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http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #Icon_and_Unicon | Icon and Unicon | procedure main(args)
n := integer(!args) | 5
every !(A := list(n)) := list(n)
A := zigzag(A)
show(A)
end
procedure show(A)
every writes(right(!A,5) | "\n")
end
procedure zigzag(A)
x := [0,0]
every i := 0 to (*A^2 -1) do {
x := nextIndices(*A, x)
A[x[1]][x[2]] := i
}
return A
end
procedure nextIndices(n, x)
return if (x[1]+x[2])%2 = 0
then if x[2] = n then [x[1]+1, x[2]] else [max(1, x[1]-1), x[2]+1]
else if x[1] = n then [x[1], x[2]+1] else [x[1]+1, max(1, x[2]-1)]
end |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #SIMPOL | SIMPOL | constant FIRST20 "62060698786608744707"
constant LAST20 "92256259918212890625"
function main()
integer i
string s, s2
i = .ipower(5, .ipower(4, .ipower(3, 2)))
s2 = .tostr(i, 10)
if .lstr(s2, 20) == FIRST20 and .rstr(s2, 20) == LAST20
s = "Success! The integer matches both the first 20 and the last 20 digits. There are " + .tostr(.len(s2), 10) + " digits in the result.{d}{a}"
else
s = ""
if .lstr(s2, 20) != FIRST20
s = "Failure! The first 20 digits are: " + .lstr(s2, 20) + " but they should be: " + FIRST20 + "{d}{a}"
end if
if .rstr(s2, 20) != LAST20
s = s + "Failure! The first 20 digits are: " + .lstr(s2, 20) + " but they should be: " + LAST20 + "{d}{a}"
end if
end if
end function s |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Smalltalk | Smalltalk | |num|
num := (5 raisedTo: (4 raisedTo: (3 raisedTo: 2))) asString.
Transcript
show: (num first: 20), '...', (num last: 20); cr;
show: 'digits: ', num size asString. |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #Standard_ML | Standard ML |
val zeckList = fn from => fn to =>
let
open IntInf
val rec npow = fn n => fn 0 => fromInt 1 | m => n* (npow n (m-1)) ;
val fib = fn 0 => 1 | 1 => 1 | n => let val rec fb = fn x => fn y => fn 1=>y | n=> fb y (x+y) (n-1) in
fb 0 1 n
end;
val argminfi = fn n => (* lowest k with fibonacci number over n *)
let
val rec afb = fn k => if fib k > n then k else afb (k+1)
in
afb 0
end;
val Zeck = fn n =>
let
val rec calzk = fn (0,z) => (0,z)
| (n,z) => let val k = argminfi n in
calzk ( n - fib (k-1) , z + (npow 10 (k-3) ) )
end
in
#2 (calzk (n,0))
end
in
List.tabulate (toInt ( to - from) ,
fn i:Int.int => ( from + (fromInt i),
Zeck ( from + (fromInt i) )))
end;
|
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #EchoLisp | EchoLisp |
; initial state = closed = #f
(define doors (make-vector 101 #f))
; run pass 100 to 1
(for*
((pass (in-range 100 0 -1))
(door (in-range 0 101 pass)))
(when (and
(vector-set! doors door (not (vector-ref doors door)))
(= pass 1))
(writeln door "is open")))
1 "is open"
4 "is open"
9 "is open"
16 "is open"
25 "is open"
36 "is open"
49 "is open"
64 "is open"
81 "is open"
100 "is open"
|
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #Julia | Julia | julia> A = cell(3) # create an heterogeneous array of length 3
3-element Array{Any,1}:
#undef
#undef
#undef
julia> A[1] = 4.5 ; A[3] = "some string" ; show(A)
{4.5,#undef,"some string"}
julia> A[1] # access a value. Arrays are 1-indexed
4.5
julia> push!(A, :symbol) ; show(A) # append an element
{4.5,#undef,"some string",:symbol}
julia> A[10] # error if the index is out of range
ERROR: BoundsError() |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, you may also try something like:
x = 0
y = 0
z = x**y
say 'z=' z
Show the result here.
And of course use any symbols or notation that is supported in your computer programming language for exponentiation.
See also
The Wiki entry: Zero to the power of zero.
The Wiki entry: History of differing points of view.
The MathWorld™ entry: exponent laws.
Also, in the above MathWorld™ entry, see formula (9):
x
0
=
1
{\displaystyle x^{0}=1}
.
The OEIS entry: The special case of zero to the zeroth power
| #XLISP | XLISP | XLISP 3.3, September 6, 2002 Copyright (c) 1984-2002, by David Betz
[1] (expt 0 0)
1
[2] |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, you may also try something like:
x = 0
y = 0
z = x**y
say 'z=' z
Show the result here.
And of course use any symbols or notation that is supported in your computer programming language for exponentiation.
See also
The Wiki entry: Zero to the power of zero.
The Wiki entry: History of differing points of view.
The MathWorld™ entry: exponent laws.
Also, in the above MathWorld™ entry, see formula (9):
x
0
=
1
{\displaystyle x^{0}=1}
.
The OEIS entry: The special case of zero to the zeroth power
| #XPL0 | XPL0 | RlOut(0, Pow(0., 0.)) |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #Nim | Nim | import algorithm, strformat, sequtils
type
Color {.pure.} = enum Blue, Green, Red, White, Yellow
Person {.pure.} = enum Dane, English, German, Norwegian, Swede
Pet {.pure.} = enum Birds, Cats, Dog, Horse, Zebra
Drink {.pure.} = enum Beer, Coffee, Milk, Tea, Water
Cigarettes {.pure.} = enum Blend, BlueMaster = "Blue Master",
Dunhill, PallMall = "Pall Mall", Prince
House = tuple
color: Color
person: Person
pet: Pet
drink: Drink
cigarettes: Cigarettes
Houses = array[5, House]
iterator permutations[T](): array[5, T] =
## Yield the successive permutations of values of type T.
var term = [T(0), T(1), T(2), T(3), T(4)]
yield term
while term.nextPermutation():
yield term
proc findSolutions(): seq[Houses] =
## Return all the solutions.
for colors in permutations[Color]():
if colors.find(White) != colors.find(Green) + 1: continue # 5
for persons in permutations[Person]():
if persons[0] != Norwegian: continue # 10
if colors.find(Red) != persons.find(English): continue # 2
if abs(persons.find(Norwegian) - colors.find(Blue)) != 1: continue # 15
for pets in permutations[Pet]():
if persons.find(Swede) != pets.find(Dog): continue # 3
for drinks in permutations[Drink]():
if drinks[2] != Milk: continue # 9
if persons.find(Dane) != drinks.find(Tea): continue # 4
if colors.find(Green) != drinks.find(Coffee): continue # 6
for cigarettes in permutations[Cigarettes]():
if cigarettes.find(PallMall) != pets.find(Birds): continue # 7
if cigarettes.find(Dunhill) != colors.find(Yellow): continue # 8
if cigarettes.find(BlueMaster) != drinks.find(Beer): continue # 13
if cigarettes.find(Prince) != persons.find(German): continue # 14
if abs(cigarettes.find(Blend) - pets.find(Cats)) != 1: continue # 11
if abs(cigarettes.find(Dunhill) - pets.find(Horse)) != 1: continue # 12
if abs(cigarettes.find(Blend) - drinks.find(Water)) != 1: continue # 16
var houses: Houses
for i in 0..4:
houses[i] = (colors[i], persons[i], pets[i], drinks[i], cigarettes[i])
result.add houses
let solutions = findSolutions()
echo "Number of solutions: ", solutions.len
let sol = solutions[0]
echo()
echo "Number Color Person Pet Drink Cigarettes"
echo "—————— —————— ————————— ————— —————— ———————————"
for i in 0..4:
echo &"{i + 1:3} {sol[i].color:6} {sol[i].person:9} ",
&"{sol[i].pet:5} {sol[i].drink:6} {sol[i].cigarettes: 11}"
let owner = sol.filterIt(it.pet == Zebra)[0].person
echo &"\nThe {owner} owns the zebra." |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #Ruby | Ruby | #Example taken from the REXML tutorial (http://www.germane-software.com/software/rexml/docs/tutorial.html)
require "rexml/document"
include REXML
#create the REXML Document from the string (%q is Ruby's multiline string, everything between the two @-characters is the string)
doc = Document.new(
%q@<inventory title="OmniCorp Store #45x10^3">
...
</inventory>
@
)
# The invisibility cream is the first <item>
invisibility = XPath.first( doc, "//item" )
# Prints out all of the prices
XPath.each( doc, "//price") { |element| puts element.text }
# Gets an array of all of the "name" elements in the document.
names = XPath.match( doc, "//name" ) |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #Scala | Scala |
scala> val xml: scala.xml.Elem =
| <inventory title="OmniCorp Store #45x10^3">
| <section name="health">
| <item upc="123456789" stock="12">
| <name>Invisibility Cream</name>
| <price>14.50</price>
| <description>Makes you invisible</description>
| </item>
| <item upc="445322344" stock="18">
| <name>Levitation Salve</name>
| <price>23.99</price>
| <description>Levitate yourself for up to 3 hours per application</description>
| </item>
| </section>
| <section name="food">
| <item upc="485672034" stock="653">
| <name>Blork and Freen Instameal</name>
| <price>4.95</price>
| <description>A tasty meal in a tablet; just add water</description>
| </item>
| <item upc="132957764" stock="44">
| <name>Grob winglets</name>
| <price>3.56</price>
| <description>Tender winglets of Grob. Just add water</description>
| </item>
| </section>
| </inventory>
scala> val firstItem = xml \\ "item" take 1
firstItem: scala.xml.NodeSeq =
NodeSeq(<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>)
scala> xml \\ "price" map (_.text) foreach println
14.50
23.99
4.95
3.56
scala> val names = (xml \\ "name").toArray
names: Array[scala.xml.Node] = Array(<name>Invisibility Cream</name>, <name>Levitation Salve</name>, <name>Blork and Freen Instameal</name>, <name>Grob winglets</name>) |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Perl | Perl | sub circle {
my ($radius, $cx, $cy, $fill, $stroke) = @_;
print "<circle cx='$cx' cy='$cy' r='$radius' ",
"fill='$fill' stroke='$stroke' stroke-width='1'/>\n";
}
sub yin_yang {
my ($rad, $cx, $cy, %opt) = @_;
my ($c, $w) = (1, 0);
$opt{fill} //= 'white';
$opt{stroke} //= 'black';
$opt{recurangle} //= 0;
print "<g transform='rotate($opt{angle}, $cx, $cy)'>"
if $opt{angle};
if ($opt{flip}) { ($c, $w) = ($w, $c) };
circle($rad, $cx, $cy, $opt{fill}, $opt{stroke});
print "<path d='M $cx ", $cy + $rad, "A ",
$rad/2, " ", $rad/2, " 0 0 $c $cx $cy ",
$rad/2, " ", $rad/2, " 0 0 $w $cx ", $cy - $rad, " ",
$rad, " ", $rad, " 0 0 $c $cx ", $cy + $rad, " ",
"z' fill='$opt{stroke}' stroke='none' />";
if ($opt{recur} and $rad > 1) {
# recursive "eyes" are slightly larger
yin_yang($rad/4, $cx, $cy + $rad/2, %opt,
angle => $opt{recurangle},
fill => $opt{stroke},
stroke => $opt{fill} );
yin_yang($rad/4, $cx, $cy - $rad/2, %opt,
angle => 180 + $opt{recurangle});
} else {
circle($rad/5, $cx, $cy + $rad/2, $opt{fill}, $opt{stroke});
circle($rad/5, $cx, $cy - $rad/2, $opt{stroke}, $opt{fill});
}
print "</g>" if $opt{angle};
}
print <<'HEAD';
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
HEAD
yin_yang(200, 250, 250, recur=>1,
angle=>0, recurangle=>90, fill=>'white', stroke=>'black');
yin_yang(100, 500, 500);
print "</svg>" |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #GAP | GAP | Y := function(f)
local u;
u := x -> x(x);
return u(y -> f(a -> y(y)(a)));
end;
fib := function(f)
local u;
u := function(n)
if n < 2 then
return n;
else
return f(n-1) + f(n-2);
fi;
end;
return u;
end;
Y(fib)(10);
# 55
fac := function(f)
local u;
u := function(n)
if n < 2 then
return 1;
else
return n*f(n-1);
fi;
end;
return u;
end;
Y(fac)(8);
# 40320 |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #IS-BASIC | IS-BASIC | 100 PROGRAM "ZigZag.bas"
110 LET SIZE=5
120 NUMERIC A(1 TO SIZE,1 TO SIZE)
130 LET I,J=1
140 FOR E=0 TO SIZE^2-1
150 LET A(I,J)=E
160 IF ((I+J) BAND 1)=0 THEN
170 IF J<SIZE THEN
180 LET J=J+1
190 ELSE
200 LET I=I+2
210 END IF
220 IF I>1 THEN LET I=I-1
230 ELSE
240 IF I<SIZE THEN
250 LET I=I+1
260 ELSE
270 LET J=J+2
280 END IF
290 IF J>1 THEN LET J=J-1
300 END IF
310 NEXT
320 FOR ROW=1 TO SIZE
330 FOR COL=1 TO SIZE
340 PRINT USING " ##":A(ROW,COL);
350 NEXT
360 PRINT
370 NEXT |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #SPL | SPL | t = #.str(5^(4^(3^2)))
n = #.size(t)
#.output(n," digits")
#.output(#.mid(t,1,20),"...",#.mid(t,n-19,20)) |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Standard_ML | Standard ML | let
val answer = IntInf.pow (5, IntInf.toInt (IntInf.pow (4, IntInf.toInt (IntInf.pow (3, 2)))))
val s = IntInf.toString answer
val len = size s
in
print ("has " ^ Int.toString len ^ " digits: " ^
substring (s, 0, 20) ^ " ... " ^
substring (s, len-20, 20) ^ "\n")
end; |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #Tcl | Tcl | package require Tcl 8.5
# Generates the Fibonacci sequence (starting at 1) up to the largest item that
# is no larger than the target value. Could use tricks to precompute, but this
# is actually a pretty cheap linear operation.
proc fibseq target {
set seq {}; set prev 1; set fib 1
for {set n 1;set i 1} {$fib <= $target} {incr n} {
for {} {$i < $n} {incr i} {
lassign [list $fib [incr fib $prev]] prev fib
}
if {$fib <= $target} {
lappend seq $fib
}
}
return $seq
}
# Produce the given Zeckendorf number.
proc zeckendorf n {
# Special case: only value that begins with 0
if {$n == 0} {return 0}
set zs {}
foreach f [lreverse [fibseq $n]] {
lappend zs [set z [expr {$f <= $n}]]
if {$z} {incr n [expr {-$f}]}
}
return [join $zs ""]
} |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #ECL | ECL |
Doors := RECORD
UNSIGNED1 DoorNumber;
STRING6 State;
END;
AllDoors := DATASET([{0,0}],Doors);
Doors OpenThem(AllDoors L,INTEGER Cnt) := TRANSFORM
SELF.DoorNumber := Cnt;
SELF.State := IF((CNT * 10) % (SQRT(CNT)*10)<>0,'Closed','Opened');
END;
OpenDoors := NORMALIZE(AllDoors,100,OpenThem(LEFT,COUNTER));
OpenDoors;
|
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #KonsolScript | KonsolScript | //creates an array of length 3
Array:New array[3]:Number;
function main() {
Var:Number length;
Array:GetLength(array, length) //retrieve length of array
Konsol:Log(length)
array[0] = 5; //assign value
Konsol:Log(array[0]) //retrieve value and display
} |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, you may also try something like:
x = 0
y = 0
z = x**y
say 'z=' z
Show the result here.
And of course use any symbols or notation that is supported in your computer programming language for exponentiation.
See also
The Wiki entry: Zero to the power of zero.
The Wiki entry: History of differing points of view.
The MathWorld™ entry: exponent laws.
Also, in the above MathWorld™ entry, see formula (9):
x
0
=
1
{\displaystyle x^{0}=1}
.
The OEIS entry: The special case of zero to the zeroth power
| #Zig | Zig | const std = @import("std");
pub fn main() !void {
const stdout = std.io.getStdOut().writer();
try stdout.print("0^0 = {d:.8}\n", .{std.math.pow(f32, 0, 0)});
} |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, you may also try something like:
x = 0
y = 0
z = x**y
say 'z=' z
Show the result here.
And of course use any symbols or notation that is supported in your computer programming language for exponentiation.
See also
The Wiki entry: Zero to the power of zero.
The Wiki entry: History of differing points of view.
The MathWorld™ entry: exponent laws.
Also, in the above MathWorld™ entry, see formula (9):
x
0
=
1
{\displaystyle x^{0}=1}
.
The OEIS entry: The special case of zero to the zeroth power
| #zkl | zkl | (0.0).pow(0) //--> 1.0
var BN=Import("zklBigNum"); // big ints
BN(0).pow(0) //--> 1 |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #Pari.2FGp | Pari/Gp |
perm(arr) = {
n=#arr;i=n-1;
while(i > -1,if (arr[i] < arr[i+1],break);i--);
j=n;
while(arr[j]<= arr[i],j -=1);
tmp = arr[i] ;arr[i]=arr[j];arr[j]=tmp;
i +=1; j = n;
while(i < j ,tmp = arr[i] ;arr[i]=arr[j];arr[j]=tmp;
i +=1; j -=1);
return(arr);
}
perms(arr)={
n=#arr;
result = List();
listput(result,arr);
for(i=1,n!-1,arr=perm(arr);listput(result,arr));
return(result);
}
adj(x,xs,y,ys)={
abs(select(z->z==x,xs,1)[1] - select(z->z==y,ys,1)[1])==1;
}
eq(x,xs,y,ys)={
select(z->z==x,xs,1) == select(z->z==y,ys,1);
}
colors =Vec(perms( ["Blue", "Green", "Red", "White", "Yellow"]));;
drinks =Vec(perms( ["Beer", "Coffee", "Milk", "Tea", "Water"]));;
nations =Vec(perms( ["Denmark", "England", "Germany", "Norway", "Sweden"]));;
smokes =Vec(perms( ["Blend", "BlueMaster", "Dunhill", "PallMall", "Prince"]));;
pets =Vec(perms( ["Birds", "Cats", "Dog", "Horse", "Zebra"]));;;
colors= select(x->select(z->z=="White",x,1)[1] - select(z->z=="Green",x,1)[1]==1,colors);
drinks=select(x->x[3]=="Milk",drinks);
nations=select(x->x[1]=="Norway",nations);
for(n=1,#nations,for(c=1,#colors,\
if(eq("Red",colors[c],"England",nations[n]) && adj("Norway",nations[n],"Blue",colors[c]),\
for(d=1,#drinks,\
if(eq("Denmark",nations[n],"Tea",drinks[d])&& eq("Coffee",drinks[d],"Green",colors[c]),\
for(s=1,#smokes,\
if(eq("Yellow",colors[c],"Dunhill",smokes[s]) &&\
eq("BlueMaster",smokes[s],"Beer",drinks[d]) &&\
eq("Germany",nations[n],"Prince",smokes[s]),\
for(p=1,#pets,\
if(eq("Birds",pets[p],"PallMall",smokes[s]) &&\
eq("Sweden",nations[n],"Dog",pets[p]) &&\
adj("Blend",smokes[s],"Cats",pets[p]) &&\
adj("Horse",pets[p],"Dunhill",smokes[s]),\
print("Zebra is owned by ",nations[n][select(z->z=="Zebra",pets[p],1)[1]]);print();\
for(i=1,5,printf("House:%s %6s %10s %10s %10s %10s\n",i,colors[c][i],nations[n][i],pets[p][i],drinks[d][i],smokes[s][i]));\
)))))))));
|
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #SenseTalk | SenseTalk | Set XMLSource to {{
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
}}
put node "//item[1]" of XMLSource
put node "//price/text()" of XMLSource
put all nodes "//name" of XMLSource |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #Sidef | Sidef | require('XML::XPath');
var x = %s'XML::XPath'.new(ARGF.slurp);
[x.findnodes('//item[1]')][0];
say [x.findnodes('//price')].map{x.getNodeText(_)};
[x.findnodes('//name')]; |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Phix | Phix | --
-- demo\rosetta\Yin_and_yang.exw
-- =============================
--
with javascript_semantics
include pGUI.e
Ihandle dlg, canvas
cdCanvas cd_canvas
procedure cdCanvasSecArc(cdCanvas hCdCanvas, atom xc, atom yc, atom w, atom h, atom angle1, atom angle2)
-- cdCanvasSector does not draw anti-aliased edges, but cdCanvasArc does, so over-draw...
cdCanvasSector(hCdCanvas, xc, yc, w, h, angle1, angle2)
cdCanvasArc (hCdCanvas, xc, yc, w, h, angle1, angle2)
end procedure
procedure yinyang(atom cx, cy, r)
cdCanvasArc(cd_canvas, cx, cy, r, r, 0, 360)
cdCanvasSecArc(cd_canvas, cx, cy, r, r, 270, 90)
cdCanvasSecArc(cd_canvas, cx, cy-r/4, r/2-1, r/2-1, 0, 360)
cdCanvasSetForeground(cd_canvas, CD_WHITE)
cdCanvasSecArc(cd_canvas, cx, cy+r/4, r/2-1, r/2-1, 0, 360)
cdCanvasSecArc(cd_canvas, cx, cy-r/4, r/8, r/8, 0, 360)
cdCanvasSetForeground(cd_canvas, CD_BLACK)
cdCanvasSecArc(cd_canvas, cx, cy+r/4, r/8, r/8, 0, 360)
end procedure
function redraw_cb(Ihandle /*ih*/)
integer {width, height} = IupGetIntInt(canvas, "DRAWSIZE"),
r = min(width,height)-40,
cx = floor(width/2),
cy = floor(height/2)
cdCanvasActivate(cd_canvas)
cdCanvasClear(cd_canvas)
yinyang(cx-r*.43,cy+r*.43,r/6)
yinyang(cx,cy,r)
cdCanvasFlush(cd_canvas)
return IUP_DEFAULT
end function
function map_cb(Ihandle ih)
IupGLMakeCurrent(canvas)
if platform()=JS then
cd_canvas = cdCreateCanvas(CD_IUP, canvas)
else
atom res = IupGetDouble(NULL, "SCREENDPI")/25.4
cd_canvas = cdCreateCanvas(CD_GL, "10x10 %g", {res})
end if
cdCanvasSetBackground(cd_canvas, CD_WHITE)
cdCanvasSetForeground(cd_canvas, CD_BLACK)
return IUP_DEFAULT
end function
function canvas_resize_cb(Ihandle /*canvas*/)
integer {canvas_width, canvas_height} = IupGetIntInt(canvas, "DRAWSIZE")
atom res = IupGetDouble(NULL, "SCREENDPI")/25.4
cdCanvasSetAttribute(cd_canvas, "SIZE", "%dx%d %g", {canvas_width, canvas_height, res})
return IUP_DEFAULT
end function
procedure main()
IupOpen()
canvas = IupGLCanvas("RASTERSIZE=340x340")
IupSetCallbacks(canvas, {"MAP_CB", Icallback("map_cb"),
"RESIZE_CB", Icallback("canvas_resize_cb"),
"ACTION", Icallback("redraw_cb")})
dlg = IupDialog(canvas, `TITLE="Yin and Yang"`)
IupShow(dlg)
IupSetAttribute(canvas, "RASTERSIZE", NULL) -- release the minimum limitation
if platform()!=JS then
IupMainLoop()
IupClose()
end if
end procedure
main()
|
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #Genyris | Genyris | def fac (f)
function (n)
if (equal? n 0) 1
* n (f (- n 1))
def fib (f)
function (n)
cond
(equal? n 0) 0
(equal? n 1) 1
else (+ (f (- n 1)) (f (- n 2)))
def Y (f)
(function (x) (x x))
function (y)
f
function (&rest args) (apply (y y) args)
assertEqual ((Y fac) 5) 120
assertEqual ((Y fib) 8) 21 |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #J | J | ($ [: /:@; <@|.`</.@i.)@,~ 5
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24 |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Stata | Stata | set bigValue [expr {5**4**3**2}]
puts "5**4**3**2 has [string length $bigValue] digits"
if {[string match "62060698786608744707*92256259918212890625" $bigValue]} {
puts "Value starts with 62060698786608744707, ends with 92256259918212890625"
} else {
puts "Value does not match 62060698786608744707...92256259918212890625"
} |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Tcl | Tcl | set bigValue [expr {5**4**3**2}]
puts "5**4**3**2 has [string length $bigValue] digits"
if {[string match "62060698786608744707*92256259918212890625" $bigValue]} {
puts "Value starts with 62060698786608744707, ends with 92256259918212890625"
} else {
puts "Value does not match 62060698786608744707...92256259918212890625"
} |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #uBasic.2F4tH | uBasic/4tH | For x = 0 to 20 ' Print Zeckendorf numbers 0 - 20
Print x,
Push x : Gosub _Zeckendorf ' get Zeckendorf number repres.
Print ' terminate line
Next
End
_Fibonacci
Push Tos() ' duplicate TOS()
@(0) = 0 ' This function returns the
@(1) = 1 ' Fibonacci number which is smaller
' or equal to TOS()
Do While @(1) < Tos() + 1
Push (@(1))
@(1) = @(0) + @(1) ' get next Fibonacci number
@(0) = Pop()
Loop ' loop if not exceeded TOS()
Gosub _Drop ' clear TOS()
Push @(0) ' return Fibonacci number
Return
_Zeckendorf
GoSub _Fibonacci ' This function breaks TOS() up
Print Tos(); ' into its Zeckendorf components
Push -(Pop() - Pop()) ' first digit is always there
' the remainder to resolve
Do While Tos() ' now go for the next digits
GoSub _Fibonacci
Print " + ";Tos(); ' print the next digit
Push -(Pop() - Pop())
Loop
Gosub _Drop ' clear TOS()
Return ' and return
_Drop
If Pop()%1 = 0 Then Return ' This function clears TOS() |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #EDSAC_order_code | EDSAC order code |
[Hundred doors problem from Rosetta Code website]
[EDSAC program, Initial Orders 2]
[Library subroutine M3. Prints header and is then overwritten.
Here, the last character sets the teleprinter to figures.]
PFGKIFAFRDLFUFOFE@A6FG@E8FEZPF
@&*THE!OPEN!DOORS!ARE@&#
..PZ [blank tape, needed to mark end of header text]
[Library subroutine P6. Prints strictly positive integer.
32 locations; working locations 1, 4, 5]
T56K [define load address for subroutine]
GKA3FT25@H29@VFT4DA3@TFH30@S6@T1F
V4DU4DAFG26@TFTFO5FA4DF4FS4F
L4FT4DA1FS3@G9@EFSFO31@E20@J995FJF!F
T88K [define load address for main program]
GK [set @ (theta) for relative addresses]
[The 100 doors are at locations 200..299.
Doors are numbered 0..99 internally, and 1..100 for output.
The base address and the number of doors can be varied.
The value of a door is 0 if open, negative if closed.]
[Constants. Program also uses order 'P 1 F'
which is permanently at absolute address 2.]
[0] P200F [address of door #0]
[1] P100F [number of doors, as an address]
[2] UF [makes S order from T, since 'S' = 'T' + 'U']
[3] MF [makes A order from T, since 'A' = 'T' + 'M']
[4] V2047D [all 1's for "closed" (any negative value will do)]
[5] &F [line feed]
[6] @F [carriage return]
[7] K4096F [teleprinter null[
[Variables]
[8] PF [pass number; step when toggling doors]
[9] PF [door number, as address, 0-based]
[10] PF [order referring to door 0]
[Enter with acc = 0]
[Part 1 : close all the doors]
[11] T8@ [pass := 0 (used in part 2)]
T9@ [door number := 0]
A16@ [load 'T F' order]
A@ [add base address]
T10@ [store T order for door #0]
[16] TF [clear acc; also serves as constant]
A9@ [load door number]
A10@ [make T order]
T21@ [plant in code]
A4@ [load value for "closed"]
[21] TF [store in current door]
A9@ [load door number]
A2F [add 1]
U9@ [update door number]
S1@ [done all doors yet?]
G16@ [if not, loop back]
[Part 2 : 100 passes, toggling the doors]
[27] TF [clear acc]
A8@ [load pass number]
A2F [add 1]
T8@ [save updated pass number]
S2F [make -1]
U9@ [door number := -1]
A8@ [add pass number to get first door toggled on this pass]
S1@ [gone beyond end?]
E50@ [if so, move on to part 3]
[36] A1@ [restore acc after test]
U9@ [store current door number]
A10@ [make T order to load status]
U44@ [plant T order for first door in pass]
A2@ [convert to S order]
T43@ [plant S order]
A4@ [load value for "closed"]
[43] SF [subtract status; toggles status]
[44] TF [update status]
A9@ [load door number just toggled]
A8@ [add pass number to get next door in pass]
S1@ [gone beyond end?]
G36@ [no, loop to do next door]
E27@ [yes, loop to do next pass]
[Part 3 : Print list of open doors.
Header has set teleprinter to figures.]
[50] TF [clear acc]
T9@ [door nr := 0]
A10@ [T order for door 0]
A3@ [convert to A order]
T10@
[55] TF
A9@ [load door number]
A10@ [make A order to load value]
T59@ [plant in next order]
[59] AF [acc := 0 if open, < 0 if closed]
G69@ [skip if closed]
A9@ [door number as address]
A2F [add 1 for 1-based output]
RD [shift 1 right, address --> integer]
TF [store integer at 0 for printing]
[65] A65@ [for return from subroutine]
G56F [call subroutine to print door number]
O6@ [followed by CRLF]
O5@
[69] TF [clear acc]
A9@ [load door number]
A2F [add 1]
U9@ [update door number]
S1@ [done all doors yet?]
G55@ [if not, loop back]
[75] O7@ [output null to flush teleprinter buffer]
ZF [stop]
E11Z [define relative start address]
PF
|
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #Kotlin | Kotlin | fun main(x: Array<String>) {
var a = arrayOf(1, 2, 3, 4)
println(a.asList())
a += 5
println(a.asList())
println(a.reversedArray().asList())
} |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #Perl | Perl | #!/usr/bin/perl
use utf8;
use strict;
binmode STDOUT, ":utf8";
my (@tgt, %names);
sub setprops {
my %h = @_;
my @p = keys %h;
for my $p (@p) {
my @v = @{ $h{$p} };
@tgt = map(+{idx=>$_-1, map{ ($_, undef) } @p}, 1 .. @v)
unless @tgt;
$names{$_} = $p for @v;
}
}
my $solve = sub {
for my $i (@tgt) {
printf("%12s", ucfirst($i->{$_} // "¿Qué?"))
for reverse sort keys %$i;
print "\n";
}
"there is only one" # <--- change this to a false value to find all solutions (if any)
};
sub pair {
my ($a, $b, @v) = @_;
if ($a =~ /^(\d+)$/) {
$tgt[$1]{ $names{$b} } = $b;
return;
}
@v = (0) unless @v;
my %allowed;
$allowed{$_} = 1 for @v;
my ($p1, $p2) = ($names{$a}, $names{$b});
my $e = $solve;
$solve = sub { # <--- sorta like how TeX \let...\def macro
my ($x, $y);
($x) = grep { $_->{$p1} eq $a } @tgt;
($y) = grep { $_->{$p2} eq $b } @tgt;
$x and $y and
return $allowed{ $x->{idx} - $y->{idx} } && $e->();
my $try_stuff = sub {
my ($this, $p, $v, $sign) = @_;
for (@v) {
my $i = $this->{idx} + $sign * $_;
next unless $i >= 0 && $i < @tgt && !$tgt[$i]{$p};
local $tgt[$i]{$p} = $v;
$e->() and return 1;
}
return
};
$x and return $try_stuff->($x, $p2, $b, 1);
$y and return $try_stuff->($y, $p1, $a, -1);
for $x (@tgt) {
next if $x->{$p1};
local $x->{$p1} = $a;
$try_stuff->($x, $p2, $b, 1) and return 1;
}
};
}
# ---- above should be generic for all similar puzzles ---- #
# ---- below: per puzzle setup ---- #
# property names and values
setprops (
# Svensk n. a Swede, not a swede (kålrot).
# AEnglisk (from middle Viking "Æŋløsåksen") n. a Brit.
'Who' => [ qw(Deutsch Svensk Norske Danske AEnglisk) ],
'Pet' => [ qw(birds dog horse zebra cats) ],
'Drink' => [ qw(water tea milk beer coffee) ],
'Smoke' => [ qw(dunhill blue_master prince blend pall_mall) ],
'Color' => [ qw(red green yellow white blue) ]
);
# constraints
pair qw( AEnglisk red );
pair qw( Svensk dog );
pair qw( Danske tea );
pair qw( green white 1 ); # "to the left of" can mean either 1 or -1: ambiguous
pair qw( coffee green );
pair qw( pall_mall birds );
pair qw( yellow dunhill );
pair qw( 2 milk );
pair qw( 0 Norske );
pair qw( blend cats -1 1 );
pair qw( horse dunhill -1 1 );
pair qw( blue_master beer ); # Nicht das Deutsche Bier trinken? Huh.
pair qw( Deutsch prince );
pair qw( Norske blue -1 1 );
pair qw( water blend -1 1 );
$solve->(); |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #Tcl | Tcl | # assume $xml holds the XML data
package require tdom
set doc [dom parse $xml]
set root [$doc documentElement]
set allNames [$root selectNodes //name]
puts [llength $allNames] ;# ==> 4
set firstItem [lindex [$root selectNodes //item] 0]
puts [$firstItem @upc] ;# ==> 123456789
foreach node [$root selectNodes //price] {
puts [$node text]
} |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #TUSCRIPT | TUSCRIPT |
$$ MODE TUSCRIPT,{}
MODE DATA
$$ XML=*
<inventory title="OmniCorp Store #45x10³">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
$$ MODE TUSCRIPT
FILE = "test.xml"
ERROR/STOP CREATE (file,fdf-o,-std-)
FILE/ERASE/UTF8 $FILE = xml
BUILD S_TABLE beg=":<item*>:<name>:<price>:"
BUILD S_TABLE end=":</item>:</name>:</price>:"
BUILD S_TABLE modifiedbeg=":<name>:<price>:"
BUILD S_TABLE modifiedend=":</name>:</price>:"
firstitem=names="",countitem=0
ACCESS q: READ/STREAM/UTF8 $FILE s,a/beg+t+e/end
LOOP
READ/EXIT q
IF (a=="<name>") names=APPEND(names,t)
IF (a=="<price>") PRINT t
IF (a.sw."<item") countitem=1
IF (countitem==1) THEN
firstitem=CONCAT(firstitem,a)
firstitem=CONCAT(firstitem,t)
firstitem=CONCAT(firstitem,e)
IF (e=="</item>") THEN
COUNTITEM=0
MODIFY ACCESS q s_TABLE modifiedbeg,-,modifiedend
ENDIF
ENDIF
ENDLOOP
ENDACCESS q
ERROR/STOP CLOSE (file)
firstitem=EXCHANGE (firstitem,":{2-00} ::")
firstitem=INDENT_TAGS (firstitem,-," ")
names=SPLIT(names)
TRACE *firstitem,names
|
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #PHL | PHL | module circles;
extern printf;
@Boolean in_circle(@Integer centre_x, @Integer centre_y, @Integer radius, @Integer x, @Integer y) [
return (x-centre_x)*(x-centre_x)+(y-centre_y)*(y-centre_y) <= radius*radius;
]
@Boolean in_big_circle (@Integer radius, @Integer x, @Integer y) [
return in_circle(0, 0, radius, x, y);
]
@Boolean in_while_semi_circle (@Integer radius, @Integer x, @Integer y) [
return in_circle(0, radius/2, radius/2, x, y);
]
@Boolean in_small_white_circle (@Integer radius, @Integer x, @Integer y) [
return in_circle(0, 0-radius/2, radius/6, x, y);
]
@Boolean in_black_semi_circle (@Integer radius, @Integer x, @Integer y) [
return in_circle(0, 0-radius/2, radius/2, x, y);
]
@Boolean in_small_black_circle (@Integer radius, @Integer x, @Integer y) [
return in_circle(0, radius/2, radius/6, x, y);
]
@Void print_yin_yang(@Integer radius) [
var white = '.';
var black = '#';
var clear = ' ';
var scale_y = 1;
var scale_x = 2;
for (var sy = radius*scale_y; sy >= -(radius*scale_y); sy=sy-1) {
for (var sx = -(radius*scale_x); sx <= radius*scale_x; sx=sx+1) {
var x = sx/(scale_x);
var y = sy/(scale_y);
if (in_big_circle(radius, x, y)) {
if (in_while_semi_circle(radius, x, y))
if (in_small_black_circle(radius, x, y))
printf("%c", black);
else
printf("%c", white);
else if (in_black_semi_circle(radius, x, y))
if (in_small_white_circle(radius, x, y))
printf("%c", white);
else
printf("%c", black);
else if (x < 0)
printf("%c", white);
else
printf("%c", black);
} else printf("%c", clear);
}
printf("\n");
}
]
@Integer main [
print_yin_yang(17);
print_yin_yang(8);
return 0;
] |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #PicoLisp | PicoLisp | (de circle (X Y C R)
(>=
(* R R)
(+
(* (setq X (/ X 2)) X)
(* (dec 'Y C) Y) ) ) )
(de yinYang (R)
(for Y (range (- R) R)
(for X (range (- 0 R R) (+ R R))
(prin
(cond
((circle X Y (- (/ R 2)) (/ R 6))
"#" )
((circle X Y (/ R 2) (/ R 6))
"." )
((circle X Y (- (/ R 2)) (/ R 2))
"." )
((circle X Y (/ R 2) (/ R 2))
"#" )
((circle X Y 0 R)
(if (lt0 X) "." "#") )
(T " ") ) ) )
(prinl) ) ) |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #Go_2 | Go | package main
import "fmt"
type Func func(int) int
type FuncFunc func(Func) Func
type RecursiveFunc func (RecursiveFunc) Func
func main() {
fac := Y(almost_fac)
fib := Y(almost_fib)
fmt.Println("fac(10) = ", fac(10))
fmt.Println("fib(10) = ", fib(10))
}
func Y(f FuncFunc) Func {
g := func(r RecursiveFunc) Func {
return f(func(x int) int {
return r(r)(x)
})
}
return g(g)
}
func almost_fac(f Func) Func {
return func(x int) int {
if x <= 1 {
return 1
}
return x * f(x-1)
}
}
func almost_fib(f Func) Func {
return func(x int) int {
if x <= 2 {
return 1
}
return f(x-1)+f(x-2)
}
} |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #Java | Java | public static int[][] Zig_Zag(final int size)
{
int[][] data = new int[size][size];
int i = 1;
int j = 1;
for (int element = 0; element < size * size; element++)
{
data[i - 1][j - 1] = element;
if ((i + j) % 2 == 0)
{
// Even stripes
if (j < size)
j++;
else
i+= 2;
if (i > 1)
i--;
}
else
{
// Odd stripes
if (i < size)
i++;
else
j+= 2;
if (j > 1)
j--;
}
}
return data;
} |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #TXR | TXR | @(bind (f20 l20 ndig)
@(let* ((str (tostring (expt 5 4 3 2)))
(len (length str)))
(list [str :..20] [str -20..:] len)))
@(bind f20 "62060698786608744707")
@(bind l20 "92256259918212890625")
@(output)
@f20...@l20
ndigits=@ndig
@(end) |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Ursa | Ursa | import "unbounded_int"
decl unbounded_int x
x.set ((x.valueof 5).pow ((x.valueof 4).pow ((x.valueof 3).pow 2)))
decl string first last xstr
set xstr (string x)
# get the first twenty digits
decl int i
for (set i 0) (< i 20) (inc i)
set first (+ first xstr<i>)
end for
# get the last twenty digits
for (set i (- (size xstr) 20)) (< i (size xstr)) (inc i)
set last (+ last xstr<i>)
end for
out "the first and last digits of 5^(4^(3^2)) are " first "..." console
out last " (the result was " (size xstr) " digits long)" endl endl console
if (and (and (= first "62060698786608744707") (= last "92256259918212890625")) (= (size xstr) 183231))
out "(pass)" endl console
else
out "FAIL" endl console
end if |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Ursala | Ursala | #import std
#import nat
#import bcd
#show+
main = <.@ixtPX take/$20; ^|T/~& '...'--@x,'length: '--@h+ %nP+ length@t>@h %vP power=> <5_,4_,3_,2_> |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #VBA | VBA | Private Function zeckendorf(ByVal n As Integer) As Integer
Dim r As Integer: r = 0
Dim c As Integer
Dim fib As New Collection
fib.Add 1
fib.Add 1
Do While fib(fib.Count) < n
fib.Add fib(fib.Count - 1) + fib(fib.Count)
Loop
For i = fib.Count To 2 Step -1
c = n >= fib(i)
r = r + r - c
n = n + c * fib(i)
Next i
zeckendorf = r
End Function
Public Sub main()
Dim i As Integer
For i = 0 To 20
Debug.Print Format(i, "@@"); ":"; Format(WorksheetFunction.Dec2Bin(zeckendorf(i)), "@@@@@@@")
Next i
End Sub |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #Eero | Eero |
#import <Foundation/Foundation.h>
int main()
square := 1, increment = 3
for int door in 1 .. 100
printf("door #%d", door)
if door == square
puts(" is open.")
square += increment
increment += 2
else
puts(" is closed.")
return 0
|
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #LabVIEW | LabVIEW |
// Create a new array with length 0
{def myArray1 {A.new}}
-> []
// Create an array with 2 members (length is 2)
{def myArray2 {A.new Item1 Item2}}
-> [Item1,Item2]
// Edit a value in an array
{def myArray3 {A.new 1 2 3}}
{A.set! 1 hello {myArray3}}
-> [1,hello,3]
// Add a value at the head of an array
{def myArray4 {A.new 1 2 3}}-> myArray4
{A.addfirst! hello {myArray4}}
-> [hello,1,2,3]
// Add a value at the tail of an array
{def myArray5 {A.new 1 2 3}}
{A.addlast! hello {myArray5}}
-> [1,2,3,hello]
and so on...
|
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #Phix | Phix | enum Colour, Nationality, Drink, Smoke, Pet
constant Colours = {"red","white","green","yellow","blue"},
Nationalities = {"English","Swede","Dane","Norwegian","German"},
Drinks = {"tea","coffee","milk","beer","water"},
Smokes = {"Pall Mall","Dunhill","Blend","Blue Master","Prince"},
Pets = {"dog","birds","cats","horse","zebra"},
Sets = {Colours,Nationalities,Drinks,Smokes,Pets}
constant tagset5 = tagset(5) -- {1,2,3,4,5}, oft-permuted
sequence perm = repeat(tagset5,5) -- perm[1] is Colour of each house, etc
function house(integer i, string name)
return find(find(name,Sets[i]),perm[i])
end function
function left_of(integer h1, integer h2)
return (h1-h2)==1
end function
function next_to(integer h1, integer h2)
return abs(h1-h2)==1
end function
procedure print_house(integer i)
printf(1,"%d:%s,%s,%s,%s,%s\n",{i,
Colours[perm[Colour][i]],
Nationalities[perm[Nationality][i]],
Drinks[perm[Drink][i]],
Smokes[perm[Smoke][i]],
Pets[perm[Pet][i]]})
end procedure
integer solutions = 0
sequence solperms = {}
atom t0 = time()
constant factorial5 = factorial(5)
for C=1 to factorial5 do
perm[Colour] = permute(C,tagset5)
if left_of(house(Colour,"green"),house(Colour,"white")) then
for N=1 to factorial5 do
perm[Nationality] = permute(N,tagset5)
if house(Nationality,"Norwegian")==1
and house(Nationality,"English")==house(Colour,"red")
and next_to(house(Nationality,"Norwegian"),house(Colour,"blue")) then
for D=1 to factorial5 do
perm[Drink] = permute(D,tagset5)
if house(Nationality,"Dane")==house(Drink,"tea")
and house(Drink,"coffee")==house(Colour,"green")
and house(Drink,"milk")==3 then
for S=1 to factorial5 do
perm[Smoke] = permute(S,tagset5)
if house(Colour,"yellow")==house(Smoke,"Dunhill")
and house(Nationality,"German")==house(Smoke,"Prince")
and house(Smoke,"Blue Master")==house(Drink,"beer")
and next_to(house(Drink,"water"),house(Smoke,"Blend")) then
for P=1 to factorial5 do
perm[Pet] = permute(P,tagset5)
if house(Nationality,"Swede")==house(Pet,"dog")
and house(Smoke,"Pall Mall")==house(Pet,"birds")
and next_to(house(Smoke,"Blend"),house(Pet,"cats"))
and next_to(house(Pet,"horse"),house(Smoke,"Dunhill")) then
for i=1 to 5 do
print_house(i)
end for
solutions += 1
solperms = append(solperms,perm)
end if
end for
end if
end for
end if
end for
end if
end for
end if
end for
printf(1,"%d solution%s found (%3.3fs).\n",{solutions,iff(solutions>1,"s",""),time()-t0})
for i=1 to length(solperms) do
perm = solperms[i]
printf(1,"The %s owns the Zebra\n",{Nationalities[house(Pet,"zebra")]})
end for
|
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #VBScript | VBScript |
Set objXMLDoc = CreateObject("msxml2.domdocument")
objXMLDoc.load("In.xml")
Set item_nodes = objXMLDoc.selectNodes("//item")
i = 1
For Each item In item_nodes
If i = 1 Then
WScript.StdOut.Write item.xml
WScript.StdOut.WriteBlankLines(2)
Exit For
End If
Next
Set price_nodes = objXMLDoc.selectNodes("//price")
list_price = ""
For Each price In price_nodes
list_price = list_price & price.text & ", "
Next
WScript.StdOut.Write list_price
WScript.StdOut.WriteBlankLines(2)
Set name_nodes = objXMLDoc.selectNodes("//name")
list_name = ""
For Each name In name_nodes
list_name = list_name & name.text & ", "
Next
WScript.StdOut.Write list_name
WScript.StdOut.WriteBlankLines(2)
|
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #Visual_Basic_.NET | Visual Basic .NET | Dim first_item = xml.XPathSelectElement("//item")
Console.WriteLine(first_item)
For Each price In xml.XPathSelectElements("//price")
Console.WriteLine(price.Value)
Next
Dim names = (From item In xml.XPathSelectElements("//name") Select item.Value).ToArray |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Plain_English | Plain English | To run:
Start up.
Clear the screen to the gray color.
Draw the Taijitu symbol 4 inches wide at the screen's center.
Put the screen's center into a spot. Move the spot 4 inches right.
Draw the Taijitu symbol 2 inches wide at the spot.
Refresh the screen.
Wait for the escape key.
Shut down.
To draw the Taijitu symbol some twips wide at a spot:
Imagine a box the twips high by the twips wide.
Imagine an ellipse given the box.
Center the ellipse on the spot.
Mask outside the ellipse.
Imagine a left half box with the screen's left and the screen's top and the spot's x coord and the screen's bottom.
Fill the left half with the white color.
Imagine a right half box with the spot's x coord and the screen's top and the screen's right and the screen's bottom.
Fill the right half with the black color.
Imagine a swirl ellipse given the box.
Scale the swirl given 1/2.
Put the spot into an upper spot. Move the upper spot up the twips divided by 4.
Put the spot into a lower spot. Move the lower spot down the twips divided by 4.
Fill the swirl on the upper spot with the white color.
Fill the swirl on the lower spot with the black color.
Put the swirl into a dot.
Scale the dot given 1/4.
Fill the dot on the lower spot with the white color.
Fill the dot on the upper spot with the black color.
Unmask everything.
Use the fat pen.
Draw the ellipse. |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #PL.2FI | PL/I | yinyang: procedure options(main);
yinyang: procedure(r);
circle: procedure(x, y, c, r) returns(bit);
declare (x, y, c, r) fixed;
return( r*r >= (x/2) * (x/2) + (y-c) * (y-c) );
end circle;
pixel: procedure(x, y, r) returns(char);
declare (x, y, r) fixed;
if circle(x, y, -r/2, r/6) then return('#');
if circle(x, y, r/2, r/6) then return('.');
if circle(x, y, -r/2, r/2) then return('.');
if circle(x, y, r/2, r/2) then return('#');
if circle(x, y, 0, r) then do;
if x<0 then return('.');
else return('#');
end;
return(' ');
end pixel;
declare (x, y, r) fixed;
do y=-r to r;
do x=-2*r to 2*r;
put edit(pixel(x, y, r)) (A(1));
end;
put skip;
end;
end yinyang;
call yinyang(4);
put skip;
call yinyang(8);
end yinyang; |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #Groovy | Groovy | def Y = { le -> ({ f -> f(f) })({ f -> le { x -> f(f)(x) } }) }
def factorial = Y { fac ->
{ n -> n <= 2 ? n : n * fac(n - 1) }
}
assert 2432902008176640000 == factorial(20G)
def fib = Y { fibStar ->
{ n -> n <= 1 ? n : fibStar(n - 1) + fibStar(n - 2) }
}
assert fib(10) == 55 |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #JavaScript | JavaScript | function ZigZagMatrix(n) {
this.height = n;
this.width = n;
this.mtx = [];
for (var i = 0; i < n; i++)
this.mtx[i] = [];
var i=1, j=1;
for (var e = 0; e < n*n; e++) {
this.mtx[i-1][j-1] = e;
if ((i + j) % 2 == 0) {
// Even stripes
if (j < n) j ++;
else i += 2;
if (i > 1) i --;
} else {
// Odd stripes
if (i < n) i ++;
else j += 2;
if (j > 1) j --;
}
}
}
ZigZagMatrix.prototype = Matrix.prototype;
var z = new ZigZagMatrix(5);
print(z);
print();
z = new ZigZagMatrix(4);
print(z); |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Visual_Basic_.NET | Visual Basic .NET | Imports System.Console
Imports BI = System.Numerics.BigInteger
Module Module1
Dim Implems() As String = {"Built-In", "Recursive", "Iterative"},
powers() As Integer = {5, 4, 3, 2}
Function intPowR(val As BI, exp As BI) As BI
If exp = 0 Then Return 1
Dim ne As BI, vs As BI = val * val
If exp.IsEven Then ne = exp >> 1 : Return If (ne > 1, intPowR(vs, ne), vs)
ne = (exp - 1) >> 1 : Return If (ne > 1, intPowR(vs, ne), vs) * val
End Function
Function intPowI(val As BI, exp As BI) As BI
intPowI = 1 : While (exp > 0) : If Not exp.IsEven Then intPowI *= val
val *= val : exp >>= 1 : End While
End Function
Sub DoOne(title As String, p() As Integer)
Dim st As DateTime = DateTime.Now, res As BI, resStr As String
Select Case (Array.IndexOf(Implems, title))
Case 0 : res = BI.Pow(p(0), CInt(BI.Pow(p(1), CInt(BI.Pow(p(2), p(3))))))
Case 1 : res = intPowR(p(0), intPowR(p(1), intPowR(p(2), p(3))))
Case Else : res = intPowI(p(0), intPowI(p(1), intPowI(p(2), p(3))))
End Select : resStr = res.ToString()
Dim et As TimeSpan = DateTime.Now - st
Debug.Assert(resStr.Length = 183231)
Debug.Assert(resStr.StartsWith("62060698786608744707"))
Debug.Assert(resStr.EndsWith("92256259918212890625"))
WriteLine("n = {0}", String.Join("^", powers))
WriteLine("n = {0}...{1}", resStr.Substring(0, 20), resStr.Substring(resStr.Length - 20, 20))
WriteLine("n digits = {0}", resStr.Length)
WriteLine("{0} elasped: {1} milliseconds." & vblf, title, et.TotalMilliseconds)
End Sub
Sub Main()
For Each itm As String in Implems : DoOne(itm, powers) : Next
If Debugger.IsAttached Then Console.ReadKey()
End Sub
End Module |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #VBScript | VBScript |
Function Zeckendorf(n)
num = n
Set fibonacci = CreateObject("System.Collections.Arraylist")
fibonacci.Add 1 : fibonacci.Add 2
i = 1
Do While fibonacci(i) < num
fibonacci.Add fibonacci(i) + fibonacci(i-1)
i = i + 1
Loop
tmp = ""
For j = fibonacci.Count-1 To 0 Step -1
If fibonacci(j) <= num And (tmp = "" Or Left(tmp,1) <> "1") Then
tmp = tmp & "1"
num = num - fibonacci(j)
Else
tmp = tmp & "0"
End If
Next
Zeckendorf = CLng(tmp)
End Function
'testing the function
For k = 0 To 20
WScript.StdOut.WriteLine k & ": " & Zeckendorf(k)
Next
|
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #Egel | Egel |
import "prelude.eg"
using System
using List
data open, closed
def toggle =
[ open N -> closed N | closed N -> open N ]
def doors =
[ N -> map [ N -> closed N ] (fromto 1 N) ]
def toggleK =
[ K nil -> nil
| K (cons (D N) DD) ->
let DOOR = if (N%K) == 0 then toggle (D N) else D N in
cons DOOR (toggleK K DD) ]
def toggleEvery =
[ nil DOORS -> DOORS
| (cons K KK) DOORS -> toggleEvery KK (toggleK K DOORS) ]
def run =
[ N -> toggleEvery (fromto 1 N) (doors N) ]
def main = run 100
|
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #Lambdatalk | Lambdatalk |
// Create a new array with length 0
{def myArray1 {A.new}}
-> []
// Create an array with 2 members (length is 2)
{def myArray2 {A.new Item1 Item2}}
-> [Item1,Item2]
// Edit a value in an array
{def myArray3 {A.new 1 2 3}}
{A.set! 1 hello {myArray3}}
-> [1,hello,3]
// Add a value at the head of an array
{def myArray4 {A.new 1 2 3}}-> myArray4
{A.addfirst! hello {myArray4}}
-> [hello,1,2,3]
// Add a value at the tail of an array
{def myArray5 {A.new 1 2 3}}
{A.addlast! hello {myArray5}}
-> [1,2,3,hello]
and so on...
|
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #Picat | Picat | import cp.
main =>
Nat = [English, Swede, Dane, German, Norwegian],
Color = [Red, Green, White, Yellow, Blue],
Smoke = [PallMall, Dunhill, Blend, SBlue, Prince],
Pet = [Dog, Bird, Cat, Horse, Zebra],
Drink = [Tea, Coffee, Milk, Beer, Water],
Nat :: 1..5,
Color :: 1..5,
Smoke :: 1..5,
Pet :: 1..5,
Drink :: 1..5,
all_different(Nat),
all_different(Color),
all_different(Smoke),
all_different(Pet),
all_different(Drink),
English = Red,
Swede = Dog,
Dane = Tea,
Green #= White-1,
Coffee = Green,
Bird = PallMall,
Yellow = Dunhill,
Milk = 3,
Norwegian = 1,
abs(Blend-Cat) #= 1,
abs(Dunhill-Horse) #= 1,
SBlue = Beer,
German = Prince,
abs(Norwegian-Blue) #= 1,
abs(Blend-Water) #= 1,
solve(Nat ++ Color ++ Smoke ++ Pet ++ Drink),
L = [English=english,
Swede=swede,
Dane=dane,
German=german,
Norwegian=norwegian].sort(),
member(Zebra=ZebraOwner, L),
writef("The %w owns the zebra\n", ZebraOwner),
writeln(L).
|
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #Wren | Wren | import "/pattern" for Pattern
var doc = """
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
"""
var p1 = Pattern.new("<item ")
var match1 = p1.find(doc)
var p2 = Pattern.new("<//item>")
var match2 = p2.find(doc)
System.print("The first 'item' element is:")
System.print(" " + doc[match1.index..match2.index + 6])
var p3 = Pattern.new("<price>[+1^<]<//price>")
var matches = p3.findAll(doc)
System.print("\nThe 'prices' are:")
for (m in matches) System.print(m.captures[0].text)
var p4 = Pattern.new("<name>[+1^<]<//name>")
var matches2 = p4.findAll(doc)
var names = matches2.map { |m| m.captures[0].text }.toList
System.print("\nThe 'names' are:")
System.print(names.join("\n")) |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #PostScript | PostScript | %!PS-Adobe-3.0
%%BoundingBox: 0 0 400 400
/fs 10 def
/ed { exch def } def
/dist { 3 -1 roll sub dup mul 3 1 roll sub dup mul add sqrt } def
/circ {
/r exch def
[r neg 1 r {
/y exch def
[ r 2 mul neg 1 r 2 mul {
/x ed x 2 div y 0 0 dist r .05 add gt {( )}{
x 2 div y 0 r 2 div dist dup
r 5 div le { pop (.) } {
r 2 div le { (@) }{
x 2 div y 0 r 2 div neg dist dup
r 5 div le { pop (@)} {
r 2 div le {(.)}{
x 0 le {(.)}{(@)}ifelse
} ifelse
} ifelse
} ifelse
} ifelse
} ifelse
} for]
} for]
} def
/dis { moveto gsave
{ grestore 0 fs 1.15 mul neg rmoveto gsave
{show} forall
} forall grestore
} def
/Courier findfont fs scalefont setfont
11 circ 10 390 dis
6 circ 220 180 dis
showpage
%%EOF |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #Haskell | Haskell | newtype Mu a = Roll
{ unroll :: Mu a -> a }
fix :: (a -> a) -> a
fix = g <*> (Roll . g)
where
g = (. (>>= id) unroll)
- this version is not in tail call position...
-- fac :: Integer -> Integer
-- fac =
-- fix $ \f n -> if n <= 0 then 1 else n * f (n - 1)
-- this version builds a progression from tail call position and is more efficient...
fac :: Integer -> Integer
fac =
(fix $ \f n i -> if i <= 0 then n else f (i * n) (i - 1)) 1
-- make fibs a function, else memory leak as
-- head of the list can never be released as per:
-- https://wiki.haskell.org/Memory_leak, type 1.1
-- overly complex version...
{--
fibs :: () -> [Integer]
fibs() =
fix $
(0 :) . (1 :) .
(fix
(\f (x:xs) (y:ys) ->
case x + y of n -> n `seq` n : f xs ys) <*> tail)
--}
-- easier to read, simpler (faster) version...
fibs :: () -> [Integer]
fibs() = 0 : 1 : fix fibs_ 0 1
where
fibs_ fnc f s =
case f + s of n -> n `seq` n : fnc s n
main :: IO ()
main =
mapM_
print
[ map fac [1 .. 20]
, take 20 $ fibs()
] |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #Joy | Joy |
(*
From the library.
*)
DEFINE reverse == [] swap shunt;
shunt == [swons] step.
(*
Split according to the parameter given.
*)
DEFINE take-drop == [dup] swap dup [[] cons [take swap] concat concat] dip []
cons concat [drop] concat.
(*
Take the first of a list of lists.
*)
DEFINE take-first == [] cons 3 [dup] times [dup] swap concat [take [first] map
swap dup] concat swap concat [drop swap] concat swap
concat [take [rest] step []] concat swap concat [[cons]
times swap concat 1 drop] concat.
DEFINE zigzag ==
(*
Use take-drop to generate a list of lists.
*)
4 [dup] times 1 swap from-to-list swap pred 1 swap from-to-list reverse concat
swap dup * pred 0 swap from-to-list swap [take-drop i] step [pop list] [cons]
while
(*
The odd numbers must be modified with reverse.
*)
[dup size 2 div popd [1 =] [pop reverse] [pop] ifte] map
(*
Take the first of the first of n lists.
*)
swap dup take-first [i] cons times pop
(*
Merge the n separate lists.
*)
[] [pop list] [cons] while
(*
And print them.
*)
swap dup * pred 'd 1 1 format size succ [] cons 'd swons [1 format putchars]
concat [step '\n putch] cons step.
11 zigzag. |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Vlang | Vlang | import math.big
import math
fn main() {
mut x := u32(math.pow(3,2))
x = u32(math.pow(4,x))
mut y := big.integer_from_int(5)
y = y.pow(x)
str := y.str()
println("5^(4^(3^2)) has $str.len digits: ${str[..20]} ... ${str[str.len-20..]}")
} |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Wren | Wren | import "/fmt" for Fmt
import "/big" for BigInt
var p = BigInt.three.pow(BigInt.two)
p = BigInt.four.pow(p)
p = BigInt.five.pow(p)
var s = p.toString
Fmt.print("5 ^ 4 ^ 3 ^ 2 has $,d digits.\n", s.count)
System.print("The first twenty are : %(s[0..19])")
System.print("and the last twenty are : %(s[-20..-1])") |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #Vlang | Vlang | fn main() {
for i := 0; i <= 20; i++ {
println("${i:2} ${zeckendorf(i):7b}")
}
}
fn zeckendorf(n int) int {
// initial arguments of fib0 = 1 and fib1 = 1 will produce
// the Fibonacci sequence {1, 2, 3,..} on the stack as successive
// values of fib1.
_, set := zr(1, 1, n, 0)
return set
}
fn zr(fib0 int, fib1 int, n int, bit u32) (int, int) {
mut set := 0
mut remaining := 0
if fib1 > n {
return n, 0
}
// recurse.
// construct sequence on the way in, construct ZR on the way out.
remaining, set = zr(fib1, fib0+fib1, n, bit+1)
if fib1 <= remaining {
set |= 1 << bit
remaining -= fib1
}
return remaining, set
} |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #Wren | Wren | import "/fmt" for Fmt
var LIMIT = 46 // to stay within range of signed 32 bit integer
var fibonacci = Fn.new { |n|
if (n < 2 || n > LIMIT) Fiber.abort("n must be between 2 and %(LIMIT)")
var fibs = List.filled(n, 1)
for (i in 2...n) fibs[i] = fibs[i - 1] + fibs[i - 2]
return fibs
}
var fibs = fibonacci.call(LIMIT)
var zeckendorf = Fn.new { |n|
if (n < 0) Fiber.abort("n must be non-negative")
if (n < 2) return n.toString
var lastFibIndex = 1
for (i in 2..LIMIT) {
if (fibs[i] > n) {
lastFibIndex = i - 1
break
}
}
n = n - fibs[lastFibIndex]
lastFibIndex = lastFibIndex - 1
var zr = "1"
for (i in lastFibIndex..1) {
if (fibs[i] <= n) {
zr = zr + "1"
n = n - fibs[i]
} else {
zr = zr + "0"
}
}
return zr
}
System.print(" n z")
for (i in 0..20) Fmt.print("$2d : $s", i, zeckendorf.call(i)) |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #EGL | EGL |
program OneHundredDoors
function main()
doors boolean[] = new boolean[100];
n int = 100;
for (i int from 1 to n)
for (j int from i to n by i)
doors[j] = !doors[j];
end
end
for (i int from 1 to n)
if (doors[i])
SysLib.writeStdout( "Door " + i + " is open" );
end
end
end
end
|
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #lang5 | lang5 | []
1 append
['foo 'bar] append
2 reshape
0 remove 2 swap 2 compress collapse . |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #PicoLisp | PicoLisp | (be match (@House @Person @Drink @Pet @Cigarettes)
(permute (red blue green yellow white) @House)
(left-of @House white @House green)
(permute (Norwegian English Swede German Dane) @Person)
(has @Person English @House red)
(equal @Person (Norwegian . @))
(next-to @Person Norwegian @House blue)
(permute (tea coffee milk beer water) @Drink)
(has @Drink tea @Person Dane)
(has @Drink coffee @House green)
(equal @Drink (@ @ milk . @))
(permute (dog birds cats horse zebra) @Pet)
(has @Pet dog @Person Swede)
(permute (Pall-Mall Dunhill Blend Blue-Master Prince) @Cigarettes)
(has @Cigarettes Pall-Mall @Pet birds)
(has @Cigarettes Dunhill @House yellow)
(next-to @Cigarettes Blend @Pet cats)
(next-to @Cigarettes Dunhill @Pet horse)
(has @Cigarettes Blue-Master @Drink beer)
(has @Cigarettes Prince @Person German)
(next-to @Drink water @Cigarettes Blend) )
(be has ((@A . @X) @A (@B . @Y) @B))
(be has ((@ . @X) @A (@ . @Y) @B)
(has @X @A @Y @B) )
(be right-of ((@A . @X) @A (@ @B . @Y) @B))
(be right-of ((@ . @X) @A (@ . @Y) @B)
(right-of @X @A @Y @B) )
(be left-of ((@ @A . @X) @A (@B . @Y) @B))
(be left-of ((@ . @X) @A (@ . @Y) @B)
(left-of @X @A @Y @B) )
(be next-to (@X @A @Y @B) (right-of @X @A @Y @B))
(be next-to (@X @A @Y @B) (left-of @X @A @Y @B)) |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #XProc | XProc | <p:pipeline xmlns:p="http://www.w3.org/ns/xproc"
name="one-two-three"
version="1.0">
<p:identity>
<p:input port="source">
<p:inline>
<root>
<first/>
<prices/>
<names/>
</root>
</p:inline>
</p:input>
</p:identity>
<p:insert match="/root/first" position="first-child">
<p:input port="insertion" select="(//item)[1]">
<p:pipe port="source" step="one-two-three"/>
</p:input>
</p:insert>
<p:insert match="/root/prices" position="first-child">
<p:input port="insertion" select="//price">
<p:pipe port="source" step="one-two-three"/>
</p:input>
</p:insert>
<p:insert match="/root/names" position="first-child">
<p:input port="insertion" select="//name">
<p:pipe port="source" step="one-two-three"/>
</p:input>
</p:insert>
</p:pipeline> |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #XQuery | XQuery | (:
1. Retrieve the first "item" element
Notice the braces around //item. This evaluates first all item elements and then retrieving the first one.
Whithout the braces you get the first item for every section.
:)
let $firstItem := (//item)[1]
(: 2. Perform an action on each "price" element (print it out) :)
let $price := //price/data(.)
(: 3. Get an array of all the "name" elements :)
let $names := //name
return
<result>
<firstItem>{$firstItem}</firstItem>
<prices>{$price}</prices>
<names>{$names}</names>
</result> |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #POV-Ray | POV-Ray |
// ====== General Scene setup ======
#version 3.7;
global_settings { assumed_gamma 2.2 }
camera{ location <0,2.7,4> look_at <0,.1,0> right x*1.6
aperture .2 focal_point <1,0,0> blur_samples 200 variance 1/10000 }
light_source{<2,4,8>, 1 spotlight point_at 0 radius 10}
sky_sphere {pigment {granite scale <1,.1,1> color_map {[0 rgb 1][1 rgb <0,.4,.6>]}}}
#default {finish {diffuse .9 reflection {.1 metallic} ambient .3}
normal {granite scale .2}}
plane { y, -1 pigment {hexagon color rgb .7 color rgb .75 color rgb .65}
normal {hexagon scale 5}}
// ====== Declare one side of the symbol as a sum and difference of discs ======
#declare yang =
difference {
merge {
difference {
cylinder {0 <0,.1,0> 1} // flat disk
box {-1 <1,1,0>} // cut in half
cylinder {<.5,-.1,0> <.5,.2,0> .5} // remove half-cicle on one side
}
cylinder {<-.5,0,0> <-.5,.1,0> .5} // add on the other side
cylinder {<.5,0,0> <.5,.1,0> .15} // also add a little dot
}
cylinder {<-.5,-.1,0> <-.5,.2,0> .15} // and carve out a hole
pigment{color rgb 0.1}
}
// ====== The other side is white and 180-degree turned ======
#declare yin =
object {
yang
rotate <0,180,0>
pigment{color rgb 1}
}
// ====== Here we put the two together: ======
#macro yinyang( ysize )
union {
object {yin}
object {yang}
scale ysize
}
#end
// ====== Here we put one into a scene: ======
object { yinyang(1)
translate -y*1.08 }
// ====== And a bunch more just for fun: ======
#declare scl=1.1;
#while (scl > 0.01)
object { yinyang(scl)
rotate <0,180,0> translate <-scl*4,scl*2-1,0>
rotate <0,scl*360,0> translate <-.5,0,0>}
object { yinyang(scl)
translate <-scl*4,scl*2-1,0>
rotate <0,scl*360+180,0> translate <.5,0,0>}
#declare scl = scl*0.85;
#end |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Prolog | Prolog | ying_yang(N) :-
R is N * 100,
sformat(Title, 'Yin Yang ~w', [N]),
new(W, window(Title)),
new(Wh, colour(@default, 255*255, 255*255, 255*255)),
new(Bl, colour(@default, 0, 0, 0)),
CX is R + 50,
CY is R + 50,
R1 is R / 2,
R2 is R / 8,
CY1 is R1 + 50,
CY2 is 3 * R1 + 50,
new(E, semi_disk(point(CX, CY), R, w, Bl)),
new(F, semi_disk(point(CX, CY), R, e, Wh)),
new(D1, disk(point(CX, CY1), R, Bl)),
new(D2, disk(point(CX, CY2), R, Wh)),
new(D3, disk(point(CX, CY1), R2, Wh)),
new(D4, disk(point(CX, CY2), R2, Bl)),
send_list(W, display, [E, F, D1, D2, D3, D4]),
WD is 2 * R + 100,
send(W, size, size(WD, WD )),
send(W, open).
:- pce_begin_class(semi_disk, path, "Semi disk with color ").
initialise(P, C, R, O, Col) :->
send(P, send_super, initialise),
get(C, x, CX),
get(C, y, CY),
choose(O, Deb, End),
forall(between(Deb, End, I),
( X is R * cos(I * pi/180) + CX,
Y is R * sin(I * pi/180) + CY,
send(P, append, point(X,Y)))),
send(P, closed, @on),
send(P, fill_pattern, Col).
:- pce_end_class.
choose(s, 0, 180).
choose(n, 180, 360).
choose(w, 90, 270).
choose(e, -90, 90).
:- pce_begin_class(disk, ellipse, "disk with color ").
initialise(P, C, R, Col) :->
send(P, send_super, initialise, R, R),
send(P, center, C),
send(P, pen, 0),
send(P, fill_pattern, Col).
:- pce_end_class. |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #J | J | Y=. '('':''<@;(1;~":0)<@;<@((":0)&;))'(2 : 0 '')
(1 : (m,'u'))(1 : (m,'''u u`:6('',(5!:5<''u''),'')`:6 y'''))(1 :'u u`:6')
)
|
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #jq | jq | # Create an m x n matrix
def matrix(m; n; init):
if m == 0 then []
elif m == 1 then [range(0;n)] | map(init)
elif m > 0 then
matrix(1;n;init) as $row
| [range(0;m)] | map( $row )
else error("matrix\(m);_;_) invalid")
end ;
# Print a matrix neatly, each cell occupying n spaces
def neatly(n):
def right: tostring | ( " " * (n-length) + .);
. as $in
| length as $length
| reduce range (0;$length) as $i
(""; . + reduce range(0;$length) as $j
(""; "\(.) \($in[$i][$j] | right )" ) + "\n" ) ;
|
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #Zig | Zig | const std = @import("std");
const bigint = std.math.big.int.Managed;
pub fn main() !void {
var gpa = std.heap.GeneralPurposeAllocator(.{}){};
const allocator = &gpa.allocator;
defer _ = gpa.deinit();
var a = try bigint.initSet(allocator, 5);
try a.pow(a.toConst(), try std.math.powi(u32, 4, try std.math.powi(u32, 3, 2)));
defer a.deinit();
var as = try a.toString(allocator, 10, false);
defer allocator.free(as);
std.debug.print("{s}...{s}\n", .{ as[0..20], as[as.len - 20 ..] });
std.debug.print("{} digits\n", .{as.len});
} |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
{\displaystyle 5^{4^{3^{2}}}}
Confirm that the first and last twenty digits of the answer are:
62060698786608744707...92256259918212890625
Find and show the number of decimal digits in the answer.
Note: Do not submit an implementation of arbitrary precision arithmetic. The intention is to show the capabilities of the language as supplied. If a language has a single, overwhelming, library of varied modules that is endorsed by its home site – such as CPAN for Perl or Boost for C++ – then that may be used instead.
Strictly speaking, this should not be solved by fixed-precision numeric libraries where the precision has to be manually set to a large value; although if this is the only recourse then it may be used with a note explaining that the precision must be set manually to a large enough value.
Related tasks
Long multiplication
Exponentiation order
exponentiation operator
Exponentiation with infix operators in (or operating on) the base
| #zkl | zkl | var BN=Import("zklBigNum");
n:=BN(5).pow(BN(4).pow(BN(3).pow(2)));
s:=n.toString();
"%,d".fmt(s.len()).println();
println(s[0,20],"...",s[-20,*]); |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #XPL0 | XPL0 | include c:\cxpl\codes; \intrinsic 'code' declarations
proc Zeckendorf(N); \Display Zeckendorf number (N <= 20)
int N;
int Fib, LZ, I;
[Fib:= [1, 2, 3, 5, 8, 13]; \Fibonacci sequence
LZ:= true; \suppress leading zeros
for I:= 5 downto 1 do
[if N >= Fib(I) then [N:= N-Fib(I); ChOut(0, ^1); LZ:= false]
else ChOut(0, if LZ then ^ else ^0);
];
ChOut(0, N+^0); \output final digit, which can be 0
];
int N;
[for N:= 0 to 20 do
[if N<10 then ChOut(0,^ ); IntOut(0, N); Text(0, ": ");
Zeckendorf(N); CrLf(0);
];
] |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #Yabasic | Yabasic | sub Zeckendorf(n)
local i, n$, c
do
n$ = bin$(i)
if not instr(n$,"11") then
print c,":\t",n$
if c = n break
c = c + 1
end if
i = i + 1
loop
end sub
Zeckendorf(20)
|
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #Eiffel | Eiffel | note
description: "100 Doors problem"
date: "08-JUL-2015"
revision: "1.1"
class
APPLICATION
create
make
feature {NONE} -- Initialization
make
-- Main application routine.
do
initialize_closed_doors
toggle_doors
output_door_states
end
feature -- Access
doors: ARRAYED_LIST [DOOR]
-- A set of doors (self-initialized to capacity of `max_door_count').
attribute
create Result.make (max_door_count)
end
feature -- Basic Operations
initialize_closed_doors
-- Initialize all `doors'.
do
across min_door_count |..| max_door_count as ic_address_list loop
doors.extend (create {DOOR}.make_closed (ic_address_list.item))
end
ensure
has_all_closed_doors: across doors as ic_doors_list all not ic_doors_list.item.is_open end
end
toggle_doors
-- Toggle all `doors'.
do
across min_door_count |..| max_door_count as ic_addresses_list loop
across doors as ic_doors_list loop
if is_door_to_toggle (ic_doors_list.item.address, ic_addresses_list.item) then
ic_doors_list.item.toggle_door
end
end
end
end
output_door_states
-- Output the state of all `doors'.
do
doors.do_all (agent door_state_out)
end
feature -- Status Report
is_door_to_toggle (a_door_address, a_index_address: like {DOOR}.address): BOOLEAN
-- Is the door at `a_door_address' needing to be toggled, when compared to `a_index_address'?
do
Result := a_door_address \\ a_index_address = 0
ensure
only_modulus_zero: Result = (a_door_address \\ a_index_address = 0)
end
feature -- Outputs
door_state_out (a_door: DOOR)
-- Output the state of `a_door'.
do
print ("Door " + a_door.address.out + " is ")
if a_door.is_open then
print ("open.")
else
print ("closed.")
end
io.new_line
end
feature {DOOR} -- Constants
min_door_count: INTEGER = 1
-- Minimum number of doors.
max_door_count: INTEGER = 100
-- Maximum number of doors.
end |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #langur | langur | var .a1 = [1, 2, 3, "abc"]
val .a2 = series 4..10
val .a3 = .a1 ~ .a2
writeln "initial values ..."
writeln ".a1: ", .a1
writeln ".a2: ", .a2
writeln ".a3: ", .a3
writeln()
.a1[4] = .a2[4]
writeln "after setting .a1[4] = .a2[4] ..."
writeln ".a1: ", .a1
writeln ".a2: ", .a2
writeln ".a3: ", .a3
writeln()
writeln ".a2[1]: ", .a2[1]
writeln()
writeln "using index alternate ..."
writeln ".a2[5; 0]: ", .a2[5; 0]
writeln ".a2[10; 0]: ", .a2[10; 0]
writeln() |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #Prolog | Prolog | select([A|As],S):- select(A,S,S1),select(As,S1).
select([],_).
next_to(A,B,C):- left_of(A,B,C) ; left_of(B,A,C).
left_of(A,B,C):- append(_,[A,B|_],C).
zebra(Owns, HS):- % color,nation,pet,drink,smokes
HS = [ h(_,norwegian,_,_,_), _, h(_,_,_,milk,_), _, _],
select( [ h(red,englishman,_,_,_), h(_,swede,dog,_,_),
h(_,dane,_,tea,_), h(_,german,_,_,prince) ], HS),
select( [ h(_,_,birds,_,pallmall), h(yellow,_,_,_,dunhill),
h(_,_,_,beer,bluemaster) ], HS),
left_of( h(green,_,_,coffee,_), h(white,_,_,_,_), HS),
next_to( h(_,_,_,_,dunhill), h(_,_,horse,_,_), HS),
next_to( h(_,_,_,_,blend), h(_,_,cats, _,_), HS),
next_to( h(_,_,_,_,blend), h(_,_,_,water,_), HS),
next_to( h(_,norwegian,_,_,_), h(blue,_,_,_,_), HS),
member( h(_,Owns,zebra,_,_), HS).
:- ?- time(( zebra(Who, HS), maplist(writeln,HS), nl, write(Who), nl, nl, fail
; write('No more solutions.') )). |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="health">
<item upc="123456789" stock="12">
<name>Invisibility Cream</name>
<price>14.50</price>
<description>Makes you invisible</description>
</item>
<item upc="445322344" stock="18">
<name>Levitation Salve</name>
<price>23.99</price>
<description>Levitate yourself for up to 3 hours per application</description>
</item>
</section>
<section name="food">
<item upc="485672034" stock="653">
<name>Blork and Freen Instameal</name>
<price>4.95</price>
<description>A tasty meal in a tablet; just add water</description>
</item>
<item upc="132957764" stock="44">
<name>Grob winglets</name>
<price>3.56</price>
<description>Tender winglets of Grob. Just add water</description>
</item>
</section>
</inventory>
| #XSLT | XSLT | <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" />
<xsl:template match="/">
<!-- 1. first item element -->
<xsl:text>
The first item element is</xsl:text>
<xsl:value-of select="//item[1]" />
<!-- 2. Print each price element -->
<xsl:text>
The prices are: </xsl:text>
<xsl:for-each select="//price">
<xsl:text>
</xsl:text>
<xsl:copy-of select="." />
</xsl:for-each>
<!-- 3. Collect all the name elements -->
<xsl:text>
The names are: </xsl:text>
<xsl:copy-of select="//name" />
</xsl:template>
</xsl:stylesheet> |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Python | Python | import math
def yinyang(n=3):
radii = [i * n for i in (1, 3, 6)]
ranges = [list(range(-r, r+1)) for r in radii]
squares = [[ (x,y) for x in rnge for y in rnge]
for rnge in ranges]
circles = [[ (x,y) for x,y in sqrpoints
if math.hypot(x,y) <= radius ]
for sqrpoints, radius in zip(squares, radii)]
m = {(x,y):' ' for x,y in squares[-1]}
for x,y in circles[-1]:
m[x,y] = '*'
for x,y in circles[-1]:
if x>0: m[(x,y)] = '·'
for x,y in circles[-2]:
m[(x,y+3*n)] = '*'
m[(x,y-3*n)] = '·'
for x,y in circles[-3]:
m[(x,y+3*n)] = '·'
m[(x,y-3*n)] = '*'
return '\n'.join(''.join(m[(x,y)] for x in reversed(ranges[-1])) for y in ranges[-1]) |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #Java_2 | Java | import java.util.function.Function;
public interface YCombinator {
interface RecursiveFunction<F> extends Function<RecursiveFunction<F>, F> { }
public static <A,B> Function<A,B> Y(Function<Function<A,B>, Function<A,B>> f) {
RecursiveFunction<Function<A,B>> r = w -> f.apply(x -> w.apply(w).apply(x));
return r.apply(r);
}
public static void main(String... arguments) {
Function<Integer,Integer> fib = Y(f -> n ->
(n <= 2)
? 1
: (f.apply(n - 1) + f.apply(n - 2))
);
Function<Integer,Integer> fac = Y(f -> n ->
(n <= 1)
? 1
: (n * f.apply(n - 1))
);
System.out.println("fib(10) = " + fib.apply(10));
System.out.println("fac(10) = " + fac.apply(10));
}
} |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #Julia | Julia | function zigzag_matrix(n::Int)
matrix = zeros(Int, n, n)
x, y = 1, 1
for i = 0:(n*n-1)
matrix[y,x] = i
if (x + y) % 2 == 0
# Even stripes
if x < n
x += 1
y -= (y > 1)
else
y += 1
end
else
# Odd stripes
if y < n
x -= (x > 1)
y += 1
else
x += 1
end
end
end
return matrix
end |
http://rosettacode.org/wiki/Zeckendorf_number_representation | Zeckendorf number representation | Just as numbers can be represented in a positional notation as sums of multiples of the powers of ten (decimal) or two (binary); all the positive integers can be represented as the sum of one or zero times the distinct members of the Fibonacci series.
Recall that the first six distinct Fibonacci numbers are: 1, 2, 3, 5, 8, 13.
The decimal number eleven can be written as 0*13 + 1*8 + 0*5 + 1*3 + 0*2 + 0*1 or 010100 in positional notation where the columns represent multiplication by a particular member of the sequence. Leading zeroes are dropped so that 11 decimal becomes 10100.
10100 is not the only way to make 11 from the Fibonacci numbers however; 0*13 + 1*8 + 0*5 + 0*3 + 1*2 + 1*1 or 010011 would also represent decimal 11. For a true Zeckendorf number there is the added restriction that no two consecutive Fibonacci numbers can be used which leads to the former unique solution.
Task
Generate and show here a table of the Zeckendorf number representations of the decimal numbers zero to twenty, in order.
The intention in this task to find the Zeckendorf form of an arbitrary integer. The Zeckendorf form can be iterated by some bit twiddling rather than calculating each value separately but leave that to another separate task.
Also see
OEIS A014417 for the the sequence of required results.
Brown's Criterion - Numberphile
Related task
Fibonacci sequence
| #zkl | zkl | // return powers (0|1) of fib sequence (1,2,3,5,8...) that sum to n
fcn zeckendorf(n){ //-->String of 1s & 0s, no consecutive 1's
if(n<=0) return("0");
fibs:=fcn(ab){ ab.append(ab.sum()).pop(0) }.fp(L(1,2));
(0).pump(*,List,fibs,'wrap(fib){ if(fib>n)Void.Stop else fib })
.reverse()
.pump(String,fcn(fib,rn){
if(fib>rn.value)"0" else { rn.set(rn.value-fib); "1" } }.fp1(Ref(n)))
} |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #Ela | Ela | open generic
type Door = Open | Closed
deriving Show
gate [] _ = []
gate (x::xs) (y::ys)
| x == y = Open :: gate xs ys
| else = Closed :: gate xs ys
run n = gate [1..n] [& k*k \\ k <- [1..]] |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #Lasso | Lasso | // Create a new empty array
local(array1) = array
// Create an array with 2 members (#myarray->size is 2)
local(array1) = array('ItemA','ItemB')
// Assign a value to member [2]
#array1->get(2) = 5
// Retrieve a value from an array
#array1->get(2) + #array1->size // 8
// Merge arrays
local(
array1 = array('a','b','c'),
array2 = array('a','b','c')
)
#array1->merge(#array2) // a, b, c, a, b, c
// Sort an array
#array1->sort // a, a, b, b, c, c
// Remove value by index
#array1->remove(2) // a, b, b, c, c
// Remove matching items
#array1->removeall('b') // a, c, c
// Insert item
#array1->insert('z') // a, c, c, z
// Insert item at specific position
#array1->insert('0',1) // 0, a, c, c, z |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #Python | Python |
from logpy import *
from logpy.core import lall
import time
def lefto(q, p, list):
# give me q such that q is left of p in list
# zip(list, list[1:]) gives a list of 2-tuples of neighboring combinations
# which can then be pattern-matched against the query
return membero((q,p), zip(list, list[1:]))
def nexto(q, p, list):
# give me q such that q is next to p in list
# match lefto(q, p) OR lefto(p, q)
# requirement of vector args instead of tuples doesn't seem to be documented
return conde([lefto(q, p, list)], [lefto(p, q, list)])
houses = var()
zebraRules = lall(
# there are 5 houses
(eq, (var(), var(), var(), var(), var()), houses),
# the Englishman's house is red
(membero, ('Englishman', var(), var(), var(), 'red'), houses),
# the Swede has a dog
(membero, ('Swede', var(), var(), 'dog', var()), houses),
# the Dane drinks tea
(membero, ('Dane', var(), 'tea', var(), var()), houses),
# the Green house is left of the White house
(lefto, (var(), var(), var(), var(), 'green'),
(var(), var(), var(), var(), 'white'), houses),
# coffee is the drink of the green house
(membero, (var(), var(), 'coffee', var(), 'green'), houses),
# the Pall Mall smoker has birds
(membero, (var(), 'Pall Mall', var(), 'birds', var()), houses),
# the yellow house smokes Dunhills
(membero, (var(), 'Dunhill', var(), var(), 'yellow'), houses),
# the middle house drinks milk
(eq, (var(), var(), (var(), var(), 'milk', var(), var()), var(), var()), houses),
# the Norwegian is the first house
(eq, (('Norwegian', var(), var(), var(), var()), var(), var(), var(), var()), houses),
# the Blend smoker is in the house next to the house with cats
(nexto, (var(), 'Blend', var(), var(), var()),
(var(), var(), var(), 'cats', var()), houses),
# the Dunhill smoker is next to the house where they have a horse
(nexto, (var(), 'Dunhill', var(), var(), var()),
(var(), var(), var(), 'horse', var()), houses),
# the Blue Master smoker drinks beer
(membero, (var(), 'Blue Master', 'beer', var(), var()), houses),
# the German smokes Prince
(membero, ('German', 'Prince', var(), var(), var()), houses),
# the Norwegian is next to the blue house
(nexto, ('Norwegian', var(), var(), var(), var()),
(var(), var(), var(), var(), 'blue'), houses),
# the house next to the Blend smoker drinks water
(nexto, (var(), 'Blend', var(), var(), var()),
(var(), var(), 'water', var(), var()), houses),
# one of the houses has a zebra--but whose?
(membero, (var(), var(), var(), 'zebra', var()), houses)
)
t0 = time.time()
solutions = run(0, houses, zebraRules)
t1 = time.time()
dur = t1-t0
count = len(solutions)
zebraOwner = [house for house in solutions[0] if 'zebra' in house][0][0]
print "%i solutions in %.2f seconds" % (count, dur)
print "The %s is the owner of the zebra" % zebraOwner
print "Here are all the houses:"
for line in solutions[0]:
print str(line)
|
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Quackery | Quackery | [ $ "turtleduck.qky" loadfile ] now!
[ -1 4 turn
2dup -v fly
1 4 turn
4 wide
' [ 0 0 0 ] colour
' [ 0 0 0 ] fill
[ 2dup 2 1 v/ 1 2 arc
2dup -2 1 v/ 1 2 arc
2dup -v 1 2 arc ]
2dup -v 1 2 arc
1 4 turn
2dup 2 1 v/ fly
' [ 0 0 0 ] colour
1 wide
' [ 255 255 255 ] fill
[ 2dup 7 1 v/ circle ]
2dup fly
' [ 255 255 255 ] colour
' [ 0 0 0 ] fill
[ 2dup 7 1 v/ circle ]
-2 1 v/ fly
-1 4 turn ] is yinyang ( n/d --> )
turtle
-110 1 fly
100 1 yinyang
420 1 fly
300 1 yinyang |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #R | R | plot.yin.yang <- function(x=5, y=5, r=3, s=10, add=F){
suppressMessages(require("plotrix"))
if(!add) plot(1:10, type="n", xlim=c(0,s), ylim=c(0,s), xlab="", ylab="", xaxt="n", yaxt="n", bty="n", asp=1)
draw.circle(x, y, r, border="white", col= "black")
draw.ellipse(x, y, r, r, col="white", angle=0, segment=c(90,270), arc.only=F)
draw.ellipse(x, y - r * 0.5, r * 0.5, r * 0.5, col="black", border="black", angle=0, segment=c(90,270), arc.only=F)
draw.circle(x, y - r * 0.5, r * 0.125, border="white", col= "white")
draw.circle(x, y + r * 0.5, r * 0.5, col="white", border="white")
draw.circle(x, y + r * 0.5, r * 0.125, border="black", lty=1, col= "black")
draw.circle(x, y, r, border="black")
}
png("yin_yang.png")
plot.yin.yang()
plot.yin.yang(1,7,1, add=T)
dev.off() |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #JavaScript | JavaScript | function Y(f) {
var g = f((function(h) {
return function() {
var g = f(h(h));
return g.apply(this, arguments);
}
})(function(h) {
return function() {
var g = f(h(h));
return g.apply(this, arguments);
}
}));
return g;
}
var fac = Y(function(f) {
return function (n) {
return n > 1 ? n * f(n - 1) : 1;
};
});
var fib = Y(function(f) {
return function(n) {
return n > 1 ? f(n - 1) + f(n - 2) : n;
};
}); |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #Klingphix | Klingphix | include ..\Utilitys.tlhy
%Size 5 !Size
0 ( $Size dup ) dim
%i 1 !i %j 1 !j
$Size 2 power [
1 -
( $i $j ) set
$i $j + 1 band 0 == (
[$j $Size < ( [$j 1 + !j] [$i 2 + !i] ) if
$i 1 > [ $i 1 - !i] if ]
[$i $Size < ( [$i 1 + !i] [$j 2 + !j] ) if
$j 1 > [ $j 1 - !j] if ]
) if
] for
$Size [
%row !row
$Size [
%col !col
( $row $col ) get tostr 32 32 chain chain 1 3 slice print drop
] for
nl
] for
nl "End " input |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the 100th door.
Task
Answer the question: what state are the doors in after the last pass? Which are open, which are closed?
Alternate:
As noted in this page's discussion page, the only doors that remain open are those whose numbers are perfect squares.
Opening only those doors is an optimization that may also be expressed;
however, as should be obvious, this defeats the intent of comparing implementations across programming languages.
| #Elena | Elena | import system'routines;
import extensions;
public program()
{
var Doors := Array.allocate(100).populate:(n=>false);
for(int i := 0, i < 100, i := i + 1)
{
for(int j := i, j < 100, j := j + i + 1)
{
Doors[j] := Doors[j].Inverted
}
};
for(int i := 0, i < 100, i := i + 1)
{
console.printLine("Door #",i + 1," :",Doors[i].iif("Open","Closed"))
};
console.readChar()
} |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available, show both fixed-length arrays and
dynamic arrays, pushing a value into it).
Please discuss at Village Pump: Arrays.
Please merge code in from these obsolete tasks:
Creating an Array
Assigning Values to an Array
Retrieving an Element of an Array
Related tasks
Collections
Creating an Associative Array
Two-dimensional array (runtime)
| #Latitude | Latitude | ;; Construct an array.
foo := [1, 2, 3].
;; Arrays can also be constructed explicitly.
bar := Array clone.
bar pushBack (1).
bar pushBack (2).
bar pushBack (3).
;; Accessing values.
println: foo nth (2). ;; 3
;; Mutating values.
foo nth (1) = 99.
println: foo. ;; [1, 99, 3]
;; Appending to either the front or the back of the array.
foo pushBack ("back").
foo pushFront ("front").
println: foo. ;; ["front", 1, 99, 3, "back"]
;; Popping from the front or back.
println: foo popBack. ;; "back"
println: foo popBack. ;; 3
println: foo popFront. ;; "front"
println: foo. ;; [1, 99] |
http://rosettacode.org/wiki/Zebra_puzzle | Zebra puzzle | Zebra puzzle
You are encouraged to solve this task according to the task description, using any language you may know.
The Zebra puzzle, a.k.a. Einstein's Riddle,
is a logic puzzle which is to be solved programmatically.
It has several variants, one of them this:
There are five houses.
The English man lives in the red house.
The Swede has a dog.
The Dane drinks tea.
The green house is immediately to the left of the white house.
They drink coffee in the green house.
The man who smokes Pall Mall has birds.
In the yellow house they smoke Dunhill.
In the middle house they drink milk.
The Norwegian lives in the first house.
The man who smokes Blend lives in the house next to the house with cats.
In a house next to the house where they have a horse, they smoke Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
They drink water in a house next to the house where they smoke Blend.
The question is, who owns the zebra?
Additionally, list the solution for all the houses.
Optionally, show the solution is unique.
Related tasks
Dinesman's multiple-dwelling problem
Twelve statements
| #R | R |
library(combinat)
col <- factor(c("Red","Green","White","Yellow","Blue"))
own <- factor(c("English","Swedish","Danish","German","Norwegian"))
pet <- factor(c("Dog","Birds","Cats","Horse","Zebra"))
drink <- factor(c("Coffee","Tea","Milk","Beer","Water"))
smoke <- factor(c("PallMall", "Blend", "Dunhill", "BlueMaster", "Prince"))
col_p <- permn(levels(col))
own_p <- permn(levels(own))
pet_p <- permn(levels(pet))
drink_p <- permn(levels(drink))
smoke_p <- permn(levels(smoke))
imright <- function(h1,h2){
return(h1-h2==1)
}
nextto <- function(h1,h2){
return(abs(h1-h2)==1)
}
house_with <- function(f,val){
return(which(levels(f)==val))
}
for (i in seq(length(col_p))){
col <- factor(col, levels=col_p[[i]])
if (imright(house_with(col,"Green"),house_with(col,"White"))) {
for (j in seq(length(own_p))){
own <- factor(own, levels=own_p[[j]])
if(house_with(own,"English") == house_with(col,"Red")){
if(house_with(own,"Norwegian") == 1){
if(nextto(house_with(own,"Norwegian"),house_with(col,"Blue"))){
for(k in seq(length(drink_p))){
drink <- factor(drink, levels=drink_p[[k]])
if(house_with(drink,"Coffee") == house_with(col,"Green")){
if(house_with(own,"Danish") == house_with(drink,"Tea")){
if(house_with(drink,"Milk") == 3){
for(l in seq(length(smoke_p))){
smoke <- factor(smoke, levels=smoke_p[[l]])
if(house_with(smoke,"Dunhill") == house_with(col,"Yellow")){
if(house_with(smoke,"BlueMaster") == house_with(drink,"Beer")){
if(house_with(own,"German") == house_with(smoke,"Prince")){
if(nextto(house_with(smoke,"Blend"),house_with(drink,"Water"))){
for(m in seq(length(pet_p))){
pet <- factor(pet, levels=pet_p[[m]])
if(house_with(own,"Swedish") == house_with(pet,"Dog")){
if(house_with(smoke,"PallMall") == house_with(pet,"Birds")){
if(nextto(house_with(smoke,"Blend"),house_with(pet,"Cats"))){
if(nextto(house_with(smoke,"Dunhill"),house_with(pet,"Horse"))){
res <- sapply(list(own,col,pet,smoke,drink),levels)
colnames(res) <- c("Nationality","Colour","Pet","Drink","Smoke")
print(res)
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
}
} |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Racket | Racket |
#lang racket
(require slideshow/pict)
(define (yin-yang d)
(define base
(hc-append (inset/clip (circle d) 0 0 (- (/ d 2)) 0)
(inset/clip (disk d) (- (/ d 2)) 0 0 0)))
(define with-top
(ct-superimpose
base
(cc-superimpose (colorize (disk (/ d 2)) "white")
(disk (/ d 8)))))
(define with-bottom
(cb-superimpose
with-top
(cc-superimpose (disk (/ d 2))
(colorize (disk (/ d 8)) "white"))))
(cc-superimpose with-bottom (circle d)))
(yin-yang 200)
|
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #Raku | Raku | sub circle ($rad, $cx, $cy, $fill = 'white', $stroke = 'black' ){
say "<circle cx='$cx' cy='$cy' r='$rad' fill='$fill' stroke='$stroke' stroke-width='1'/>";
}
sub yin_yang ($rad, $cx, $cy, :$fill = 'white', :$stroke = 'black', :$angle = 90) {
my ($c, $w) = (1, 0);
say "<g transform='rotate($angle, $cx, $cy)'>" if $angle;
circle($rad, $cx, $cy, $fill, $stroke);
say "<path d='M $cx {$cy + $rad}A {$rad/2} {$rad/2} 0 0 $c $cx $cy ",
"{$rad/2} {$rad/2} 0 0 $w $cx {$cy - $rad} $rad $rad 0 0 $c $cx ",
"{$cy + $rad} z' fill='$stroke' stroke='none' />";
circle($rad/5, $cx, $cy + $rad/2, $fill, $stroke);
circle($rad/5, $cx, $cy - $rad/2, $stroke, $fill);
say "</g>" if $angle;
}
say '<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg height="400" width="400" xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">';
yin_yang(100, 130, 130);
yin_yang(50, 300, 300);
say '</svg>'; |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's state is used in the body of the function.
The Y combinator is itself a stateless function that, when applied to another stateless function, returns a recursive version of the function.
The Y combinator is the simplest of the class of such functions, called fixed-point combinators.
Task
Define the stateless Y combinator and use it to compute factorials and Fibonacci numbers from other stateless functions or lambda expressions.
Cf
Jim Weirich: Adventures in Functional Programming
| #Joy | Joy | DEFINE y == [dup cons] swap concat dup cons i;
fac == [ [pop null] [pop succ] [[dup pred] dip i *] ifte ] y. |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, given 5, produce this array:
0 1 5 6 14
2 4 7 13 15
3 8 12 16 21
9 11 17 20 22
10 18 19 23 24
Related tasks
Spiral matrix
Identity matrix
Ulam spiral (for primes)
See also
Wiktionary entry: anti-diagonals
| #Kotlin | Kotlin | // version 1.1.3
typealias Vector = IntArray
typealias Matrix = Array<Vector>
fun zigzagMatrix(n: Int): Matrix {
val result = Matrix(n) { Vector(n) }
var down = false
var count = 0
for (col in 0 until n) {
if (down)
for (row in 0..col) result[row][col - row] = count++
else
for (row in col downTo 0) result[row][col - row] = count++
down = !down
}
for (row in 1 until n) {
if (down)
for (col in n - 1 downTo row) result[row + n - 1 - col][col] = count++
else
for (col in row until n) result[row + n - 1 - col][col] = count++
down = !down
}
return result
}
fun printMatrix(m: Matrix) {
for (i in 0 until m.size) {
for (j in 0 until m.size) print("%2d ".format(m[i][j]))
println()
}
println()
}
fun main(args: Array<String>) {
printMatrix(zigzagMatrix(5))
printMatrix(zigzagMatrix(10))
} |
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