Now));
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#Haskell
Haskell
import Data.Set (Set, member, insert, empty) import Data.List (group, sort)   step :: String -> String step = concatMap (\list -> show (length list) ++ [head list]) . group . sort   findCycle :: (Ord a) => [a] -> [a] findCycle = aux empty where aux set (x : xs) | x `member` set = [] | otherwise = x : aux (insert x set) xs   select :: [[a]] -> [[a]] select = snd . foldl (\(len, acc) xs -> case len `compare` length xs of LT -> (length xs, [xs]) EQ -> (len, xs : acc) GT -> (len, acc)) (0, [])   main :: IO () main = mapM_ (mapM_ print) $ -- Print out all the numbers select $ -- find the longest ones map findCycle $ -- run the sequences until there is a repeat map (iterate step) $ -- produce the sequence map show -- turn the numbers into digits [1..1000000] -- The input seeds  
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#Racket
Racket
#lang racket   (module sutherland-hodgman racket (provide clip-to) (provide make-edges) (provide (struct-out point))   (struct point (x y) #:transparent) (struct edge (p1 p2) #:transparent) (struct polygon (points edges) #:transparent)   (define (make-edges points) (let ([points-shifted (match points [(list a b ...) (append b (list a))])]) (map edge points points-shifted)))   (define (is-point-left? pt ln) (match-let ([(point x y) pt] [(edge (point px py) (point qx qy)) ln]) (>= (* (- qx px) (- y py)) (* (- qy py) (- x px)))))   ;; Return the intersection of two lines (define (isect-lines l1 l2) (match-let ([(edge (point x1 y1) (point x2 y2)) l1] [(edge (point x3 y3) (point x4 y4)) l2]) (let* ([r (- (* x1 y2) (* y1 x2))] [s (- (* x3 y4) (* y3 x4))] [t (- x1 x2)] [u (- y3 y4)] [v (- y1 y2)] [w (- x3 x4)] [d (- (* t u) (* v w))]) (point (/ (- (* r w) (* t s)) d) (/ (- (* r u) (* v s)) d)))))   ;; Intersect the line segment (p0,p1) with the clipping line's left halfspace, ;; returning the point closest to p1. In the special case where p0 lies outside ;; the halfspace and p1 lies inside we return both the intersection point and p1. ;; This ensures we will have the necessary segment along the clipping line.   (define (intersect segment clip-line) (define (isect) (isect-lines segment clip-line))   (match-let ([(edge p0 p1) segment]) (match/values (values (is-point-left? p0 clip-line) (is-point-left? p1 clip-line)) [(#f #f) '()] [(#f #t) (list (isect) p1)] [(#t #f) (list (isect))] [(#t #t) (list p1)])))   ;; Intersect the polygon with the clipping line's left halfspace (define (isect-polygon poly-edges clip-line) (for/fold ([p '()]) ([e poly-edges]) (append p (intersect e clip-line))))   ;; Intersect a subject polygon with a clipping polygon. The latter is assumed to be convex. (define (clip-to sp-pts cp-edges) (for/fold ([out-poly sp-pts]) ([clip-line cp-edges]) (isect-polygon (make-edges out-poly) clip-line))))
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Groovy
Groovy
def symDiff = { Set s1, Set s2 -> assert s1 != null assert s2 != null (s1 + s2) - (s1.intersect(s2)) }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Haskell
Haskell
import Data.Set   a = fromList ["John", "Bob", "Mary", "Serena"] b = fromList ["Jim", "Mary", "John", "Bob"]   (-|-) :: Ord a => Set a -> Set a -> Set a x -|- y = (x \\ y) `union` (y \\ x) -- Equivalently: (x `union` y) \\ (x `intersect` y)
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Python
Python
import sys, datetime, shutil   if len(sys.argv) == 1: try: with open('notes.txt', 'r') as f: shutil.copyfileobj(f, sys.stdout) except IOError: pass else: with open('notes.txt', 'a') as f: f.write(datetime.datetime.now().isoformat() + '\n') f.write("\t%s\n" % ' '.join(sys.argv[1:]))
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#R
R
#!/usr/bin/env Rscript --default-packages=methods   args <- commandArgs(trailingOnly=TRUE)   if (length(args) == 0) { conn <- file("notes.txt", 'r') cat(readLines(conn), sep="\n") } else { conn <- file("notes.txt", 'a') cat(file=conn, date(), "\n\t", paste(args, collapse=" "), "\n", sep="") } close(conn)
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#Sidef
Sidef
const ( a = 200, b = 200, n = 2.5, )   # y in terms of x func y(x) { b * (1 - abs(x/a)**n -> root(n)) -> int }   func pline(q) { <<-"EOT"; <polyline points="#{q.join(' ')}" style="fill:none; stroke:black; stroke-width:3" transform="translate(#{a}, #{b})" /> EOT }   # Generate an SVG image say <<-"EOT" <?xml version="1.0" standalone="no"?> <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"> <svg height="#{b*2}" width="#{a*2}" version="1.1" xmlns="http://www.w3.org/2000/svg"> EOT   # find point pairs for one quadrant var q = { |x| (x, y(x)) }.map(0..200 `by` 2)   [ pline(q), pline(q »*« [ 1,-1]), # flip and mirror pline(q »*« [-1,-1]), # for the other pline(q »*« [-1, 1]), # three quadrants ].each { .print }   say '</svg>'
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#Visual_Basic_.NET
Visual Basic .NET
  Imports System.Text   Module Module1   Function GetTaxicabNumbers(length As Integer) As IDictionary(Of Long, IList(Of Tuple(Of Integer, Integer))) Dim sumsOfTwoCubes As New SortedList(Of Long, IList(Of Tuple(Of Integer, Integer)))   For i = 1 To Integer.MaxValue - 1 For j = 1 To Integer.MaxValue - 1 Dim sum = CLng(Math.Pow(i, 3) + Math.Pow(j, 3))   If Not sumsOfTwoCubes.ContainsKey(sum) Then sumsOfTwoCubes.Add(sum, New List(Of Tuple(Of Integer, Integer))) End If   sumsOfTwoCubes(sum).Add(Tuple.Create(i, j))   If j >= i Then Exit For End If Next   REM Found that you need to keep going for a while after the length, because higher i values fill in gaps If sumsOfTwoCubes.AsEnumerable.Count(Function(t) t.Value.Count >= 2) >= length * 1.1 Then Exit For End If Next   Dim values = (From t In sumsOfTwoCubes Where t.Value.Count >= 2 Select t) _ .Take(2006) _ .ToDictionary(Function(u) u.Key, Function(u) u.Value) Return values End Function   Sub PrintTaxicabNumbers(values As IDictionary(Of Long, IList(Of Tuple(Of Integer, Integer)))) Dim i = 1 For Each taxicabNumber In values.Keys Dim output As New StringBuilder output.AppendFormat("{0,10}" + vbTab + "{1,4}", i, taxicabNumber)   For Each numbers In values(taxicabNumber) output.AppendFormat(vbTab + "= {0}^3 + {1}^3", numbers.Item1, numbers.Item2) Next   If i <= 25 OrElse (i >= 2000 AndAlso i <= 2006) Then Console.WriteLine(output.ToString) End If   i += 1 Next End Sub   Sub Main() Dim taxicabNumbers = GetTaxicabNumbers(2006) PrintTaxicabNumbers(taxicabNumbers) End Sub   End Module
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Fortran
Fortran
Program Temperature implicit none   real :: kel, cel, fah, ran   write(*,*) "Input Kelvin temperature to convert" read(*,*) kel   call temp_convert(kel, cel, fah, ran) write(*, "((a10), f10.3)") "Kelvin", kel write(*, "((a10), f10.3)") "Celsius", cel write(*, "((a10), f10.3)") "Fahrenheit", fah write(*, "((a10), f10.3)") "Rankine", ran   contains   subroutine temp_convert(kelvin, celsius, fahrenheit, rankine) real, intent(in) :: kelvin real, intent(out) :: celsius, fahrenheit, rankine   celsius = kelvin - 273.15 fahrenheit = kelvin * 1.8 - 459.67 rankine = kelvin * 1.8   end subroutine end program
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Tcl
Tcl
package require Tcl 8.5 namespace eval ternary { # Code generator proc maketable {name count values} { set sep "" for {set i 0; set c 97} {$i<$count} {incr i;incr c} { set v [format "%c" $c] lappend args $v; append key $sep "$" $v set sep "," } foreach row [split $values \n] { if {[llength $row]>1} { lassign $row from to lappend table $from [list return $to] } } proc $name $args \ [list ckargs $args]\;[concat [list switch -glob --] $key [list $table]] namespace export $name } # Helper command to check argument syntax proc ckargs argList { foreach var $argList { upvar 1 $var v switch -exact -- $v { true - maybe - false { continue } default { return -level 2 -code error "bad ternary value \"$v\"" } } } }   # The "truth" tables; “*” means “anything” maketable not 1 { true false maybe maybe false true } maketable and 2 { true,true true false,* false *,false false * maybe } maketable or 2 { true,* true *,true true false,false false * maybe } maketable implies 2 { false,* true *,true true true,false false * maybe } maketable equiv 2 { *,maybe maybe maybe,* maybe true,true true false,false true * false } }
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#REXX
REXX
/*REXX program displays the verses of the song: "The 12 days of Christmas". */ ordD= 'first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth' pad= left('', 20) /*used for indenting the shown verses. */ @.1= 'A partridge in a pear-tree.'; @.7 = "Seven swans a-swimming," @.2= 'Two Turtle Doves, and'  ; @.8 = "Eight maids a-milking," @.3= 'Three French Hens,'  ; @.9 = "Nine ladies dancing," @.4= 'Four Calling Birds,'  ; @.10= "Ten lords a-leaping," @.5= 'Five Golden Rings,'  ; @.11= "Eleven pipers piping," @.6= 'Six geese a-laying,'  ; @.12= "Twelve drummers drumming," do day=1 for 12 say pad 'On the' word(ordD, day) "day of Christmas" /*display line 1 prologue.*/ say pad 'My True Love gave to me:' /* " " 2 " */ do j=day by -1 to 1; say pad @.j /* " the daily gifts.*/ end /*j*/ say /*add a blank line between the verses. */ end /*day*/ /*stick a fork in it, we're all done. */
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Rust
Rust
use std::fs::File; use std::io::BufRead; use std::io::BufReader;   use std::sync::mpsc::{channel, sync_channel}; use std::thread;   fn main() { // The reader sends lines to the writer via an async channel, so the reader is never blocked. let (reader_send, writer_recv) = channel();   // The writer sends the final count via a blocking channel with bound 0, // meaning the buffer is exactly the size of the result. let (writer_send, reader_recv) = sync_channel(0);   // Define the work the reader will do. let reader_work = move || { let file = File::open("input.txt").expect("Failed to open input.txt"); let reader = BufReader::new(file);   for line in reader.lines() { match line { Ok(msg) => reader_send .send(msg) .expect("Failed to send via the channel"), Err(e) => println!("{}", e), } }   // Dropping the sender disconnects it and tells the receiver the connection is closed. drop(reader_send);   // Now that we've sent all the lines, // block until the writer gives us the final count. let count = reader_recv .recv() .expect("Failed to receive count from printer.");   println!("{}", count); };   // Define the work the writer will do. let writer_work = move || { let mut line_count = 0;   loop { match writer_recv.recv() { Ok(msg) => { println!("{}", msg); line_count += 1; } Err(_) => break, // indicates the connection has been closed by the sender. } }   // Send the final count back to the reader. writer_send .send(line_count) .expect("Failed to send line count from writer.");   drop(writer_send); };   // Spawn each as a thread. let reader_handle = thread::spawn(reader_work); thread::spawn(writer_work);   reader_handle .join() .expect("Failed to join the reader thread."); }
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Scala
Scala
case class HowMany(asker: Actor)   val printer = actor { var count = 0 while (true) { receive { case line: String => print(line); count = count + 1 case HowMany(asker: Actor) => asker ! count; exit() } } }   def reader(printer: Actor) { scala.io.Source.fromFile("c:\\input.txt").getLines foreach { printer ! _ } printer ! HowMany( actor { receive { case count: Int => println("line count = " + count) } }) }   reader(printer)
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#E
E
println(timer.now())
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#EasyLang
EasyLang
print timestr systime
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#Icon_and_Unicon
Icon and Unicon
link printf   procedure main() every L := !longestselfrefseq(1000000) do every printf(" %i : %i\n",i := 1 to *L,L[i]) end     procedure longestselfrefseq(N) #: find longest sequences from 1 to N   mlen := 0 every L := selfrefseq(n := 1 to N) do { if mlen <:= *L then ML := [L] else if mlen = *L then put(ML,L) }   return ML end   procedure selfrefseq(n) #: return list of sequence oeis:A036058 for seed n S := set() L := [] every p := seq(1) do if member(S,n) then return L # ends at a repeat else { insert(S,n) put(L,n) n := nextselfrefseq(n) } end   procedure nextselfrefseq(n) #: return next element of sequence oeis:A036058 every (Counts := table(0))[integer(!n)] +:= 1 # count digits every (n := "") ||:= (0 < Counts[i := 9 to 0 by -1]) || i # assemble counts return integer(n) end
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#Raku
Raku
sub intersection ($L11, $L12, $L21, $L22) { my ($Δ1x, $Δ1y) = $L11 »-« $L12; my ($Δ2x, $Δ2y) = $L21 »-« $L22; my $n1 = $L11[0] * $L12[1] - $L11[1] * $L12[0]; my $n2 = $L21[0] * $L22[1] - $L21[1] * $L22[0]; my $n3 = 1 / ($Δ1x * $Δ2y - $Δ2x * $Δ1y); (($n1 * $Δ2x - $n2 * $Δ1x) * $n3, ($n1 * $Δ2y - $n2 * $Δ1y) * $n3) }     sub is-inside ($p1, $p2, $p3) { ($p2[0] - $p1[0]) * ($p3[1] - $p1[1]) > ($p2[1] - $p1[1]) * ($p3[0] - $p1[0]) }   sub sutherland-hodgman (@polygon, @clip) { my @output = @polygon; my $clip-point1 = @clip.tail; for @clip -> $clip-point2 { my @input = @output; @output = (); my $start = @input.tail; for @input -> $end { if is-inside($clip-point1, $clip-point2, $end) { @output.push: intersection($clip-point1, $clip-point2, $start, $end) unless is-inside($clip-point1, $clip-point2, $start); @output.push: $end; } elsif is-inside($clip-point1, $clip-point2, $start) { @output.push: intersection($clip-point1, $clip-point2, $start, $end); } $start = $end; } $clip-point1 = $clip-point2; } @output }   my @polygon = (50, 150), (200, 50), (350, 150), (350, 300), (250, 300), (200, 250), (150, 350), (100, 250), (100, 200);   my @clip = (100, 100), (300, 100), (300, 300), (100, 300);   my @clipped = sutherland-hodgman(@polygon, @clip);   say "Clipped polygon: ", @clipped;   # Output an SVG as well as it is easier to visualize use SVG; my $outfile = 'Sutherland-Hodgman-polygon-clipping-perl6.svg'.IO.open(:w); $outfile.say: SVG.serialize( svg => [ :400width, :400height, :rect[ :400width, :400height, :fill<white> ], :text[ :10x, :20y, "Polygon (blue)" ], :text[ :10x, :35y, "Clip port (green)" ], :text[ :10x, :50y, "Clipped polygon (red)" ], :polyline[ :points(@polygon.join: ','), :style<stroke:blue>, :fill<blue>, :opacity<.3> ], :polyline[ :points( @clip.join: ','), :style<stroke:green>, :fill<green>, :opacity<.3> ], :polyline[ :points(@clipped.join: ','), :style<stroke:red>, :fill<red>, :opacity<.5> ], ], );
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#HicEst
HicEst
CALL SymmDiff("John,Serena,Bob,Mary,Serena,", "Jim,Mary,John,Jim,Bob,") CALL SymmDiff("John,Bob,Mary,Serena,", "Jim,Mary,John,Bob,")   SUBROUTINE SymmDiff(set1, set2) CHARACTER set1, set2, answer*50 answer = " " CALL setA_setB( set1, set2, answer ) CALL setA_setB( set2, set1, answer ) WRITE(Messagebox,Name) answer ! answer = "Serena,Jim," in both cases END   SUBROUTINE setA_setB( set1, set2, differences ) CHARACTER set1, set2, differences, a*100 a = set1 EDIT(Text=a, $inLeXicon=set2) ! eg a <= $John,Serena,$Bob,$Mary,Serena, EDIT(Text=a, Right="$", Mark1, Right=",", Mark2, Delete, DO) ! Serena,Serena, EDIT(Text=a, Option=1, SortDelDbls=a) ! Option=1: keep case; Serena, differences = TRIM( differences ) // a END
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Racket
Racket
  #!/usr/bin/env racket #lang racket (define file "NOTES.TXT") (require racket/date) (command-line #:args notes (if (null? notes) (if (file-exists? file) (call-with-input-file* file (λ(i) (copy-port i (current-output-port)))) (raise-user-error 'notes "missing ~a file" file)) (call-with-output-file* file #:exists 'append (λ(o) (fprintf o "~a\n\t~a\n" (date->string (current-date) #t) (string-join notes))))))  
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Raku
Raku
my $file = 'notes.txt';   multi MAIN() { print slurp($file); }   multi MAIN(*@note) { my $fh = open($file, :a); $fh.say: DateTime.now, "\n\t", @note; $fh.close; }
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#Stata
Stata
sca a=200 sca b=200 sca n=2.5 twoway function y=b*(1-(abs(x/a))^n)^(1/n), range(-200 200) || function y=-b*(1-(abs(x/a))^n)^(1/n), range(-200 200)
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#Wren
Wren
import "/sort" for Sort import "/fmt" for Fmt   var cubesSum = {} var taxicabs = []   for (i in 1..1199) { for (j in i+1..1200) { var sum = i*i*i + j*j*j if (!cubesSum[sum]) { cubesSum[sum] = [i, j] } else { taxicabs.add([sum, cubesSum[sum], [i, j]]) } } } var cmp = Fn.new { |a, b| (a[0] - b[0]).sign } Sort.quick(taxicabs, 0, taxicabs.count-1, cmp) // remove those numbers which have additional pairs of cubes for (i in taxicabs.count-2..0) { if (taxicabs[i][0] == taxicabs[i+1][0]) taxicabs.removeAt(i+1) }   System.print("The first 25 taxicab numbers are:") for (i in 1..25) { var t = taxicabs[i-1] Fmt.lprint("$2d: $,7d = $2d³ + $2d³ = $2d³ + $2d³", [i, t[0], t[1][0], t[1][1], t[2][0], t[2][1]]) }   System.print("\nThe 2,000th to 2,006th taxicab numbers are:") for (i in 2000..2006) { var t = taxicabs[i-1] Fmt.lprint("$,5d: $,13d = $3d³ + $,5d³ = $3d³ + $,5d³", [i, t[0], t[1][0], t[1][1], t[2][0], t[2][1]]) }
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   Sub convKelvin(temp As Double) Dim f As String = "####.##" Print Using f; temp; Print " degrees Kelvin" Print Using f; temp - 273.15; Print " degrees Celsius" Print Using f; (temp - 273.15) * 1.8 + 32.0; Print " degrees Fahreneit" Print Using f; (temp - 273.15) * 1.8 + 32.0 + 459.67; Print " degrees Rankine" End Sub   convKelvin(0.0) Print convKelvin(21.0) Print Print "Press any key to quit" Sleep
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#True_BASIC
True BASIC
  FUNCTION and3(a, b) IF a < b then LET and3 = a else LET and3 = b END FUNCTION   FUNCTION eq3(a, b) IF a = tDontknow or b = tDontKnow then LET eq3 = tdontknow ELSEIF a = b then LET eq3 = ttrue ELSE LET eq3 = tfalse END IF END FUNCTION   FUNCTION longname3$(i) SELECT CASE i CASE 1 LET longname3$ = "Don't know" CASE 2 LET longname3$ = "True" CASE else LET longname3$ = "False" END SELECT END FUNCTION   FUNCTION not3(b) LET not3 = 2-b END FUNCTION   FUNCTION or3(a, b) IF a > b then LET or3 = a else LET or3 = b END FUNCTION   FUNCTION shortname3$(i) LET shortname3$ = ("F?T")[i+1:i+1+1-1] END FUNCTION   FUNCTION xor3(a, b) LET xor3 = not3(eq3(a,b)) END FUNCTION   LET tfalse = 0 LET tdontknow = 1 LET ttrue = 2   PRINT "Nombres cortos y largos para valores lógicos ternarios:" FOR i = tfalse to ttrue PRINT shortname3$(i); " "; longname3$(i) NEXT i PRINT PRINT "Funciones de parámetro único" PRINT "x"; " "; "=x"; " "; "not(x)" FOR i = tfalse to ttrue PRINT shortname3$(i); " "; shortname3$(i); " "; shortname3$(not3(i)) NEXT i PRINT PRINT "Funciones de doble parámetro" PRINT "x"; " "; "y"; " "; "x AND y"; " "; "x OR y"; " "; "x EQ y"; " "; "x XOR y" FOR a = tfalse to ttrue FOR b = tfalse to ttrue PRINT shortname3$(a); " "; shortname3$(b); " "; PRINT shortname3$(and3(a,b)); " "; shortname3$(or3(a,b)); " "; PRINT shortname3$(eq3(a,b)); " "; shortname3$(xor3(a,b)) NEXT b NEXT a END  
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Ring
Ring
  # Project : The Twelve Days of Christmas   gifts = "A partridge in a pear tree,Two turtle doves,Three french hens,Four calling birds,Five golden rings,Six geese a-laying,Seven swans a-swimming,Eight maids a-milking,Nine ladies dancing,Ten lords a-leaping,Eleven pipers piping,Twelve drummers drumming" days = "first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth" lstgifts = str2list(substr(gifts,",", nl)) lstdays = str2list(substr(days, " ", nl)) for i = 1 to 12 see "On the "+ lstdays[i]+ " day of Christmas" + nl see "My true love gave to me:" + nl for j = i to 1 step -1 if i > 1 and j = 1 see "and " + nl ok see "" + lstgifts[j] + nl next see nl next    
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Ruby
Ruby
gifts = "A partridge in a pear tree Two turtle doves and Three french hens Four calling birds Five golden rings Six geese a-laying Seven swans a-swimming Eight maids a-milking Nine ladies dancing Ten lords a-leaping Eleven pipers piping Twelve drummers drumming".split("\n")   days = %w(first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth)   days.each_with_index do |day, i| puts "On the #{day} day of Christmas" puts "My true love gave to me:" puts gifts[0, i+1].reverse puts end
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Swift
Swift
// // Reader.swift //   import Foundation   class Reader: NSObject { let inputPath = "~/Desktop/input.txt".stringByExpandingTildeInPath var gotNumberOfLines = false   override init() { super.init() NSNotificationCenter.defaultCenter().addObserver(self, selector: "linesPrinted:", name: "LinesPrinted", object: nil) }   deinit { NSNotificationCenter.defaultCenter().removeObserver(self) }   // Selector for the number of lines printed func linesPrinted(not:NSNotification) { println(not.object!) self.gotNumberOfLines = true exit(0) }   func readFile() { var err:NSError? let fileString = NSString(contentsOfFile: self.inputPath, encoding: NSUTF8StringEncoding, error: &err)   if let lines = fileString?.componentsSeparatedByString("\n") { for line in lines { NSNotificationCenter.defaultCenter().postNotificationName("Line", object: line) } NSNotificationCenter.defaultCenter().postNotificationName("LineNumberRequest", object: nil)   while !self.gotNumberOfLines { sleep(1 as UInt32) } } } }
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#SystemVerilog
SystemVerilog
program main;   mailbox#(bit) p2c_cmd = new; mailbox#(string) p2c_data = new; mailbox#(int) c2p_data = new;   initial begin int fh = $fopen("input.txt", "r"); string line; int count; while ($fgets(line, fh)) begin p2c_cmd.put(0); p2c_data.put(line); end p2c_cmd.put(1); c2p_data.get(count); $display( "COUNT: %0d", count ); end   initial begin bit done; int count; while (!done) begin p2c_cmd.get(done); if (done) begin c2p_data.put(count); end else begin string line; p2c_data.get(line); $display( "LINE: %s", line); count++; end end end   endprogram
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Elena
Elena
import extensions; import system'calendar;   public program() { console.printLine(Date.Now); }
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Elixir
Elixir
:os.timestamp # => {MegaSecs, Secs, MicroSecs} :erlang.time # => {Hour, Minute, Second} :erlang.date # => {Year, Month, Day} :erlang.localtime # => {{Year, Month, Day}, {Hour, Minute, Second}} :erlang.universaltime # => {{Year, Month, Day}, {Hour, Minute, Second}}   :calendar.local_time # => {{Year, Month, Day}, {Hour, Minute, Second}} :calendar.universal_time # => {{Year, Month, Day}, {Hour, Minute, Second}}
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#J
J
require'stats' digits=: 10&#.inv"0 :. ([: ".@; (<'x'),~":&.>) summar=: (#/.~ ,@,. ~.)@\:~&.digits sequen=: ~.@(, summar@{:)^:_ values=: ~. \:~&.digits i.1e6 allvar=: [:(#~(=&<.&(10&^.) >./))@~.({~ perm@#)&.(digits"1)
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#Ruby
Ruby
Point = Struct.new(:x,:y) do def to_s; "(#{x}, #{y})" end end   def sutherland_hodgman(subjectPolygon, clipPolygon) # These inner functions reduce the argument passing to # "inside" and "intersection". cp1, cp2, s, e = nil inside = proc do |p| (cp2.x-cp1.x)*(p.y-cp1.y) > (cp2.y-cp1.y)*(p.x-cp1.x) end intersection = proc do dcx, dcy = cp1.x-cp2.x, cp1.y-cp2.y dpx, dpy = s.x-e.x, s.y-e.y n1 = cp1.x*cp2.y - cp1.y*cp2.x n2 = s.x*e.y - s.y*e.x n3 = 1.0 / (dcx*dpy - dcy*dpx) Point[(n1*dpx - n2*dcx) * n3, (n1*dpy - n2*dcy) * n3] end   outputList = subjectPolygon cp1 = clipPolygon.last for cp2 in clipPolygon inputList = outputList outputList = [] s = inputList.last for e in inputList if inside[e] outputList << intersection[] unless inside[s] outputList << e elsif inside[s] outputList << intersection[] end s = e end cp1 = cp2 end outputList end   subjectPolygon = [[50, 150], [200, 50], [350, 150], [350, 300], [250, 300], [200, 250], [150, 350], [100, 250], [100, 200]].collect{|pnt| Point[*pnt]}   clipPolygon = [[100, 100], [300, 100], [300, 300], [100, 300]].collect{|pnt| Point[*pnt]}   puts sutherland_hodgman(subjectPolygon, clipPolygon)
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#Icon_and_Unicon
Icon and Unicon
procedure main()   a := set(["John", "Serena", "Bob", "Mary", "Serena"]) b := set(["Jim", "Mary", "John", "Jim", "Bob"])   showset("a",a) showset("b",b) showset("(a\\b) \xef (b\\a)",(a -- b) ++ (b -- a)) showset("(a\\b)",a -- b) showset("(b\\a)",b -- a) end     procedure showset(n,x) writes(n," = { ") every writes(!x," ") write("}") return end
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#REBOL
REBOL
rebol [ Title: "Notes" URL: http://rosettacode.org/wiki/Take_notes_on_the_command_line ]   notes: %notes.txt   either any [none? args: system/script/args empty? args] [ if exists? notes [print read notes] ] [ write/binary/append notes rejoin [now lf tab args lf] ]
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#REXX
REXX
/*REXX program implements the "NOTES" command (append text to a file from the C.L.).*/ timestamp=right(date(),11,0) time() date('W') /*create a (current) date & time stamp.*/ nFID = 'NOTES.TXT' /*the fileID of the "notes" file. */   if 'f2'x==2 then tab="05"x /*this is an EBCDIC system. */ else tab="09"x /* " " " ASCII " */   if arg()==0 then do while lines(nFID) /*No arguments? Then display the file.*/ say linein(Nfid) /*display a line of file ──► screen. */ end /*while*/ else do call lineout nFID,timestamp /*append the timestamp to "notes" file.*/ call lineout nFID,tab||arg(1) /* " " text " " " */ end /*stick a fork in it, we're all done. */
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#Wren
Wren
import "graphics" for Canvas, Color, Point   class Game { static init() { Canvas.resize(500, 500) // draw 200 concentric superellipses with gradually decreasing 'n'. for (a in 200..1) { superEllipse(a/80, a) } }   static update() {}   static draw(alpha) {}   static superEllipse(n, a) { var hw = Canvas.width / 2 var hh = Canvas.height / 2   // calculate y for each x var y = List.filled(a + 1, 0) for (x in 0..a) { var aa = a.pow(n) var xx = x.pow(n) y[x] = (aa-xx).pow(1/n) }   // draw quadrants var prev = Point.new(hw + a, hh - y[a]) for (x in a-1..0) { var curr = Point.new(hw + x, hh - y[x]) Canvas.line(prev.x, prev.y, curr.x, curr.y, Color.white) prev = Point.new(curr.x, curr.y) }   prev = Point.new(hw, hh + y[0]) for (x in 1..a) { var curr = Point.new(hw + x, hh + y[x]) Canvas.line(prev.x, prev.y, curr.x, curr.y, Color.white) prev = Point.new(curr.x, curr.y) }   prev = Point.new(hw - a, hh + y[a]) for (x in a-1..0) { var curr = Point.new(hw - x, hh + y[x]) Canvas.line(prev.x, prev.y, curr.x, curr.y, Color.white) prev = Point.new(curr.x, curr.y) }   prev = Point.new(hw, hh - y[0]) for (x in 1..a) { var curr = Point.new(hw - x, hh - y[x]) Canvas.line(prev.x, prev.y, curr.x, curr.y, Color.white) prev = Point.new(curr.x, curr.y) } } }
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#XPL0
XPL0
int N, I, J, SI, SJ, Count, Tally; [Count:= 0; N:= 0; repeat Tally:= 0; I:= 1; repeat J:= I+1; repeat if N = I*I*I + J*J*J then [Tally:= Tally+1; if Tally >= 2 then [Count:= Count+1; IntOut(0, Count); Text(0, ": "); IntOut(0, N); Text(0, " = "); IntOut(0, SI); Text(0, "^^3 + "); IntOut(0, SJ); Text(0, "^^3 = "); IntOut(0, I); Text(0, "^^3 + "); IntOut(0, J); Text(0, "^^3"); CrLf(0); J:= 1000; I:= J; ]; SI:= I; SJ:= J; ]; J:= J+1; until I*I*I + J*J*J > N; I:= I+1; until I*I*I*2 > N; N:= N+1; until Count >= 25; ]
http://rosettacode.org/wiki/Taxicab_numbers
Taxicab numbers
A   taxicab number   (the definition that is being used here)   is a positive integer that can be expressed as the sum of two positive cubes in more than one way. The first taxicab number is   1729,   which is: 13   +   123       and also 93   +   103. Taxicab numbers are also known as:   taxi numbers   taxi-cab numbers   taxi cab numbers   Hardy-Ramanujan numbers Task Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format). For each of the taxicab numbers, show the number as well as it's constituent cubes. Extra credit Show the 2,000th taxicab number, and a half dozen more See also A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences. Hardy-Ramanujan Number on MathWorld. taxicab number on MathWorld. taxicab number on Wikipedia   (includes the story on how taxi-cab numbers came to be called).
#zkl
zkl
fcn taxiCabNumbers{ const HeapSZ=0d5_000_000; iCubes:=[1..120].apply("pow",3); sum2cubes:=Data(HeapSZ).fill(0); // BFheap of 1 byte zeros taxiNums:=List(); foreach i,i3 in ([1..].zip(iCubes)){ foreach j,j3 in ([i+1..].zip(iCubes[i,*])){ ij3:=i3+j3; if(z:=sum2cubes[ij3]){ taxiNums.append(T(ij3, z,(ij3-z.pow(3)).toFloat().pow(1.0/3).round().toInt(), i,j)); } else sum2cubes[ij3]=i; } } taxiNums.sort(fcn([(a,_)],[(b,_)]){ a<b }) }
http://rosettacode.org/wiki/Temperature_conversion
Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones: Kelvin, Celsius, Fahrenheit, and Rankine. The Celsius and Kelvin scales have the same magnitude, but different null points. 0 degrees Celsius corresponds to 273.15 kelvin. 0 kelvin is absolute zero. The Fahrenheit and Rankine scales also have the same magnitude, but different null points. 0 degrees Fahrenheit corresponds to 459.67 degrees Rankine. 0 degrees Rankine is absolute zero. The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9. Task Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result. Example K 21.00 C -252.15 F -421.87 R 37.80
#Gambas
Gambas
Public Sub Form_Open() Dim fKelvin As Float   fKelvin = InputBox("Enter a Kelvin value", "Kelvin converter")   Print "Kelvin =\t" & Format(Str(fKelvin), "#.00") Print "Celsius =\t" & Format(Str(fKelvin - 273.15), "#.00") Print "Fahrenheit =\t" & Format(Str(fKelvin * 1.8 - 459.67), "#.00") Print "Rankine =\t" & Format(Str(fKelvin * 1.8), "#.00")   End
http://rosettacode.org/wiki/Ternary_logic
Ternary logic
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value. This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false. Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski. These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945. Example Ternary Logic Operators in Truth Tables: not a ¬ True False Maybe Maybe False True a and b ∧ True Maybe False True True Maybe False Maybe Maybe Maybe False False False False False a or b ∨ True Maybe False True True True True Maybe True Maybe Maybe False True Maybe False if a then b ⊃ True Maybe False True True Maybe False Maybe True Maybe Maybe False True True True a is equivalent to b ≡ True Maybe False True True Maybe False Maybe Maybe Maybe Maybe False False Maybe True Task Define a new type that emulates ternary logic by storing data trits. Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit. Generate a sampling of results using trit variables. Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic. Note:   Setun   (Сетунь) was a   balanced ternary   computer developed in 1958 at   Moscow State University.   The device was built under the lead of   Sergei Sobolev   and   Nikolay Brusentsov.   It was the only modern   ternary computer,   using three-valued ternary logic
#Wren
Wren
var False = -1 var Maybe = 0 var True = 1 var Chrs = ["F", "M", "T"]   class Trit { construct new(v) { if (v != False && v != Maybe && v != True) Fiber.abort("Invalid argument.") _v = v }   v { _v }   ! { Trit.new(-_v) }   &(other) { (_v < other.v) ? this : other }   |(other) { (_v > other.v) ? this : other }   >>(other) { (-_v > other.v) ? !this : other }   ==(other) { Trit.new(_v * other.v) }   toString { Chrs[_v + 1] } }   var trits = [Trit.new(True), Trit.new(Maybe), Trit.new(False)]   System.print("not") System.print("-------") for (t in trits) System.print(" %(t) | %(!t)")   System.print("\nand | T M F") System.print("-------------") for (t in trits) { System.write(" %(t) | ") for (u in trits) System.write("%(t & u) ") System.print() }   System.print("\nor | T M F") System.print("-------------") for (t in trits) { System.write(" %(t) | ") for (u in trits) System.write("%(t | u) ") System.print() }   System.print("\nimp | T M F") System.print("-------------") for (t in trits) { System.write(" %(t) | ") for (u in trits) System.write("%(t >> u) ") System.print() }   System.print("\neqv | T M F") System.print("-------------") for (t in trits) { System.write(" %(t) | ") for (u in trits) System.write("%(t == u) ") System.print() }
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Run_BASIC
Run BASIC
gifts$ = " A partridge in a pear tree., Two turtle doves, Three french hens, Four calling birds, Five golden rings, Six geese a-laying, Seven swans a-swimming, Eight maids a-milking, Nine ladies dancing, Ten lords a-leaping, Eleven pipers piping, Twelve drummers drumming"   days$ = "first second third fourth fifth sixth seventh eighth ninth tenth eleventh twelfth"   for i = 1 to 12 print "On the ";word$(days$,i," ");" day of Christmas" print "My true love gave to me:" for j = i to 1 step -1 if i > 1 and j = 1 then print "and "; print mid$(word$(gifts$,j,","),2) next j print next i  
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas
The Twelve Days of Christmas
Task Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas. The lyrics can be found here. (You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.) 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
#Rust
Rust
fn main() { let days = ["first", "second", "third", "fourth", "fifth", "sixth", "seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth"];   let gifts = ["A Patridge in a Pear Tree", "Two Turtle Doves and", "Three French Hens", "Four Calling Birds", "Five Golden Rings", "Six Geese a Laying", "Seven Swans a Swimming", "Eight Maids a Milking", "Nine Ladies Dancing", "Ten Lords a Leaping", "Eleven Pipers Piping", "Twelve Drummers Drumming"];   for i in 0..12 { println!("On the {} day of Christmas,", days[i]); println!("My true love gave to me:");   for j in (0..i + 1).rev() { println!("{}", gifts[j]); } println!() } }
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#Tcl
Tcl
package require Thread   # Define the input thread set input [thread::create { proc readFile {filename receiver} { set f [open $filename] while {[gets $f line] >= 0} { thread::send $receiver [list line $line] } close $f thread::send $receiver lineCount lines puts "got $lines lines" } thread::wait }] # Define the output thread set output [thread::create { set lines 0 proc line {string} { puts $string incr ::lines } proc lineCount {} {return $::lines} thread::wait }]   # Connect everything together and start the processing thread::send $input [list readFile "input.txt" $output]
http://rosettacode.org/wiki/Synchronous_concurrency
Synchronous concurrency
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes. One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit. This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
#TXR
TXR
(defstruct thread nil suspended cont (:method resume (self) [self.cont]) (:method give (self item) [self.cont item]) (:method get (self) (yield-from run nil)) (:method start (self) (set self.cont (obtain self.(run))) (unless self.suspended self.(resume))) (:postinit (self) self.(start)))   (defstruct consumer thread (count 0) (:method run (self) (whilet ((item self.(get))) (prinl item) (inc self.count))))   (defstruct producer thread consumer (:method run (self) (whilet ((line (get-line))) self.consumer.(give line))))   (let* ((con (new consumer)) (pro (new producer suspended t consumer con))) pro.(resume) (put-line `count = @{con.count}`))
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Emacs_Lisp
Emacs Lisp
(message "%s" (current-time-string)) ;; => "Wed Oct 14 22:21:05 1987"
http://rosettacode.org/wiki/System_time
System time
Task Output the system time   (any units will do as long as they are noted) either by a system command or one built into the language. The system time can be used for debugging, network information, random number seeds, or something as simple as program performance. Related task   Date format See also   Retrieving system time (wiki)
#Erlang
Erlang
1> os:timestamp(). {1250,222584,635452}
http://rosettacode.org/wiki/Summarize_and_say_sequence
Summarize and say sequence
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits: 0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ... The terms generated grow in length geometrically and never converge. Another way to generate a self-referential sequence is to summarize the previous term. Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence. 0, 10, 1110, 3110, 132110, 13123110, 23124110 ... Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term. Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.) Task Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted. Seed Value(s): 9009 9090 9900 Iterations: 21 Sequence: (same for all three seeds except for first element) 9009 2920 192210 19222110 19323110 1923123110 1923224110 191413323110 191433125110 19151423125110 19251413226110 1916151413325110 1916251423127110 191716151413326110 191726151423128110 19181716151413327110 19182716151423129110 29181716151413328110 19281716151423228110 19281716151413427110 19182716152413228110 Related tasks   Fours is the number of letters in the ...   Look-and-say sequence   Number names   Self-describing numbers   Spelling of ordinal numbers 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 Also see   The On-Line Encyclopedia of Integer Sequences.
#Java
Java
import java.util.*; import java.util.concurrent.ConcurrentHashMap; import java.util.stream.IntStream;   public class SelfReferentialSequence {   static Map<String, Integer> cache = new ConcurrentHashMap<>(10_000);   public static void main(String[] args) { Seeds res = IntStream.range(0, 1000_000) .parallel() .mapToObj(n -> summarize(n, false)) .collect(Seeds::new, Seeds::accept, Seeds::combine);   System.out.println("Seeds:"); res.seeds.forEach(e -> System.out.println(Arrays.toString(e)));   System.out.println("\nSequence:"); summarize(res.seeds.get(0)[0], true); }   static int[] summarize(int seed, boolean display) { String n = String.valueOf(seed);   String k = Arrays.toString(n.chars().sorted().toArray()); if (!display && cache.get(k) != null) return new int[]{seed, cache.get(k)};   Set<String> seen = new HashSet<>(); StringBuilder sb = new StringBuilder();   int[] freq = new int[10];   while (!seen.contains(n)) { seen.add(n);   int len = n.length(); for (int i = 0; i < len; i++) freq[n.charAt(i) - '0']++;   sb.setLength(0); for (int i = 9; i >= 0; i--) { if (freq[i] != 0) { sb.append(freq[i]).append(i); freq[i] = 0; } } if (display) System.out.println(n); n = sb.toString(); }   cache.put(k, seen.size());   return new int[]{seed, seen.size()}; }   static class Seeds { int largest = Integer.MIN_VALUE; List<int[]> seeds = new ArrayList<>();   void accept(int[] s) { int size = s[1]; if (size >= largest) { if (size > largest) { largest = size; seeds.clear(); } seeds.add(s); } }   void combine(Seeds acc) { acc.seeds.forEach(this::accept); } } }
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#Rust
Rust
#[derive(Debug, Clone)] struct Point { x: f64, y: f64, }   #[derive(Debug, Clone)] struct Polygon(Vec<Point>);   fn is_inside(p: &Point, cp1: &Point, cp2: &Point) -> bool { (cp2.x - cp1.x) * (p.y - cp1.y) > (cp2.y - cp1.y) * (p.x - cp1.x) }   fn compute_intersection(cp1: &Point, cp2: &Point, s: &Point, e: &Point) -> Point { let dc = Point { x: cp1.x - cp2.x, y: cp1.y - cp2.y, }; let dp = Point { x: s.x - e.x, y: s.y - e.y, }; let n1 = cp1.x * cp2.y - cp1.y * cp2.x; let n2 = s.x * e.y - s.y * e.x; let n3 = 1.0 / (dc.x * dp.y - dc.y * dp.x); Point { x: (n1 * dp.x - n2 * dc.x) * n3, y: (n1 * dp.y - n2 * dc.y) * n3, } }   fn sutherland_hodgman_clip(subject_polygon: &Polygon, clip_polygon: &Polygon) -> Polygon { let mut result_ring = subject_polygon.0.clone(); let mut cp1 = clip_polygon.0.last().unwrap(); for cp2 in &clip_polygon.0 { let input = result_ring; let mut s = input.last().unwrap(); result_ring = vec![]; for e in &input { if is_inside(e, cp1, cp2) { if !is_inside(s, cp1, cp2) { result_ring.push(compute_intersection(cp1, cp2, s, e)); } result_ring.push(e.clone()); } else if is_inside(s, cp1, cp2) { result_ring.push(compute_intersection(cp1, cp2, s, e)); } s = e; } cp1 = cp2; } Polygon(result_ring) }   fn main() { let _p = |x: f64, y: f64| Point { x, y }; let subject_polygon = Polygon(vec![ _p(50.0, 150.0), _p(200.0, 50.0), _p(350.0, 150.0), _p(350.0, 300.0), _p(250.0, 300.0), _p(200.0, 250.0), _p(150.0, 350.0), _p(100.0, 250.0), _p(100.0, 200.0), ]); let clip_polygon = Polygon(vec![ _p(100.0, 100.0),_p(300.0, 100.0),_p(300.0, 300.0),_p(100.0, 300.0), ]); let result = sutherland_hodgman_clip(&subject_polygon, &clip_polygon); println!("{:?}", result); }
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping
Sutherland-Hodgman polygon clipping
The   Sutherland-Hodgman clipping algorithm   finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”). It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed. Task Take the closed polygon defined by the points: [ ( 50 , 150 ) , ( 200 , 50 ) , ( 350 , 150 ) , ( 350 , 300 ) , ( 250 , 300 ) , ( 200 , 250 ) , ( 150 , 350 ) , ( 100 , 250 ) , ( 100 , 200 ) ] {\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]} and clip it by the rectangle defined by the points: [ ( 100 , 100 ) , ( 300 , 100 ) , ( 300 , 300 ) , ( 100 , 300 ) ] {\displaystyle [(100,100),(300,100),(300,300),(100,300)]} Print the sequence of points that define the resulting clipped polygon. Extra credit Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon. (When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
#Scala
Scala
import javax.swing.{ JFrame, JPanel }   object SutherlandHodgman extends JFrame with App { import java.awt.BorderLayout   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) setVisible(true) val content = getContentPane() content.setLayout(new BorderLayout()) content.add(SutherlandHodgmanPanel, BorderLayout.CENTER) setTitle("SutherlandHodgman") pack() setLocationRelativeTo(null) }   object SutherlandHodgmanPanel extends JPanel { import java.awt.{ Color, Graphics, Graphics2D }   setPreferredSize(new java.awt.Dimension(600, 500))   // subject and clip points are assumed to be valid val subject = Seq((50D, 150D), (200D, 50D), (350D, 150D), (350D, 300D), (250D, 300D), (200D, 250D), (150D, 350D), (100D, 250D), (100D, 200D)) val clipper = Seq((100D, 100D), (300D, 100D), (300D, 300D), (100D, 300D)) var result = subject   val len = clipper.size for (i <- 0 until len) { val len2 = result.size val input = result result = Seq()   val A = clipper((i + len - 1) % len) val B = clipper(i)   for (j <- 0 until len2) { val P = input((j + len2 - 1) % len2) val Q = input(j)   if (inside(A, B, Q)) { if (!inside(A, B, P)) result = result :+ intersection(A, B, P, Q) result = result :+ Q } else if (inside(A, B, P)) result = result :+ intersection(A, B, P, Q) } }   override def paintComponent(g: Graphics) { import java.awt.RenderingHints._   super.paintComponent(g) val g2 = g.asInstanceOf[Graphics2D] g2.translate(80, 60) g2.setStroke(new java.awt.BasicStroke(3)) g2.setRenderingHint(KEY_ANTIALIASING, VALUE_ANTIALIAS_ON) g2.draw_polygon(subject, Color.blue) g2.draw_polygon(clipper, Color.red) g2.draw_polygon(result, Color.green) }   private def inside(a: (Double, Double), b: (Double, Double), c: (Double, Double)) = (a._1 - c._1) * (b._2 - c._2) > (a._2 - c._2) * (b._1 - c._1)   private def intersection(a: (Double, Double), b: (Double, Double), p: (Double, Double), q: (Double, Double)) = { val A1 = b._2 - a._2 val B1 = a._1 - b._1 val C1 = A1 * a._1 + B1 * a._2 val A2 = q._2 - p._2 val B2 = p._1 - q._1 val C2 = A2 * p._1 + B2 * p._2   val det = A1 * B2 - A2 * B1 ((B2 * C1 - B1 * C2) / det, (A1 * C2 - A2 * C1) / det) }   private implicit final class Polygon_drawing(g: Graphics2D) { def draw_polygon(points: Seq[(Double, Double)], color: Color) { g.setColor(color) val len = points.length val line = new java.awt.geom.Line2D.Double() for (i <- 0 until len) { val p1 = points(i) val p2 = points((i + 1) % len) line.setLine(p1._1, p1._2, p2._1, p2._2) g.draw(line) } } } }
http://rosettacode.org/wiki/Symmetric_difference
Symmetric difference
Task Given two sets A and B, compute ( A ∖ B ) ∪ ( B ∖ A ) . {\displaystyle (A\setminus B)\cup (B\setminus A).} That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B. In other words: ( A ∪ B ) ∖ ( A ∩ B ) {\displaystyle (A\cup B)\setminus (A\cap B)} (the set of items that are in at least one of A or B minus the set of items that are in both A and B). Optionally, give the individual differences ( A ∖ B {\displaystyle A\setminus B} and B ∖ A {\displaystyle B\setminus A} ) as well. Test cases A = {John, Bob, Mary, Serena} B = {Jim, Mary, John, Bob} Notes If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order. In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
#J
J
A=: ~.;:'John Serena Bob Mary Serena' B=: ~. ;:'Jim Mary John Jim Bob'   (A-.B) , (B-.A) NB. Symmetric Difference ┌──────┬───┐ │Serena│Jim│ └──────┴───┘ A (-. , -.~) B NB. Tacit equivalent ┌──────┬───┐ │Serena│Jim│ └──────┴───┘
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Ruby
Ruby
notes = 'NOTES.TXT' if ARGV.empty? File.copy_stream(notes, $stdout) rescue nil else File.open(notes, 'a') {|file| file.puts "%s\n\t%s" % [Time.now, ARGV.join(' ')]} end
http://rosettacode.org/wiki/Take_notes_on_the_command_line
Take notes on the command line
Take notes on the command line is part of Short Circuit's Console Program Basics selection. Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists. If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline. Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT. If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
#Rust
Rust
extern crate chrono;   use std::fs::OpenOptions; use std::io::{self, BufReader, BufWriter}; use std::io::prelude::*; use std::env;   const FILENAME: &str = "NOTES.TXT";   fn show_notes() -> Result<(), io::Error> { let file = OpenOptions::new() .read(true) .create(true) // create the file if not found .write(true) // necessary to create the file .open(FILENAME)?; let mut buf_reader = BufReader::new(file); let mut contents = String::new(); buf_reader.read_to_string(&mut contents)?; println!("{}", contents); Ok(()) }   fn add_to_notes(note: &str) -> Result<(), io::Error> { let file = OpenOptions::new() .append(true) // disables overwriting, writes to the end of the file .create(true) .open(FILENAME)?; let mut buf_writer = BufWriter::new(file);   let date_and_time = chrono::Local::now(); writeln!(buf_writer, "{}", date_and_time)?;   writeln!(buf_writer, "\t{}", note) }   fn main() { let note = env::args().skip(1).collect::<Vec<_>>();   if note.is_empty() { show_notes().expect("failed to print NOTES.TXT"); } else { add_to_notes(&note.join(" ")).expect("failed to write to NOTES.TXT"); } }
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#XPL0
XPL0
def X0=640/2, Y0=480/2, Scale=25.0, N=2.5; real X, Y; int IX, IY;   proc OctPoint; [ Point(X0+IX, Y0-IY, $F); Point(X0-IX, Y0-IY, $F); Point(X0+IX, Y0+IY, $F); Point(X0-IX, Y0+IY, $F); Point(X0+IY, Y0-IX, $F); Point(X0-IY, Y0-IX, $F); Point(X0+IY, Y0+IX, $F); Point(X0-IY, Y0+IX, $F); ];   [SetVid($101); \VESA graphics 640x480x8 IX:= 0; repeat X:= float(IX)/Scale; Y:= Pow(200.0 - Pow(X,N), 1.0/N); IY:= fix(Y*Scale); OctPoint; IX:= IX+1; until IX >= IY; ]
http://rosettacode.org/wiki/Superellipse
Superellipse
A superellipse is a geometric figure defined as the set of all points (x, y) with | x a | n + | y b | n = 1 , {\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,} where n, a, and b are positive numbers. Task Draw a superellipse with n = 2.5, and a = b = 200
#Yabasic
Yabasic
open window 700, 600 backcolor 0,0,0 clear window   a=200 b=200 n=2.5 na=2/n t=.01 color 0,0,255 for i = 0 to 314 xp=a*sig(cos(t))*abs((cos(t)))^na+350 yp=b*sig(sin(t))*abs((sin(t)))^na+275 t=t+.02 line to xp, yp next i