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http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#Logtalk
Logtalk
dot_product(A, B, Sum) :- dot_product(A, B, 0, Sum).   dot_product([], [], Sum, Sum). dot_product([A| As], [B| Bs], Acc, Sum) :- Acc2 is Acc + A*B, dot_product(As, Bs, Acc2, Sum).
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead of any character that is immediately repeated. If a character string has a specified   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). A specified   immediately repeated   character is any specified character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   squeeze.} Examples In the following character string with a specified   immediately repeated   character of   e: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   e   is an specified repeated character,   indicated by an underscore (above),   even though they (the characters) appear elsewhere in the character string. So, after squeezing the string, the result would be: The better the 4-whel drive, the further you'll be from help when ya get stuck! Another example: In the following character string,   using a specified immediately repeated character   s: headmistressship The "squeezed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate a   specified immediately repeated   character and   squeeze   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   specified repeated character   (to be searched for and possibly squeezed):   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: immediately string repeated number character ( ↓ a blank, a minus, a seven, a period) ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ' ' ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ '-' 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ '7' 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ '.' 5 ║ --- Harry S Truman ║ (below) ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ ↑ │ │ For the 5th string (Truman's signature line), use each of these specified immediately repeated characters: • a blank • a minus • a lowercase r Note:   there should be seven results shown,   one each for the 1st four strings,   and three results for the 5th string. 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
#Vlang
Vlang
// Returns squeezed string, original and new lengths in // unicode code points (not normalized). fn squeeze(s string, c string) (string, int, int) { mut r := s.runes() mut t := c.runes()[0] le, mut del := r.len, 0 for i := le - 2; i >= 0; i-- { if r[i] == t && r[i] == r[i+1] { r.delete(i) del++ } } if del == 0 { return s, le, le } r = r[..le-del] return r.string(), le, r.len }   fn main() { strings := [ "", '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ', "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman ", "The better the 4-wheel drive, the further you'll be from help when ya get stuck!", "headmistressship", "aardvark", "😍😀🙌💃😍😍😍🙌", ] chars := [[' '], ['-'], ['7'], ['.'], [' ', '-', 'r'], ['e'], ['s'], ['a'], ['😍']]   for i, s in strings { for c in chars[i] { ss, olen, slen := squeeze(s, c) println("specified character = $c") println("original : length = ${olen:2}, string = «««$s»»»") println("squeezed : length = ${slen:2}, string = «««$ss»»»\n") } } }
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead of any character that is immediately repeated. If a character string has a specified   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). A specified   immediately repeated   character is any specified character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   squeeze.} Examples In the following character string with a specified   immediately repeated   character of   e: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   e   is an specified repeated character,   indicated by an underscore (above),   even though they (the characters) appear elsewhere in the character string. So, after squeezing the string, the result would be: The better the 4-whel drive, the further you'll be from help when ya get stuck! Another example: In the following character string,   using a specified immediately repeated character   s: headmistressship The "squeezed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate a   specified immediately repeated   character and   squeeze   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   specified repeated character   (to be searched for and possibly squeezed):   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: immediately string repeated number character ( ↓ a blank, a minus, a seven, a period) ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ' ' ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ '-' 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ '7' 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ '.' 5 ║ --- Harry S Truman ║ (below) ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ ↑ │ │ For the 5th string (Truman's signature line), use each of these specified immediately repeated characters: • a blank • a minus • a lowercase r Note:   there should be seven results shown,   one each for the 1st four strings,   and three results for the 5th string. 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
#Wren
Wren
import "/fmt" for Fmt   // Returns squeezed string, original and new lengths in // unicode code points (not normalized). var squeeze = Fn.new { |s, ch| var c = s.codePoints.toList var le = c.count if (le < 2) return [s, le, le] for (i in le-2..0) { if (c[i] == ch.codePoints[0] && c[i] == c[i+1]) c.removeAt(i) } var cc = c.reduce("") { |acc, cp| acc + String.fromCodePoint(cp) } return [cc, le, cc.count] }   var strings = [ "", "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ", "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman ", "The better the 4-wheel drive, the further you'll be from help when ya get stuck!", "headmistressship", "aardvark", "😍😀🙌💃😍😍😍🙌" ]   var chars = [ [" "], ["-"], ["7"], ["."], [" ", "-", "r"], ["e"], ["s"], ["a"], ["😍"] ]   var i = 0 for (s in strings) { for (ch in chars[i]) { var r = squeeze.call(s, ch) System.print("Specified character = '%(ch)'") System.print("original : length = %(Fmt.d(2, r[1])), string = «««%(s)»»»") System.print("squeezed : length = %(Fmt.d(2, r[2])), string = «««%(r[0])»»»\n") } i = i + 1 }
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and must add up to   12. The Chief of the Police doesn't like odd numbers and wants to have an even number for his department. Task Write a computer program which outputs all valid combinations. Possible output   (for the 1st and 14th solutions): --police-- --sanitation-- --fire-- 2 3 7 6 5 1
#Delphi
Delphi
  program Department_numbers;   {$APPTYPE CONSOLE}   uses System.SysUtils;   var i, j, k, count: Integer;   begin writeln('Police Sanitation Fire'); writeln('------ ---------- ----'); count := 0; i := 2; while i < 7 do begin for j := 1 to 7 do begin if j = i then Continue; for k := 1 to 7 do begin if (k = i) or (k = j) then Continue; if i + j + k <> 12 then Continue; writeln(format('  %d  %d  %d', [i, j, k])); inc(count); end; end; inc(i, 2); end; writeln(#10, count, ' valid combinations'); readln; end.
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#Oforth
Oforth
Object Class new: Delegate1   Object Class new: Delegate2 Delegate2 method: thing "Delegate implementation" println ;   Object Class new: Delegator(delegate) Delegator method: initialize  := delegate ;   Delegator method: operation @delegate respondTo(#thing) ifTrue: [ @delegate thing return ] "Default implementation" println ;
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#ooRexx
ooRexx
  delegator = .delegator~new -- no delegate say delegator~operation -- an invalid delegate type delegator~delegate = "Some string" say delegator~operation -- a good delegate delegator~delegate = .thing~new say delegator~operation -- a directory object with a thing entry defined d = .directory~new d~thing = "delegate implementation" delegator~delegate = d say delegator~operation   -- a class we can use as a delegate ::class thing ::method thing return "delegate implementation"   ::class delegator ::method init expose delegate use strict arg delegate = .nil   ::attribute delegate   ::method operation expose delegate if delegate == .nil then return "default implementation"   -- Note: We could use delegate~hasMethod("THING") to check -- for a THING method, but this will fail of the object relies -- on an UNKNOWN method to handle the method. By trapping -- NOMETHOD conditions, we can allow those calls to go -- through signal on nomethod return delegate~thing   nomethod: return "default implementation"  
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#OxygenBasic
OxygenBasic
  class DelegateA 'not implmenting thing() '============== ' string message   end class   class DelegateB 'implementing thing() '============== ' string message   method thing() as string return message end method ' end class     Class Delegator '============== ' has DelegateA dgA has DelegateB dgB ' method operation() as DelegateB dgB.message="Delegate Implementation" return @dgB end method   method thing() as string return "not using Delegate" end method ' end class   '==== 'TEST '====   Delegator dgr let dg=dgr.operation print dgr.thing 'result "not using Delegate" print dg.thing 'result "Delegate Implementation"  
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)   (0,0),(5,0),(2.5,5)   and   (0,4),(2.5,-1),(5,4)   (0,0),(1,1),(0,2)     and   (2,1),(3,0),(3,2)   (0,0),(1,1),(0,2)     and   (2,1),(3,-2),(3,4) Optionally, see what the result is when only a single corner is in contact (there is no definitive correct answer):   (0,0),(1,0),(0,1)   and   (1,0),(2,0),(1,1)
#Perl
Perl
use strict; use warnings;   sub det2D { my $p1 = shift or die "4 Missing first point\n"; my $p2 = shift or die "Missing second point\n"; my $p3 = shift or die "Missing third point\n";   return $p1->{x} * ($p2->{y} - $p3->{y}) + $p2->{x} * ($p3->{y} - $p1->{y}) + $p3->{x} * ($p1->{y} - $p2->{y}); }   sub checkTriWinding { my $p1 = shift or die "14 Missing first point\n"; my $p2 = shift or die "Missing second point\n"; my $p3 = shift or die "Missing third point\n"; my $allowReversed = shift;   my $detTri = det2D($p1, $$p2, $$p3); if ($detTri < 0.0) { if ($allowReversed) { my $t = $$p3; $$p3 = $$p2; $$p2 = $t; } else { die "triangle has wrong winding direction"; } } return undef; }   sub boundaryCollideChk { my $p1 = shift or die "33 Missing first point\n"; my $p2 = shift or die "Missing second point\n"; my $p3 = shift or die "Missing third point\n"; my $eps = shift;   return det2D($p1, $p2, $p3) < $eps; }   sub boundaryDoesntCollideChk { my $p1 = shift or die "42 Missing first point\n"; my $p2 = shift or die "Missing second point\n"; my $p3 = shift or die "Missing third point\n"; my $eps = shift;   return det2D($p1, $p2, $p3) <= $eps; }   sub triTri2D { my $t1 = shift or die "Missing first triangle to calculate with\n"; my $t2 = shift or die "Missing second triangle to calculate with\n"; my $eps = shift; my $allowReversed = shift; my $onBoundary = shift;   # triangles must be expressed anti-clockwise checkTriWinding($t1->[0], \$t1->[1], \$t1->[2], $allowReversed); checkTriWinding($t2->[0], \$t2->[1], \$t2->[2], $allowReversed);   my $chkEdge; if ($onBoundary) { # points on the boundary are considered as colliding $chkEdge = \&boundaryCollideChk; } else { # points on the boundary are NOT considered as colliding $chkEdge = \&boundaryDoesntCollideChk; }   # for edge E of triangle 1 foreach my $i (0, 1, 2) { my $j = ($i + 1) % 3;   # check all points of triangle 2 lay on the external side of edge E # if they do, the triangles do not collide if ($chkEdge->($t1->[$i], $t1->[$j], $t2->[0], $eps) and $chkEdge->($t1->[$i], $t1->[$j], $t2->[1], $eps) and $chkEdge->($t1->[$i], $t1->[$j], $t2->[2], $eps)) { return 0; # false } }   # for edge E of triangle 2 foreach my $i (0, 1, 2) { my $j = ($i + 1) % 3;   # check all points of triangle 1 lay on the external side of edge E # if they do, the triangles do not collide if ($chkEdge->($t2->[$i], $t2->[$j], $t1->[0], $eps) and $chkEdge->($t2->[$i], $t2->[$j], $t1->[1], $eps) and $chkEdge->($t2->[$i], $t2->[$j], $t1->[2], $eps)) { return 0; # false } }   return 1; # true }   sub formatTri { my $t = shift or die "Missing triangle to format\n"; my $p1 = $t->[0]; my $p2 = $t->[1]; my $p3 = $t->[2]; return "Triangle: ($p1->{x}, $p1->{y}), ($p2->{x}, $p2->{y}), ($p3->{x}, $p3->{y})"; }   sub overlap { my $t1 = shift or die "Missing first triangle to calculate with\n"; my $t2 = shift or die "Missing second triangle to calculate with\n"; my $eps = shift; my $allowReversed = shift or 0; # false my $onBoundary = shift or 1; # true   unless ($eps) { $eps = 0.0; }   if (triTri2D($t1, $t2, $eps, $allowReversed, $onBoundary)) { return "overlap\n"; } else { return "do not overlap\n"; } }   ################################################### # Main ###################################################   my @t1 = ({x=>0, y=>0}, {x=>5, y=>0}, {x=>0, y=>5}); my @t2 = ({x=>0, y=>0}, {x=>5, y=>0}, {x=>0, y=>6}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2), "\n";   @t1 = ({x=>0, y=>0}, {x=>0, y=>5}, {x=>5, y=>0}); @t2 = ({x=>0, y=>0}, {x=>0, y=>5}, {x=>5, y=>0}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2, 0.0, 1), "\n";   @t1 = ({x=>0, y=>0}, {x=>5, y=>0}, {x=>0, y=>5}); @t2 = ({x=>-10, y=>0}, {x=>-5, y=>0}, {x=>-1, y=>6}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2), "\n";   @t1 = ({x=>0, y=>0}, {x=>5, y=>0}, {x=>2.5, y=>5}); @t2 = ({x=>0, y=>4}, {x=>2.5, y=>-1}, {x=>5, y=>4}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2), "\n";   @t1 = ({x=>0, y=>0}, {x=>1, y=>1}, {x=>0, y=>2}); @t2 = ({x=>2, y=>1}, {x=>3, y=>0}, {x=>3, y=>2}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2), "\n";   @t1 = ({x=>0, y=>0}, {x=>1, y=>1}, {x=>0, y=>2}); @t2 = ({x=>2, y=>1}, {x=>3, y=>-2}, {x=>3, y=>4}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2), "\n";   # Barely touching @t1 = ({x=>0, y=>0}, {x=>1, y=>0}, {x=>0, y=>1}); @t2 = ({x=>1, y=>0}, {x=>2, y=>0}, {x=>1, y=>1}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2, 0.0, 0, 1), "\n";   # Barely touching @t1 = ({x=>0, y=>0}, {x=>1, y=>0}, {x=>0, y=>1}); @t2 = ({x=>1, y=>0}, {x=>2, y=>0}, {x=>1, y=>1}); print formatTri(\@t1), " and\n", formatTri(\@t2), "\n", overlap(\@t1, \@t2, 0.0, 0, 0), "\n";
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Groovy
Groovy
// Gets the first filesystem root. On most systems this will be / or c:\ def fsRoot = File.listRoots().first()   // Create our list of files (including directories) def files = [ new File("input.txt"), new File(fsRoot, "input.txt"), new File("docs"), new File(fsRoot, "docs") ]   /* We use it.directory to determine whether each file is a regular file or directory. If it is a directory, we delete it with deleteDir(), otherwise we just use delete(). */ files.each{ it.directory ? it.deleteDir() : it.delete() }
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by perm ⁡ ( A ) = ∑ σ ∏ i = 1 n M i , σ i {\displaystyle \operatorname {perm} (A)=\sum _{\sigma }\prod _{i=1}^{n}M_{i,\sigma _{i}}} In both cases the sum is over the permutations σ {\displaystyle \sigma } of the permutations of 1, 2, ..., n. (A permutation's sign is 1 if there are an even number of inversions and -1 otherwise; see parity of a permutation.) More efficient algorithms for the determinant are known: LU decomposition, see for example wp:LU decomposition#Computing the determinant. Efficient methods for calculating the permanent are not known. Related task Permutations by swapping
#PowerShell
PowerShell
  function det-perm ($array) { if($array) { $size = $array.Count function prod($A) { $prod = 1 if($A) { $A | foreach{$prod *= $_} } $prod } function generate($sign, $n, $A) { if($n -eq 1) { $i = 0 $prod = prod @($A | foreach{$array[$i++][$_]}) [pscustomobject]@{det = $sign*$prod; perm = $prod} } else{ for($i = 0; $i -lt ($n - 1); $i += 1) { generate $sign ($n - 1) $A if($n % 2 -eq 0){ $i1, $i2 = $i, ($n-1) $A[$i1], $A[$i2] = $A[$i2], $A[$i1] } else{ $i1, $i2 = 0, ($n-1) $A[$i1], $A[$i2] = $A[$i2], $A[$i1] } $sign *= -1 } generate $sign ($n - 1) $A } } $det = $perm = 0 generate 1 $size @(0..($size-1)) | foreach{ $det += $_.det $perm += $_.perm } [pscustomobject]@{det = "$det"; perm = "$perm"} } else {Write-Error "empty array"} } det-perm 5 det-perm @(@(1,0,0),@(0,1,0),@(0,0,1)) det-perm @(@(0,0,1),@(0,1,0),@(1,0,0)) det-perm @(@(4,3),@(2,5)) det-perm @(@(2,5),@(4,3)) det-perm @(@(4,4),@(2,2))  
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#JavaScript
JavaScript
function divByZero(dividend,divisor) { var quotient=dividend/divisor; if(isNaN(quotient)) return 0; //Can be changed to whatever is desired by the programmer to be 0, false, or Infinity return quotient; //Will return Infinity or -Infinity in cases of, for example, 5/0 or -7/0 respectively } alert(divByZero(0,0));
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#jq
jq
def div(x;y): if y==0 then error("NaN") else x/y end;
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. 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
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   Dim Shared symbols(0 To 15) As UByte For i As Integer = 48 to 57 symbols(i - 48) = i Next For i As Integer = 97 to 102 symbols(i - 87) = i Next   Const plus As UByte = 43 Const minus As Ubyte = 45 Const dot As UByte = 46   Function isNumeric(s As Const String, base_ As Integer = 10) As Boolean If s = "" OrElse s = "." OrElse s = "+" OrElse s = "-" Then Return False Err = 0   If base_ < 2 OrElse base_ > 16 Then Err = 1000 Return False End If   Dim t As String = LCase(s)   If (t[0] = plus) OrElse (t[0] = minus) Then t = Mid(t, 2) End If   If Left(t, 2) = "&h" Then If base_ <> 16 Then Return False t = Mid(t, 3) End if   If Left(t, 2) = "&o" Then If base_ <> 8 Then Return False t = Mid(t, 3) End if   If Left(t, 2) = "&b" Then If base_ <> 2 Then Return False t = Mid(t, 3) End if   If Len(t) = 0 Then Return False Dim As Boolean isValid, hasDot = false   For i As Integer = 0 To Len(t) - 1 isValid = False   For j As Integer = 0 To base_ - 1 If t[i] = symbols(j) Then isValid = True Exit For End If If t[i] = dot Then If CInt(Not hasDot) AndAlso (base_ = 10) Then hasDot = True IsValid = True Exit For End If Return False ' either more than one dot or not base 10 End If Next j   If Not isValid Then Return False Next i   Return True End Function   Dim s As String s = "1234.056789" Print s, " (base 10) => "; isNumeric(s) s = "1234.56" Print s, " (base 7) => "; isNumeric(s, 7) s = "021101" Print s, " (base 2) => "; isNumeric(s, 2) s = "Dog" Print s, " (base 16) => "; isNumeric(s, 16) s = "Bad125" Print s, " (base 16) => "; isNumeric(s, 16) s = "-0177" Print s, " (base 8) => "; isNumeric(s, 8) s = "+123abcd.ef" Print s, " (base 16) => "; isNumeric(s, 8) s = "54321" Print s, " (base 6) => "; isNumeric(s, 6) s = "123xyz" Print s, " (base 10) => "; isNumeric(s) s = "xyz" Print s, " (base 10) => "; isNumeric(s) Print Print "Press any key to quit" Sleep
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as unique   process the strings from left─to─right   if       unique,   display a message saying such   if not unique,   then:   display a message saying such   display what character is duplicated   only the 1st non─unique character need be displayed   display where "both" duplicated characters are in the string   the above messages can be part of a single message   display the hexadecimal value of the duplicated character Use (at least) these five test values   (strings):   a string of length     0   (an empty string)   a string of length     1   which is a single period   (.)   a string of length     6   which contains:   abcABC   a string of length     7   which contains a blank in the middle:   XYZ  ZYX   a string of length   36   which   doesn't   contain the letter "oh": 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ Show all output here on this page. 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
#Nanoquery
Nanoquery
def analyze(s) s = str(s) println "Examining [" + s + "] which has a length of " + str(len(s)) + ":"   if len(s) < 2 println "\tAll characters in the string are unique." return end   seen = list() for i in range(0, len(s) - 2) if s[i] in seen println "\tNot all characters in the string are unique." println "\t'" + s[i] + "' " + format("(0x%x)", ord(s[i])) +\ " is duplicated at positions " + str(i + 1) + " and " +\ str(s.indexOf(s[i]) + 1) return end seen.append(s[i]) end   println "\tAll characters in the string are unique." end   tests = {"", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ"} for s in tests analyze(s) end
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as unique   process the strings from left─to─right   if       unique,   display a message saying such   if not unique,   then:   display a message saying such   display what character is duplicated   only the 1st non─unique character need be displayed   display where "both" duplicated characters are in the string   the above messages can be part of a single message   display the hexadecimal value of the duplicated character Use (at least) these five test values   (strings):   a string of length     0   (an empty string)   a string of length     1   which is a single period   (.)   a string of length     6   which contains:   abcABC   a string of length     7   which contains a blank in the middle:   XYZ  ZYX   a string of length   36   which   doesn't   contain the letter "oh": 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ Show all output here on this page. 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
#Nim
Nim
import unicode, strformat   proc checkUniqueChars(s: string) =   echo fmt"Checking string ""{s}"":" let runes = s.toRunes for i in 0..<runes.high: let rune = runes[i] for j in (i+1)..runes.high: if runes[j] == rune: echo "The string contains duplicate characters." echo fmt"Character {rune} ({int(rune):x}) is present at positions {i+1} and {j+1}." echo "" return echo "All characters in the string are unique." echo ""   const Strings = ["", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ", "hétérogénéité", "🎆🎃🎇🎈", "😍😀🙌💃😍🙌", "🐠🐟🐡🦈🐬🐳🐋🐡"]   for s in Strings: s.checkUniqueChars()
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#Sidef
Sidef
func squeeze(str) { str.gsub(/(.)\1+/, {|s1| s1 }) }   var strings = ["", '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ', "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman ", "The better the 4-wheel drive, the further you'll be from help when ya get stuck!", "headmistressship", "aardvark", "😍😀🙌💃😍😍😍🙌"]   strings.each {|str| var ssq = squeeze(str) say "«««#{str}»»» (length: #{str.len})" say "«««#{ssq}»»» (length: #{ssq.len})\n" }
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#Smalltalk
Smalltalk
#( 'The better the 4-wheel drive, the further you''ll be from help when ya get stuck!' 'headmistressship' 'aardvark' '😍😀🙌💃😍😍😍🙌' ) do:[:eachWord | |shortened|   shortened := String streamContents:[:out | eachWord inject:nil into:[:prev :this | prev ~= this ifTrue:[out nextPut:this]. this ] ]. Transcript showCR:( eachWord,'(length:',eachWord size,')' ); showCR:( shortened,'(length:',shortened size,')' ). ]
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as all the same character(s)   process the strings from left─to─right   if       all the same character,   display a message saying such   if not all the same character,   then:   display a message saying such   display what character is different   only the 1st different character need be displayed   display where the different character is in the string   the above messages can be part of a single message   display the hexadecimal value of the different character Use (at least) these seven test values   (strings):   a string of length   0   (an empty string)   a string of length   3   which contains three blanks   a string of length   1   which contains:   2   a string of length   3   which contains:   333   a string of length   3   which contains:   .55   a string of length   6   which contains:   tttTTT   a string of length   9   with a blank in the middle:   4444   444k Show all output here on this page. 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
#PicoLisp
PicoLisp
(de equal? (Str) (let (Lst (chop Str) C (car Lst) P 2 F) (prin Str ": ") (for A (cdr Lst) (NIL (= A C) (on F) (prin "First different character " A)) (inc 'P) ) (if F (prinl " at position: " P) (prinl "all characters are the same")) ) ) (equal?) (equal? " ") (equal? "333") (equal? ".55") (equal? "tttTTT")
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as all the same character(s)   process the strings from left─to─right   if       all the same character,   display a message saying such   if not all the same character,   then:   display a message saying such   display what character is different   only the 1st different character need be displayed   display where the different character is in the string   the above messages can be part of a single message   display the hexadecimal value of the different character Use (at least) these seven test values   (strings):   a string of length   0   (an empty string)   a string of length   3   which contains three blanks   a string of length   1   which contains:   2   a string of length   3   which contains:   333   a string of length   3   which contains:   .55   a string of length   6   which contains:   tttTTT   a string of length   9   with a blank in the middle:   4444   444k Show all output here on this page. 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
#Plain_English
Plain English
To run: Start up. Show the uniformity of "". Show the uniformity of " ". Show the uniformity of "2". Show the uniformity of "333". Show the uniformity of ".55". Show the uniformity of "tttTTT". Show the uniformity of "4444 444k". Wait for the escape key. Shut down.   To find the first different character in a string giving a byte and a count: If the string is blank, put -1 into the count; exit. Put the string's first's target into a first letter. Slap a substring on the string. Loop. If a counter is past the string's length, put -1 into the count; exit. Put the substring's first's target into a letter. If the letter is not the first letter, put the letter into the byte; put the counter minus 1 into the count; exit. Add 1 to the substring's first. Repeat.   To show the uniformity of a string: Write """" then the string then """ (length " then the string's length then ") " on the console without advancing. Find the first different character in the string giving a byte and a count. If the count is -1, write "contains all the same character." on the console; exit. Convert the byte to a nibble string. Write "contains a different character at index " then the count then ": '" then the byte then "' (0x" then the nibble string then ")." on the console.
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a round table with five individual seats. For eating each philosopher needs two forks (the resources). There are five forks on the table, one left and one right of each seat. When a philosopher cannot grab both forks it sits and waits. Eating takes random time, then the philosopher puts the forks down and leaves the dining room. After spending some random time thinking about the nature of the universe, he again becomes hungry, and the circle repeats itself. It can be observed that a straightforward solution, when forks are implemented by semaphores, is exposed to deadlock. There exist two deadlock states when all five philosophers are sitting at the table holding one fork each. One deadlock state is when each philosopher has grabbed the fork left of him, and another is when each has the fork on his right. There are many solutions of the problem, program at least one, and explain how the deadlock is prevented.
#REXX
REXX
/*REXX program demonstrates a solution in solving the dining philosophers problem. */ signal on halt /*branches to HALT: (on Ctrl─break).*/ parse arg seed diners /*obtain optional arguments from the CL*/ if datatype(seed, 'W') then call random ,, seed /*this allows for random repeatability.*/ if diners= '' then diners = 'Aristotle, Kant, Spinoza, Marx, Russell' tell= left(seed, 1) \== '+' /*Leading + in SEED? Then no statistics*/ diners= space( translate(diners, , ',') ) /*change to an uncommatized diners list*/ #= words(diners); @.= 0 /*#: the number of dining philosophers.*/ eatL= 15; eatH= 60 /*minimum & maximum minutes for eating.*/ thinkL= 30; thinkH= 180 /* " " " " " thinking*/ forks.= 1 /*indicate that all forks are on table.*/ do tic=1 /*'til halted.*/ /*use "minutes" for time advancement.*/ call grabForks /*determine if anybody can grab 2 forks*/ call passTime /*handle philosophers eating|thinking. */ end /*tic*/ /* ··· and time marches on ··· */ /* [↓] this REXX program was halted,*/ halt: say ' ··· REXX program halted!' /*probably by Ctrl─Break or equivalent.*/ exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ fork: parse arg x 1 ox; x= abs(x) ; L= x - 1 ; if L==0 then L= # /*use "round Robin"*/ if ox<0 then do; forks.L= 1; forks.x=1; return; end /*drop the forks. */ got2= forks.L & forks.x /*get 2 forks │ not*/ if got2 then do; forks.L= 0; forks.x=0; end /*obtained 2 forks */ return got2 /*return with success ··· or failure. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ grabForks: do person=1 for # /*see if any person can grab two forks.*/ if @.person.state\==0 then iterate /*this diner ain't in a waiting state. */ if \fork(person) then iterate /* " " didn't grab two forks. */ @.person.state= 'eating' /* " " is slurping spaghetti. */ @.person.dur= random(eatL, eatH) /*how long will this diner eat pasta ? */ end /*person*/ /* [↑] process the dining philosophers*/ return /*all the diners have been examined. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ passTime: if tell then say /*display a handy blank line separator.*/ do p=1 for # /*handle each of the diner's activity. */ if tell then say right(tic, 9, .) right( word( diners, p), 20), right(word(@.p.state 'waiting',1+(@.p.state==0)),9) right(@.p.dur,5) if @.p.dur==0 then iterate /*this diner is waiting for two forks. */ @.p.dur= @.p.dur - 1 /*indicate single time unit has passed.*/ if @.p.dur\==0 then iterate /*Activity done? No, then keep it up.*/ if @.p.state=='eating' then do /*now, leave the table.*/ call fork -p /*drop the darn forks. */ @.p.state= 'thinking' /*status.*/ @.p.dur= random(thinkL, thinkH) /*length.*/ end /* [↓] a diner goes ──► the table. */ else if @.p.state=='thinking' then @.p.state=0 end /*p*/ /*[↑] P (person)≡ dining philosophers.*/ return /*now, have some human beans grab forks*/
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Racket
Racket
#lang racket/base ;;;; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ;;;; Derived from 'D' Implementation ;;;; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (require racket/date racket/match)   (define seasons '(Chaos Discord Confusion Bureaucracy |The Aftermath|)) (define weekday '(Sweetmorn Boomtime Pungenday Prickle-Prickle |Setting Orange|)) (define apostle '(Mungday Mojoday Syaday Zaraday Maladay)) (define holiday '(Chaoflux Discoflux Confuflux Bureflux Afflux))   (define (ymd->date y m d) (seconds->date (find-seconds 0 0 0 d m y))) (define (leap-year? y) (with-handlers ((exn? (λ (x) #f))) (= 29 (date-day (ymd->date y 2 29)))))   (define (discordian-date d) (define leap? (leap-year? (date-year d))) (define year-day (match* (leap? (date-year-day d)) [(#t (? (λ (D) (>= D 59)) d0)) d0] [(_ d0) (add1 d0)]))   (define season-day (modulo year-day 73)) ; season day (define (list-ref-season l) (define season-index (quotient year-day 73)) (symbol->string (list-ref l season-index)))   (string-append (match* (season-day leap? (date-month d) (date-day d)) [( _ #t 2 29) "St. Tib's Day,"] [((app (match-lambda (5 apostle) (50 holiday) (_ #f)) (and (not #f) special)) _ _ _) (string-append (list-ref-season special) ",")] [( _ _ _ _) (define week-day-name (list-ref weekday (modulo (sub1 year-day) 5))) (format "~a, day ~a of ~a" week-day-name season-day (list-ref-season seasons))]) " in the YOLD " (number->string (+ (date-year d) 1166))))   (displayln (discordian-date (current-date)))   ;; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ;; passing these tests makes me consistent with D implementation (module+ test (require rackunit) (define discordian/ymd (compose discordian-date ymd->date)) (check-equal? (discordian/ymd 2010 7 22) "Pungenday, day 57 of Confusion in the YOLD 3176") (check-equal? (discordian/ymd 2012 2 28) "Prickle-Prickle, day 59 of Chaos in the YOLD 3178") (check-equal? (discordian/ymd 2012 2 29) "St. Tib's Day, in the YOLD 3178"); (check-equal? (discordian/ymd 2012 3 1) "Setting Orange, day 60 of Chaos in the YOLD 3178") (check-equal? (discordian/ymd 2010 1 5) "Mungday, in the YOLD 3176") (check-equal? (discordian/ymd 2011 5 3) "Discoflux, in the YOLD 3177")) ;; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~FIN
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path problem for a graph with non-negative edge path costs, producing a shortest path tree. This algorithm is often used in routing and as a subroutine in other graph algorithms. For a given source vertex (node) in the graph, the algorithm finds the path with lowest cost (i.e. the shortest path) between that vertex and every other vertex. For instance If the vertices of the graph represent cities and edge path costs represent driving distances between pairs of cities connected by a direct road,   Dijkstra's algorithm can be used to find the shortest route between one city and all other cities. As a result, the shortest path first is widely used in network routing protocols, most notably:   IS-IS   (Intermediate System to Intermediate System)   and   OSPF   (Open Shortest Path First). Important note The inputs to Dijkstra's algorithm are a directed and weighted graph consisting of 2 or more nodes, generally represented by:   an adjacency matrix or list,   and   a start node. A destination node is not specified. The output is a set of edges depicting the shortest path to each destination node. An example, starting with a──►b, cost=7, lastNode=a a──►c, cost=9, lastNode=a a──►d, cost=NA, lastNode=a a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►b so a──►b is added to the output.   There is a connection from b──►d so the input is updated to: a──►c, cost=9, lastNode=a a──►d, cost=22, lastNode=b a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►c so a──►c is added to the output.   Paths to d and f are cheaper via c so the input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a a──►f, cost=11, lastNode=c   The lowest cost is a──►f so c──►f is added to the output.   The input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a   The lowest cost is a──►d so c──►d is added to the output.   There is a connection from d──►e so the input is updated to: a──►e, cost=26, lastNode=d   Which just leaves adding d──►e to the output.   The output should now be: [ d──►e c──►d c──►f a──►c a──►b ] Task Implement a version of Dijkstra's algorithm that outputs a set of edges depicting the shortest path to each reachable node from an origin. Run your program with the following directed graph starting at node   a. Write a program which interprets the output from the above and use it to output the shortest path from node   a   to nodes   e   and f. Vertices Number Name 1 a 2 b 3 c 4 d 5 e 6 f Edges Start End Cost a b 7 a c 9 a f 14 b c 10 b d 15 c d 11 c f 2 d e 6 e f 9 You can use numbers or names to identify vertices in your program. See also Dijkstra's Algorithm vs. A* Search vs. Concurrent Dijkstra's Algorithm (youtube)
#Ruby
Ruby
class Graph Vertex = Struct.new(:name, :neighbours, :dist, :prev)   def initialize(graph) @vertices = Hash.new{|h,k| h[k]=Vertex.new(k,[],Float::INFINITY)} @edges = {} graph.each do |(v1, v2, dist)| @vertices[v1].neighbours << v2 @vertices[v2].neighbours << v1 @edges[[v1, v2]] = @edges[[v2, v1]] = dist end @dijkstra_source = nil end   def dijkstra(source) return if @dijkstra_source == source q = @vertices.values q.each do |v| v.dist = Float::INFINITY v.prev = nil end @vertices[source].dist = 0 until q.empty? u = q.min_by {|vertex| vertex.dist} break if u.dist == Float::INFINITY q.delete(u) u.neighbours.each do |v| vv = @vertices[v] if q.include?(vv) alt = u.dist + @edges[[u.name, v]] if alt < vv.dist vv.dist = alt vv.prev = u.name end end end end @dijkstra_source = source end   def shortest_path(source, target) dijkstra(source) path = [] u = target while u path.unshift(u) u = @vertices[u].prev end return path, @vertices[target].dist end   def to_s "#<%s vertices=%p edges=%p>" % [self.class.name, @vertices.values, @edges] end end   g = Graph.new([ [:a, :b, 7], [:a, :c, 9], [:a, :f, 14], [:b, :c, 10], [:b, :d, 15], [:c, :d, 11], [:c, :f, 2], [:d, :e, 6], [:e, :f, 9], ])   start, stop = :a, :e path, dist = g.shortest_path(start, stop) puts "shortest path from #{start} to #{stop} has cost #{dist}:" puts path.join(" -> ")
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displaystyle X} has only one digit. The additive persistence is the number of summations required to obtain the single digit. The task is to calculate the additive persistence and the digital root of a number, e.g.: 627615 {\displaystyle 627615} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; 39390 {\displaystyle 39390} has additive persistence 2 {\displaystyle 2} and digital root of 6 {\displaystyle 6} ; 588225 {\displaystyle 588225} has additive persistence 2 {\displaystyle 2} and digital root of 3 {\displaystyle 3} ; 393900588225 {\displaystyle 393900588225} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; The digital root may be calculated in bases other than 10. See Casting out nines for this wiki's use of this procedure. Digital root/Multiplicative digital root Sum digits of an integer Digital root sequence on OEIS Additive persistence sequence on OEIS Iterated digits squaring
#Phix
Phix
with javascript_semantics procedure digital_root(atom n, integer base=10) integer root, persistence = 1 atom work = n while true do root = 0 while work!=0 do root += remainder(work,base) work = floor(work/base) end while if root<base then exit end if work = root persistence += 1 end while printf(1,"%15d root: %d persistence: %d\n",{n,root,persistence}) end procedure digital_root(627615) digital_root(39390) digital_root(588225) digital_root(393900588225)
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of expression are valued. Examples may be be split into "setup", "problem statement", and "output" sections where the ease and naturalness of stating the problem and getting an answer, as well as the ease and flexibility of modifying the problem are the primary concerns. Example output should be shown here, as well as any comments on the examples flexibility. The problem Baker, Cooper, Fletcher, Miller, and Smith live on different floors of an apartment house that contains only five floors.   Baker does not live on the top floor.   Cooper does not live on the bottom floor.   Fletcher does not live on either the top or the bottom floor.   Miller lives on a higher floor than does Cooper.   Smith does not live on a floor adjacent to Fletcher's.   Fletcher does not live on a floor adjacent to Cooper's. Where does everyone live?
#Sidef
Sidef
func dinesman(problem) { var lines = problem.split('.') var names = lines.first.scan(/\b[A-Z]\w*/) var re_names = Regex(names.join('|'))   # Later on, search for these keywords (the word "not" is handled separately). var words = %w(first second third fourth fifth sixth seventh eighth ninth tenth bottom top higher lower adjacent) var re_keywords = Regex(words.join('|'))   # Build an array of lambda's var predicates = lines.ft(1, lines.end-1).map{ |line| var keywords = line.scan(re_keywords) var (name1, name2) = line.scan(re_names)...   keywords.map{ |keyword| var l = do { given(keyword) { when ("bottom") { ->(c) { c.first == name1 } } when ("top") { ->(c) { c.last == name1 } } when ("higher") { ->(c) { c.index(name1) > c.index(name2) } } when ("lower") { ->(c) { c.index(name1) < c.index(name2) } } when ("adjacent") { ->(c) { c.index(name1) - c.index(name2) -> abs == 1 } } default { ->(c) { c[words.index(keyword)] == name1 } } } } line ~~ /\bnot\b/ ? func(c) { l(c) -> not } : l; # handle "not" } }.flat   names.permutations { |*candidate| predicates.all { |predicate| predicate(candidate) } && return candidate } }
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#Lua
Lua
function dotprod(a, b) local ret = 0 for i = 1, #a do ret = ret + a[i] * b[i] end return ret end   print(dotprod({1, 3, -5}, {4, -2, 1}))
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead of any character that is immediately repeated. If a character string has a specified   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). A specified   immediately repeated   character is any specified character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   squeeze.} Examples In the following character string with a specified   immediately repeated   character of   e: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   e   is an specified repeated character,   indicated by an underscore (above),   even though they (the characters) appear elsewhere in the character string. So, after squeezing the string, the result would be: The better the 4-whel drive, the further you'll be from help when ya get stuck! Another example: In the following character string,   using a specified immediately repeated character   s: headmistressship The "squeezed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate a   specified immediately repeated   character and   squeeze   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   specified repeated character   (to be searched for and possibly squeezed):   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: immediately string repeated number character ( ↓ a blank, a minus, a seven, a period) ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ' ' ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ '-' 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ '7' 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ '.' 5 ║ --- Harry S Truman ║ (below) ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ ↑ │ │ For the 5th string (Truman's signature line), use each of these specified immediately repeated characters: • a blank • a minus • a lowercase r Note:   there should be seven results shown,   one each for the 1st four strings,   and three results for the 5th string. 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
#XPL0
XPL0
string 0; char C, I, J, Last;   proc Squeeze(Char, S); \Eliminate specified repeated characters from string char Char, S; [I:= 0; J:= 0; Last:= -1; loop [if S(I) # Last or Char # Last then [C(J):= S(I); if S(I) = 0 then quit; J:= J+1; ]; Last:= S(I); I:= I+1; ]; ];   int String, K, Char; [String:= [ "", "^"If I were two-faced, would I be wearing this one?^" --- Abraham Lincoln ", "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman "]; Char:= [0, ^-, ^1, ^l, ^ , ^-, ^r]; C:= Reserve(79+1); \space for collapsed string for K:= 0 to 4+2 do [Squeeze(Char(K), String(if K>4 then 4 else K)); Text(0, "<<<"); Text(0, String(if K>4 then 4 else K)); Text(0, ">>> "); IntOut(0, I); CrLf(0); Text(0, "<<<"); Text(0, C); Text(0, ">>> "); IntOut(0, J); CrLf(0); ]; ]
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead of any character that is immediately repeated. If a character string has a specified   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). A specified   immediately repeated   character is any specified character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   squeeze.} Examples In the following character string with a specified   immediately repeated   character of   e: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   e   is an specified repeated character,   indicated by an underscore (above),   even though they (the characters) appear elsewhere in the character string. So, after squeezing the string, the result would be: The better the 4-whel drive, the further you'll be from help when ya get stuck! Another example: In the following character string,   using a specified immediately repeated character   s: headmistressship The "squeezed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate a   specified immediately repeated   character and   squeeze   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   specified repeated character   (to be searched for and possibly squeezed):   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: immediately string repeated number character ( ↓ a blank, a minus, a seven, a period) ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ' ' ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ '-' 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ '7' 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ '.' 5 ║ --- Harry S Truman ║ (below) ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ ↑ │ │ For the 5th string (Truman's signature line), use each of these specified immediately repeated characters: • a blank • a minus • a lowercase r Note:   there should be seven results shown,   one each for the 1st four strings,   and three results for the 5th string. 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
#zkl
zkl
fcn squeeze(c,str){ // Works with UTF-8 s,cc,sz,n := Data(Void,str), String(c,c), c.len(), 0; // byte buffer in case of LOTs of deletes while(Void != (n=s.find(cc,n))){ str=s.del(n,sz) } // and searching is faster for big strings s.text }
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and must add up to   12. The Chief of the Police doesn't like odd numbers and wants to have an even number for his department. Task Write a computer program which outputs all valid combinations. Possible output   (for the 1st and 14th solutions): --police-- --sanitation-- --fire-- 2 3 7 6 5 1
#Draco
Draco
proc main() void: byte police, sanitation, fire;   writeln("Police Sanitation Fire"); for police from 2 by 2 upto 7 do for sanitation from 1 upto 7 do for fire from 1 upto 7 do if police /= sanitation and police /= fire and sanitation /= fire and police + sanitation + fire = 12 then writeln(police:6, " ", sanitation:10, " ", fire:4) fi od od od corp
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and must add up to   12. The Chief of the Police doesn't like odd numbers and wants to have an even number for his department. Task Write a computer program which outputs all valid combinations. Possible output   (for the 1st and 14th solutions): --police-- --sanitation-- --fire-- 2 3 7 6 5 1
#Elixir
Elixir
  IO.puts("P - F - S") for p <- [2,4,6], f <- 1..7, s <- 1..7, p != f and p != s and f != s and p + f + s == 12 do "#{p} - #{f} - #{s}" end |> Enum.each(&IO.puts/1)    
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#Oz
Oz
declare class Delegator from BaseObject attr delegate:unit   meth set(DG) {Object.is DG} = true %% assert: DG must be an object delegate := DG end   meth operation($) if @delegate == unit then {self default($)} else try {@delegate thing($)} catch error(object(lookup ...) ...) then %% the delegate did not understand the message {self default($)} end end end   meth default($) "default implementation" end end   class Delegate from BaseObject meth thing($) "delegate Implementation" end end   A = {New Delegator noop} in {System.showInfo {A operation($)}}   {A set({New BaseObject noop})} {System.showInfo {A operation($)}}   {A set({New Delegate noop})} {System.showInfo {A operation($)}}
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#Pascal
Pascal
use strict;   package Delegator; sub new { bless {} } sub operation { my ($self) = @_; if (defined $self->{delegate} && $self->{delegate}->can('thing')) { $self->{delegate}->thing; } else { 'default implementation'; } } 1;   package Delegate; sub new { bless {}; } sub thing { 'delegate implementation' } 1;     package main; # No delegate my $a = Delegator->new; $a->operation eq 'default implementation' or die;   # With a delegate that does not implement "thing" $a->{delegate} = 'A delegate may be any object'; $a->operation eq 'default implementation' or die;   # With delegate that implements "thing" $a->{delegate} = Delegate->new; $a->operation eq 'delegate implementation' or die;  
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)   (0,0),(5,0),(2.5,5)   and   (0,4),(2.5,-1),(5,4)   (0,0),(1,1),(0,2)     and   (2,1),(3,0),(3,2)   (0,0),(1,1),(0,2)     and   (2,1),(3,-2),(3,4) Optionally, see what the result is when only a single corner is in contact (there is no definitive correct answer):   (0,0),(1,0),(0,1)   and   (1,0),(2,0),(1,1)
#Phix
Phix
-- -- demo\rosetta\Determine_if_two_triangles_overlap.exw -- with javascript_semantics include pGUI.e Ihandle dlg, canvas cdCanvas cddbuffer, cdcanvas constant triangles = {{{{0,0},{5,0},{0,5}},{{0,0},{5,0},{0,6}}}, {{{0,0},{0,5},{5,0}},{{0,0},{0,5},{5,0}}}, {{{0,0},{5,0},{0,5}},{{-10,0},{-5,0},{-1,6}}}, {{{0,0},{5,0},{2.5,5}},{{0,4},{2.5,-1},{5,4}}}, {{{0,0},{1,1},{0,2}},{{2,1},{3,0},{3,2}}}, {{{0,0},{1,1},{0,2}},{{2,1},{3,-2},{3,4}}}, {{{0,0},{1,0},{0,1}},{{1,0},{2,0},{1,1}}}, {{{0,0},{1,0},{0,1}},{{1,0},{2,0},{1,1}}}} procedure draw_triangle(sequence t, integer cx,cy, c) cdCanvasSetForeground(cddbuffer, c) cdCanvasBegin(cddbuffer,CD_CLOSED_LINES) for c=1 to 3 do atom {x,y} = t[c] cdCanvasVertex(cddbuffer, cx+x*10, cy+y*10) end for cdCanvasEnd(cddbuffer) end procedure function det2D(sequence triangle) atom {{p1x,p1y},{p2x,p2y},{p3x,p3y}} := triangle return p1x*(p2y-p3y) + p2x*(p3y-p1y) + p3x*(p1y-p2y) end function bool bReversed function checkWinding(sequence triangle, bool allowReversed) atom detTri := det2D(triangle); if detTri<0.0 then if allowReversed then bReversed = true triangle = extract(triangle,{1,3,2}) else throw("triangle has wrong winding direction") end if end if return triangle end function function overlap(sequence t1, t2, atom epsilon=0.0, bool allowReversed=false, onBoundary=true) -- Trangles must be expressed anti-clockwise bReversed = false t1 = checkWinding(t1, allowReversed) t2 = checkWinding(t2, allowReversed) for t=1 to 2 do -- check t1 then t2 for edge=1 to 3 do -- check each edge sequence p1 = t1[edge], p2 = t1[mod(edge,3)+1] -- Check all points of trangle 2 lay on the external side -- of the edge E. If they do, the triangles do not collide. integer onside = 0 for k=1 to 3 do integer c = compare(det2D({p1,p2,t2[k]}),epsilon) if onBoundary then if not (c<0) then exit end if else if not (c<=0) then exit end if end if -- -- (the following incomprehensible one-liner is equivalent:) -- if compare(det2D({p1,p2,t2[k]}),epsilon)>-onBoundary then exit end if onside += 1 end for if onside=3 then return iff(onBoundary?"no overlap":"no overlap (no boundary)") end if end for {t2,t1} = {t1,t2} -- flip and re-test end for return iff(bReversed?"overlap (reversed)":"overlap") end function function redraw_cb(Ihandle /*ih*/) cdCanvasActivate(cddbuffer) integer cy = 200, cx = 100 for i=1 to length(triangles) do sequence {t1,t2} = triangles[i] draw_triangle(t1,cx,cy,CD_RED) integer s = (i<=2) -- (smudge tests[1..2] by one -- pixel to show them better) draw_triangle(t2,cx+s,cy+s,CD_BLUE) cdCanvasSetForeground(cddbuffer, CD_BLACK) cdCanvasText(cddbuffer,cx+10,cy-40,overlap(t1,t2,0,i=2,i!=8)) if i=4 then cy = 100 cx = 100 else cx += 300 end if end for cdCanvasFlush(cddbuffer) return IUP_DEFAULT end function function map_cb(Ihandle ih) cdcanvas = cdCreateCanvas(CD_IUP, ih) cddbuffer = cdCreateCanvas(CD_DBUFFER, cdcanvas) cdCanvasSetBackground(cddbuffer, CD_WHITE) return IUP_DEFAULT end function procedure main() IupOpen() canvas = IupCanvas("RASTERSIZE=1250x300") IupSetCallbacks(canvas, {"MAP_CB", Icallback("map_cb"), "ACTION", Icallback("redraw_cb")}) dlg = IupDialog(canvas,`RESIZE=NO, TITLE="Triangle overlap"`) IupShow(dlg) IupSetAttribute(canvas, "RASTERSIZE", NULL) if platform()!=JS then IupMainLoop() IupClose() end if end procedure main()
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Haskell
Haskell
import System.IO import System.Directory   main = do removeFile "output.txt" removeDirectory "docs" removeFile "/output.txt" removeDirectory "/docs"
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#HicEst
HicEst
SYSTEM(DIR="docs") ! create docs in current directory (if not existent), make it current OPEN (FILE="input.txt", "NEW") ! in current directory = docs WRITE(FIle="input.txt", DELETE=1) ! no command to DELETE a DIRECTORY in HicEst   SYSTEM(DIR="C:\docs") ! create C:\docs (if not existent), make it current OPEN (FILE="input.txt", "NEW") ! in current directory = C:\docs WRITE(FIle="input.txt", DELETE=1)
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by perm ⁡ ( A ) = ∑ σ ∏ i = 1 n M i , σ i {\displaystyle \operatorname {perm} (A)=\sum _{\sigma }\prod _{i=1}^{n}M_{i,\sigma _{i}}} In both cases the sum is over the permutations σ {\displaystyle \sigma } of the permutations of 1, 2, ..., n. (A permutation's sign is 1 if there are an even number of inversions and -1 otherwise; see parity of a permutation.) More efficient algorithms for the determinant are known: LU decomposition, see for example wp:LU decomposition#Computing the determinant. Efficient methods for calculating the permanent are not known. Related task Permutations by swapping
#Python
Python
from itertools import permutations from operator import mul from math import fsum from spermutations import spermutations   def prod(lst): return reduce(mul, lst, 1)   def perm(a): n = len(a) r = range(n) s = permutations(r) return fsum(prod(a[i][sigma[i]] for i in r) for sigma in s)   def det(a): n = len(a) r = range(n) s = spermutations(n) return fsum(sign * prod(a[i][sigma[i]] for i in r) for sigma, sign in s)   if __name__ == '__main__': from pprint import pprint as pp   for a in ( [ [1, 2], [3, 4]],   [ [1, 2, 3, 4], [4, 5, 6, 7], [7, 8, 9, 10], [10, 11, 12, 13]],   [ [ 0, 1, 2, 3, 4], [ 5, 6, 7, 8, 9], [10, 11, 12, 13, 14], [15, 16, 17, 18, 19], [20, 21, 22, 23, 24]], ): print('') pp(a) print('Perm: %s Det: %s' % (perm(a), det(a)))
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Jsish
Jsish
if (!isFinite(numerator/denominator)) puts("result is infinity or not a number");
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Julia
Julia
isdefinite(n::Number) = !isnan(n) && !isinf(n)   for n in (1, 1//1, 1.0, 1im, 0) d = n / 0 println("Dividing $n by 0 ", isdefinite(d) ? "results in $d." : "yields an indefinite value ($d).") end
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. 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
#Gambas
Gambas
Public Sub Form_Open() Dim sAnswer, sString As String   sString = Trim(InputBox("Enter as string", "String or Numeric"))   If IsNumber(sString) Then sAnswer = "'" & sString & "' is numeric" Else sAnswer = "'" & sString & "' is a string" Print sAnswer   End
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as unique   process the strings from left─to─right   if       unique,   display a message saying such   if not unique,   then:   display a message saying such   display what character is duplicated   only the 1st non─unique character need be displayed   display where "both" duplicated characters are in the string   the above messages can be part of a single message   display the hexadecimal value of the duplicated character Use (at least) these five test values   (strings):   a string of length     0   (an empty string)   a string of length     1   which is a single period   (.)   a string of length     6   which contains:   abcABC   a string of length     7   which contains a blank in the middle:   XYZ  ZYX   a string of length   36   which   doesn't   contain the letter "oh": 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ Show all output here on this page. 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
#Perl
Perl
use strict; use warnings; use feature 'say'; use utf8; binmode(STDOUT, ':utf8'); use List::AllUtils qw(uniq); use Unicode::UCD 'charinfo';   for my $str ( '', '.', 'abcABC', 'XYZ ZYX', '1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ', '01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X', 'Δ👍👨👍Δ', 'ΔδΔ̂ΔΛ', ) { my @S; push @S, $1 while $str =~ /(\X)/g; printf qq{\n"$str" (length: %d) has }, scalar @S; if (@S != uniq @S ) { say "duplicated characters:"; my %P; push @{ $P{$S[$_]} }, 1+$_ for 0..$#S; for my $k (sort keys %P) { next unless @{$P{$k}} > 1; printf "'%s' %s (0x%x) in positions: %s\n", $k, charinfo(ord $k)->{'name'}, ord($k), join ', ', @{$P{$k}}; } } else { say "no duplicated characters." } }
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#Swift
Swift
let strings = [ "", #""If I were two-faced, would I be wearing this one?" --- Abraham Lincoln "#, "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman ", "The better the 4-wheel drive, the further you'll be from help when ya get stuck!", "headmistressship", "aardvark", "😍😀🙌💃😍😍😍🙌" ]   let collapsedStrings = strings.map { $0.replacingOccurrences( of: #"(.)\1*"#, with: "$1", options: .regularExpression)}   for (original, collapsed) in zip(strings, collapsedStrings) { print (String(format: "%03d «%@»\n%03d «%@»\n", original.count, original, collapsed.count, collapsed)) }
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#Tcl
Tcl
set test { {} {"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln } {..1111111111111111111111111111111111111111111111111111111111111117777888} {I never give 'em hell, I just tell the truth, and they think it's hell. } ;# ' { --- Harry S Truman } {The better the 4-wheel drive, the further you'll be from help when ya get stuck!} ;# ' {headmistressship} }   foreach {str} $test { # Uses regexp lookbehind to detect repeated characters set sub [regsub -all {(.)(\1+)} $str {\1}]   # Output puts [format "Original (length %3d): %s" [string length $str] $str] puts [format "Subbed (length %3d): %s" [string length $sub] $sub] puts ---------------------- }  
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as all the same character(s)   process the strings from left─to─right   if       all the same character,   display a message saying such   if not all the same character,   then:   display a message saying such   display what character is different   only the 1st different character need be displayed   display where the different character is in the string   the above messages can be part of a single message   display the hexadecimal value of the different character Use (at least) these seven test values   (strings):   a string of length   0   (an empty string)   a string of length   3   which contains three blanks   a string of length   1   which contains:   2   a string of length   3   which contains:   333   a string of length   3   which contains:   .55   a string of length   6   which contains:   tttTTT   a string of length   9   with a blank in the middle:   4444   444k Show all output here on this page. 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
#Prolog
Prolog
  :- system:set_prolog_flag(double_quotes,chars) .   main :- same_or_different("") , same_or_different(" ") , same_or_different("2") , same_or_different("333") , same_or_different(".55") , same_or_different("tttTTT") , same_or_different("4444 444k") .   %! same_or_different(INPUTz0)   same_or_different(INPUTz0) :- system:format('input string is "~s" .~n',[INPUTz0]) , examine(INPUTz0) .   %! examine(INPUTz0)   examine([]) :- ! , system:format('all the same characters .~n',[]) .   examine([COMPARE0|INPUTz0]) :- examine(INPUTz0,COMPARE0,2,_INDEX_) .   %! examine(INPUTz0,COMPARE0,INDEX0,INDEX)   examine([],_COMPARE0_,INDEX0,INDEX0) :- ! , system:format('all the same characters .~n',[]) .   examine([COMPARE0|INPUTz0],COMPARE0,INDEX0,INDEX) :- ! , INDEX1 is INDEX0 + 1 , examine(INPUTz0,COMPARE0,INDEX1,INDEX) .   examine([DIFFERENT0|_INPUTz0_],COMPARE0,INDEX0,INDEX0) :- prolog:char_code(DIFFERENT0,DIFFERENT_CODE) , system:format('character "~s" (hex ~16r) different than "~s" at 1-based index ~10r .~n',[[DIFFERENT0],DIFFERENT_CODE,[COMPARE0],INDEX0]) .    
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a round table with five individual seats. For eating each philosopher needs two forks (the resources). There are five forks on the table, one left and one right of each seat. When a philosopher cannot grab both forks it sits and waits. Eating takes random time, then the philosopher puts the forks down and leaves the dining room. After spending some random time thinking about the nature of the universe, he again becomes hungry, and the circle repeats itself. It can be observed that a straightforward solution, when forks are implemented by semaphores, is exposed to deadlock. There exist two deadlock states when all five philosophers are sitting at the table holding one fork each. One deadlock state is when each philosopher has grabbed the fork left of him, and another is when each has the fork on his right. There are many solutions of the problem, program at least one, and explain how the deadlock is prevented.
#Ruby
Ruby
require 'mutex_m'   class Philosopher def initialize(name, left_fork, right_fork) @name = name @left_fork = left_fork @right_fork = right_fork @meals = 0 end   def go while @meals < 5 think dine end puts "philosopher #@name is full!" end   def think puts "philosopher #@name is thinking..." sleep(rand()) puts "philosopher #@name is hungry..." end   def dine fork1, fork2 = @left_fork, @right_fork while true pickup(fork1, :wait => true) puts "philosopher #@name has fork #{fork1.fork_id}..." if pickup(fork2, :wait => false) break end puts "philosopher #@name cannot pickup second fork #{fork2.fork_id}..." release(fork1) fork1, fork2 = fork2, fork1 end puts "philosopher #@name has the second fork #{fork2.fork_id}..."   puts "philosopher #@name eats..." sleep(rand()) puts "philosopher #@name belches" @meals += 1   release(@left_fork) release(@right_fork) end   def pickup(fork, opt) puts "philosopher #@name attempts to pickup fork #{fork.fork_id}..." opt[:wait] ? fork.mutex.mu_lock : fork.mutex.mu_try_lock end   def release(fork) puts "philosopher #@name releases fork #{fork.fork_id}..." fork.mutex.unlock end end   n = 5   Fork = Struct.new(:fork_id, :mutex) forks = Array.new(n) {|i| Fork.new(i, Object.new.extend(Mutex_m))}   philosophers = Array.new(n) do |i| Thread.new(i, forks[i], forks[(i+1)%n]) do |id, f1, f2| ph = Philosopher.new(id, f1, f2).go end end   philosophers.each {|thread| thread.join}
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Raku
Raku
my @seasons = << Chaos Discord Confusion Bureaucracy 'The Aftermath' >>; my @days = << Sweetmorn Boomtime Pungenday Prickle-Prickle 'Setting Orange' >>; sub ordinal ( Int $n ) { $n ~ ( $n % 100 == 11|12|13 ?? 'th' !! < th st nd rd th th th th th th >[$n % 10] ) }   sub ddate ( Str $ymd ) { my $d = DateTime.new: "{$ymd}T00:00:00Z" or die;   my $yold = 'in the YOLD ' ~ $d.year + 1166;   my $day_of_year0 = $d.day-of-year - 1;   if $d.is-leap-year { return "St. Tib's Day, $yold" if $d.month == 2 and $d.day == 29; $day_of_year0-- if $day_of_year0 >= 60; # Compensate for St. Tib's Day }   my $weekday = @days[ $day_of_year0 mod 5 ]; my $season = @seasons[ $day_of_year0 div 73 ]; my $season_day = ordinal( $day_of_year0 mod 73 + 1 );   return "$weekday, the $season_day day of $season $yold"; }   say "$_ is {.&ddate}" for < 2010-07-22 2012-02-28 2012-02-29 2012-03-01 >;  
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path problem for a graph with non-negative edge path costs, producing a shortest path tree. This algorithm is often used in routing and as a subroutine in other graph algorithms. For a given source vertex (node) in the graph, the algorithm finds the path with lowest cost (i.e. the shortest path) between that vertex and every other vertex. For instance If the vertices of the graph represent cities and edge path costs represent driving distances between pairs of cities connected by a direct road,   Dijkstra's algorithm can be used to find the shortest route between one city and all other cities. As a result, the shortest path first is widely used in network routing protocols, most notably:   IS-IS   (Intermediate System to Intermediate System)   and   OSPF   (Open Shortest Path First). Important note The inputs to Dijkstra's algorithm are a directed and weighted graph consisting of 2 or more nodes, generally represented by:   an adjacency matrix or list,   and   a start node. A destination node is not specified. The output is a set of edges depicting the shortest path to each destination node. An example, starting with a──►b, cost=7, lastNode=a a──►c, cost=9, lastNode=a a──►d, cost=NA, lastNode=a a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►b so a──►b is added to the output.   There is a connection from b──►d so the input is updated to: a──►c, cost=9, lastNode=a a──►d, cost=22, lastNode=b a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►c so a──►c is added to the output.   Paths to d and f are cheaper via c so the input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a a──►f, cost=11, lastNode=c   The lowest cost is a──►f so c──►f is added to the output.   The input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a   The lowest cost is a──►d so c──►d is added to the output.   There is a connection from d──►e so the input is updated to: a──►e, cost=26, lastNode=d   Which just leaves adding d──►e to the output.   The output should now be: [ d──►e c──►d c──►f a──►c a──►b ] Task Implement a version of Dijkstra's algorithm that outputs a set of edges depicting the shortest path to each reachable node from an origin. Run your program with the following directed graph starting at node   a. Write a program which interprets the output from the above and use it to output the shortest path from node   a   to nodes   e   and f. Vertices Number Name 1 a 2 b 3 c 4 d 5 e 6 f Edges Start End Cost a b 7 a c 9 a f 14 b c 10 b d 15 c d 11 c f 2 d e 6 e f 9 You can use numbers or names to identify vertices in your program. See also Dijkstra's Algorithm vs. A* Search vs. Concurrent Dijkstra's Algorithm (youtube)
#Rust
Rust
use std::cmp::Ordering; use std::collections::BinaryHeap; use std::usize;     struct Grid<T> { nodes: Vec<Node<T>>, }   struct Node<T> { data: T, edges: Vec<(usize,usize)>, }   #[derive(Copy, Clone, Eq, PartialEq)] struct State { node: usize, cost: usize, }   // Manually implement Ord so we get a min-heap instead of a max-heap impl Ord for State { fn cmp(&self, other: &Self) -> Ordering { other.cost.cmp(&self.cost) } }   impl PartialOrd for State { fn partial_cmp(&self, other: &Self) -> Option<Ordering> { Some(self.cmp(other)) } }   type WeightedEdge = (usize, usize, usize);   impl<T> Grid<T> { fn new() -> Self { Grid { nodes: Vec::new() } }   fn add_node(&mut self, data: T) -> usize { let node = Node { edges: Vec::new(), data: data, }; self.nodes.push(node); self.nodes.len() - 1 }   fn create_edges<'a, I>(&mut self, iterator: I) where I: IntoIterator<Item=&'a WeightedEdge> { for &(start,end,weight) in iterator.into_iter() { self.nodes[start].edges.push((end,weight)); self.nodes[end].edges.push((start,weight)); }   }   fn find_path(&self, start: usize, end: usize) -> Option<(Vec<usize>, usize)> { let mut dist = vec![(usize::MAX, None); self.nodes.len()];   let mut heap = BinaryHeap::new(); dist[start] = (0, None); heap.push(State { node: start, cost: 0, });   while let Some(State { node, cost }) = heap.pop() { if node == end { let mut path = Vec::with_capacity(dist.len() / 2); let mut current_dist = dist[end]; path.push(end); while let Some(prev) = current_dist.1 { path.push(prev); current_dist = dist[prev]; } path.reverse(); return Some((path, cost)); }   if cost > dist[node].0 { continue; } for edge in &self.nodes[node].edges { let next = State { node: edge.0, cost: cost + edge.1, }; if next.cost < dist[next.node].0 { dist[next.node] = (next.cost, Some(node)); heap.push(next); } } } None } }   fn main() { let mut grid = Grid::new(); let (a,b,c,d,e,f) = (grid.add_node("a"), grid.add_node("b"), grid.add_node("c"), grid.add_node("d"), grid.add_node("e"), grid.add_node("f"));   grid.create_edges(&[ (a,b,7) ,(a,c,9) ,(a,f,14), (b,c,10),(b,d,15),(c,d,11), (c,f,2) ,(d,e,6) ,(e,f,9) , ]);   let (path, cost) = grid.find_path(a,e).unwrap();   print!("{}", grid.nodes[path[0]].data); for i in path.iter().skip(1) { print!(" -> {}", grid.nodes[*i].data); } println!("\nCost: {}", cost);   }
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displaystyle X} has only one digit. The additive persistence is the number of summations required to obtain the single digit. The task is to calculate the additive persistence and the digital root of a number, e.g.: 627615 {\displaystyle 627615} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; 39390 {\displaystyle 39390} has additive persistence 2 {\displaystyle 2} and digital root of 6 {\displaystyle 6} ; 588225 {\displaystyle 588225} has additive persistence 2 {\displaystyle 2} and digital root of 3 {\displaystyle 3} ; 393900588225 {\displaystyle 393900588225} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; The digital root may be calculated in bases other than 10. See Casting out nines for this wiki's use of this procedure. Digital root/Multiplicative digital root Sum digits of an integer Digital root sequence on OEIS Additive persistence sequence on OEIS Iterated digits squaring
#Picat
Picat
go => foreach(N in [627615,39390,588225,393900588225, 58142718981673030403681039458302204471300738980834668522257090844071443085937]) [Sum,Persistence] = digital_root(N), printf("%w har addititive persistence %d and digital root of %d\n", N,Persistence,Sum) end, nl.   % % (Reduced) digit sum (digital root) of a number % digital_root(N) = [Sum,Persistence], integer(N) => Sum = N, Persistence = 0, while(Sum > 9) Sum := sum([I.to_integer() : I in Sum.to_string()]), Persistence := Persistence + 1 end.
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displaystyle X} has only one digit. The additive persistence is the number of summations required to obtain the single digit. The task is to calculate the additive persistence and the digital root of a number, e.g.: 627615 {\displaystyle 627615} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; 39390 {\displaystyle 39390} has additive persistence 2 {\displaystyle 2} and digital root of 6 {\displaystyle 6} ; 588225 {\displaystyle 588225} has additive persistence 2 {\displaystyle 2} and digital root of 3 {\displaystyle 3} ; 393900588225 {\displaystyle 393900588225} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; The digital root may be calculated in bases other than 10. See Casting out nines for this wiki's use of this procedure. Digital root/Multiplicative digital root Sum digits of an integer Digital root sequence on OEIS Additive persistence sequence on OEIS Iterated digits squaring
#PicoLisp
PicoLisp
(for N (627615 39390 588225 393900588225) (for ((A . I) N T (sum format (chop I))) (T (> 10 I) (prinl N " has additive persistance " (dec A) " and digital root of " I ";") ) ) )
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of expression are valued. Examples may be be split into "setup", "problem statement", and "output" sections where the ease and naturalness of stating the problem and getting an answer, as well as the ease and flexibility of modifying the problem are the primary concerns. Example output should be shown here, as well as any comments on the examples flexibility. The problem Baker, Cooper, Fletcher, Miller, and Smith live on different floors of an apartment house that contains only five floors.   Baker does not live on the top floor.   Cooper does not live on the bottom floor.   Fletcher does not live on either the top or the bottom floor.   Miller lives on a higher floor than does Cooper.   Smith does not live on a floor adjacent to Fletcher's.   Fletcher does not live on a floor adjacent to Cooper's. Where does everyone live?
#Tailspin
Tailspin
  templates permutations when <=1> do [1] ! otherwise def n: $; templates expand def p: $; 1..$n -> \(def k: $; [$p(1..$k-1)..., $n, $p($k..last)...] !\) ! end expand $n - 1 -> permutations -> expand ! end permutations   templates index&{of:} $ -> \[i](<=$of> $i! \) ...! end index   def names: ['Baker', 'Cooper', 'Fletcher', 'Miller', 'Smith'];   5 -> permutations -> $names($) -> \(<?($ -> index&{of: 'Baker'} <~=5>)> $! \) -> \(<?($ -> index&{of: 'Cooper'} <~=1>)> $! \) -> \(<?($ -> index&{of: 'Fletcher'} <~=1|=5>)> $! \) -> \(<?($ -> index&{of: 'Cooper'} <..($ -> index&{of:'Miller'})>)> $! \) -> \(<?(($ -> index&{of: 'Smith'}) - ($ -> index&{of:'Fletcher'}) <~=1|=-1>)> $! \) -> \(<?(($ -> index&{of: 'Cooper'}) - ($ -> index&{of:'Fletcher'}) <~=1|=-1>)> $! \) -> \[i]('$i;:$;$#10;' ! \) -> $(last..first:-1) -> '$...;$#10;' -> !OUT::write  
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#M2000_Interpreter
M2000 Interpreter
  Module dot_product { A=(1,3,-5) B=(4,-2,-1) Function Dot(a, b) { if len(a)<>len(b) Then Error "not same length" if len(a)=0 then Error "empty vectors" Let a1=each(a), b1=each(b), sum=0 While a1, b1 {sum+=array(a1)*array(b1)} =sum } Print Dot(A, B) Print Dot((1,3,-5), (4,-2,-1)) } Module dot_product  
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#Maple
Maple
<1,2,3> . <4,5,6>
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and must add up to   12. The Chief of the Police doesn't like odd numbers and wants to have an even number for his department. Task Write a computer program which outputs all valid combinations. Possible output   (for the 1st and 14th solutions): --police-- --sanitation-- --fire-- 2 3 7 6 5 1
#Excel
Excel
departmentNumbers =validRows( LAMBDA(ab, LET( x, INDEX(ab, 0, 1), y, INDEX(ab, 0, 2), z, 12 - (x + y),   IF(y <> z, IF(1 <= z, IF(7 >= z, CHOOSE({1, 2, 3}, x, y, z), NA() ), NA() ), NA() ) ) )( cartesianProduct({2;4;6})( SEQUENCE(7, 1, 1, 1) ) ) )
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#Perl
Perl
use strict;   package Delegator; sub new { bless {} } sub operation { my ($self) = @_; if (defined $self->{delegate} && $self->{delegate}->can('thing')) { $self->{delegate}->thing; } else { 'default implementation'; } } 1;   package Delegate; sub new { bless {}; } sub thing { 'delegate implementation' } 1;     package main; # No delegate my $a = Delegator->new; $a->operation eq 'default implementation' or die;   # With a delegate that does not implement "thing" $a->{delegate} = 'A delegate may be any object'; $a->operation eq 'default implementation' or die;   # With delegate that implements "thing" $a->{delegate} = Delegate->new; $a->operation eq 'delegate implementation' or die;  
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#Phix
Phix
enum OTHER, OPERATION   function operation(object o) integer rid = o[OPERATION] if rid!=NULL then return call_func(rid,{}) end if return "no implementation" end function   function xthing() return "default implementation" end function   function newX() return {1,routine_id("xthing"),2} end function   function newY() object res = newX() res[OTHER] = "something else" -- remove delegate: res[OPERATION] = NULL return res end function   function zthing() return "delegate implementation" end function   function newZ() object res = newX() -- replace delegate: res[OPERATION] = routine_id("zthing") return res end function   object x = newX(), y = newY(), z = newZ()   ?operation(x) ?operation(y) ?operation(z)
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)   (0,0),(5,0),(2.5,5)   and   (0,4),(2.5,-1),(5,4)   (0,0),(1,1),(0,2)     and   (2,1),(3,0),(3,2)   (0,0),(1,1),(0,2)     and   (2,1),(3,-2),(3,4) Optionally, see what the result is when only a single corner is in contact (there is no definitive correct answer):   (0,0),(1,0),(0,1)   and   (1,0),(2,0),(1,1)
#Python
Python
from __future__ import print_function import numpy as np   def CheckTriWinding(tri, allowReversed): trisq = np.ones((3,3)) trisq[:,0:2] = np.array(tri) detTri = np.linalg.det(trisq) if detTri < 0.0: if allowReversed: a = trisq[2,:].copy() trisq[2,:] = trisq[1,:] trisq[1,:] = a else: raise ValueError("triangle has wrong winding direction") return trisq   def TriTri2D(t1, t2, eps = 0.0, allowReversed = False, onBoundary = True): #Trangles must be expressed anti-clockwise t1s = CheckTriWinding(t1, allowReversed) t2s = CheckTriWinding(t2, allowReversed)   if onBoundary: #Points on the boundary are considered as colliding chkEdge = lambda x: np.linalg.det(x) < eps else: #Points on the boundary are not considered as colliding chkEdge = lambda x: np.linalg.det(x) <= eps   #For edge E of trangle 1, for i in range(3): edge = np.roll(t1s, i, axis=0)[:2,:]   #Check all points of trangle 2 lay on the external side of the edge E. If #they do, the triangles do not collide. if (chkEdge(np.vstack((edge, t2s[0]))) and chkEdge(np.vstack((edge, t2s[1]))) and chkEdge(np.vstack((edge, t2s[2])))): return False   #For edge E of trangle 2, for i in range(3): edge = np.roll(t2s, i, axis=0)[:2,:]   #Check all points of trangle 1 lay on the external side of the edge E. If #they do, the triangles do not collide. if (chkEdge(np.vstack((edge, t1s[0]))) and chkEdge(np.vstack((edge, t1s[1]))) and chkEdge(np.vstack((edge, t1s[2])))): return False   #The triangles collide return True   if __name__=="__main__": t1 = [[0,0],[5,0],[0,5]] t2 = [[0,0],[5,0],[0,6]] print (TriTri2D(t1, t2), True)   t1 = [[0,0],[0,5],[5,0]] t2 = [[0,0],[0,6],[5,0]] print (TriTri2D(t1, t2, allowReversed = True), True)   t1 = [[0,0],[5,0],[0,5]] t2 = [[-10,0],[-5,0],[-1,6]] print (TriTri2D(t1, t2), False)   t1 = [[0,0],[5,0],[2.5,5]] t2 = [[0,4],[2.5,-1],[5,4]] print (TriTri2D(t1, t2), True)   t1 = [[0,0],[1,1],[0,2]] t2 = [[2,1],[3,0],[3,2]] print (TriTri2D(t1, t2), False)   t1 = [[0,0],[1,1],[0,2]] t2 = [[2,1],[3,-2],[3,4]] print (TriTri2D(t1, t2), False)   #Barely touching t1 = [[0,0],[1,0],[0,1]] t2 = [[1,0],[2,0],[1,1]] print (TriTri2D(t1, t2, onBoundary = True), True)   #Barely touching t1 = [[0,0],[1,0],[0,1]] t2 = [[1,0],[2,0],[1,1]] print (TriTri2D(t1, t2, onBoundary = False), False)
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Icon_and_Unicon
Icon and Unicon
every dir := !["./","/"] do { remove(f := dir || "input.txt") |stop("failure for file remove ",f) rmdir(f := dir || "docs") |stop("failure for directory remove ",f) }  
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Io
Io
Directory fileNamed("input.txt") remove Directory directoryNamed("docs") remove RootDir := Directory clone setPath("/") RootDir fileNamed("input.txt") remove RootDir directoryNamed("docs") remove
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by perm ⁡ ( A ) = ∑ σ ∏ i = 1 n M i , σ i {\displaystyle \operatorname {perm} (A)=\sum _{\sigma }\prod _{i=1}^{n}M_{i,\sigma _{i}}} In both cases the sum is over the permutations σ {\displaystyle \sigma } of the permutations of 1, 2, ..., n. (A permutation's sign is 1 if there are an even number of inversions and -1 otherwise; see parity of a permutation.) More efficient algorithms for the determinant are known: LU decomposition, see for example wp:LU decomposition#Computing the determinant. Efficient methods for calculating the permanent are not known. Related task Permutations by swapping
#R
R
library(combinat) perm <- function(A) { stopifnot(is.matrix(A)) n <- nrow(A) if(n != ncol(A)) stop("Matrix is not square.") if(n < 1) stop("Matrix has a dimension of size 0.") sum(sapply(combinat::permn(n), function(sigma) prod(sapply(1:n, function(i) A[i, sigma[i]])))) }   #We copy our test cases from the Python example. testData <- list("Test 1" = rbind(c(1, 2), c(3, 4)), "Test 2" = rbind(c(1, 2, 3, 4), c(4, 5, 6, 7), c(7, 8, 9, 10), c(10, 11, 12, 13)), "Test 3" = rbind(c(0, 1, 2, 3, 4), c(5, 6, 7, 8, 9), c(10, 11, 12, 13, 14), c(15, 16, 17, 18, 19), c(20, 21, 22, 23, 24))) print(sapply(testData, function(x) list(Determinant = det(x), Permanent = perm(x))))
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Kotlin
Kotlin
// version 1.1   fun divideByZero(x: Int, y:Int): Boolean = try { x / y false } catch(e: ArithmeticException) { true }   fun main(args: Array<String>) { val x = 1 val y = 0 if (divideByZero(x, y)) { println("Attempted to divide by zero") } else { @Suppress("DIVISION_BY_ZERO") println("$x / $y = ${x / y}") } }
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Lambdatalk
Lambdatalk
  {def DivByZero? {lambda {:w} {W.equal? :w Infinity}}}   {DivByZero? {/ 3 2}} -> false {DivByZero? {/ 3 0}} -> true  
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. 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
#Go
Go
package main   import ( "fmt" "strconv" )   func isNumeric(s string) bool { _, err := strconv.ParseFloat(s, 64) return err == nil }   func main() { fmt.Println("Are these strings numeric?") strings := []string{"1", "3.14", "-100", "1e2", "NaN", "rose"} for _, s := range strings { fmt.Printf("  %4s -> %t\n", s, isNumeric(s)) } }
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as unique   process the strings from left─to─right   if       unique,   display a message saying such   if not unique,   then:   display a message saying such   display what character is duplicated   only the 1st non─unique character need be displayed   display where "both" duplicated characters are in the string   the above messages can be part of a single message   display the hexadecimal value of the duplicated character Use (at least) these five test values   (strings):   a string of length     0   (an empty string)   a string of length     1   which is a single period   (.)   a string of length     6   which contains:   abcABC   a string of length     7   which contains a blank in the middle:   XYZ  ZYX   a string of length   36   which   doesn't   contain the letter "oh": 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ Show all output here on this page. 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
#Phix
Phix
procedure all_uniq(sequence s) string chars = "" sequence posns = {}, multi = {} integer lm = 0 for i=1 to length(s) do integer si = s[i], k = find(si,chars) if k=0 then chars &= si posns &= {{i}} else posns[k] &= i if length(posns[k])=2 then multi &= k lm += 1 end if end if end for string msg = sprintf("\"%s\" (length %d): ",{s,length(s)}), nod = ordinal(lm,true), ess = "s"[1..lm>1], res = iff(lm=0?"all characters are unique" :sprintf("contains %s duplicate%s:",{nod,ess})) printf(1,"%s %s\n",{msg,res}) res = repeat(' ',length(msg)) for i=1 to length(multi) do integer mi = multi[i], ci = chars[mi] printf(1,"%s '%c'(#%02x) at %V\n",{res,ci,ci,posns[mi]}) end for printf(1,"\n") end procedure constant tests = {"",".","abcABC","XYZ ZYX","1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ", "01234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ0X", " ","2","333","55","tttTTT","tTTTtt","4444 444k"} papply(tests,all_uniq)
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#Visual_Basic_.NET
Visual Basic .NET
Module Module1   Function Collapse(s As String) As String If String.IsNullOrEmpty(s) Then Return "" End If Return s(0) + New String(Enumerable.Range(1, s.Length - 1).Where(Function(i) s(i) <> s(i - 1)).Select(Function(i) s(i)).ToArray) End Function   Sub Main() Dim input() = { "", "The better the 4-wheel drive, the further you'll be from help when ya get stuck!", "headmistressship", ControlChars.Quote + "If I were two-faced, would I be wearing this one?" + ControlChars.Quote + " --- Abraham Lincoln ", "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman " } For Each s In input Console.WriteLine($"old: {s.Length} «««{s}»»»") Dim c = Collapse(s) Console.WriteLine($"new: {c.Length} «««{c}»»»") Next End Sub   End Module
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#VBA
VBA
Function Collapse(strIn As String) As String Dim i As Long, strOut As String If Len(strIn) > 0 Then strOut = Mid$(strIn, 1, 1) For i = 2 To Len(strIn) If Mid$(strIn, i, 1) <> Mid$(strIn, i - 1, 1) Then strOut = strOut & Mid$(strIn, i, 1) End If Next i End If Collapse = strOut End Function
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as all the same character(s)   process the strings from left─to─right   if       all the same character,   display a message saying such   if not all the same character,   then:   display a message saying such   display what character is different   only the 1st different character need be displayed   display where the different character is in the string   the above messages can be part of a single message   display the hexadecimal value of the different character Use (at least) these seven test values   (strings):   a string of length   0   (an empty string)   a string of length   3   which contains three blanks   a string of length   1   which contains:   2   a string of length   3   which contains:   333   a string of length   3   which contains:   .55   a string of length   6   which contains:   tttTTT   a string of length   9   with a blank in the middle:   4444   444k Show all output here on this page. 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
#Python
Python
'''Determine if a string has all the same characters'''   from itertools import groupby     # firstDifferingCharLR :: String -> Either String Dict def firstDifferingCharLR(s): '''Either a message reporting that no character changes were seen, or a dictionary with details of the first character (if any) that differs from that at the head of the string. ''' def details(xs): c = xs[1][0] return { 'char': repr(c), 'hex': hex(ord(c)), 'index': s.index(c), 'total': len(s) } xs = list(groupby(s)) return Right(details(xs)) if 1 < len(xs) else ( Left('Total length ' + str(len(s)) + ' - No character changes.') )     # TEST ---------------------------------------------------- # main :: IO () def main(): '''Test of 7 strings'''   print(fTable('First, if any, points of difference:\n')(repr)( either(identity)( lambda dct: dct['char'] + ' (' + dct['hex'] + ') at character ' + str(1 + dct['index']) + ' of ' + str(dct['total']) + '.' ) )(firstDifferingCharLR)([ '', ' ', '2', '333', '.55', 'tttTTT', '4444 444' ]))     # GENERIC -------------------------------------------------   # either :: (a -> c) -> (b -> c) -> Either a b -> c def either(fl): '''The application of fl to e if e is a Left value, or the application of fr to e if e is a Right value. ''' return lambda fr: lambda e: fl(e['Left']) if ( None is e['Right'] ) else fr(e['Right'])     # identity :: a -> a def identity(x): '''The identity function.''' return x     # fTable :: String -> (a -> String) -> # (b -> String) -> (a -> b) -> [a] -> String def fTable(s): '''Heading -> x display function -> fx display function -> f -> xs -> tabular string. ''' def go(xShow, fxShow, f, xs): ys = [xShow(x) for x in xs] w = max(map(len, ys)) return s + '\n' + '\n'.join(map( lambda x, y: y.rjust(w, ' ') + ' -> ' + fxShow(f(x)), xs, ys )) return lambda xShow: lambda fxShow: lambda f: lambda xs: go( xShow, fxShow, f, xs )     # Left :: a -> Either a b def Left(x): '''Constructor for an empty Either (option type) value with an associated string. ''' return {'type': 'Either', 'Right': None, 'Left': x}     # Right :: b -> Either a b def Right(x): '''Constructor for a populated Either (option type) value''' return {'type': 'Either', 'Left': None, 'Right': x}     # MAIN --- if __name__ == '__main__': main()
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a round table with five individual seats. For eating each philosopher needs two forks (the resources). There are five forks on the table, one left and one right of each seat. When a philosopher cannot grab both forks it sits and waits. Eating takes random time, then the philosopher puts the forks down and leaves the dining room. After spending some random time thinking about the nature of the universe, he again becomes hungry, and the circle repeats itself. It can be observed that a straightforward solution, when forks are implemented by semaphores, is exposed to deadlock. There exist two deadlock states when all five philosophers are sitting at the table holding one fork each. One deadlock state is when each philosopher has grabbed the fork left of him, and another is when each has the fork on his right. There are many solutions of the problem, program at least one, and explain how the deadlock is prevented.
#Rust
Rust
use std::thread; use std::sync::{Mutex, Arc};   struct Philosopher { name: String, left: usize, right: usize, }   impl Philosopher { fn new(name: &str, left: usize, right: usize) -> Philosopher { Philosopher { name: name.to_string(), left: left, right: right, } }   fn eat(&self, table: &Table) { let _left = table.forks[self.left].lock().unwrap(); let _right = table.forks[self.right].lock().unwrap();   println!("{} is eating.", self.name);   thread::sleep_ms(1000);   println!("{} is done eating.", self.name); } }   struct Table { forks: Vec<Mutex<()>>, }   fn main() { let table = Arc::new(Table { forks: vec![ Mutex::new(()), Mutex::new(()), Mutex::new(()), Mutex::new(()), Mutex::new(()), ]});   let philosophers = vec![ Philosopher::new("Baruch Spinoza", 0, 1), Philosopher::new("Gilles Deleuze", 1, 2), Philosopher::new("Karl Marx", 2, 3), Philosopher::new("Friedrich Nietzsche", 3, 4), Philosopher::new("Michel Foucault", 0, 4), ];   let handles: Vec<_> = philosophers.into_iter().map(|p| { let table = table.clone();   thread::spawn(move || { p.eat(&table); }) }).collect();   for h in handles { h.join().unwrap(); } }
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#REXX
REXX
/*REXX program converts a mm/dd/yyyy Gregorian date ───► a Discordian date. */ @day.1= 'Sweetness' /*define the 1st day─of─Discordian─week*/ @day.2= 'Boomtime' /* " " 2nd " " " " */ @day.3= 'Pungenday' /* " " 3rd " " " " */ @day.4= 'Prickle-Prickle' /* " " 4th " " " " */ @day.5= 'Setting Orange' /* " " 5th " " " " */   @seas.0= "St. Tib's day," /*define the leap─day of Discordian yr.*/ @seas.1= 'Chaos' /* " 1st season─of─Discordian─year.*/ @seas.2= 'Discord' /* " 2nd " " " " */ @seas.3= 'Confusion' /* " 3rd " " " " */ @seas.4= 'Bureaucracy' /* " 4th " " " " */ @seas.5= 'The Aftermath' /* " 5th " " " " */   parse arg gM '/' gD "/" gY . /*obtain the specified Gregorian date. */ if gM=='' | gM=="," | gM=='*' then parse value date("U") with gM '/' gD "/" gY .   gY=left( right( date(), 4), 4 - length(Gy) )gY /*adjust for two─digit year or no year.*/   /* [↓] day─of─year, leapyear adjust. */ doy= date('d', gY || right(gM, 2, 0)right(gD ,2, 0), "s") - (leapyear(gY) & gM>2)   dW= doy//5; if dW==0 then dW= 5 /*compute the Discordian weekday. */ dS= (doy-1) % 73 + 1 /* " " " season. */ dD= doy//73; if dD==0 then dD= 73 /* " " " day─of─month. */ if leapyear(gY) & gM==2 & gD==29 then ds= 0 /*is this St. Tib's day (leapday) ? */ if ds==0 then dD= /*adjust for the Discordian leap day. */   say space(@day.dW',' @seas.dS dD"," gY + 1166) /*display Discordian date to terminal. */ exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ leapyear: procedure; parse arg y /*obtain a four─digit Gregorian year. */ if y//4 \== 0 then return 0 /*Not ÷ by 4? Then not a leapyear. */ return y//100 \== 0 | y//400 == 0 /*apply the 100 and 400 year rules.*/
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path problem for a graph with non-negative edge path costs, producing a shortest path tree. This algorithm is often used in routing and as a subroutine in other graph algorithms. For a given source vertex (node) in the graph, the algorithm finds the path with lowest cost (i.e. the shortest path) between that vertex and every other vertex. For instance If the vertices of the graph represent cities and edge path costs represent driving distances between pairs of cities connected by a direct road,   Dijkstra's algorithm can be used to find the shortest route between one city and all other cities. As a result, the shortest path first is widely used in network routing protocols, most notably:   IS-IS   (Intermediate System to Intermediate System)   and   OSPF   (Open Shortest Path First). Important note The inputs to Dijkstra's algorithm are a directed and weighted graph consisting of 2 or more nodes, generally represented by:   an adjacency matrix or list,   and   a start node. A destination node is not specified. The output is a set of edges depicting the shortest path to each destination node. An example, starting with a──►b, cost=7, lastNode=a a──►c, cost=9, lastNode=a a──►d, cost=NA, lastNode=a a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►b so a──►b is added to the output.   There is a connection from b──►d so the input is updated to: a──►c, cost=9, lastNode=a a──►d, cost=22, lastNode=b a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►c so a──►c is added to the output.   Paths to d and f are cheaper via c so the input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a a──►f, cost=11, lastNode=c   The lowest cost is a──►f so c──►f is added to the output.   The input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a   The lowest cost is a──►d so c──►d is added to the output.   There is a connection from d──►e so the input is updated to: a──►e, cost=26, lastNode=d   Which just leaves adding d──►e to the output.   The output should now be: [ d──►e c──►d c──►f a──►c a──►b ] Task Implement a version of Dijkstra's algorithm that outputs a set of edges depicting the shortest path to each reachable node from an origin. Run your program with the following directed graph starting at node   a. Write a program which interprets the output from the above and use it to output the shortest path from node   a   to nodes   e   and f. Vertices Number Name 1 a 2 b 3 c 4 d 5 e 6 f Edges Start End Cost a b 7 a c 9 a f 14 b c 10 b d 15 c d 11 c f 2 d e 6 e f 9 You can use numbers or names to identify vertices in your program. See also Dijkstra's Algorithm vs. A* Search vs. Concurrent Dijkstra's Algorithm (youtube)
#SAS
SAS
/* create SAS data set */ data Edges; input Start $ End $ Cost; datalines; a b 7 a c 9 a f 14 b c 10 b d 15 c d 11 c f 2 d e 6 e f 9 ;   /* call OPTMODEL procedure in SAS/OR */ proc optmodel; /* declare sets and parameters, and read input data */ set <str,str> LINKS; num cost {LINKS}; read data Edges into LINKS=[start end] cost; set NODES = union {<i,j> in LINKS} {i,j}; set SOURCES = {'a'}; set SINKS = {'e'}; /* <source,sink,order,from,to> */ set <str,str,num,str,str> PATHS;   /* call network solver */ solve with network / shortpath=(source=SOURCES sink=SINKS) links=(weight=cost) out=(sppaths=PATHS);   /* write shortest path to SAS data set */ create data path from [source sink order from to]=PATHS cost[from,to]; quit;   /* print shortest path */ proc print data=path; run;
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displaystyle X} has only one digit. The additive persistence is the number of summations required to obtain the single digit. The task is to calculate the additive persistence and the digital root of a number, e.g.: 627615 {\displaystyle 627615} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; 39390 {\displaystyle 39390} has additive persistence 2 {\displaystyle 2} and digital root of 6 {\displaystyle 6} ; 588225 {\displaystyle 588225} has additive persistence 2 {\displaystyle 2} and digital root of 3 {\displaystyle 3} ; 393900588225 {\displaystyle 393900588225} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; The digital root may be calculated in bases other than 10. See Casting out nines for this wiki's use of this procedure. Digital root/Multiplicative digital root Sum digits of an integer Digital root sequence on OEIS Additive persistence sequence on OEIS Iterated digits squaring
#PL.2FI
PL/I
digrt: Proc Options(main); /* REXX *************************************************************** * Test digroot **********************************************************************/   Call digrtst('7'); Call digrtst('627615'); Call digrtst('39390'); Call digrtst('588225'); Call digrtst('393900588225');   digrtst: Proc(n); Dcl n Char(100) Var; Dcl dr Pic'9'; Dcl p Dec Fixed(5); Call digroot(n,dr,p); Put Edit(n,dr,p)(skip,a,col(20),f(1),f(3)); End;   digroot: Proc(n,dr,p); /********************************************************************** * Compute the digital root and persistence of the given decimal number * 27.07.2012 Walter Pachl (derived from REXX) **********************************************************************/ Dcl n Char(100) Var; Dcl dr Pic'9'; Dcl p Dec Fixed(5); Dcl s Pic'(14)Z9'; Dcl v Char(100) Var; p=0; v=strip(n); /* copy the number */ If length(v)=1 Then dr=v; Else Do; Do While(length(v)>1); /* more than one digit in v */ s=0; /* initialize sum */ p+=1; /* increment persistence */ Do i=1 To length(v); /* loop over all digits */ dig=substr(v,i,1); /* pick a digit */ s=s+dig; /* add to the new sum */ End; /*Put Skip Data(v,p,s);*/ v=strip(s); /* the 'new' number */ End; dr=Decimal(s,1,0); End; Return; End;   strip: Proc(x) Returns(Char(100) Var); Dcl x Char(*); Dcl res Char(100) Var Init(''); Do i=1 To length(x); If substr(x,i,1)>' ' Then res=res||substr(x,i,1); End; Return(res); End; End;
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of expression are valued. Examples may be be split into "setup", "problem statement", and "output" sections where the ease and naturalness of stating the problem and getting an answer, as well as the ease and flexibility of modifying the problem are the primary concerns. Example output should be shown here, as well as any comments on the examples flexibility. The problem Baker, Cooper, Fletcher, Miller, and Smith live on different floors of an apartment house that contains only five floors.   Baker does not live on the top floor.   Cooper does not live on the bottom floor.   Fletcher does not live on either the top or the bottom floor.   Miller lives on a higher floor than does Cooper.   Smith does not live on a floor adjacent to Fletcher's.   Fletcher does not live on a floor adjacent to Cooper's. Where does everyone live?
#Tcl
Tcl
package require Tcl 8.5 package require struct::list   proc dinesmanSolve {floors people constraints} { # Search for a possible assignment that satisfies the constraints struct::list foreachperm p $floors { lassign $p {*}$people set found 1 foreach c $constraints { if {![expr $c]} { set found 0 break } } if {$found} break } # Found something, or exhausted possibilities if {!$found} { error "no solution possible" } # Generate in "nice" order foreach f $floors { foreach person $people { if {[set $person] == $f} { lappend result $f $person break } } } return $result }
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
{1,3,-5}.{4,-2,-1}
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#MATLAB
MATLAB
A = [1 3 -5] B = [4 -2 -1] C = dot(A,B)
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and must add up to   12. The Chief of the Police doesn't like odd numbers and wants to have an even number for his department. Task Write a computer program which outputs all valid combinations. Possible output   (for the 1st and 14th solutions): --police-- --sanitation-- --fire-- 2 3 7 6 5 1
#F.23
F#
  // A function to generate department numbers. Nigel Galloway: May 2nd., 2018 type dNum = {Police:int; Fire:int; Sanitation:int} let fN n=n.Police%2=0&&n.Police+n.Fire+n.Sanitation=12&&n.Police<>n.Fire&&n.Police<>n.Sanitation&&n.Fire<>n.Sanitation List.init (7*7*7) (fun n->{Police=n%7+1;Fire=(n/7)%7+1;Sanitation=(n/49)+1})|>List.filter fN|>List.iter(printfn "%A")  
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#PHP
PHP
class Delegator { function __construct() { $this->delegate = NULL ; } function operation() { if(method_exists($this->delegate, "thing")) return $this->delegate->thing() ; return 'default implementation' ; } }   class Delegate { function thing() { return 'Delegate Implementation' ; } }   $a = new Delegator() ; print "{$a->operation()}\n" ;   $a->delegate = 'A delegate may be any object' ; print "{$a->operation()}\n" ;   $a->delegate = new Delegate() ; print "{$a->operation()}\n" ;
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects responsibilities: Delegator: Keep an optional delegate instance. Implement "operation" method, returning the delegate "thing" if the delegate respond to "thing", or the string "default implementation". Delegate: Implement "thing" and return the string "delegate implementation" Show how objects are created and used. First, without a delegate, then with a delegate that does not implement "thing", and last with a delegate that implements "thing".
#PicoLisp
PicoLisp
(class +Delegator) # delegate   (dm operation> () (if (: delegate) (thing> @) "default implementation" ) )     (class +Delegate) # thing   (dm T (Msg) (=: thing Msg) )   (dm thing> () (: thing) )     (let A (new '(+Delegator)) # Without a delegate (println (operation> A))   # With delegate that does not implement 'thing>' (put A 'delegate (new '(+Delegate))) (println (operation> A))   # With delegate that implements 'thing>' (put A 'delegate (new '(+Delegate) "delegate implementation")) (println (operation> A)) )
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)   (0,0),(5,0),(2.5,5)   and   (0,4),(2.5,-1),(5,4)   (0,0),(1,1),(0,2)     and   (2,1),(3,0),(3,2)   (0,0),(1,1),(0,2)     and   (2,1),(3,-2),(3,4) Optionally, see what the result is when only a single corner is in contact (there is no definitive correct answer):   (0,0),(1,0),(0,1)   and   (1,0),(2,0),(1,1)
#QB64
QB64
  DATA 0,0,5,0,0,5,0,0,5,0,0,6 DATA 0,0,0,5,5,0,0,0,0,5,5,0 DATA 0,0,5,0,0,5,-10,0,-5,0,-1,6 DATA 0,0,5,0,2.5,5,0,4,2.5,-1,5,4 DATA 0,0,1,1,0,2,2,1,3,0,3,2 DATA 0,0,1,1,0,2,2,1,3,-2,3,4   TYPE point x AS INTEGER y AS INTEGER END TYPE   DIM coord(12, 3) AS point   workscreen = _NEWIMAGE(800, 800, 32) backscreen = _NEWIMAGE(800, 800, 32)   SCREEN workscreen FOR i = 1 TO 12 '12 triangles FOR j = 1 TO 3 'with 3 coordinates for each READ coord(i, j).x 'X coord READ coord(i, j).y 'Y coord FixCoord coord(i, j) NEXT   NEXT _DELAY .5 _SCREENMOVE _MIDDLE     FOR i = 1 TO 12 _DEST workscreen CLS _DEST backscreen _DONTBLEND CLS , 0 PSET (coord(i, 1).x, coord(i, 1).y), _RGBA32(255, 255, 255, 128) FOR j = 2 TO 3 LINE -(coord(i, j).x, coord(i, j).y), _RGBA32(255, 255, 255, 128) NEXT LINE -(coord(i, 1).x, coord(i, 1).y), _RGBA32(255, 255, 255, 128) xinside = (coord(i, 1).x + coord(i, 2).x + coord(i, 3).x) / 3 yinside = (coord(i, 1).y + coord(i, 2).y + coord(i, 3).y) / 3 PAINT (xinside, yinside), _RGBA32(255, 255, 255, 128) _BLEND _PUTIMAGE , backscreen, 0 CLS , 0 _DONTBLEND i = i + 1 PSET (coord(i, 1).x, coord(i, 1).y), _RGBA32(255, 0, 0, 128) FOR j = 2 TO 3 LINE -(coord(i, j).x, coord(i, j).y), _RGBA32(255, 0, 0, 128) NEXT LINE -(coord(i, 1).x, coord(i, 1).y), _RGBA32(255, 0, 0, 128) xinside = (coord(i, 1).x + coord(i, 2).x + coord(i, 3).x) / 3 yinside = (coord(i, 1).y + coord(i, 2).y + coord(i, 3).y) / 3 PAINT (xinside, yinside), _RGBA32(255, 0, 0, 128) _BLEND _PUTIMAGE , backscreen, 0 _DEST workscreen _SOURCE workscreen overlap = 0 FOR x = 0 TO 999 FOR y = 0 TO 999 IF POINT(x, y) = _RGBA32(190, 63, 63, 255) THEN overlap = -1: GOTO overlap NEXT NEXT overlap: IF overlap THEN PRINT "OVERLAP" ELSE PRINT "NO OVERLAP" SLEEP NEXT SYSTEM   SUB FixCoord (p AS point) p.x = (10 + p.x) * 30 + 100 p.y = (10 + p.y) * 30 END SUB  
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#J
J
load 'files' ferase 'input.txt' ferase '\input.txt' ferase 'docs' ferase '\docs'   NB. Or all at once... ferase 'input.txt';'/input.txt';'docs';'/docs'
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Java
Java
import java.io.File;   public class FileDeleteTest { public static boolean deleteFile(String filename) { boolean exists = new File(filename).delete(); return exists; }   public static void test(String type, String filename) { System.out.println("The following " + type + " called " + filename + (deleteFile(filename) ? " was deleted." : " could not be deleted.") ); }   public static void main(String args[]) { test("file", "input.txt"); test("file", File.seperator + "input.txt"); test("directory", "docs"); test("directory", File.seperator + "docs" + File.seperator); } }
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by perm ⁡ ( A ) = ∑ σ ∏ i = 1 n M i , σ i {\displaystyle \operatorname {perm} (A)=\sum _{\sigma }\prod _{i=1}^{n}M_{i,\sigma _{i}}} In both cases the sum is over the permutations σ {\displaystyle \sigma } of the permutations of 1, 2, ..., n. (A permutation's sign is 1 if there are an even number of inversions and -1 otherwise; see parity of a permutation.) More efficient algorithms for the determinant are known: LU decomposition, see for example wp:LU decomposition#Computing the determinant. Efficient methods for calculating the permanent are not known. Related task Permutations by swapping
#Racket
Racket
  #lang racket (require math) (define determinant matrix-determinant)   (define (permanent M) (define n (matrix-num-rows M)) (for/sum ([σ (in-permutations (range n))]) (for/product ([i n] [σi σ]) (matrix-ref M i σi))))  
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by perm ⁡ ( A ) = ∑ σ ∏ i = 1 n M i , σ i {\displaystyle \operatorname {perm} (A)=\sum _{\sigma }\prod _{i=1}^{n}M_{i,\sigma _{i}}} In both cases the sum is over the permutations σ {\displaystyle \sigma } of the permutations of 1, 2, ..., n. (A permutation's sign is 1 if there are an even number of inversions and -1 otherwise; see parity of a permutation.) More efficient algorithms for the determinant are known: LU decomposition, see for example wp:LU decomposition#Computing the determinant. Efficient methods for calculating the permanent are not known. Related task Permutations by swapping
#Raku
Raku
sub insert ($x, @xs) { ([flat @xs[0 ..^ $_], $x, @xs[$_ .. *]] for 0 .. @xs) } sub order ($sg, @xs) { $sg > 0 ?? @xs !! @xs.reverse }   multi σ_permutations ([]) { [] => 1 }   multi σ_permutations ([$x, *@xs]) { σ_permutations(@xs).map({ |order($_.value, insert($x, $_.key)) }) Z=> |(1,-1) xx * }   sub m_arith ( @a, $op ) { note "Not a square matrix" and return if [||] map { @a.elems cmp @a[$_].elems }, ^@a; sum σ_permutations([^@a]).race.map: { my $permutation = .key; my $term = $op eq 'perm' ?? 1 !! .value; for $permutation.kv -> $i, $j { $term *= @a[$i][$j] }; $term } }   ######### helper subs ######### sub hilbert-matrix (\h) {[(1..h).map(-> \n {[(n..^n+h).map: {(1/$_).FatRat}]})]}   sub rat-or-int ($num) { return $num unless $num ~~ Rat|FatRat; return $num.narrow if $num.narrow.WHAT ~~ Int; $num.nude.join: '/'; }   sub say-it ($message, @array) { my $max; @array.map: {$max max= max $_».&rat-or-int.comb(/\S+/)».chars}; say "\n$message"; $_».&rat-or-int.fmt(" %{$max}s").put for @array; }   ########### Testing ########### my @tests = ( [ [ 1, 2 ], [ 3, 4 ] ], [ [ 1, 2, 3, 4 ], [ 4, 5, 6, 7 ], [ 7, 8, 9, 10 ], [ 10, 11, 12, 13 ] ], hilbert-matrix 7 );   for @tests -> @matrix { say-it 'Matrix:', @matrix; say "Determinant:\t", rat-or-int @matrix.&m_arith: <det>; say "Permanent: \t", rat-or-int @matrix.&m_arith: <perm>; say '-' x 40; }
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#LabVIEW
LabVIEW
define dividehandler(a,b) => { ( #a->isNotA(::integer) && #a->isNotA(::decimal) || #b->isNotA(::integer) && #b->isNotA(::decimal) ) ? return 'Error: Please supply all params as integers or decimals' protect => { handle_error => { return 'Error: Divide by zero' } local(x = #a / #b) return #x } }   dividehandler(1,0)
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Lasso
Lasso
define dividehandler(a,b) => { ( #a->isNotA(::integer) && #a->isNotA(::decimal) || #b->isNotA(::integer) && #b->isNotA(::decimal) ) ? return 'Error: Please supply all params as integers or decimals' protect => { handle_error => { return 'Error: Divide by zero' } local(x = #a / #b) return #x } }   dividehandler(1,0)
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Lingo
Lingo
on div (a, b) -- for simplicity type check of vars omitted res = value("float(a)/b") if voidP(res) then _player.alert("Division by zero!") else return res end if end
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. 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
#Groovy
Groovy
def isNumeric = { def formatter = java.text.NumberFormat.instance def pos = [0] as java.text.ParsePosition formatter.parse(it, pos)   // if parse position index has moved to end of string // them the whole string was numeric pos.index == it.size() }
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. 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
#Haskell
Haskell
isInteger s = case reads s :: [(Integer, String)] of [(_, "")] -> True _ -> False   isDouble s = case reads s :: [(Double, String)] of [(_, "")] -> True _ -> False   isNumeric :: String -> Bool isNumeric s = isInteger s || isDouble s
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as unique   process the strings from left─to─right   if       unique,   display a message saying such   if not unique,   then:   display a message saying such   display what character is duplicated   only the 1st non─unique character need be displayed   display where "both" duplicated characters are in the string   the above messages can be part of a single message   display the hexadecimal value of the duplicated character Use (at least) these five test values   (strings):   a string of length     0   (an empty string)   a string of length     1   which is a single period   (.)   a string of length     6   which contains:   abcABC   a string of length     7   which contains a blank in the middle:   XYZ  ZYX   a string of length   36   which   doesn't   contain the letter "oh": 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ Show all output here on this page. 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
#PicoLisp
PicoLisp
(de burn (Lst) (let P 0 (by '((A) (set A (inc 'P)) (put A 'P (char A)) ) group Lst ) ) ) (de first (Lst) (mini '((L) (nand (cdr L) (apply min (mapcar val L)) ) ) Lst ) ) (de uniq? (Str) (let M (first (burn (chop Str))) (ifn M (prinl Str " (length " (length Str) "): all characters are unique") (prin Str " (length " (length Str) "): first duplicate character " (car M) " at positions " ) (println (mapcar val M)) ) ) ) (uniq?) (uniq? ".") (uniq? "abcABC") (uniq? "XYZ ZYX") (uniq? "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ")
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as unique   process the strings from left─to─right   if       unique,   display a message saying such   if not unique,   then:   display a message saying such   display what character is duplicated   only the 1st non─unique character need be displayed   display where "both" duplicated characters are in the string   the above messages can be part of a single message   display the hexadecimal value of the duplicated character Use (at least) these five test values   (strings):   a string of length     0   (an empty string)   a string of length     1   which is a single period   (.)   a string of length     6   which contains:   abcABC   a string of length     7   which contains a blank in the middle:   XYZ  ZYX   a string of length   36   which   doesn't   contain the letter "oh": 1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ Show all output here on this page. 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
#Prolog
Prolog
report_duplicates(S) :- duplicates(S, Dups), format('For value "~w":~n', S), report(Dups), nl.   report(Dups) :- maplist(only_one_position, Dups), format(' All characters are unique~n').   report(Dups) :- exclude(only_one_position, Dups, [c(Char,Positions)|_]), reverse(Positions, PosInOrder), atomic_list_concat(PosInOrder, ', ', PosAsList), format(' The character ~w is non unique at ~p~n', [Char, PosAsList]).   only_one_position(c(_,[_])).   duplicates(S, Count) :- atom_chars(S, Chars), char_count(Chars, 0, [], Count).   char_count([], _, C, C). char_count([C|T], Index, Counted, Result) :- select(c(C,Positions), Counted, MoreCounted), succ(Index, Index1), char_count(T, Index1, [c(C,[Index|Positions])|MoreCounted], Result). char_count([C|T], Index, Counted, Result) :- \+ member(c(C,_), Counted), succ(Index, Index1), char_count(T, Index1, [c(C,[Index])|Counted], Result).   test :- report_duplicates(''). test :- report_duplicates('.'). test :- report_duplicates('abcABC'). test :- report_duplicates('XYZ ZYX'). test :- report_duplicates('1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ').
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#Vlang
Vlang
// Returns collapsed string, original and new lengths in // unicode code points (not normalized). fn collapse(s string) (string, int, int) { mut r := s.runes() le, mut del := r.len, 0 for i := le - 2; i >= 0; i-- { if r[i] == r[i+1] { r.delete(i) del++ } } if del == 0 { return s, le, le } r = r[..le-del] return r.string(), le, r.len }   fn main() { strings:= [ "", '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ', "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman ", "The better the 4-wheel drive, the further you'll be from help when ya get stuck!", "headmistressship", "aardvark", "😍😀🙌💃😍😍😍🙌", ] for s in strings { cs, olen, clen := collapse(s) println("original : length = ${olen:2}, string = «««$s»»»") println("collapsed: length = ${clen:2}, string = «««$cs»»»\n") } }
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediately repeated   character is any character that is   immediately   followed by an identical character (or characters).   Another word choice could've been   duplicated character,   but that might have ruled out   (to some readers)   triplicated characters   ···   or more. {This Rosetta Code task was inspired by a newly introduced   (as of around November 2019)   PL/I   BIF:   collapse.} Examples In the following character string: The better the 4-wheel drive, the further you'll be from help when ya get stuck! Only the 2nd   t,   e, and   l   are repeated characters,   indicated by underscores (above),   even though they (those characters) appear elsewhere in the character string. So, after collapsing the string, the result would be: The beter the 4-whel drive, the further you'l be from help when ya get stuck! Another example: In the following character string: headmistressship The "collapsed" string would be: headmistreship Task Write a subroutine/function/procedure/routine···   to locate   repeated   characters and   collapse   (delete)   them from the character string.   The character string can be processed from either direction. Show all output here, on this page:   the   original string and its length   the resultant string and its length   the above strings should be "bracketed" with   <<<   and   >>>   (to delineate blanks)   «««Guillemets may be used instead for "bracketing" for the more artistic programmers,   shown used here»»» Use (at least) the following five strings,   all strings are length seventy-two (characters, including blanks),   except the 1st string: string number ╔╗ 1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero) 2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║ 3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║ 4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║ 5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks ╚════════════════════════════════════════════════════════════════════════╝ 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
#Wren
Wren
import "/fmt" for Fmt   // Returns collapsed string, original and new lengths in // unicode code points (not normalized). var collapse = Fn.new { |s| var c = s.codePoints.toList var le = c.count if (le < 2) return [s, le, le] for (i in le-2..0) { if (c[i] == c[i+1]) c.removeAt(i) } var cc = c.reduce("") { |acc, cp| acc + String.fromCodePoint(cp) } return [cc, le, cc.count] }   var strings = [ "", "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ", "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and they think it's hell. ", " --- Harry S Truman ", "The better the 4-wheel drive, the further you'll be from help when ya get stuck!", "headmistressship", "aardvark", "😍😀🙌💃😍😍😍🙌" ]   for (s in strings) { var r = collapse.call(s) System.print("original : length = %(Fmt.d(2, r[1])), string = «««%(s)»»»") System.print("collapsed: length = %(Fmt.d(2, r[2])), string = «««%(r[0])»»»\n") }
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as all the same character(s)   process the strings from left─to─right   if       all the same character,   display a message saying such   if not all the same character,   then:   display a message saying such   display what character is different   only the 1st different character need be displayed   display where the different character is in the string   the above messages can be part of a single message   display the hexadecimal value of the different character Use (at least) these seven test values   (strings):   a string of length   0   (an empty string)   a string of length   3   which contains three blanks   a string of length   1   which contains:   2   a string of length   3   which contains:   333   a string of length   3   which contains:   .55   a string of length   6   which contains:   tttTTT   a string of length   9   with a blank in the middle:   4444   444k Show all output here on this page. 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
  [ 0 swap dup size 0 = iff drop done behead swap witheach [ over != if [ drop i^ 1+ swap conclude ] ] drop ] is allsame ( [ --> n )   ( 0 indicates all items are the same, otherwise n is first different item )   [ say ' String: "' dup echo$ say '" length ' dup size echo dup allsame dup 0 = iff [ say ', all characters are the same.' 2drop ] else [ say ', first difference is item ' dup echo say ', char "' peek dup emit say '", hex: ' 16 base put echo base release say '.' ] cr ] is task ( $ --> )   $ "" task $ " " task $ "2" task $ ".55" task $ "tttTTT" task $ "4444 444k" task
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the strings are being examined)   a zero─length (empty) string shall be considered as all the same character(s)   process the strings from left─to─right   if       all the same character,   display a message saying such   if not all the same character,   then:   display a message saying such   display what character is different   only the 1st different character need be displayed   display where the different character is in the string   the above messages can be part of a single message   display the hexadecimal value of the different character Use (at least) these seven test values   (strings):   a string of length   0   (an empty string)   a string of length   3   which contains three blanks   a string of length   1   which contains:   2   a string of length   3   which contains:   333   a string of length   3   which contains:   .55   a string of length   6   which contains:   tttTTT   a string of length   9   with a blank in the middle:   4444   444k Show all output here on this page. 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
isAllSame <- function(string) { strLength <- nchar(string) if(length(strLength) > 1) { #R has a distinction between the length of a string and that of a character vector. It is a common source #of problems when coming from another language. We will try to avoid the topic here. #For our purposes, let us only say that there is a good reason why we have made #isAllSame(c("foo", "bar") immediately throw an error. stop("This task is intended for character vectors with lengths of at most 1.") } else if(length(strLength) == 0) { cat("Examining a character vector of length 0.\n") TRUE } else if(strLength == 0) { cat("Examining a character vector of length 1, containing an empty string.\n") TRUE } else { cat("Examining the string", paste0(sQuote(string), ","), "which is of length", paste0(strLength, ":"), "\n") #strsplit outputs a list. Its first element is the vector of characters that we desire. characters <- strsplit(string, "")[[1]] #Our use of match is using R's vector recycling rules. Every element is being checked #against the first. differentElementIndex <- match(FALSE, characters[1] == characters, nomatch = 0) if(differentElementIndex == 0) { cat("It has no duplicates.\n") TRUE } else { cat("It has duplicates. ") firstDifferentCharacter <- characters[differentElementIndex] cat(sQuote(firstDifferentCharacter), "is the first different character. It has hex value", sprintf("0x%X", as.integer(charToRaw(firstDifferentCharacter))), "and is at index", paste0(differentElementIndex, "."), "\n") FALSE } } }   #Tests: cat("Test: A string of length 0 (an empty string):\n") cat("Test 1 of 2: An empty character vector:\n") print(isAllSame(character(0))) cat("Test 2 of 2: A character vector containing the empty string:\n") print(isAllSame("")) cat("Test: A string of length 3 which contains three blanks:\n") print(isAllSame(" ")) cat("Test: A string of length 1 which contains 2:\n") print(isAllSame("2")) cat("Test: A string of length 3 which contains 333:\n") print(isAllSame("333")) cat("Test: A string of length 3 which contains .55:\n") print(isAllSame(".55")) cat("Test: A string of length 6 which contains tttTTT:\n") print(isAllSame("tttTTT")) cat("Test: A string of length 9 which contains 4444 444k:\n") print(isAllSame("4444 444k"))
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a round table with five individual seats. For eating each philosopher needs two forks (the resources). There are five forks on the table, one left and one right of each seat. When a philosopher cannot grab both forks it sits and waits. Eating takes random time, then the philosopher puts the forks down and leaves the dining room. After spending some random time thinking about the nature of the universe, he again becomes hungry, and the circle repeats itself. It can be observed that a straightforward solution, when forks are implemented by semaphores, is exposed to deadlock. There exist two deadlock states when all five philosophers are sitting at the table holding one fork each. One deadlock state is when each philosopher has grabbed the fork left of him, and another is when each has the fork on his right. There are many solutions of the problem, program at least one, and explain how the deadlock is prevented.
#Simula
Simula
COMMENT ! DEADLOCK IS PREVENTED BY REVERSING THE ORDER OF TAKING THE CHOPSTICKS FOR THE LAST PHILOSOPHER. ! THAT MEANS ALL PHILOSOPHERS FIRST TAKE THE LEFT CHOPSTICK, THEN THE RIGHT CHOPSTICK. ! BUT THE LAST PHILOSOPHER FIRST TAKES THE RIGHT CHOPSTICK, THEN THE LEFT. ! ! THE DETACH STATEMENT IN CLASS PHILOSOPHER GIVES CONTROL BACK TO THE MAIN BLOCK. ! THE MAIN BLOCK CALLS/RESUMES ALL THE PHILOSOPHERS USING THE RESUME(PHILOSOPHER) STATEMENT. ! THIS CONTINUES THE CODE IN THE PHILOSOPHER CLASS AFTER THE LAST DETACH STATEMENT. ! (ANOTHER NAME FOR THIS FEATURE IS THE CONCEPT OF A COROUTINE) ; BEGIN INTEGER N; INTEGER PNR, CNR; INTEGER SEED; SEED := ININT; N := 5; BEGIN   CLASS CHOPSTICK; BEGIN REF(PHILOSOPHER) OWNER; INTEGER ID; ID := CNR := CNR + 1; END CHOPSTICK;   CLASS PHILOSOPHER(L,R); REF(CHOPSTICK) L,R; BEGIN INTEGER ID; ID := PNR := PNR + 1; WHILE TRUE DO BEGIN DETACH;   OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") THINKING..."); OUTIMAGE; DETACH;   WHILE RANDINT(0,1,SEED) = 0 DO BEGIN OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") THINKING DEEPER..."); OUTIMAGE; DETACH; END;   WHILE L.OWNER =/= NONE DO BEGIN OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") WAITING FOR LEFT CHOPSTICK("); OUTINT(L.ID, 0); OUTTEXT(") ..."); OUTIMAGE; DETACH; END; L.OWNER :- THIS PHILOSOPHER; OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") GRABBED LEFT CHOPSTICK("); OUTINT(L.ID, 0); OUTTEXT(")"); OUTIMAGE;   WHILE R.OWNER =/= NONE DO BEGIN OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") WAITING FOR RIGHT CHOPSTICK("); OUTINT(R.ID, 0); OUTTEXT(") ..."); OUTIMAGE; DETACH; END; R.OWNER :- THIS PHILOSOPHER; OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") GRABBED RIGHT CHOPSTICK("); OUTINT(R.ID, 0); OUTTEXT(")"); OUTIMAGE;   OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") EATING..."); OUTIMAGE; WHILE RANDINT(0,1,SEED) = 0 DO BEGIN DETACH; OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") STILL EATING..."); OUTIMAGE; END; L.OWNER :- NONE; R.OWNER :- NONE; OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") RELEASED LEFT CHOPSTICK("); OUTINT(L.ID, 0); OUTTEXT(")"); OUTIMAGE; OUTTEXT("PHILOSOPHER("); OUTINT(ID, 0); OUTTEXT(") RELEASED RIGHT CHOPSTICK("); OUTINT(R.ID, 0); OUTTEXT(")"); OUTIMAGE; END; END PHILOSOPHER;    !---------------------------------------|  ! |  ! |  ! (3) |  ! P2 P3 |  ! |  ! (2) (4) |  ! |  ! |  ! P1 P4 |  ! |  ! |  ! (1) (5) |  ! |  ! P5 | only P5 takes Right first (5), then Left (1)  ! |  !---------------------------------------|  !;   REF(PHILOSOPHER) ARRAY PHILS (1:N); REF(CHOPSTICK) L, R; INTEGER I, LOOPS;   R :- NEW CHOPSTICK; FOR I := 1 STEP 1 UNTIL N-1 DO BEGIN L :- NEW CHOPSTICK; PHILS(I) :- NEW PHILOSOPHER(L,R); R :- L; END;  ! REVERSED ORDER FOR THE LAST PHILOSOPHER ; PHILS(N) :- NEW PHILOSOPHER(R,PHILS(1).R);   FOR I := 1 STEP 1 UNTIL N DO BEGIN OUTTEXT("PHILOSOPHER(ID="); OUTINT(PHILS(I).ID, 0); OUTTEXT(", L="); OUTINT(PHILS(I).L.ID, 0); OUTTEXT(", R="); OUTINT(PHILS(I).R.ID, 0); OUTTEXT(")"); OUTIMAGE; END;   FOR LOOPS := 1 STEP 1 UNTIL 10 DO BEGIN FOR I := 1 STEP 1 UNTIL N DO BEGIN RESUME(PHILS(I)); END; END;   END; END.
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Ruby
Ruby
require 'date'   class DiscordianDate SEASON_NAMES = ["Chaos","Discord","Confusion","Bureaucracy","The Aftermath"] DAY_NAMES = ["Sweetmorn","Boomtime","Pungenday","Prickle-Prickle","Setting Orange"] YEAR_OFFSET = 1166 DAYS_PER_SEASON = 73 DAYS_PER_WEEK = 5 ST_TIBS_DAY_OF_YEAR = 60   def initialize(year, month, day) gregorian_date = Date.new(year, month, day) @day_of_year = gregorian_date.yday   @st_tibs = false if gregorian_date.leap? if @day_of_year == ST_TIBS_DAY_OF_YEAR @st_tibs = true elsif @day_of_year > ST_TIBS_DAY_OF_YEAR @day_of_year -= 1 end end   @season, @day = (@day_of_year-1).divmod(DAYS_PER_SEASON) @day += 1 #← ↑ fixes of-by-one error (only visible at season changes) @year = gregorian_date.year + YEAR_OFFSET end attr_reader :year, :day   def season SEASON_NAMES[@season] end   def weekday if @st_tibs "St. Tib's Day" else DAY_NAMES[(@day_of_year - 1) % DAYS_PER_WEEK] end end   def to_s %Q{#{@st_tibs ? "St. Tib's Day" : "%s, %s %d" % [weekday, season, day]}, #{year} YOLD} end end
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path problem for a graph with non-negative edge path costs, producing a shortest path tree. This algorithm is often used in routing and as a subroutine in other graph algorithms. For a given source vertex (node) in the graph, the algorithm finds the path with lowest cost (i.e. the shortest path) between that vertex and every other vertex. For instance If the vertices of the graph represent cities and edge path costs represent driving distances between pairs of cities connected by a direct road,   Dijkstra's algorithm can be used to find the shortest route between one city and all other cities. As a result, the shortest path first is widely used in network routing protocols, most notably:   IS-IS   (Intermediate System to Intermediate System)   and   OSPF   (Open Shortest Path First). Important note The inputs to Dijkstra's algorithm are a directed and weighted graph consisting of 2 or more nodes, generally represented by:   an adjacency matrix or list,   and   a start node. A destination node is not specified. The output is a set of edges depicting the shortest path to each destination node. An example, starting with a──►b, cost=7, lastNode=a a──►c, cost=9, lastNode=a a──►d, cost=NA, lastNode=a a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►b so a──►b is added to the output.   There is a connection from b──►d so the input is updated to: a──►c, cost=9, lastNode=a a──►d, cost=22, lastNode=b a──►e, cost=NA, lastNode=a a──►f, cost=14, lastNode=a   The lowest cost is a──►c so a──►c is added to the output.   Paths to d and f are cheaper via c so the input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a a──►f, cost=11, lastNode=c   The lowest cost is a──►f so c──►f is added to the output.   The input is updated to: a──►d, cost=20, lastNode=c a──►e, cost=NA, lastNode=a   The lowest cost is a──►d so c──►d is added to the output.   There is a connection from d──►e so the input is updated to: a──►e, cost=26, lastNode=d   Which just leaves adding d──►e to the output.   The output should now be: [ d──►e c──►d c──►f a──►c a──►b ] Task Implement a version of Dijkstra's algorithm that outputs a set of edges depicting the shortest path to each reachable node from an origin. Run your program with the following directed graph starting at node   a. Write a program which interprets the output from the above and use it to output the shortest path from node   a   to nodes   e   and f. Vertices Number Name 1 a 2 b 3 c 4 d 5 e 6 f Edges Start End Cost a b 7 a c 9 a f 14 b c 10 b d 15 c d 11 c f 2 d e 6 e f 9 You can use numbers or names to identify vertices in your program. See also Dijkstra's Algorithm vs. A* Search vs. Concurrent Dijkstra's Algorithm (youtube)
#Scala
Scala
object Dijkstra {   type Path[Key] = (Double, List[Key])   def Dijkstra[Key](lookup: Map[Key, List[(Double, Key)]], fringe: List[Path[Key]], dest: Key, visited: Set[Key]): Path[Key] = fringe match { case (dist, path) :: fringe_rest => path match {case key :: path_rest => if (key == dest) (dist, path.reverse) else { val paths = lookup(key).flatMap {case (d, key) => if (!visited.contains(key)) List((dist + d, key :: path)) else Nil} val sorted_fringe = (paths ++ fringe_rest).sortWith {case ((d1, _), (d2, _)) => d1 < d2} Dijkstra(lookup, sorted_fringe, dest, visited + key) } } case Nil => (0, List()) }   def main(x: Array[String]): Unit = { val lookup = Map( "a" -> List((7.0, "b"), (9.0, "c"), (14.0, "f")), "b" -> List((10.0, "c"), (15.0, "d")), "c" -> List((11.0, "d"), (2.0, "f")), "d" -> List((6.0, "e")), "e" -> List((9.0, "f")), "f" -> Nil ) val res = Dijkstra[String](lookup, List((0, List("a"))), "e", Set()) println(res) } }
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displaystyle X} has only one digit. The additive persistence is the number of summations required to obtain the single digit. The task is to calculate the additive persistence and the digital root of a number, e.g.: 627615 {\displaystyle 627615} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; 39390 {\displaystyle 39390} has additive persistence 2 {\displaystyle 2} and digital root of 6 {\displaystyle 6} ; 588225 {\displaystyle 588225} has additive persistence 2 {\displaystyle 2} and digital root of 3 {\displaystyle 3} ; 393900588225 {\displaystyle 393900588225} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; The digital root may be calculated in bases other than 10. See Casting out nines for this wiki's use of this procedure. Digital root/Multiplicative digital root Sum digits of an integer Digital root sequence on OEIS Additive persistence sequence on OEIS Iterated digits squaring
#PL.2FM
PL/M
100H: /* SHOW THE DIGITAL ROOT AND PERSISTENCE OF SOME NUMBERS */   /* BDOS SYSTEM CALL */ BDOS: PROCEDURE( FN, ARG ); DECLARE FN BYTE, ARG ADDRESS; GOTO 5; END; /* PRINTS A BYTE AS A CHARACTER */ PRINT$CHAR: PROCEDURE( CH ); DECLARE CH BYTE; CALL BDOS( 2, CH ); END; /* PRINTS A BYTE AS A NUMBER */ PRINT$BYTE: PROCEDURE( N ); DECLARE N BYTE; DECLARE ( V, D2 ) BYTE; IF ( V := N / 10 ) <> 0 THEN DO; D2 = V MOD 10; IF ( V := V / 10 ) <> 0 THEN CALL PRINT$CHAR( '0' + V ); CALL PRINT$CHAR( '0' + D2 ); END; CALL PRINT$CHAR( '0' + N MOD 10 ); END PRINT$BYTE; /* PRINTS A $ TERMINATED STRING */ PRINT$STRING: PROCEDURE( S ); DECLARE S ADDRESS; CALL BDOS( 9, S ); END;   /* PRINTS N1, N2, N3 AS A SINGLE NUMBER */ /* N1, N2, N3 MUST ALL BE BETWEEN 0 AND 9999 INCLUSIVE */ PRINT$NUMBER3: PROCEDURE( N1, N2, N3 ); DECLARE ( N1, N2, N3 ) ADDRESS; DECLARE V ADDRESS, N$STR( 14 ) BYTE, ( W, I, J ) BYTE; W = LAST( N$STR ); N$STR( W ) = '$'; /* ADD THE DIGITS OF THE THREE NUMBERS TO N$STR */ DO I = 0 TO 2; DO CASE I; V = N3; V = N2; V = N1; END; DO J = 1 TO 4; N$STR( W := W - 1 ) = '0' + ( V MOD 10 ); V = V / 10; END; END; /* SPACE FILL THE REMAINDER OF THE NUMBER */ I = W; DO WHILE( I > 0 ); N$STR( I := I - 1 ) = ' '; END; /* SUPPRESS LEADING ZEROS */ DO WHILE( W < LAST( N$STR ) - 1 AND N$STR( W ) = '0' ); N$STR( W ) = ' '; W = W + 1; END; CALL PRINT$STRING( .N$STR ); END PRINT$NUMBER3;   /* CALCULATES THE DIGITAL ROOT AND PERSISTENCE OF AN INTEGER IN BASE 10 */ /* IN ORDER TO ALLOW FOR NUMBERS LARGER THAN 2^15, THE NUMBER IS PASSED */ /* AS THE UPPER, MIDDLE AND LOWER DIGITS IN N1, N2 AND N3 */ /* E.G. 393900588225 CAN BE PROCESSED BY N1=3939, N2=0058, N3=8225 */ FIND$DIGITAL$ROOT: PROCEDURE( N1, N2, N3, ROOT$PTR, PERSISTENCE$PTR ); DECLARE ( N1, N2, N3, ROOT$PTR, PERSISTENCE$PTR ) ADDRESS; DECLARE DIGITAL$ROOT BASED ROOT$PTR BYTE; DECLARE PERSISTENCE BASED PERSISTENCE$PTR BYTE;   SUM$DIGITS: PROCEDURE( N ) ADDRESS; DECLARE N ADDRESS; DECLARE DIGITS ADDRESS, SUM BYTE; DIGITS = N; SUM = 0; DO WHILE DIGITS > 0; SUM = SUM + ( DIGITS MOD 10 ); DIGITS = DIGITS / 10; END; RETURN SUM; END SUM$DIGITS;   DIGITAL$ROOT = SUM$DIGITS( N1 ) + SUM$DIGITS( N2 ) + SUM$DIGITS( N3 ); PERSISTENCE = 1; DO WHILE( DIGITAL$ROOT > 9 ); PERSISTENCE = PERSISTENCE + 1; DIGITAL$ROOT = SUM$DIGITS( DIGITAL$ROOT ); END; END FIND$DIGITAL$ROOT ;   /* CALCULATES AND PRINTS THE DIGITAL ROOT AND PERSISTENCE OF THE */ /* NUMBER FORMED FROM THE CONCATENATION OF N1, N2 AND N3 */ PRINT$DR$AND$PERSISTENCE: PROCEDURE( N1, N2, N3 ); DECLARE ( N1, N2, N3 ) ADDRESS; DECLARE ( DIGITAL$ROOT, PERSISTENCE ) BYTE; CALL FIND$DIGITAL$ROOT( N1, N2, N3, .DIGITAL$ROOT, .PERSISTENCE ); CALL PRINT$NUMBER3( N1, N2, N3 ); CALL PRINT$STRING( .': DIGITAL ROOT: $' ); CALL PRINT$BYTE( DIGITAL$ROOT ); CALL PRINT$STRING( .', PERSISTENCE: $' ); CALL PRINT$BYTE( PERSISTENCE ); CALL PRINT$STRING( .( 0DH, 0AH, '$' ) ); END PRINT$DR$AND$PERSISTENCE;   /* TEST THE DIGITAL ROOT AND PERSISTENCE PROCEDURES */ CALL PRINT$DR$ANDPERSISTENCE( 0, 62, 7615 ); CALL PRINT$DR$ANDPERSISTENCE( 0, 3, 9390 ); CALL PRINT$DR$ANDPERSISTENCE( 0, 58, 8225 ); CALL PRINT$DR$ANDPERSISTENCE( 3939, 0058, 8225 );   EOF
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displaystyle X} has only one digit. The additive persistence is the number of summations required to obtain the single digit. The task is to calculate the additive persistence and the digital root of a number, e.g.: 627615 {\displaystyle 627615} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; 39390 {\displaystyle 39390} has additive persistence 2 {\displaystyle 2} and digital root of 6 {\displaystyle 6} ; 588225 {\displaystyle 588225} has additive persistence 2 {\displaystyle 2} and digital root of 3 {\displaystyle 3} ; 393900588225 {\displaystyle 393900588225} has additive persistence 2 {\displaystyle 2} and digital root of 9 {\displaystyle 9} ; The digital root may be calculated in bases other than 10. See Casting out nines for this wiki's use of this procedure. Digital root/Multiplicative digital root Sum digits of an integer Digital root sequence on OEIS Additive persistence sequence on OEIS Iterated digits squaring
#Potion
Potion
digital = (x) : dr = x string # Digital Root. ap = 0 # Additive Persistence. while (dr length > 1) : sum = 0 dr length times (i): sum = sum + dr(i) number integer. dr = sum string ap++ . (x, " has additive persistence ", ap, " and digital root ", dr, ";\n") join print .   digital(627615) digital(39390) digital(588225) digital(393900588225)
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of expression are valued. Examples may be be split into "setup", "problem statement", and "output" sections where the ease and naturalness of stating the problem and getting an answer, as well as the ease and flexibility of modifying the problem are the primary concerns. Example output should be shown here, as well as any comments on the examples flexibility. The problem Baker, Cooper, Fletcher, Miller, and Smith live on different floors of an apartment house that contains only five floors.   Baker does not live on the top floor.   Cooper does not live on the bottom floor.   Fletcher does not live on either the top or the bottom floor.   Miller lives on a higher floor than does Cooper.   Smith does not live on a floor adjacent to Fletcher's.   Fletcher does not live on a floor adjacent to Cooper's. Where does everyone live?
#UNIX_Shell
UNIX Shell
#!/bin/bash   # NAMES is a list of names. It can be changed as needed. It can be more than five names, or less. NAMES=(Baker Cooper Fletcher Miller Smith)   # CRITERIA are the rules imposed on who lives where. Each criterion must be a valid bash expression # that will be evaluated. TOP is the top floor; BOTTOM is the bottom floor.   # The CRITERIA can be changed to create different rules.   CRITERIA=( 'Baker  != TOP' # Baker does not live on the top floor 'Cooper  != BOTTOM' # Cooper does not live on the bottom floor 'Fletcher != TOP' # Fletcher does not live on the top floor 'Fletcher != BOTTOM' # and Fletch also does not live on the bottom floor 'Miller > Cooper' # Miller lives above Cooper '$(abs $(( Smith - Fletcher )) ) > 1' # Smith and Fletcher are not on adjacent floors '$(abs $(( Fletcher - Cooper )) ) > 1' # Fletcher and Cooper are not on adjacent floors )   # Code below here shouldn't need to change to vary parameters let BOTTOM=0 let TOP=${#NAMES[@]}-1   # Not available as a builtin abs() { local n=$(( 10#$1 )) ; echo $(( n < 0 ? -n : n )) ; }   # Algorithm we use to iterate over the permutations # requires that we start with the array sorted lexically NAMES=($(printf "%s\n" "${NAMES[@]}" | sort)) while true; do # set each name to its position in the array for (( i=BOTTOM; i<=TOP; ++i )); do eval "${NAMES[i]}=$i" done   # check to see if we've solved the problem let solved=1 for criterion in "${CRITERIA[@]}"; do if ! eval "(( $criterion ))"; then let solved=0 break fi done if (( solved )); then echo "From bottom to top: ${NAMES[@]}" break fi   # Bump the names list to the next permutation let j=TOP-1 while (( j >= BOTTOM )) && ! [[ "${NAMES[j]}" < "${NAMES[j+1]}" ]]; do let j-=1 done if (( j < BOTTOM )); then break; fi let k=TOP while (( k > j )) && [[ "${NAMES[k]}" < "${NAMES[j]}" ]]; do let k-=1 done if (( k <= j )); then break; fi t="${NAMES[j]}" NAMES[j]="${NAMES[k]}" NAMES[k]="$t" for (( k=1; k<=(TOP-j); ++k )); do a=BOTTOM+j+k b=TOP-k+1 if (( a < b )); then t="${NAMES[a]}" NAMES[a]="${NAMES[b]}" NAMES[b]="$t" fi done done
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#Maxima
Maxima
[1, 3, -5] . [4, -2, -1]; /* 3 */
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot product of two vectors directly:   each vector must be the same length   multiply corresponding terms from each vector   sum the products   (to produce the answer) Related task   Vector products
#Mercury
Mercury
:- module dot_product. :- interface.   :- import_module io. :- pred main(io::di, io::uo) is det.   :- implementation. :- import_module int, list.   main(!IO) :- io.write_int([1, 3, -5] `dot_product` [4, -2, -1], !IO), io.nl(!IO).   :- func dot_product(list(int), list(int)) = int.   dot_product(As, Bs) = list.foldl_corresponding((func(A, B, Acc) = Acc + A * B), As, Bs, 0).
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and must add up to   12. The Chief of the Police doesn't like odd numbers and wants to have an even number for his department. Task Write a computer program which outputs all valid combinations. Possible output   (for the 1st and 14th solutions): --police-- --sanitation-- --fire-- 2 3 7 6 5 1
#Factor
Factor
USING: formatting io kernel math math.combinatorics math.ranges sequences sets ; IN: rosetta-code.department-numbers   7 [1,b] 3 <k-permutations> [ [ first even? ] [ sum 12 = ] bi and ] filter   "{ Police, Sanitation, Fire }" print nl [ "%[%d, %]\n" printf ] each
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and must add up to   12. The Chief of the Police doesn't like odd numbers and wants to have an even number for his department. Task Write a computer program which outputs all valid combinations. Possible output   (for the 1st and 14th solutions): --police-- --sanitation-- --fire-- 2 3 7 6 5 1
#Fermat
Fermat
!!'Police Sanitation Fire'; !!'------|----------|----'; for p = 2 to 6 by 2 do for s = 1 to 7 do for f = 1 to 7 do if p+f+s=12 and f<>p and f<>s and s<>p then !!(' ',p,' ',s,' ',f); fi od od od;