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http://rosettacode.org/wiki/Taxicab_numbers | Taxicab numbers |
A taxicab number (the definition that is being used here) is a positive integer that can be expressed as the sum of two positive cubes in more than one way.
The first taxicab number is 1729, which is:
13 + 123 and also
93 + 103.
Taxicab numbers are also known as:
taxi numbers
taxi-cab numbers
taxi cab numbers
Hardy-Ramanujan numbers
Task
Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format).
For each of the taxicab numbers, show the number as well as it's constituent cubes.
Extra credit
Show the 2,000th taxicab number, and a half dozen more
See also
A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences.
Hardy-Ramanujan Number on MathWorld.
taxicab number on MathWorld.
taxicab number on Wikipedia (includes the story on how taxi-cab numbers came to be called).
| #Julia | Julia | using Printf, DataStructures, IterTools
function findtaxinumbers(nmax::Integer)
cube2n = Dict{Int,Int}(x ^ 3 => x for x in 0:nmax)
sum2cubes = DefaultDict{Int,Set{NTuple{2,Int}}}(Set{NTuple{2,Int}})
for ((c1, _), (c2, _)) in product(cube2n, cube2n)
if c1 ≥ c2
push!(sum2cubes[c1 + c2], (cube2n[c1], cube2n[c2]))
end
end
taxied = collect((k, v) for (k, v) in sum2cubes if length(v) ≥ 2)
return sort!(taxied, by = first)
end
taxied = findtaxinumbers(1200)
for (ith, (cube, set)) in zip(1:25, taxied[1:25])
@printf "%2i: %7i = %s\n" ith cube join(set, ", ")
# println(ith, ": ", cube, " = ", join(set, ", "))
end
println("...")
for (ith, (cube, set)) in zip(2000:2006, taxied[2000:2006])
@printf "%-4i: %i = %s\n" ith cube join(set, ", ")
end
# version 2
function findtaxinumbers(nmax::Integer)
cubes, crev = collect(x ^ 3 for x in 1:nmax), Dict{Int,Int}()
for (x, x3) in enumerate(cubes)
crev[x3] = x
end
sums = collect(x + y for x in cubes for y in cubes if y < x)
sort!(sums)
idx = 0
for i in 2:(endof(sums) - 1)
if sums[i-1] != sums[i] && sums[i] == sums[i+1]
idx += 1
if 25 < idx < 2000 || idx > 2006 continue end
n, p = sums[i], NTuple{2,Int}[]
for x in cubes
n < 2x && break
if haskey(crev, n - x)
push!(p, (crev[x], crev[n - x]))
end
end
@printf "%4d: %10d" idx n
for x in p @printf(" = %4d ^ 3 + %4d ^ 3", x...) end
println()
end
end
end
findtaxinumbers(1200) |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'.
The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'.
A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'.
A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end.
The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations.
Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations.
The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Reference
The Minimal Superpermutation Problem. by Nathaniel Johnston.
oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872.
Superpermutations - Numberphile. A video
Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress.
New Superpermutations Discovered! Standupmaths & Numberphile.
| #J | J | approxmin=:3 :0
seqs=. y{~(A.&i.~ !)#y
r=.{.seqs
seqs=.}.seqs
while.#seqs do.
for_n. i.-#y do.
tail=. (-n){. r
b=. tail -:"1 n{."1 seqs
if. 1 e.b do.
j=. b i.1
r=. r, n}.j{seqs
seqs=. (<<<j) { seqs
break.
end.
end.
end.
r
) |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'.
The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'.
A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'.
A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end.
The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations.
Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations.
The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Reference
The Minimal Superpermutation Problem. by Nathaniel Johnston.
oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872.
Superpermutations - Numberphile. A video
Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress.
New Superpermutations Discovered! Standupmaths & Numberphile.
| #Java | Java | import static java.util.stream.IntStream.rangeClosed;
public class Test {
final static int nMax = 12;
static char[] superperm;
static int pos;
static int[] count = new int[nMax];
static int factSum(int n) {
return rangeClosed(1, n)
.map(m -> rangeClosed(1, m).reduce(1, (a, b) -> a * b)).sum();
}
static boolean r(int n) {
if (n == 0)
return false;
char c = superperm[pos - n];
if (--count[n] == 0) {
count[n] = n;
if (!r(n - 1))
return false;
}
superperm[pos++] = c;
return true;
}
static void superPerm(int n) {
String chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
pos = n;
superperm = new char[factSum(n)];
for (int i = 0; i < n + 1; i++)
count[i] = i;
for (int i = 1; i < n + 1; i++)
superperm[i - 1] = chars.charAt(i);
while (r(n)) {
}
}
public static void main(String[] args) {
for (int n = 0; n < nMax; n++) {
superPerm(n);
System.out.printf("superPerm(%2d) len = %d", n, superperm.length);
System.out.println();
}
}
} |
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #REXX | REXX | /*REXX pgm displays N tau numbers, an integer divisible by the # of its divisors). */
parse arg n cols . /*obtain optional argument from the CL.*/
if n=='' | n=="," then n= 100 /*Not specified? Then use the default.*/
if cols=='' | cols=="," then cols= 10 /*Not specified? Then use the default.*/
w= max(8, length(n) ) /*W: used to align 1st output column. */
@tau= ' the first ' commas(n) " tau numbers " /*the title of the tau numbers table. */
say ' index │'center(@tau, 1 + cols*(w+1) ) /*display the title of the output table*/
say '───────┼'center("" , 1 + cols*(w+1), '─') /* " " header " " " " */
idx= 1; #= 0; $= /*idx: line; #: tau numbers; $: #s */
do j=1 until #==n /*search for N tau numbers */
if j//tau(j) \==0 then iterate /*Is this a tau number? No, then skip.*/
#= # + 1 /*bump the count of tau numbers found. */
$= $ right( commas(j), w) /*add a tau number to the output list. */
if #//cols\==0 then iterate /*Not a multiple of cols? Don't show. */
say center(idx, 7)'│' substr($, 2) /*display partial list to the terminal.*/
idx= idx + cols; $= /*bump idx by number of cols; nullify $*/
end /*j*/
if $\=='' then say center(idx, 7)"│" substr($, 2) /*possible display residual output.*/
say '───────┴'center("" , 1 + cols*(w+1), '─')
exit 0 /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
commas: parse arg ?; do jc=length(?)-3 to 1 by -3; ?=insert(',', ?, jc); end; return ?
/*──────────────────────────────────────────────────────────────────────────────────────*/
tau: procedure; parse arg x 1 y /*X and $ are both set from the arg.*/
if x<6 then return 2 + (x==4) - (x==1) /*some low #s should be handled special*/
odd= x // 2 /*check if X is odd (remainder of 1).*/
if odd then do; #= 2; end /*Odd? Assume divisor count of 2. */
else do; #= 4; y= x % 2; end /*Even? " " " " 4. */
/* [↑] start with known number of divs*/
do j=3 for x%2-3 by 1+odd while j<y /*for odd number, skip even numbers. */
if x//j==0 then do /*if no remainder, then found a divisor*/
#= # + 2; y= x % j /*bump # of divisors; calculate limit.*/
if j>=y then do; #= # - 1; leave; end /*reached limit?*/
end /* ___ */
else if j*j>x then leave /*only divide up to √ x */
end /*j*/ /* [↑] this form of DO loop is faster.*/
return # |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute zero.
The Fahrenheit and Rankine scales also have the same magnitude, but different null points.
0 degrees Fahrenheit corresponds to 459.67 degrees Rankine.
0 degrees Rankine is absolute zero.
The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9.
Task
Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result.
Example
K 21.00
C -252.15
F -421.87
R 37.80
| #C | C | #include <stdio.h>
#include <stdlib.h>
double kelvinToCelsius(double k){
return k - 273.15;
}
double kelvinToFahrenheit(double k){
return k * 1.8 - 459.67;
}
double kelvinToRankine(double k){
return k * 1.8;
}
void convertKelvin(double kelvin) {
printf("K %.2f\n", kelvin);
printf("C %.2f\n", kelvinToCelsius(kelvin));
printf("F %.2f\n", kelvinToFahrenheit(kelvin));
printf("R %.2f", kelvinToRankine(kelvin));
}
int main(int argc, const char * argv[])
{
if (argc > 1) {
double kelvin = atof(argv[1]);
convertKelvin(kelvin);
}
return 0;
} |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #Nim | Nim | import math, strutils
func divcount(n: Natural): Natural =
for i in 1..sqrt(n.toFloat).int:
if n mod i == 0:
inc result
if n div i != i: inc result
echo "Count of divisors for the first 100 positive integers:"
for i in 1..100:
stdout.write ($divcount(i)).align(3)
if i mod 20 == 0: echo() |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #PARI.2FGP | PARI/GP | vector(100,X,numdiv(X)) |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #Pascal | Pascal | program tauFunction(output);
type
{ name starts with `integer…` to facilitate sorting in documentation }
integerPositive = 1..maxInt value 1;
{ the `value …` will initialize all variables to this value }
{ returns Boolean value of the expression divisor ∣ dividend ----------- }
function divides(
protected divisor: integerPositive;
protected dividend: integer
): Boolean;
begin
{ in Pascal, function result variable has the same name as function }
divides := dividend mod divisor = 0
end;
{ returns τ(i) --------------------------------------------------------- }
function tau(protected i: integerPositive): integerPositive;
var
count, potentialDivisor: integerPositive;
begin
{ count is initialized to 1 and every number is divisible by one }
for potentialDivisor := 2 to i do
begin
count := count + ord(divides(potentialDivisor, i))
end;
{ in Pascal, there must be exactly one assignment to result variable }
tau := count
end;
{ === MAIN ============================================================= }
var
i: integerPositive;
f: string(6);
begin
for i := 1 to 100 do
begin
writeStr(f, 'τ(', i:1);
writeLn(f:8, ') = ', tau(i):5)
end
end. |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #Phix | Phix | clear_screen()
|
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #PicoLisp | PicoLisp | (call 'clear) |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #Pike | Pike | int main() {
Process.system("clear");
return 0;
} |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #PowerShell | PowerShell | Clear-Host |
http://rosettacode.org/wiki/Ternary_logic | Ternary logic |
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value.
This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false.
Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski.
These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945.
Example Ternary Logic Operators in Truth Tables:
not a
¬
True
False
Maybe
Maybe
False
True
a and b
∧
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
False
False
False
False
False
a or b
∨
True
Maybe
False
True
True
True
True
Maybe
True
Maybe
Maybe
False
True
Maybe
False
if a then b
⊃
True
Maybe
False
True
True
Maybe
False
Maybe
True
Maybe
Maybe
False
True
True
True
a is equivalent to b
≡
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
Maybe
False
False
Maybe
True
Task
Define a new type that emulates ternary logic by storing data trits.
Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit.
Generate a sampling of results using trit variables.
Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic.
Note: Setun (Сетунь) was a balanced ternary computer developed in 1958 at Moscow State University. The device was built under the lead of Sergei Sobolev and Nikolay Brusentsov. It was the only modern ternary computer, using three-valued ternary logic
| #Nim | Nim | type Trit* = enum ttrue, tmaybe, tfalse
proc `$`*(a: Trit): string =
case a
of ttrue: "T"
of tmaybe: "?"
of tfalse: "F"
proc `not`*(a: Trit): Trit =
case a
of ttrue: tfalse
of tmaybe: tmaybe
of tfalse: ttrue
proc `and`*(a, b: Trit): Trit =
const t: array[Trit, array[Trit, Trit]] =
[ [ttrue, tmaybe, tfalse]
, [tmaybe, tmaybe, tfalse]
, [tfalse, tfalse, tfalse] ]
t[a][b]
proc `or`*(a, b: Trit): Trit =
const t: array[Trit, array[Trit, Trit]] =
[ [ttrue, ttrue, ttrue]
, [ttrue, tmaybe, tmaybe]
, [ttrue, tmaybe, tfalse] ]
t[a][b]
proc then*(a, b: Trit): Trit =
const t: array[Trit, array[Trit, Trit]] =
[ [ttrue, tmaybe, tfalse]
, [ttrue, tmaybe, tmaybe]
, [ttrue, ttrue, ttrue] ]
t[a][b]
proc equiv*(a, b: Trit): Trit =
const t: array[Trit, array[Trit, Trit]] =
[ [ttrue, tmaybe, tfalse]
, [tmaybe, tmaybe, tmaybe]
, [tfalse, tmaybe, ttrue] ]
t[a][b]
when isMainModule:
import strutils
for t in Trit:
echo "Not ", t , ": ", not t
for op1 in Trit:
for op2 in Trit:
echo "$# and $#: $#".format(op1, op2, op1 and op2)
echo "$# or $#: $#".format(op1, op2, op1 or op2)
echo "$# then $#: $#".format(op1, op2, op1.then op2)
echo "$# equiv $#: $#".format(op1, op2, op1.equiv op2) |
http://rosettacode.org/wiki/Ternary_logic | Ternary logic |
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value.
This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false.
Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski.
These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945.
Example Ternary Logic Operators in Truth Tables:
not a
¬
True
False
Maybe
Maybe
False
True
a and b
∧
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
False
False
False
False
False
a or b
∨
True
Maybe
False
True
True
True
True
Maybe
True
Maybe
Maybe
False
True
Maybe
False
if a then b
⊃
True
Maybe
False
True
True
Maybe
False
Maybe
True
Maybe
Maybe
False
True
True
True
a is equivalent to b
≡
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
Maybe
False
False
Maybe
True
Task
Define a new type that emulates ternary logic by storing data trits.
Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit.
Generate a sampling of results using trit variables.
Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic.
Note: Setun (Сетунь) was a balanced ternary computer developed in 1958 at Moscow State University. The device was built under the lead of Sergei Sobolev and Nikolay Brusentsov. It was the only modern ternary computer, using three-valued ternary logic
| #OCaml | OCaml | type trit = True | False | Maybe
let t_not = function
| True -> False
| False -> True
| Maybe -> Maybe
let t_and a b = match (a,b) with
| (True,True) -> True
| (False,_) | (_,False) -> False
| _ -> Maybe
let t_or a b = t_not (t_and (t_not a) (t_not b))
let t_eq a b = match (a,b) with
| (True,True) | (False,False) -> True
| (False,True) | (True,False) -> False
| _ -> Maybe
let t_imply a b = t_or (t_not a) b
let string_of_trit = function
| True -> "True"
| False -> "False"
| Maybe -> "Maybe"
let () =
let values = [| True; Maybe; False |] in
let f = string_of_trit in
Array.iter (fun v -> Printf.printf "Not %s: %s\n" (f v) (f (t_not v))) values;
print_newline ();
let print op str =
Array.iter (fun a ->
Array.iter (fun b ->
Printf.printf "%s %s %s: %s\n" (f a) str (f b) (f (op a b))
) values
) values;
print_newline ()
in
print t_and "And";
print t_or "Or";
print t_imply "Then";
print t_eq "Equiv";
;; |
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another program can be written to parse and transform the original data into a format useful to the other. The term "Data Munging" is often used in programming circles for this task.
A request on the comp.lang.awk newsgroup led to a typical data munging task:
I have to analyse data files that have the following format:
Each row corresponds to 1 day and the field logic is: $1 is the date,
followed by 24 value/flag pairs, representing measurements at 01:00,
02:00 ... 24:00 of the respective day. In short:
<date> <val1> <flag1> <val2> <flag2> ... <val24> <flag24>
Some test data is available at:
... (nolonger available at original location)
I have to sum up the values (per day and only valid data, i.e. with
flag>0) in order to calculate the mean. That's not too difficult.
However, I also need to know what the "maximum data gap" is, i.e. the
longest period with successive invalid measurements (i.e values with
flag<=0)
The data is free to download and use and is of this format:
Data is no longer available at that link. Zipped mirror available here (offsite mirror).
1991-03-30 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1
1991-03-31 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 20.000 1 20.000 1 20.000 1 35.000 1 50.000 1 60.000 1 40.000 1 30.000 1 30.000 1 30.000 1 25.000 1 20.000 1 20.000 1 20.000 1 20.000 1 20.000 1 35.000 1
1991-03-31 40.000 1 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2
1991-04-01 0.000 -2 13.000 1 16.000 1 21.000 1 24.000 1 22.000 1 20.000 1 18.000 1 29.000 1 44.000 1 50.000 1 43.000 1 38.000 1 27.000 1 27.000 1 24.000 1 23.000 1 18.000 1 12.000 1 13.000 1 14.000 1 15.000 1 13.000 1 10.000 1
1991-04-02 8.000 1 9.000 1 11.000 1 12.000 1 12.000 1 12.000 1 27.000 1 26.000 1 27.000 1 33.000 1 32.000 1 31.000 1 29.000 1 31.000 1 25.000 1 25.000 1 24.000 1 21.000 1 17.000 1 14.000 1 15.000 1 12.000 1 12.000 1 10.000 1
1991-04-03 10.000 1 9.000 1 10.000 1 10.000 1 9.000 1 10.000 1 15.000 1 24.000 1 28.000 1 24.000 1 18.000 1 14.000 1 12.000 1 13.000 1 14.000 1 15.000 1 14.000 1 15.000 1 13.000 1 13.000 1 13.000 1 12.000 1 10.000 1 10.000 1
Only a sample of the data showing its format is given above. The full example file may be downloaded here.
Structure your program to show statistics for each line of the file, (similar to the original Python, Perl, and AWK examples below), followed by summary statistics for the file. When showing example output just show a few line statistics and the full end summary.
| #PowerShell | PowerShell | $file = '.\readings.txt'
$lines = Get-Content $file # $args[0]
$valid = $true
$startDate = $currStart = $endDate = ''
$startHour = $endHour = $currHour = $max = $currMax = $total = $readings = 0
$task = @()
foreach ($var in $lines) {
$date, $rest = [regex]::Split($var,'\s+')
$reject = $accept = $sum = $cnt = 0
while ($rest) {
$cnt += 1
[Double]$val, [Double]$flag, $rest = $rest
if (0 -lt $flag) {
$currMax = 0
$sum += $val
$accept += 1
} else {
if (0 -eq $currMax) {
$currStart = $date
$currHour = $cnt
}
$currMax += 1
$reject += 1
if ($max -lt $currMax) {
$startDate, $endDate = $currStart, $date
$startHour, $endHour = $currHour, $cnt
$max = $currMax
}
}
}
$readings += $accept
$total += $sum
$average = if (0 -lt $accept) {$sum/$accept} else {0}
$task += [PSCustomObject]@{
'Line' = $date
'Reject' = $reject
'Accept' = $accept
'Sum' = $sum.ToString("N")
'Average' = $average.ToString("N3")
}
$valid = 0 -eq $reject
}
$task | Select -Last 3
$average = $total/$readings
"File(s) = $file"
"Total = {0}" -f $total.ToString("N")
"Readings = $readings"
"Average = {0}" -f $average.ToString("N3")
""
"Maximum run(s) of $max consecutive false readings."
if (0 -lt $max) {
"Consecutive false readings starts at line starting with date $startDate at hour {0:0#}:00." -f $startHour
"Consecutive false readings ends at line starting with date $endDate at hour {0:0#}:00." -f $endHour
} |
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas | The Twelve Days of Christmas | Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Lua | Lua |
local days = {
'first', 'second', 'third', 'fourth', 'fifth', 'sixth', 'seventh', 'eighth', 'ninth',
'tenth', 'eleventh', 'twelfth',
}
local gifts = {
"A partridge in a pear tree",
"Two turtle doves",
"Three french hens",
"Four calling birds",
"Five golden rings",
"Six geese a-laying",
"Seven swans a-swimming",
"Eight maids a-milking",
"Nine ladies dancing",
"Ten lords a-leaping",
"Eleven pipers piping",
"Twelve drummers drumming",
}
local verses = {}
for i = 1, 12 do
local lines = {}
lines[1] = "On the " .. days[i] .. " day of Christmas, my true love gave to me"
local j = i
local k = 2
repeat
lines[k] = gifts[j]
k = k + 1
j = j - 1
until j == 0
verses[i] = table.concat(lines, '\n')
end
print(table.concat(verses, '\n\n'))
|
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #Sidef | Sidef | var a = frequire('Term::ANSIColor');
say a.colored('RED ON WHITE', 'bold red on_white');
say a.colored('GREEN', 'bold green');
say a.colored('BLUE ON YELLOW', 'bold blue on_yellow');
say a.colored('MAGENTA', 'bold magenta');
say a.colored('CYAN ON RED', 'bold cyan on_red');
say a.colored('YELLOW', 'bold yellow'); |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #Tcl | Tcl | # Utility interfaces to the low-level command
proc capability cap {expr {![catch {exec tput -S << $cap}]}}
proc colorterm {} {expr {[capability setaf] && [capability setab]}}
proc tput args {exec tput -S << $args >/dev/tty}
array set color {black 0 red 1 green 2 yellow 3 blue 4 magenta 5 cyan 6 white 7}
proc foreground x {exec tput -S << "setaf $::color($x)" > /dev/tty}
proc background x {exec tput -S << "setab $::color($x)" > /dev/tty}
proc reset {} {exec tput sgr0 > /dev/tty}
# Demonstration of use
if {[colorterm]} {
foreground blue
background yellow
puts "Color output"
reset
} else {
puts "Monochrome only"
}
if {[capability blink]} {
tput blink
puts "Blinking output"
reset
} else {
puts "Steady only"
} |
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes.
One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit.
This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
| #F.23 | F# |
open System.IO
type Msg =
| PrintLine of string
| GetCount of AsyncReplyChannel<int>
let printer =
MailboxProcessor.Start(fun inbox ->
let rec loop count =
async {
let! msg = inbox.Receive()
match msg with
| PrintLine(s) ->
printfn "%s" s
return! loop (count + 1)
| GetCount(reply) ->
reply.Reply(count)
return! loop count
}
loop 0
)
let reader (printAgent:MailboxProcessor<Msg>) file =
File.ReadLines(file)
|> Seq.iter (fun line -> PrintLine line |> printAgent.Post)
printAgent.PostAndReply(fun reply -> GetCount(reply))
|> printfn "Lines written: %i"
reader printer @"c:\temp\input.txt"
|
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode. Choose appropriate types for each field.
For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
| #Run_BASIC | Run BASIC | sqliteconnect #mem, ":memory:" ' make handle #mem
mem$ = "
CREATE TABLE address (
addrID INTEGER PRIMARY KEY AUTOINCREMENT,
addrStreet TEXT NOT NULL,
addrCity TEXT NOT NULL,
addrState TEXT NOT NULL,
addrZIP TEXT NOT NULL
)"
#mem execute(mem$) |
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode. Choose appropriate types for each field.
For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
| #SAS | SAS |
PROC SQL;
CREATE TABLE ADDRESS
(
ADDRID CHAR(8)
,STREET CHAR(50)
,CITY CHAR(25)
,STATE CHAR(2)
,ZIP CHAR(20)
)
;QUIT;
|
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode. Choose appropriate types for each field.
For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
| #Scheme | Scheme |
(use sql-de-lite)
(define *db* (open-database "addresses"))
(exec ; create and run the SQL statement
(sql *db*
"CREATE TABLE address (
addrID INTEGER PRIMARY KEY AUTOINCREMENT,
addrStreet TEXT NOT NULL,
addrCity TEXT NOT NULL,
addrState TEXT NOT NULL,
addrZIP TEXT NOT NULL
)"
))
(close-database *db*) ; finally, close database
|
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retrieving system time (wiki)
| #Ada | Ada | with Ada.Calendar; use Ada.Calendar;
with Ada.Calendar.Formatting; use Ada.Calendar.Formatting;
with Ada.Calendar.Time_Zones; use Ada.Calendar.Time_Zones;
with Ada.Text_Io; use Ada.Text_Io;
procedure System_Time is
Now : Time := Clock;
begin
Put_line(Image(Date => Now, Time_Zone => -7*60));
end System_Time; |
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retrieving system time (wiki)
| #Aime | Aime | date d;
d_now(d);
o_form("~-/f2/-/f2/ /f2/:/f2/:/f2/\n", d_year(d), d_y_month(d), d_m_day(d),
d_d_hour(d), d_h_minute(d), d_m_second(d)); |
http://rosettacode.org/wiki/Summarize_and_say_sequence | Summarize and say sequence | There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ...
The terms generated grow in length geometrically and never converge.
Another way to generate a self-referential sequence is to summarize the previous term.
Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence.
0, 10, 1110, 3110, 132110, 13123110, 23124110 ...
Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term.
Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.)
Task
Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted.
Seed Value(s): 9009 9090 9900
Iterations: 21
Sequence: (same for all three seeds except for first element)
9009
2920
192210
19222110
19323110
1923123110
1923224110
191413323110
191433125110
19151423125110
19251413226110
1916151413325110
1916251423127110
191716151413326110
191726151423128110
19181716151413327110
19182716151423129110
29181716151413328110
19281716151423228110
19281716151413427110
19182716152413228110
Related tasks
Fours is the number of letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Spelling of ordinal numbers
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Also see
The On-Line Encyclopedia of Integer Sequences.
| #Aime | Aime | text
next(text s)
{
integer c, e, l;
index v;
data d;
l = ~s;
while (l) {
v[-s[l -= 1]] += 1;
}
for (c, e in v) {
b_form(d, "%d%c", e, -c);
}
return d;
}
integer
depth(text s, integer i, record r)
{
integer d;
d = 0;
r_j_integer(d, r, s);
if (d <= 0) {
i += 1;
d += d ? i : -i;
r[s] = d;
i = depth(next(s), i, r);
d = r[s];
if (d <= 0) {
r[s] = d = i + 1;
}
}
return d;
}
integer
main(void)
{
integer d, e, i;
record r;
list l;
d = 0;
i = 1000000;
while (i) {
i -= 1;
e = depth(itoa(i), 0, r);
if (e == d) {
lb_p_integer(l, i);
} elif (d < e) {
d = e;
l_clear(l);
lb_p_integer(l, i);
}
}
o_("longest length is ", d, "\n");
while (l_o_integer(i, l, 0)) {
text s;
o_("\n", i, "\n");
e = d - 1;
s = itoa(i);
while (e) {
o_(s = next(s), "\n");
e -= 1;
}
}
return 0;
} |
http://rosettacode.org/wiki/Summarize_primes | Summarize primes | Task
Considering in order of length, n, all sequences of consecutive
primes, p, from 2 onwards, where p < 1000 and n>0, select those
sequences whose sum is prime, and for these display the length of the
sequence, the last item in the sequence, and the sum.
| #Arturo | Arturo | print (pad "index" 6) ++ " | " ++
(pad "prime" 6) ++ " | " ++
(pad "prime sum" 11)
print "------------------------------"
s: 0
idx: 0
loop 2..999 'n [
if prime? n [
idx: idx + 1
s: s + n
if prime? s ->
print (pad to :string idx 6) ++ " | " ++
(pad to :string n 6) ++ " | " ++
(pad to :string s 11)
]
] |
http://rosettacode.org/wiki/Summarize_primes | Summarize primes | Task
Considering in order of length, n, all sequences of consecutive
primes, p, from 2 onwards, where p < 1000 and n>0, select those
sequences whose sum is prime, and for these display the length of the
sequence, the last item in the sequence, and the sum.
| #AWK | AWK |
# syntax: GAWK -f SUMMARIZE_PRIMES.AWK
BEGIN {
start = 1
stop = 999
for (i=start; i<=stop; i++) {
if (is_prime(i)) {
count1++
sum += i
if (is_prime(sum)) {
printf("the sum of %3d primes from primes 2-%-3s is %5d which is also prime\n",count1,i,sum)
count2++
}
}
}
printf("Summarized primes %d-%d: %d\n",start,stop,count2)
exit(0)
}
function is_prime(x, i) {
if (x <= 1) {
return(0)
}
for (i=2; i<=int(sqrt(x)); i++) {
if (x % i == 0) {
return(0)
}
}
return(1)
}
|
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping | Sutherland-Hodgman polygon clipping | The Sutherland-Hodgman clipping algorithm finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”).
It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed.
Task
Take the closed polygon defined by the points:
[
(
50
,
150
)
,
(
200
,
50
)
,
(
350
,
150
)
,
(
350
,
300
)
,
(
250
,
300
)
,
(
200
,
250
)
,
(
150
,
350
)
,
(
100
,
250
)
,
(
100
,
200
)
]
{\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]}
and clip it by the rectangle defined by the points:
[
(
100
,
100
)
,
(
300
,
100
)
,
(
300
,
300
)
,
(
100
,
300
)
]
{\displaystyle [(100,100),(300,100),(300,300),(100,300)]}
Print the sequence of points that define the resulting clipped polygon.
Extra credit
Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon.
(When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
| #Elixir | Elixir | defmodule SutherlandHodgman do
defp inside(cp1, cp2, p), do: (cp2.x-cp1.x)*(p.y-cp1.y) > (cp2.y-cp1.y)*(p.x-cp1.x)
defp intersection(cp1, cp2, s, e) do
{dcx, dcy} = {cp1.x-cp2.x, cp1.y-cp2.y}
{dpx, dpy} = {s.x-e.x, s.y-e.y}
n1 = cp1.x*cp2.y - cp1.y*cp2.x
n2 = s.x*e.y - s.y*e.x
n3 = 1.0 / (dcx*dpy - dcy*dpx)
%{x: (n1*dpx - n2*dcx) * n3, y: (n1*dpy - n2*dcy) * n3}
end
def polygon_clipping(subjectPolygon, clipPolygon) do
Enum.chunk([List.last(clipPolygon) | clipPolygon], 2, 1)
|> Enum.reduce(subjectPolygon, fn [cp1,cp2],acc ->
Enum.chunk([List.last(acc) | acc], 2, 1)
|> Enum.reduce([], fn [s,e],outputList ->
case {inside(cp1, cp2, e), inside(cp1, cp2, s)} do
{true, true} -> [e | outputList]
{true, false} -> [e, intersection(cp1,cp2,s,e) | outputList]
{false, true} -> [intersection(cp1,cp2,s,e) | outputList]
_ -> outputList
end
end)
|> Enum.reverse
end)
end
end
subjectPolygon = [[50, 150], [200, 50], [350, 150], [350, 300], [250, 300],
[200, 250], [150, 350], [100, 250], [100, 200]]
|> Enum.map(fn [x,y] -> %{x: x, y: y} end)
clipPolygon = [[100, 100], [300, 100], [300, 300], [100, 300]]
|> Enum.map(fn [x,y] -> %{x: x, y: y} end)
SutherlandHodgman.polygon_clipping(subjectPolygon, clipPolygon)
|> Enum.each(&IO.inspect/1) |
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping | Sutherland-Hodgman polygon clipping | The Sutherland-Hodgman clipping algorithm finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”).
It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed.
Task
Take the closed polygon defined by the points:
[
(
50
,
150
)
,
(
200
,
50
)
,
(
350
,
150
)
,
(
350
,
300
)
,
(
250
,
300
)
,
(
200
,
250
)
,
(
150
,
350
)
,
(
100
,
250
)
,
(
100
,
200
)
]
{\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]}
and clip it by the rectangle defined by the points:
[
(
100
,
100
)
,
(
300
,
100
)
,
(
300
,
300
)
,
(
100
,
300
)
]
{\displaystyle [(100,100),(300,100),(300,300),(100,300)]}
Print the sequence of points that define the resulting clipped polygon.
Extra credit
Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon.
(When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
| #Fortran | Fortran |
module SutherlandHodgmanUtil
! functions and type needed for Sutherland-Hodgman algorithm
! -------------------------------------------------------- !
type polygon
!type for polygons
! when you define a polygon, the first and the last vertices have to be the same
integer :: n
double precision, dimension(:,:), allocatable :: vertex
end type polygon
contains
! -------------------------------------------------------- !
subroutine sutherlandHodgman( ref, clip, outputPolygon )
! Sutherland Hodgman algorithm for 2d polygons
! -- parameters of the subroutine --
type(polygon) :: ref, clip, outputPolygon
! -- variables used is the subroutine
type(polygon) :: workPolygon ! polygon clipped step by step
double precision, dimension(2) :: y1,y2 ! vertices of edge to clip workPolygon
integer :: i
! allocate workPolygon with the maximal possible size
! the sum of the size of polygon ref and clip
allocate(workPolygon%vertex( ref%n+clip%n , 2 ))
! initialise the work polygon with clip
workPolygon%n = clip%n
workPolygon%vertex(1:workPolygon%n,:) = clip%vertex(1:workPolygon%n,:)
do i=1,ref%n-1 ! for each edge i of the polygon ref
y1(:) = ref%vertex(i,:) ! vertex 1 of edge i
y2(:) = ref%vertex(i+1,:) ! vertex 2 of edge i
! clip the work polygon by edge i
call edgeClipping( workPolygon, y1, y2, outputPolygon)
! workPolygon <= outputPolygon
workPolygon%n = outputPolygon%n
workPolygon%vertex(1:workPolygon%n,:) = outputPolygon%vertex(1:workPolygon%n,:)
end do
deallocate(workPolygon%vertex)
end subroutine sutherlandHodgman
! -------------------------------------------------------- !
subroutine edgeClipping( poly, y1, y2, outputPoly )
! make the clipping of the polygon by the line (x1x2)
type(polygon) :: poly, outputPoly
double precision, dimension(2) :: y1, y2, x1, x2, intersecPoint
integer :: i, c
c = 0 ! counter for the output polygon
do i=1,poly%n-1 ! for each edge i of poly
x1(:) = poly%vertex(i,:) ! vertex 1 of edge i
x2(:) = poly%vertex(i+1,:) ! vertex 2 of edge i
if ( inside(x1, y1, y2) ) then ! if vertex 1 in inside clipping region
if ( inside(x2, y1, y2) ) then ! if vertex 2 in inside clipping region
! add the vertex 2 to the output polygon
c = c+1
outputPoly%vertex(c,:) = x2(:)
else ! vertex i+1 is outside
intersecPoint = intersection(x1, x2, y1,y2)
c = c+1
outputPoly%vertex(c,:) = intersecPoint(:)
end if
else ! vertex i is outside
if ( inside(x2, y1, y2) ) then
intersecPoint = intersection(x1, x2, y1,y2)
c = c+1
outputPoly%vertex(c,:) = intersecPoint(:)
c = c+1
outputPoly%vertex(c,:) = x2(:)
end if
end if
end do
if (c .gt. 0) then
! if the last vertice is not equal to the first one
if ( (outputPoly%vertex(1,1) .ne. outputPoly%vertex(c,1)) .or. &
(outputPoly%vertex(1,2) .ne. outputPoly%vertex(c,2))) then
c=c+1
outputPoly%vertex(c,:) = outputPoly%vertex(1,:)
end if
end if
! set the size of the outputPolygon
outputPoly%n = c
end subroutine edgeClipping
! -------------------------------------------------------- !
function intersection( x1, x2, y1, y2)
! computes the intersection between segment [x1x2]
! and line the line (y1y2)
! -- parameters of the function --
double precision, dimension(2) :: x1, x2, & ! points of the segment
y1, y2 ! points of the line
double precision, dimension(2) :: intersection, vx, vy, x1y1
double precision :: a
vx(:) = x2(:) - x1(:)
vy(:) = y2(:) - y1(:)
! if the vectors are colinear
if ( crossProduct(vx,vy) .eq. 0.d0) then
x1y1(:) = y1(:) - x1(:)
! if the the segment [x1x2] is included in the line (y1y2)
if ( crossProduct(x1y1,vx) .eq. 0.d0) then
! the intersection is the last point of the segment
intersection(:) = x2(:)
end if
else ! the vectors are not colinear
! we want to find the inersection between [x1x2]
! and (y1,y2).
! mathematically, we want to find a in [0;1] such
! that :
! x1 + a vx = y1 + b vy
! <=> a vx = x1y1 + b vy
! <=> a vx^vy = x1y1^vy , ^ is cross product
! <=> a = x1y1^vy / vx^vy
x1y1(:) = y1(:) - x1(:)
! we compute a
a = crossProduct(x1y1,vy)/crossProduct(vx,vy)
! if a is not in [0;1]
if ( (a .gt. 1.d0) .or. (a .lt. 0)) then
! no intersection
else
intersection(:) = x1(:) + a*vx(:)
end if
end if
end function intersection
! -------------------------------------------------------- !
function inside( p, y1, y2)
! function that tells is the point p is at left of the line (y1y2)
double precision, dimension(2) :: p, y1, y2, v1, v2
logical :: inside
v1(:) = y2(:) - y1(:)
v2(:) = p(:) - y1(:)
if ( crossProduct(v1,v2) .ge. 0.d0) then
inside = .true.
else
inside = .false.
end if
contains
end function inside
! -------------------------------------------------------- !
function dotProduct( v1, v2)
! compute the dot product of vectors v1 and v2
double precision, dimension(2) :: v1
double precision, dimension(2) :: v2
double precision :: dotProduct
dotProduct = v1(1)*v2(1) + v1(2)*v2(2)
end function dotProduct
! -------------------------------------------------------- !
function crossProduct( v1, v2)
! compute the crossproduct of vectors v1 and v2
double precision, dimension(2) :: v1
double precision, dimension(2) :: v2
double precision :: crossProduct
crossProduct = v1(1)*v2(2) - v1(2)*v2(1)
end function crossProduct
end module SutherlandHodgmanUtil
program main
! load the module for S-H algorithm
use SutherlandHodgmanUtil, only : polygon, &
sutherlandHodgman, &
edgeClipping
type(polygon) :: p1, p2, res
integer :: c, n
double precision, dimension(2) :: y1, y2
! when you define a polygon, the first and the last vertices have to be the same
! first polygon
p1%n = 10
allocate(p1%vertex(p1%n,2))
p1%vertex(1,1)=50.d0
p1%vertex(1,2)=150.d0
p1%vertex(2,1)=200.d0
p1%vertex(2,2)=50.d0
p1%vertex(3,1)= 350.d0
p1%vertex(3,2)= 150.d0
p1%vertex(4,1)= 350.d0
p1%vertex(4,2)= 300.d0
p1%vertex(5,1)= 250.d0
p1%vertex(5,2)= 300.d0
p1%vertex(6,1)= 200.d0
p1%vertex(6,2)= 250.d0
p1%vertex(7,1)= 150.d0
p1%vertex(7,2)= 350.d0
p1%vertex(8,1)= 100.d0
p1%vertex(8,2)= 250.d0
p1%vertex(9,1)= 100.d0
p1%vertex(9,2)= 200.d0
p1%vertex(10,1)= 50.d0
p1%vertex(10,2)= 150.d0
y1 = (/ 100.d0, 300.d0 /)
y2 = (/ 300.d0, 300.d0 /)
! second polygon
p2%n = 5
allocate(p2%vertex(p2%n,2))
p2%vertex(1,1)= 100.d0
p2%vertex(1,2)= 100.d0
p2%vertex(2,1)= 300.d0
p2%vertex(2,2)= 100.d0
p2%vertex(3,1)= 300.d0
p2%vertex(3,2)= 300.d0
p2%vertex(4,1)= 100.d0
p2%vertex(4,2)= 300.d0
p2%vertex(5,1)= 100.d0
p2%vertex(5,2)= 100.d0
allocate(res%vertex(p1%n+p2%n,2))
call sutherlandHodgman( p2, p1, res)
write(*,*) "Suterland-Hodgman"
do c=1, res%n
write(*,*) res%vertex(c,1), res%vertex(c,2)
end do
deallocate(res%vertex)
end program main
|
http://rosettacode.org/wiki/Symmetric_difference | Symmetric difference | Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\displaystyle (A\cup B)\setminus (A\cap B)}
(the set of items that are in at least one of A or B minus the set of items that are in both A and B).
Optionally, give the individual differences (
A
∖
B
{\displaystyle A\setminus B}
and
B
∖
A
{\displaystyle B\setminus A}
) as well.
Test cases
A = {John, Bob, Mary, Serena}
B = {Jim, Mary, John, Bob}
Notes
If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order.
In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
| #AWK | AWK |
# syntax: GAWK -f SYMMETRIC_DIFFERENCE.AWK
BEGIN {
load("John,Bob,Mary,Serena",A)
load("Jim,Mary,John,Bob",B)
show("A \\ B",A,B)
show("B \\ A",B,A)
printf("symmetric difference: ")
for (i in C) {
if (!(i in A && i in B)) {
printf("%s ",i)
}
}
printf("\n")
exit(0)
}
function load(str,arr, i,n,temp) {
n = split(str,temp,",")
for (i=1; i<=n; i++) {
arr[temp[i]]
C[temp[i]]
}
}
function show(str,a,b, i) {
printf("%s: ",str)
for (i in a) {
if (!(i in b)) {
printf("%s ",i)
}
}
printf("\n")
}
|
http://rosettacode.org/wiki/Super-d_numbers | Super-d numbers | A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or super-d.
Task
Write a function/procedure/routine to find super-d numbers.
For d=2 through d=6, use the routine to show the first 10 super-d numbers.
Extra credit
Show the first 10 super-7, super-8, and/or super-9 numbers (optional).
See also
Wolfram MathWorld - Super-d Number.
OEIS: A014569 - Super-3 Numbers.
| #J | J | superD=: 1 e. #~@[ E. 10 #.inv ([ * ^~)&x:
assert 3 superD 753
assert -. 2 superD 753
2 3 4 5 6 ,. _ 10 {. I. 2 3 4 5 6 superD&>/i.1e6
2 19 31 69 81 105 106 107 119 127 131
3 261 462 471 481 558 753 1036 1046 1471 1645
4 1168 4972 7423 7752 8431 10267 11317 11487 11549 11680
5 4602 5517 7539 12955 14555 20137 20379 26629 32767 35689
6 27257 272570 302693 323576 364509 502785 513675 537771 676657 678146
|
http://rosettacode.org/wiki/Super-d_numbers | Super-d numbers | A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or super-d.
Task
Write a function/procedure/routine to find super-d numbers.
For d=2 through d=6, use the routine to show the first 10 super-d numbers.
Extra credit
Show the first 10 super-7, super-8, and/or super-9 numbers (optional).
See also
Wolfram MathWorld - Super-d Number.
OEIS: A014569 - Super-3 Numbers.
| #Java | Java |
import java.math.BigInteger;
public class SuperDNumbers {
public static void main(String[] args) {
for ( int i = 2 ; i <= 9 ; i++ ) {
superD(i, 10);
}
}
private static final void superD(int d, int max) {
long start = System.currentTimeMillis();
String test = "";
for ( int i = 0 ; i < d ; i++ ) {
test += (""+d);
}
int n = 0;
int i = 0;
System.out.printf("First %d super-%d numbers: %n", max, d);
while ( n < max ) {
i++;
BigInteger val = BigInteger.valueOf(d).multiply(BigInteger.valueOf(i).pow(d));
if ( val.toString().contains(test) ) {
n++;
System.out.printf("%d ", i);
}
}
long end = System.currentTimeMillis();
System.out.printf("%nRun time %d ms%n%n", end-start);
}
}
|
http://rosettacode.org/wiki/Take_notes_on_the_command_line | Take notes on the command line | Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline.
Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT.
If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
| #Factor | Factor | #! /usr/bin/env factor
USING: kernel calendar calendar.format io io.encodings.utf8 io.files
sequences command-line namespaces ;
command-line get [
"notes.txt" utf8 file-contents print
] [
" " join "\t" prepend
"notes.txt" utf8 [
now timestamp>ymdhms print
print flush
] with-file-appender
] if-empty |
http://rosettacode.org/wiki/Take_notes_on_the_command_line | Take notes on the command line | Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline.
Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT.
If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
| #Fantom | Fantom |
class Notes
{
public static Void main (Str[] args)
{
notesFile := File(`notes.txt`) // the backticks make a URI
if (args.isEmpty)
{
if (notesFile.exists)
{
notesFile.eachLine |line| { echo (line) }
}
}
else
{
// notice the following uses a block so the 'printLine/close'
// operations are all applied to the same output stream for notesFile
notesFile.out(true) // 'true' to append to file
{
printLine ( DateTime.now.toLocale("DD-MM-YY hh:mm:ss").toStr )
printLine ( "\t" + args.join(" ") )
close
}
}
}
}
|
http://rosettacode.org/wiki/Superellipse | Superellipse | A superellipse is a geometric figure defined as the set of all points (x, y) with
|
x
a
|
n
+
|
y
b
|
n
=
1
,
{\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,}
where n, a, and b are positive numbers.
Task
Draw a superellipse with n = 2.5, and a = b = 200
| #Go | Go | package main
import (
"github.com/fogleman/gg"
"math"
)
/* assumes a and b are always equal */
func superEllipse(dc *gg.Context, n float64, a int) {
hw := float64(dc.Width() / 2)
hh := float64(dc.Height() / 2)
// calculate y for each x
y := make([]float64, a+1)
for x := 0; x <= a; x++ {
aa := math.Pow(float64(a), n)
xx := math.Pow(float64(x), n)
y[x] = math.Pow(aa-xx, 1.0/n)
}
// draw quadrants
for x := a; x >= 0; x-- {
dc.LineTo(hw+float64(x), hh-y[x])
}
for x := 0; x <= a; x++ {
dc.LineTo(hw+float64(x), hh+y[x])
}
for x := a; x >= 0; x-- {
dc.LineTo(hw-float64(x), hh+y[x])
}
for x := 0; x <= a; x++ {
dc.LineTo(hw-float64(x), hh-y[x])
}
dc.SetRGB(1, 1, 1) // white ellipse
dc.Fill()
}
func main() {
dc := gg.NewContext(500, 500)
dc.SetRGB(0, 0, 0) // black background
dc.Clear()
superEllipse(dc, 2.5, 200)
dc.SavePNG("superellipse.png")
} |
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one.
Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms.
Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction.
Task
Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence.
Use that routine to show the values of the first 10 elements in the sequence.
Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction.
Related tasks
Egyptian fractions
Harmonic series
See also
OEIS A000058 - Sylvester's sequence
| #Quackery | Quackery | [ $ "bigrat.qky" loadfile ] now!
' [ 2 ] 9 times [ dup -1 peek dup 2 ** swap - 1+ join ]
dup witheach [ echo cr ] cr
0 n->v rot witheach [ n->v 1/v v+ ] 222 point$ echo$ |
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one.
Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms.
Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction.
Task
Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence.
Use that routine to show the values of the first 10 elements in the sequence.
Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction.
Related tasks
Egyptian fractions
Harmonic series
See also
OEIS A000058 - Sylvester's sequence
| #Raku | Raku | my @S = {1 + [*] @S[^($++)]} … *;
put 'First 10 elements of Sylvester\'s sequence: ', @S[^10];
say "\nSum of the reciprocals of first 10 elements: ", sum @S[^10].map: { FatRat.new: 1, $_ }; |
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one.
Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms.
Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction.
Task
Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence.
Use that routine to show the values of the first 10 elements in the sequence.
Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction.
Related tasks
Egyptian fractions
Harmonic series
See also
OEIS A000058 - Sylvester's sequence
| #REXX | REXX | /*REXX pgm finds N terms of the Sylvester's sequence & the sum of the their reciprocals.*/
parse arg n . /*obtain optional argument from the CL.*/
if n=='' | n=="," then n= 10 /*Not specified? Then use the default.*/
numeric digits max(9, 2**(n-7) * 13 + 1) /*calculate how many dec. digs we need.*/
@.0= 2 /*the value of the 1st Sylvester number*/
$= 0
do j=0 for n; jm= j - 1 /*calculate the Sylvester sequence. */
if j>0 then @.j= @.jm**2 - @.jm + 1 /*calculate a Sylvester sequence num.*/
say 'Sylvester('j") ──► " @.j /*display the Sylvester index & number.*/
$= $ + 1 / @.j /*add its reciprocal to the recip. sum.*/
end /*j*/
say /*stick a fork in it, we're all done. */
numeric digits digits() - 1
say 'sum of the first ' n " reciprocals using" digits() 'decimal digits: ' $ / 1 |
http://rosettacode.org/wiki/Taxicab_numbers | Taxicab numbers |
A taxicab number (the definition that is being used here) is a positive integer that can be expressed as the sum of two positive cubes in more than one way.
The first taxicab number is 1729, which is:
13 + 123 and also
93 + 103.
Taxicab numbers are also known as:
taxi numbers
taxi-cab numbers
taxi cab numbers
Hardy-Ramanujan numbers
Task
Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format).
For each of the taxicab numbers, show the number as well as it's constituent cubes.
Extra credit
Show the 2,000th taxicab number, and a half dozen more
See also
A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences.
Hardy-Ramanujan Number on MathWorld.
taxicab number on MathWorld.
taxicab number on Wikipedia (includes the story on how taxi-cab numbers came to be called).
| #Kotlin | Kotlin | // version 1.0.6
import java.util.PriorityQueue
class CubeSum(val x: Long, val y: Long) : Comparable<CubeSum> {
val value: Long = x * x * x + y * y * y
override fun toString() = String.format("%4d^3 + %3d^3", x, y)
override fun compareTo(other: CubeSum) = value.compareTo(other.value)
}
class SumIterator : Iterator<CubeSum> {
private val pq = PriorityQueue<CubeSum>()
private var n = 0L
override fun hasNext() = true
override fun next(): CubeSum {
while (pq.size == 0 || pq.peek().value >= n * n * n)
pq.add(CubeSum(++n, 1))
val s: CubeSum = pq.remove()
if (s.x > s.y + 1) pq.add(CubeSum(s.x, s.y + 1))
return s
}
}
class TaxiIterator : Iterator<MutableList<CubeSum>> {
private val sumIterator = SumIterator()
private var last: CubeSum = sumIterator.next()
override fun hasNext() = true
override fun next(): MutableList<CubeSum> {
var s: CubeSum = sumIterator.next()
val train = mutableListOf<CubeSum>()
while (s.value != last.value) {
last = s
s = sumIterator.next()
}
train.add(last)
do {
train.add(s)
s = sumIterator.next()
}
while (s.value == last.value)
last = s
return train
}
}
fun main(args: Array<String>) {
val taxi = TaxiIterator()
for (i in 1..2006) {
val t = taxi.next()
if (i in 26 until 2000) continue
print(String.format("%4d: %10d", i, t[0].value))
for (s in t) print(" = $s")
println()
}
} |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'.
The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'.
A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'.
A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end.
The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations.
Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations.
The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Reference
The Minimal Superpermutation Problem. by Nathaniel Johnston.
oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872.
Superpermutations - Numberphile. A video
Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress.
New Superpermutations Discovered! Standupmaths & Numberphile.
| #Julia | Julia | const nmax = 12
function r!(n, s, pos, count)
if n == 0
return false
end
c = s[pos + 1 - n]
count[n + 1] -= 1
if count[n + 1] == 0
count[n + 1] = n
if r!(n - 1, s, pos, count) == 0
return false
end
end
s[pos + 1] = c
pos += 1
true
end
function superpermutation(n)
count = zeros(nmax)
pos = n
superperm = zeros(UInt8, n < 2 ? n : mapreduce(factorial, +, 1:n))
for i in 0:n-1
count[i + 1] = i
superperm[i + 1] = Char(i + '0')
end
count[n + 1] = n
while r!(n, superperm, pos, count) ; end
superperm
end
function testsuper(N, verbose=false)
for i in 0:N-1
s = superpermutation(i)
println("Superperm($i) has length $(length(s)) ", (verbose ? String(s) : ""))
end
end
testsuper(nmax)
|
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'.
The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'.
A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'.
A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end.
The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations.
Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations.
The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Reference
The Minimal Superpermutation Problem. by Nathaniel Johnston.
oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872.
Superpermutations - Numberphile. A video
Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress.
New Superpermutations Discovered! Standupmaths & Numberphile.
| #Kotlin | Kotlin | // version 1.1.2
const val MAX = 12
var sp = CharArray(0)
val count = IntArray(MAX)
var pos = 0
fun factSum(n: Int): Int {
var s = 0
var x = 0
var f = 1
while (x < n) {
f *= ++x
s += f
}
return s
}
fun r(n: Int): Boolean {
if (n == 0) return false
val c = sp[pos - n]
if (--count[n] == 0) {
count[n] = n
if (!r(n - 1)) return false
}
sp[pos++] = c
return true
}
fun superPerm(n: Int) {
pos = n
val len = factSum(n)
if (len > 0) sp = CharArray(len)
for (i in 0..n) count[i] = i
for (i in 1..n) sp[i - 1] = '0' + i
while (r(n)) {}
}
fun main(args: Array<String>) {
for (n in 0 until MAX) {
superPerm(n)
println("superPerm(${"%2d".format(n)}) len = ${sp.size}")
}
} |
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Ring | Ring |
see "The first 100 tau numbers are:" + nl + nl
n = 1
num = 0
limit = 100
while num < limit
n = n + 1
tau = 0
for m = 1 to n
if n%m = 0
tau = tau + 1
ok
next
if n%tau = 0
num = num + 1
if num%10 = 1
see nl
ok
see "" + n + " "
ok
end
|
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Ruby | Ruby | require 'prime'
taus = Enumerator.new do |y|
(1..).each do |n|
num_divisors = n.prime_division.inject(1){|prod, n| prod *= n[1] + 1 }
y << n if n % num_divisors == 0
end
end
p taus.take(100)
|
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute zero.
The Fahrenheit and Rankine scales also have the same magnitude, but different null points.
0 degrees Fahrenheit corresponds to 459.67 degrees Rankine.
0 degrees Rankine is absolute zero.
The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9.
Task
Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result.
Example
K 21.00
C -252.15
F -421.87
R 37.80
| #C.23 | C# | using System;
namespace TemperatureConversion
{
class Program
{
static Func<double, double> ConvertKelvinToFahrenheit = x => (x * 1.8) - 459.67;
static Func<double, double> ConvertKelvinToRankine = x => x * 1.8;
static Func<double, double> ConvertKelvinToCelsius = x => x = 273.13;
static void Main(string[] args)
{
Console.Write("Enter a Kelvin Temperature: ");
string inputVal = Console.ReadLine();
double kelvinTemp = 0f;
if (double.TryParse(inputVal, out kelvinTemp))
{
Console.WriteLine(string.Format("Kelvin: {0}", kelvinTemp));
Console.WriteLine(string.Format("Fahrenheit: {0}", ConvertKelvinToFahrenheit(kelvinTemp)));
Console.WriteLine(string.Format("Rankine: {0}", ConvertKelvinToRankine(kelvinTemp)));
Console.WriteLine(string.Format("Celsius: {0}", ConvertKelvinToCelsius(kelvinTemp)));
Console.ReadKey();
}
else
{
Console.WriteLine("Invalid input value: " + inputVal);
}
}
}
} |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #Perl | Perl | use strict;
use warnings;
use feature 'say';
use ntheory 'divisors';
my @x;
push @x, scalar divisors($_) for 1..100;
say "Tau function - first 100:\n" .
((sprintf "@{['%4d' x 100]}", @x[0..100-1]) =~ s/(.{80})/$1\n/gr); |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #Phix | Phix | for i=1 to 100 do
printf(1,"%3d",{length(factors(i,1))})
if remainder(i,20)=0 then puts(1,"\n") end if
end for
|
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #ProDOS | ProDOS | clearscurrentscreentext |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #Python | Python | import os
os.system("clear") |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #Quackery | Quackery | [ $ &print("\33[2J",end='')& python ] is clearscreen |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #R | R | cat("\33[2J") |
http://rosettacode.org/wiki/Ternary_logic | Ternary logic |
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value.
This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false.
Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski.
These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945.
Example Ternary Logic Operators in Truth Tables:
not a
¬
True
False
Maybe
Maybe
False
True
a and b
∧
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
False
False
False
False
False
a or b
∨
True
Maybe
False
True
True
True
True
Maybe
True
Maybe
Maybe
False
True
Maybe
False
if a then b
⊃
True
Maybe
False
True
True
Maybe
False
Maybe
True
Maybe
Maybe
False
True
True
True
a is equivalent to b
≡
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
Maybe
False
False
Maybe
True
Task
Define a new type that emulates ternary logic by storing data trits.
Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit.
Generate a sampling of results using trit variables.
Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic.
Note: Setun (Сетунь) was a balanced ternary computer developed in 1958 at Moscow State University. The device was built under the lead of Sergei Sobolev and Nikolay Brusentsov. It was the only modern ternary computer, using three-valued ternary logic
| #ooRexx | ooRexx |
tritValues = .array~of(.trit~true, .trit~false, .trit~maybe)
tab = '09'x
say "not operation (\)"
loop a over tritValues
say "\"a":" (\a)
end
say
say "and operation (&)"
loop aa over tritValues
loop bb over tritValues
say (aa" & "bb":" (aa&bb))
end
end
say
say "or operation (|)"
loop aa over tritValues
loop bb over tritValues
say (aa" | "bb":" (aa|bb))
end
end
say
say "implies operation (&&)"
loop aa over tritValues
loop bb over tritValues
say (aa" && "bb":" (aa&&bb))
end
end
say
say "equals operation (=)"
loop aa over tritValues
loop bb over tritValues
say (aa" = "bb":" (aa=bb))
end
end
::class trit
-- making this a private method so we can control the creation
-- of these. We only allow 3 instances to exist
::method new class private
forward class(super)
::method init class
expose true false maybe
-- delayed creation
true = .nil
false = .nil
maybe = .nil
-- read only attribute access to the instances.
-- these methods create the appropriate singleton on the first call
::attribute true class get
expose true
if true == .nil then true = self~new("True")
return true
::attribute false class get
expose false
if false == .nil then false = self~new("False")
return false
::attribute maybe class get
expose maybe
if maybe == .nil then maybe = self~new("Maybe")
return maybe
-- create an instance
::method init
expose value
use arg value
-- string method to return the value of the instance
::method string
expose value
return value
-- "and" method using the operator overload
::method "&"
use strict arg other
if self == .trit~true then return other
else if self == .trit~maybe then do
if other == .trit~false then return .trit~false
else return .trit~maybe
end
else return .trit~false
-- "or" method using the operator overload
::method "|"
use strict arg other
if self == .trit~true then return .trit~true
else if self == .trit~maybe then do
if other == .trit~true then return .trit~true
else return .trit~maybe
end
else return other
-- implies method...using the XOR operator for this
::method "&&"
use strict arg other
if self == .trit~true then return other
else if self == .trit~maybe then do
if other == .trit~true then return .trit~true
else return .trit~maybe
end
else return .trit~true
-- "not" method using the operator overload
::method "\"
if self == .trit~true then return .trit~false
else if self == .trit~maybe then return .trit~maybe
else return .trit~true
-- "equals" using the "=" override. This makes a distinction between
-- the "==" operator, which is real equality and the "=" operator, which
-- is trinary equality.
::method "="
use strict arg other
if self == .trit~true then return other
else if self == .trit~maybe then return .trit~maybe
else return \other
|
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another program can be written to parse and transform the original data into a format useful to the other. The term "Data Munging" is often used in programming circles for this task.
A request on the comp.lang.awk newsgroup led to a typical data munging task:
I have to analyse data files that have the following format:
Each row corresponds to 1 day and the field logic is: $1 is the date,
followed by 24 value/flag pairs, representing measurements at 01:00,
02:00 ... 24:00 of the respective day. In short:
<date> <val1> <flag1> <val2> <flag2> ... <val24> <flag24>
Some test data is available at:
... (nolonger available at original location)
I have to sum up the values (per day and only valid data, i.e. with
flag>0) in order to calculate the mean. That's not too difficult.
However, I also need to know what the "maximum data gap" is, i.e. the
longest period with successive invalid measurements (i.e values with
flag<=0)
The data is free to download and use and is of this format:
Data is no longer available at that link. Zipped mirror available here (offsite mirror).
1991-03-30 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1
1991-03-31 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 20.000 1 20.000 1 20.000 1 35.000 1 50.000 1 60.000 1 40.000 1 30.000 1 30.000 1 30.000 1 25.000 1 20.000 1 20.000 1 20.000 1 20.000 1 20.000 1 35.000 1
1991-03-31 40.000 1 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2
1991-04-01 0.000 -2 13.000 1 16.000 1 21.000 1 24.000 1 22.000 1 20.000 1 18.000 1 29.000 1 44.000 1 50.000 1 43.000 1 38.000 1 27.000 1 27.000 1 24.000 1 23.000 1 18.000 1 12.000 1 13.000 1 14.000 1 15.000 1 13.000 1 10.000 1
1991-04-02 8.000 1 9.000 1 11.000 1 12.000 1 12.000 1 12.000 1 27.000 1 26.000 1 27.000 1 33.000 1 32.000 1 31.000 1 29.000 1 31.000 1 25.000 1 25.000 1 24.000 1 21.000 1 17.000 1 14.000 1 15.000 1 12.000 1 12.000 1 10.000 1
1991-04-03 10.000 1 9.000 1 10.000 1 10.000 1 9.000 1 10.000 1 15.000 1 24.000 1 28.000 1 24.000 1 18.000 1 14.000 1 12.000 1 13.000 1 14.000 1 15.000 1 14.000 1 15.000 1 13.000 1 13.000 1 13.000 1 12.000 1 10.000 1 10.000 1
Only a sample of the data showing its format is given above. The full example file may be downloaded here.
Structure your program to show statistics for each line of the file, (similar to the original Python, Perl, and AWK examples below), followed by summary statistics for the file. When showing example output just show a few line statistics and the full end summary.
| #PureBasic | PureBasic | #TASK="Text processing/1"
Define File$, InLine$, Part$, i, Out$, ErrEnds$, Errcnt, ErrMax
Define lsum.d, tsum.d, rejects, val.d, readings
File$=OpenFileRequester(#TASK,"readings.txt","",0)
If OpenConsole() And ReadFile(0,File$)
While Not Eof(0)
InLine$=ReadString(0)
For i=1 To 1+2*24
Part$=StringField(InLine$,i,#TAB$)
If i=1 ; Date
Out$=Part$: lsum=0: rejects=0
ElseIf i%2=0 ; Recorded value
val=ValD(Part$)
Else ; Status part
If Val(Part$)>0
Errcnt=0 : readings+1
lsum+val : tsum+val
Else
rejects+1: Errcnt+1
If Errcnt>ErrMax
ErrMax=Errcnt
ErrEnds$=Out$
EndIf
EndIf
EndIf
Next i
Out$+" Rejects: " + Str(rejects)
Out$+" Accepts: " + Str(24-rejects)
Out$+" Line_tot: "+ StrD(lsum,3)
If rejects<24
Out$+" Line_avg: "+StrD(lsum/(24-rejects),3)
Else
Out$+" Line_avg: N/A"
EndIf
PrintN("Line: "+Out$)
Wend
PrintN(#CRLF$+"File = "+GetFilePart(File$))
PrintN("Total = "+ StrD(tsum,3))
PrintN("Readings = "+ Str(readings))
PrintN("Average = "+ StrD(tsum/readings,3))
Print(#CRLF$+"Maximum of "+Str(ErrMax))
PrintN(" consecutive false readings, ends at "+ErrEnds$)
CloseFile(0)
;
Print("Press ENTER to exit"): Input()
EndIf |
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas | The Twelve Days of Christmas | Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #MAD | MAD | NORMAL MODE IS INTEGER
THROUGH VERSE, FOR I=1, 1, I.G.12
PRINT FORMAT XMS,ORD(I)
PRINT FORMAT TLV
TRANSFER TO GIFT(13-I)
GIFT(1) PRINT FORMAT G12
GIFT(2) PRINT FORMAT G11
GIFT(3) PRINT FORMAT G10
GIFT(4) PRINT FORMAT G9
GIFT(5) PRINT FORMAT G8
GIFT(6) PRINT FORMAT G7
GIFT(7) PRINT FORMAT G6
GIFT(8) PRINT FORMAT G5
GIFT(9) PRINT FORMAT G4
GIFT(10) PRINT FORMAT G3
GIFT(11) PRINT FORMAT G2
GIFT(12) PRINT FORMAT G1
VERSE PRINT FORMAT MT
VECTOR VALUES XMS =
0 $7HON THE ,C,S1,16HDAY OF CHRISTMAS*$
VECTOR VALUES ORD = $*$, $FIRST$, $SECOND$, $THIRD$
0 , $FOURTH$, $FIFTH$, $SIXTH$, $SEVENTH$, $EIGHTH$
1 , $NINTH$, $TENTH$, $ELEVENTH$, $TWELFTH$
VECTOR VALUES TLV = $23HMY TRUE LOVE GAVE TO ME*$
VECTOR VALUES G12 = $24HTWELVE DRUMMERS DRUMMING*$
VECTOR VALUES G11 = $20HELEVEN PIPERS PIPING*$
VECTOR VALUES G10 = $19HTEN LORDS A-LEAPING*$
VECTOR VALUES G9 = $19HNINE LADIES DANCING*$
VECTOR VALUES G8 = $21HEIGHT MAIDS A-MILKING*$
VECTOR VALUES G7 = $22HSEVEN SWANS A-SWIMMING*$
VECTOR VALUES G6 = $18HSIX GEESE A-LAYING*$
VECTOR VALUES G5 = $17HFIVE GOLDEN RINGS*$
VECTOR VALUES G4 = $18HFOUR CALLING BIRDS*$
VECTOR VALUES G3 = $17HTHREE FRENCH HENS*$
VECTOR VALUES G2 = $20HTWO TURTLE DOVES AND*$
VECTOR VALUES G1 = $26HA PARTRIDGE IN A PEAR TREE*$
VECTOR VALUES MT = $*$
END OF PROGRAM
|
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas | The Twelve Days of Christmas | Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Maple | Maple | gifts := ["Twelve drummers drumming",
"Eleven pipers piping", "Ten lords a-leaping",
"Nine ladies dancing", "Eight maids a-milking",
"Seven swans a-swimming", "Six geese a-laying",
"Five golden rings", "Four calling birds",
"Three french hens", "Two turtle doves and", "A partridge in a pear tree"]:
days := ["first", "second", "third", "fourth", "fifth", "sixth",
"seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth"]:
for i to 12 do
printf("On the %s day of Christmas\nMy true love gave to me:\n", days[i]);
for j from 13-i to 12 do
printf("%s\n", gifts[j]);
end do;
printf("\n");
end do; |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #TPP | TPP | --color red
This is red
--color green
This is green
--color blue
This is blue
--color cyan
This is cyan
--color magenta
This is magenta
--color yellow
This is yellow |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #True_BASIC | True BASIC | FOR n = 1 TO 15
SET COLOR n
PRINT "Rosetta Code"
NEXT n
END |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #UNIX_Shell | UNIX Shell | #!/bin/sh
# Check if the terminal supports colour
# We should know from the TERM evironment variable whether the system
# is comfigured for a colour terminal or not, but we can also check the
# tput utility to check the terminal capability records.
COLORS=8 # Assume initially that the system supports eight colours
case $TERM in
linux)
;; # We know this is a colour terminal
rxvt)
;; # We know this is a colour terminal
*)
COLORS=`tput colors 2> /dev/null` # Get the number of colours from the termcap file
esac
if [ -z $COLORS ] ; then
COLORS=1 # Watch out for an empty returned value
fi
if [ $COLORS -le 2 ] ; then
# The terminal is not colour
echo "HW65000 This application requires a colour terminal" >&2
exit 252 #ERLHW incompatible hardware
fi
# We know at this point that the terminal is colour
# Coloured text
tput setaf 1 #red
echo "Red"
tput setaf 4 #blue
echo "Blue"
tput setaf 3 # yellow
echo "Yellow"
# Blinking
tput setab 1 # red background
tput setaf 3 # yellow foreground
#tput blink # enable blinking (but does not work on some terminals)
echo "Flashing text"
tput sgr0 # reset everything before exiting |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #Wren | Wren | import "timer" for Timer
var colors = ["Black", "Red", "Green", "Yellow", "Blue", "Magenta", "Cyan", "White"]
// display words using 'bright' colors
for (i in 1..7) System.print("\e[%(30+i);1m%(colors[i])") // red to white
Timer.sleep(3000) // wait for 3 seconds
System.write("\e[47m") // set background color to white
System.write("\e[2J") // clear screen to background color
System.write("\e[H") // home the cursor
// display words again using 'blinking' colors
System.write("\e[5m") // blink on
for (i in 0..6) System.print("\e[%(30+i);1m%(colors[i])") // black to cyan
Timer.sleep(3000) // wait for 3 more seconds
System.write("\e[0m") // reset all attributes
System.write("\e[2J") // clear screen to background color
System.write("\e[H") // home the cursor |
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes.
One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit.
This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
| #Forth | Forth | \
\ co.fs Coroutines by continuations.
\
\ * Circular Queue. Capacity is power of 2.
\
VARIABLE HEAD VARIABLE TAIL
128 CELLS CONSTANT CQ#
\ * align by queue capacity
HERE DUP
CQ# 1- INVERT AND CQ# +
SWAP - ALLOT
\
HERE CQ# ALLOT CONSTANT START
\
: ADJUST ( -- ) [ CQ# 1- ]L AND START + ;
: PUT ( n-- ) TAIL @ TUCK ! CELL+ ADJUST TAIL ! ;
: TAKE ( --n ) HEAD @ DUP @ SWAP CELL+ ADJUST HEAD ! ;
: 0CQ ( -- ) START DUP HEAD ! TAIL ! ; 0CQ
: NOEMPTY? ( --f ) HEAD @ TAIL @ <> ;
: ;CO ( -- ) TAKE >R ;
\
\ * COROUTINES LEXEME
\
: CO: ( -- ) R> PUT ; \ Register continuation as coroutine. Exit.
: CO ( -- ) R> PUT TAKE >R ; \ Co-route.
: GO ( -- ) BEGIN NOEMPTY? WHILE ;CO REPEAT ; \ :-)
\
\ * CHANNELS LEXEME
\
: CHAN? ( a--f ) 2@ XOR ;
|
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes.
One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit.
This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
| #Go | Go | package main
import (
"bufio"
"fmt"
"log"
"os"
)
func main() {
lines := make(chan string)
count := make(chan int)
go func() {
c := 0
for l := range lines {
fmt.Println(l)
c++
}
count <- c
}()
f, err := os.Open("input.txt")
if err != nil {
log.Fatal(err)
}
for s := bufio.NewScanner(f); s.Scan(); {
lines <- s.Text()
}
f.Close()
close(lines)
fmt.Println("Number of lines:", <-count)
} |
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode. Choose appropriate types for each field.
For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
| #Sidef | Sidef | require('DBI');
var db = %s'DBI'.connect('DBI:mysql:database:server','login','password');
var statment = <<'EOF';
CREATE TABLE `Address` (
`addrID` int(11) NOT NULL auto_increment,
`addrStreet` varchar(50) NOT NULL default '',
`addrCity` varchar(25) NOT NULL default '',
`addrState` char(2) NOT NULL default '',
`addrZIP` char(10) NOT NULL default '',
PRIMARY KEY (`addrID`)
);
EOF
var exec = db.prepare(statment);
exec.execute; |
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode. Choose appropriate types for each field.
For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
| #SQL_PL | SQL PL |
CREATE TABLE Address (
addrID INTEGER generated BY DEFAULT AS IDENTITY,
addrStreet VARCHAR(50) NOT NULL,
addrCity VARCHAR(25) NOT NULL,
addrState CHAR(2) NOT NULL,
addrZIP CHAR(10) NOT NULL
);
|
http://rosettacode.org/wiki/Table_creation/Postal_addresses | Table creation/Postal addresses | Task
Create a table to store addresses.
You may assume that all the addresses to be stored will be located in the USA. As such, you will need (in addition to a field holding a unique identifier) a field holding the street address, a field holding the city, a field holding the state code, and a field holding the zipcode. Choose appropriate types for each field.
For non-database languages, show how you would open a connection to a database (your choice of which) and create an address table in it. You should follow the existing models here for how you would structure the table.
| #SQLite | SQLite |
CREATE TABLE address_USA (
address_ID INTEGER PRIMARY KEY,
address_Street TEXT,
address_City TEXT,
address_State TEXT,
address_Zip INTEGER
);
|
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retrieving system time (wiki)
| #ALGOL_68 | ALGOL 68 | FORMAT time repr = $"year="4d,", month="2d,", day="2d,", hours="2d,", \
minutes="2d,", seconds="2d,", day of week="d,", \
daylight-saving-time flag="dl$;
printf((time repr, local time));
printf((time repr, utc time)) |
http://rosettacode.org/wiki/Summarize_and_say_sequence | Summarize and say sequence | There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ...
The terms generated grow in length geometrically and never converge.
Another way to generate a self-referential sequence is to summarize the previous term.
Count how many of each alike digit there is, then concatenate the sum and digit for each of the sorted enumerated digits. Note that the first five terms are the same as for the previous sequence.
0, 10, 1110, 3110, 132110, 13123110, 23124110 ...
Sort the digits largest to smallest. Do not include counts of digits that do not appear in the previous term.
Depending on the seed value, series generated this way always either converge to a stable value or to a short cyclical pattern. (For our purposes, I'll use converge to mean an element matches a previously seen element.) The sequence shown, with a seed value of 0, converges to a stable value of 1433223110 after 11 iterations. The seed value that converges most quickly is 22. It goes stable after the first element. (The next element is 22, which has been seen before.)
Task
Find all the positive integer seed values under 1000000, for the above convergent self-referential sequence, that takes the largest number of iterations before converging. Then print out the number of iterations and the sequence they return. Note that different permutations of the digits of the seed will yield the same sequence. For this task, assume leading zeros are not permitted.
Seed Value(s): 9009 9090 9900
Iterations: 21
Sequence: (same for all three seeds except for first element)
9009
2920
192210
19222110
19323110
1923123110
1923224110
191413323110
191433125110
19151423125110
19251413226110
1916151413325110
1916251423127110
191716151413326110
191726151423128110
19181716151413327110
19182716151423129110
29181716151413328110
19281716151423228110
19281716151413427110
19182716152413228110
Related tasks
Fours is the number of letters in the ...
Look-and-say sequence
Number names
Self-describing numbers
Spelling of ordinal numbers
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Also see
The On-Line Encyclopedia of Integer Sequences.
| #AutoHotkey | AutoHotkey |
; The following directives and commands speed up execution:
#NoEnv
SetBatchlines -1
ListLines Off
Process, Priority,, high
iterations := 0, seed := "Seeds: "
Loop 1000000
If (newIterations := CountSubString(list := ListSequence(A_Index), "`n")) > iterations
iterations := newiterations
,final := "`nIterations: " iterations+1 "`nSequence:`n`n" A_Index "`n" list
,seed := A_Index " "
else if (newIterations = iterations)
seed .= A_Index " "
MsgBox % "Seeds: " . seed . final
ListSequence(seed){
While !InStr("`n" . out, "`n" (d:=Describe(seed)) "`n")
out .= d "`n", seed := d
return out
}
Describe(n){
Loop 10
If (t:=CountSubString(n, 10-A_Index))
out .= t . (10-A_Index)
return out
}
CountSubstring(fullstring, substring){
StringReplace, junk, fullstring, %substring%, , UseErrorLevel
return errorlevel
}
|
http://rosettacode.org/wiki/Summarize_primes | Summarize primes | Task
Considering in order of length, n, all sequences of consecutive
primes, p, from 2 onwards, where p < 1000 and n>0, select those
sequences whose sum is prime, and for these display the length of the
sequence, the last item in the sequence, and the sum.
| #C | C | #include <stdbool.h>
#include <stdio.h>
bool is_prime(int n) {
int i = 5;
if (n < 2) {
return false;
}
if (n % 2 == 0) {
return n == 2;
}
if (n % 3 == 0) {
return n == 3;
}
while (i * i <= n) {
if (n % i == 0) {
return false;
}
i += 2;
if (n % i == 0) {
return false;
}
i += 4;
}
return true;
}
int main() {
const int start = 1;
const int stop = 1000;
int sum = 0;
int count = 0;
int sc = 0;
int p;
for (p = start; p < stop; p++) {
if (is_prime(p)) {
count++;
sum += p;
if (is_prime(sum)) {
printf("The sum of %3d primes in [2, %3d] is %5d which is also prime\n", count, p, sum);
sc++;
}
}
}
printf("There are %d summerized primes in [%d, %d)\n", sc, start, stop);
return 0;
} |
http://rosettacode.org/wiki/Sutherland-Hodgman_polygon_clipping | Sutherland-Hodgman polygon clipping | The Sutherland-Hodgman clipping algorithm finds the polygon that is the intersection between an arbitrary polygon (the “subject polygon”) and a convex polygon (the “clip polygon”).
It is used in computer graphics (especially 2D graphics) to reduce the complexity of a scene being displayed by eliminating parts of a polygon that do not need to be displayed.
Task
Take the closed polygon defined by the points:
[
(
50
,
150
)
,
(
200
,
50
)
,
(
350
,
150
)
,
(
350
,
300
)
,
(
250
,
300
)
,
(
200
,
250
)
,
(
150
,
350
)
,
(
100
,
250
)
,
(
100
,
200
)
]
{\displaystyle [(50,150),(200,50),(350,150),(350,300),(250,300),(200,250),(150,350),(100,250),(100,200)]}
and clip it by the rectangle defined by the points:
[
(
100
,
100
)
,
(
300
,
100
)
,
(
300
,
300
)
,
(
100
,
300
)
]
{\displaystyle [(100,100),(300,100),(300,300),(100,300)]}
Print the sequence of points that define the resulting clipped polygon.
Extra credit
Display all three polygons on a graphical surface, using a different color for each polygon and filling the resulting polygon.
(When displaying you may use either a north-west or a south-west origin, whichever is more convenient for your display mechanism.)
| #FreeBASIC | FreeBASIC |
Type Point
As Double x,y
End Type
Type Line
As Point s,f'start/finish
End Type
Function isleft(L As Line,p As Point) As Long
Return -Sgn((L.s.x-L.f.x)*(p.y-L.f.y)-(p.x-L.f.x)*(L.s.y-L.f.y))
End Function
Function segmentintersections(L1 As Line,L2 As Line) As Long
If isleft(L2,L1.s) = isleft(L2,L1.f) Then Return 0
If isleft(L1,L2.s) = isleft(L1,L2.f) Then Return 0
Return 1
End Function
Function allintersections(l1 As Line,l2 As Line,_out As Point) As Long
Const tolerance=.01
Var p1=l1.s, p2=l1.f, p3=l2.s, p4=l2.f
Var x12=p1.x-p2.x, x34=p3.x-p4.x, y12=p1.y-p2.y, y34=p3.y-p4.y
Var c=x12*y34-y12*x34
If Abs(c)<tolerance Then Return 0
Var a=p1.x*p2.y-p1.y*p2.x, b=p3.x*p4.y-p3.y*p4.x
_out.x = (a*x34-b*x12)/c
_out.y = (a*y34-b*y12)/c
Return 1
End Function
Dim As Point p1(...)={(50,150),(200,50),(350,150),(350,300),(250,300),(200,250), _
(150,350),(100,250),(100,200)}
Dim As Point p2(...)={(100,100),(300,100),(300,300),(100,300)}
'get the line segments around the polygons
Dim As Line L1(...)={(p1(0),p1(1)),(p1(1),p1(2)),(p1(2),p1(3)),(p1(3),p1(4)),(p1(4),p1(5)),_
(p1(5),p1(6)),(p1(6),p1(7)),(p1(7),p1(8)),(p1(8),p1(0))}
Dim As Line L2(...)={(p2(0),p2(1)),(p2(1),p2(2)),(p2(2),p2(3)),(p2(3),p2(0))}
'would normally draw these lines now, but not here.
Dim As Point x
For n1 As Long=Lbound(L1) To Ubound(L1)
For n2 As Long=Lbound(L2) To Ubound(L2)
If allintersections(L1(n1),L2(n2),x) And segmentintersections(L1(n1),L2(n2)) Then
Print x.x,x.y
End If
Next
Next
Sleep
|
http://rosettacode.org/wiki/Symmetric_difference | Symmetric difference | Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\displaystyle (A\cup B)\setminus (A\cap B)}
(the set of items that are in at least one of A or B minus the set of items that are in both A and B).
Optionally, give the individual differences (
A
∖
B
{\displaystyle A\setminus B}
and
B
∖
A
{\displaystyle B\setminus A}
) as well.
Test cases
A = {John, Bob, Mary, Serena}
B = {Jim, Mary, John, Bob}
Notes
If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order.
In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
| #BBC_BASIC | BBC BASIC | DIM list$(4)
list$() = "Bob", "Jim", "John", "Mary", "Serena"
setA% = %11101
PRINT "Set A: " FNlistset(list$(), setA%)
setB% = %01111
PRINT "Set B: " FNlistset(list$(), setB%)
REM Compute symmetric difference:
setC% = setA% EOR setB%
PRINT '"Symmetric difference: " FNlistset(list$(), setC%)
REM Optional:
PRINT "Set A \ Set B: " FNlistset(list$(), setA% AND NOT setB%)
PRINT "Set B \ Set A: " FNlistset(list$(), setB% AND NOT setA%)
END
DEF FNlistset(list$(), set%)
LOCAL i%, o$
FOR i% = 0 TO 31
IF set% AND 1 << i% o$ += list$(i%) + ", "
NEXT
= LEFT$(LEFT$(o$)) |
http://rosettacode.org/wiki/Symmetric_difference | Symmetric difference | Task
Given two sets A and B, compute
(
A
∖
B
)
∪
(
B
∖
A
)
.
{\displaystyle (A\setminus B)\cup (B\setminus A).}
That is, enumerate the items that are in A or B but not both. This set is called the symmetric difference of A and B.
In other words:
(
A
∪
B
)
∖
(
A
∩
B
)
{\displaystyle (A\cup B)\setminus (A\cap B)}
(the set of items that are in at least one of A or B minus the set of items that are in both A and B).
Optionally, give the individual differences (
A
∖
B
{\displaystyle A\setminus B}
and
B
∖
A
{\displaystyle B\setminus A}
) as well.
Test cases
A = {John, Bob, Mary, Serena}
B = {Jim, Mary, John, Bob}
Notes
If your code uses lists of items to represent sets then ensure duplicate items in lists are correctly handled. For example two lists representing sets of a = ["John", "Serena", "Bob", "Mary", "Serena"] and b = ["Jim", "Mary", "John", "Jim", "Bob"] should produce the result of just two strings: ["Serena", "Jim"], in any order.
In the mathematical notation above A \ B gives the set of items in A that are not in B; A ∪ B gives the set of items in both A and B, (their union); and A ∩ B gives the set of items that are in both A and B (their intersection).
| #Bracmat | Bracmat | (SymmetricDifference=
A B x symdiff
. !arg:(?A.?B)
& :?symdiff
& ( !A !B
: ?
( %@?x
& ( !A:? !x ?&!B:? !x ?
| !symdiff:? !x ?
| !symdiff !x:?symdiff
)
& ~
)
?
| !symdiff
)); |
http://rosettacode.org/wiki/Super-d_numbers | Super-d numbers | A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or super-d.
Task
Write a function/procedure/routine to find super-d numbers.
For d=2 through d=6, use the routine to show the first 10 super-d numbers.
Extra credit
Show the first 10 super-7, super-8, and/or super-9 numbers (optional).
See also
Wolfram MathWorld - Super-d Number.
OEIS: A014569 - Super-3 Numbers.
| #jq | jq | # To take advantage of gojq's arbitrary-precision integer arithmetic:
def power($b): . as $in | reduce range(0;$b) as $i (1; . * $in);
# Input is $d, the number of consecutive digits, 2 <= $d <= 9
# $max is the number of superd numbers to be emitted.
def superd($number):
. as $d
| tostring as $s
| ($s * $d) as $target
| {count:0, j: 3 }
| while ( .count <= $number;
.emit = null
| if ((.j|power($d) * $d) | tostring) | index($target)
then .count += 1
| .emit = .j
else .
end
| .j += 1 )
| select(.emit).emit ;
# super-d for 2 <=d < 8
range(2; 8)
| "First 10 super-\(.) numbers:",
superd(10) |
http://rosettacode.org/wiki/Super-d_numbers | Super-d numbers | A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or super-d.
Task
Write a function/procedure/routine to find super-d numbers.
For d=2 through d=6, use the routine to show the first 10 super-d numbers.
Extra credit
Show the first 10 super-7, super-8, and/or super-9 numbers (optional).
See also
Wolfram MathWorld - Super-d Number.
OEIS: A014569 - Super-3 Numbers.
| #Julia | Julia | function superd(N)
println("First 10 super-$N numbers:")
count, j = 0, BigInt(3)
target = Char('0' + N)^N
while count < 10
if occursin(target, string(j^N * N))
count += 1
print("$j ")
end
j += 1
end
println()
end
for n in 2:9
@time superd(n)
end
|
http://rosettacode.org/wiki/Super-d_numbers | Super-d numbers | A super-d number is a positive, decimal (base ten) integer n such that d × nd has at least d consecutive digits d where
2 ≤ d ≤ 9
For instance, 753 is a super-3 number because 3 × 7533 = 1280873331.
Super-d numbers are also shown on MathWorld™ as super-d or super-d.
Task
Write a function/procedure/routine to find super-d numbers.
For d=2 through d=6, use the routine to show the first 10 super-d numbers.
Extra credit
Show the first 10 super-7, super-8, and/or super-9 numbers (optional).
See also
Wolfram MathWorld - Super-d Number.
OEIS: A014569 - Super-3 Numbers.
| #Kotlin | Kotlin | import java.math.BigInteger
fun superD(d: Int, max: Int) {
val start = System.currentTimeMillis()
var test = ""
for (i in 0 until d) {
test += d
}
var n = 0
var i = 0
println("First $max super-$d numbers:")
while (n < max) {
i++
val value: Any = BigInteger.valueOf(d.toLong()) * BigInteger.valueOf(i.toLong()).pow(d)
if (value.toString().contains(test)) {
n++
print("$i ")
}
}
val end = System.currentTimeMillis()
println("\nRun time ${end - start} ms\n")
}
fun main() {
for (i in 2..9) {
superD(i, 10)
}
} |
http://rosettacode.org/wiki/Take_notes_on_the_command_line | Take notes on the command line | Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline.
Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT.
If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
| #Forth | Forth | vocabulary note-words
get-current also note-words definitions
\ -- notes.txt
variable file
: open s" notes.txt" r/w open-file if
s" notes.txt" r/w create-file throw then file ! ;
: appending file @ file-size throw file @ reposition-file throw ;
: write file @ write-file throw ;
: close file @ close-file throw ;
\ -- SwiftForth console workaround
9 constant TAB
: type ( c-addr u -- )
bounds ?do
i c@ dup TAB = if drop 8 spaces else emit then
loop ;
\ -- dump notes.txt
create buf 4096 allot
: dump ( -- )
cr begin buf 4096 file @ read-file throw dup while
buf swap type
repeat drop ;
\ -- time and date
: time @time (time) ;
: date @date (date) ;
\ -- add note
: cr s\" \n" write ;
: tab s\" \t" write ;
: space s" " write ;
: add-note ( c-addr u -- ) appending
date write space time write cr
tab ( note ) write cr ;
set-current
\ -- note
: note ( "note" -- )
open 0 parse dup if add-note
else 2drop dump then close ;
previous |
http://rosettacode.org/wiki/Take_notes_on_the_command_line | Take notes on the command line | Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline.
Then all the arguments, joined with spaces, prepended with a tab, and appended with a trailing newline, are written to NOTES.TXT.
If NOTES.TXT doesn't already exist in the current directory then a new NOTES.TXT file should be created.
| #Fortran | Fortran |
program notes
implicit none
integer :: i, length, iargs, lun, ios
integer,dimension(8) :: values
character(len=:),allocatable :: arg
character(len=256) :: line
character(len=1),parameter :: tab=char(9)
iargs = command_argument_count()
open(file='notes.txt',newunit=lun,action='readwrite',position='append',status='unknown')
if(iargs.eq.0)then
rewind(lun)
do
read(lun,'(a)',iostat=ios)line
if(ios.ne.0)exit
write(*,'(a)')trim(line)
enddo
else
call date_and_time(VALUES=values)
write(lun,'(*(g0))')values(1),"-",values(2),"-",values(3),"T",values(5),":",values(6),":",values(7)
write(lun,'(a)',advance='no')tab
do i=1,iargs
call get_command_argument(number=i,length=length)
arg=repeat(' ',length)
call get_command_argument(i, arg)
write(lun,'(a,1x)',advance='no')arg
enddo
write(lun,*)
endif
end program notes
|
http://rosettacode.org/wiki/Superellipse | Superellipse | A superellipse is a geometric figure defined as the set of all points (x, y) with
|
x
a
|
n
+
|
y
b
|
n
=
1
,
{\displaystyle \left|{\frac {x}{a}}\right|^{n}\!+\left|{\frac {y}{b}}\right|^{n}\!=1,}
where n, a, and b are positive numbers.
Task
Draw a superellipse with n = 2.5, and a = b = 200
| #Haskell | Haskell | {-# LANGUAGE OverloadedStrings, RankNTypes #-}
import Reflex
import Reflex.Dom
import Data.Text (Text, pack, unpack)
import Data.Map (Map, fromList, empty)
import Text.Read (readMaybe)
width = 600
height = 500
type Point = (Float,Float)
type Segment = (Point,Point)
data Ellipse = Ellipse {a :: Float, b :: Float, n :: Float}
toFloat :: Text -> Maybe Float
toFloat = readMaybe.unpack
toEllipse :: Maybe Float -> Maybe Float -> Maybe Float -> Maybe Ellipse
toEllipse (Just a) (Just b) (Just n) =
if a < 1.0 || b <= 1.0 || n <= 0.0 -- not all floats are valid
then Nothing
else Just $ Ellipse a b n
toEllipse _ _ _ = Nothing
showError :: Maybe a -> String
showError Nothing = "invalid input"
showError _ = ""
reflect45 pts = pts ++ fmap (\(x,y) -> ( y, x)) (reverse pts)
rotate90 pts = pts ++ fmap (\(x,y) -> ( y, -x)) pts
rotate180 pts = pts ++ fmap (\(x,y) -> (-x, -y)) pts
scale a b = fmap (\(x,y) -> ( a*x, b*y ))
segments pts = zip pts $ tail pts
toLineMap :: Maybe Ellipse -> Map Int ((Float,Float),(Float,Float))
toLineMap (Just (Ellipse a b n)) =
let f p = (1 - p**n)**(1/n)
dp = iterate (*0.9) 1.0
ip = map (\p -> 1.0 -p) dp
points s =
if n > 1.0
then (\p -> zip p (map f p)) ip
else (\p -> zip (map f p) p) dp
in fromList $ -- changes list to map (for listWithKey)
zip [0..] $ -- annotates segments with index
segments $ -- changes points to line segments
scale a b $
rotate180 $ -- doubles the point count
rotate90 $ -- doubles the point count
reflect45 $ -- doubles the point count
takeWhile (\(x,y) -> x < y ) $ -- stop at 45 degree line
points 0.9
toLineMap Nothing = empty
lineAttrs :: Segment -> Map Text Text
lineAttrs ((x1,y1), (x2,y2)) =
fromList [ ( "x1", pack $ show (width/2+x1))
, ( "y1", pack $ show (height/2+y1))
, ( "x2", pack $ show (width/2+x2))
, ( "y2", pack $ show (height/2+y2))
, ( "style", "stroke:brown;stroke-width:2")
]
showLine :: MonadWidget t m => Int -> Dynamic t Segment -> m ()
showLine _ dSegment = do
elSvgns "line" (lineAttrs <$> dSegment) $ return ()
return ()
main = mainWidget $ do
elAttr "h1" ("style" =: "color:brown") $ text "Superellipse"
ta <- el "div" $ do
text "a: "
textInput def { _textInputConfig_initialValue = "200"}
tb <- el "div" $ do
text "b: "
textInput def { _textInputConfig_initialValue = "200"}
tn <- el "div" $ do
text "n: "
textInput def { _textInputConfig_initialValue = "2.5"}
let
ab = zipDynWith toEllipse (toFloat <$> value ta) (toFloat <$> value tb)
dEllipse = zipDynWith ($) ab (toFloat <$> value tn)
dLines = fmap toLineMap dEllipse
dAttrs = constDyn $ fromList
[ ("width" , pack $ show width)
, ("height", pack $ show height)
]
elAttr "div" ("style" =: "color:red") $ dynText $ fmap (pack.showError) dEllipse
el "div" $ elSvgns "svg" dAttrs $ listWithKey dLines showLine
return ()
-- At end to avoid Rosetta Code unmatched quotes problem.
elSvgns :: forall t m a. MonadWidget t m => Text -> Dynamic t (Map Text Text) -> m a -> m (El t, a)
elSvgns = elDynAttrNS' (Just "http://www.w3.org/2000/svg") |
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one.
Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms.
Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction.
Task
Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence.
Use that routine to show the values of the first 10 elements in the sequence.
Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction.
Related tasks
Egyptian fractions
Harmonic series
See also
OEIS A000058 - Sylvester's sequence
| #Ruby | Ruby | def sylvester(n) = (1..n).reduce(2){|a| a*a - a + 1 }
(0..9).each {|n| puts "#{n}: #{sylvester n}" }
puts "
Sum of reciprocals of first 10 terms:
#{(0..9).sum{|n| 1.0r / sylvester(n)}.to_f }"
|
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one.
Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms.
Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction.
Task
Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence.
Use that routine to show the values of the first 10 elements in the sequence.
Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction.
Related tasks
Egyptian fractions
Harmonic series
See also
OEIS A000058 - Sylvester's sequence
| #Scheme | Scheme | (define sylvester
(lambda (x)
(if (= x 1)
2
(let ((n (sylvester (- x 1)))) (- (* n n) n -1)))))
(define list (map sylvester '(1 2 3 4 5 6 7 8 9 10)))
(print list)
(newline)
(print (apply + (map / list))) |
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one.
Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms.
Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction.
Task
Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence.
Use that routine to show the values of the first 10 elements in the sequence.
Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction.
Related tasks
Egyptian fractions
Harmonic series
See also
OEIS A000058 - Sylvester's sequence
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "bigint.s7i";
include "bigrat.s7i";
const func bigInteger: nextSylvester (in bigInteger: prev) is
return prev * prev - prev + 1_;
const proc: main is func
local
var bigInteger: number is 2_;
var bigRational: reciprocalSum is 0_ / 1_;
var integer: n is 0;
begin
writeln("First 10 elements of Sylvester's sequence:");
for n range 1 to 10 do
writeln(number);
reciprocalSum +:= 1_ / number;
number := nextSylvester(number);
end for;
writeln("\nSum of the reciprocals of the first 10 elements:");
writeln(reciprocalSum digits 210);
end func; |
http://rosettacode.org/wiki/Sylvester%27s_sequence | Sylvester's sequence |
This page uses content from Wikipedia. The original article was at Sylvester's sequence. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In number theory, Sylvester's sequence is an integer sequence in which each term of the sequence is the product of the previous terms, plus one.
Its values grow doubly exponentially, and the sum of its reciprocals forms a series of unit fractions that converges to 1 more rapidly than any other series of unit fractions with the same number of terms.
Further, the sum of the first k terms of the infinite series of reciprocals provides the closest possible underestimate of 1 by any k-term Egyptian fraction.
Task
Write a routine (function, procedure, generator, whatever) to calculate Sylvester's sequence.
Use that routine to show the values of the first 10 elements in the sequence.
Show the sum of the reciprocals of the first 10 elements on the sequence, ideally as an exact fraction.
Related tasks
Egyptian fractions
Harmonic series
See also
OEIS A000058 - Sylvester's sequence
| #Sidef | Sidef | func sylvester_sequence(n) {
1..n -> reduce({|a| a*(a-1) + 1 }, 2)
}
say "First 10 terms in Sylvester's sequence:"
10.of(sylvester_sequence).each_kv{|k,v| '%2s: %s' % (k,v) -> say }
say "\nSum of reciprocals of first 10 terms: "
say 10.of(sylvester_sequence).sum {|n| 1/n }.as_dec(230) |
http://rosettacode.org/wiki/Taxicab_numbers | Taxicab numbers |
A taxicab number (the definition that is being used here) is a positive integer that can be expressed as the sum of two positive cubes in more than one way.
The first taxicab number is 1729, which is:
13 + 123 and also
93 + 103.
Taxicab numbers are also known as:
taxi numbers
taxi-cab numbers
taxi cab numbers
Hardy-Ramanujan numbers
Task
Compute and display the lowest 25 taxicab numbers (in numeric order, and in a human-readable format).
For each of the taxicab numbers, show the number as well as it's constituent cubes.
Extra credit
Show the 2,000th taxicab number, and a half dozen more
See also
A001235: taxicab numbers on The On-Line Encyclopedia of Integer Sequences.
Hardy-Ramanujan Number on MathWorld.
taxicab number on MathWorld.
taxicab number on Wikipedia (includes the story on how taxi-cab numbers came to be called).
| #Lua | Lua | sums, taxis, limit = {}, {}, 1200
for i = 1, limit do
for j = 1, i-1 do
sum = i^3 + j^3
sums[sum] = sums[sum] or {}
table.insert(sums[sum], i.."^3 + "..j.."^3")
end
end
for k,v in pairs(sums) do
if #v > 1 then table.insert(taxis, { sum=k, num=#v, terms=table.concat(v," = ") }) end
end
table.sort(taxis, function(a,b) return a.sum<b.sum end)
for i=1,2006 do
if i<=25 or i>=2000 or taxis[i].num==3 then
print(string.format("%4d%s: %10d = %s", i, taxis[i].num==3 and "*" or " ", taxis[i].sum, taxis[i].terms))
end
end
print("* n=3") |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'.
The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'.
A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'.
A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end.
The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations.
Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations.
The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Reference
The Minimal Superpermutation Problem. by Nathaniel Johnston.
oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872.
Superpermutations - Numberphile. A video
Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress.
New Superpermutations Discovered! Standupmaths & Numberphile.
| #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | ClearAll[OverlapDistance, ConstructDistances]
OverlapDistance[{s1_List, s2_List}] := OverlapDistance[s1, s2]
OverlapDistance[s1_List, s2_List] := Module[{overlaprange, overlap, l},
overlaprange = {Min[Length[s1], Length[s2]], 0};
l = LengthWhile[Range[Sequence @@ overlaprange, -1], Take[s1, -#] =!= Take[s2, #] &];
overlap = overlaprange[[1]] - l;
<|"Overlap" -> overlap, "Distance" -> Length[s2] - overlap|>
]
ConstructDistances[perms_List] := Module[{sel, OD, fullseq},
OD = BlockMap[OverlapDistance, perms, 2, 1];
fullseq =
Fold[Join[#1, Drop[#2[[2]], #2[[1]]["Overlap"]]] &,
First[perms], {OD, Rest[perms]} // Transpose];
fullseq
]
Dynamic[Length[perms]]
Do[
n = i;
perms = Permutations[Range[n]];
{start, perms} = TakeDrop[perms, 1];
While[Length[perms] > 0,
last = Last[start];
dists =
Table[<|"Index" -> i, OverlapDistance[last, perms[[i]]]|>, {i,
Length[perms]}];
sel = First[TakeSmallestBy[dists, #["Distance"] &, 1]];
AppendTo[start, perms[[sel["Index"]]]];
perms = Delete[perms, sel["Index"]];
];
Print[{n, Length@ConstructDistances[start]}]
,
{i, 1, 7}
] |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'.
The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'.
A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'.
A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end.
The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations.
Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations.
The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Reference
The Minimal Superpermutation Problem. by Nathaniel Johnston.
oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872.
Superpermutations - Numberphile. A video
Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress.
New Superpermutations Discovered! Standupmaths & Numberphile.
| #Nim | Nim | import strformat
const MAX = 12
var super: seq[char] = @[]
var pos: int
var cnt: array[MAX, int]
proc factSum(n: int): int =
var s, x = 0
var f = 1
while x < n:
inc x
f *= x
inc s, f
s
proc r(n: int): bool =
if n == 0:
return false
var c = super[pos - n]
dec cnt[n]
if cnt[n] == 0:
cnt[n] = n
if not r(n - 1):
return false
super[pos] = c
inc pos
true
proc superperm(n: int) =
pos = n
var le = factSum(n)
super.setLen(le)
for i in 0..n:
cnt[i] = i
for i in 1..n:
super[i-1] = char(i + ord('0'))
while r(n):
discard
for n in 0..<MAX:
write(stdout, fmt"superperm({n:2})")
superperm(n)
writeLine(stdout, fmt" len = {len(super)}") |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'.
The permutations of 'AB' are the two, (i.e. two-factorial), strings: 'AB' and 'BA'.
A too obvious method of generating a superpermutation is to just join all the permutations together forming 'ABBA'.
A little thought will produce the shorter (in fact the shortest) superpermutation of 'ABA' - it contains 'AB' at the beginning and contains 'BA' from the middle to the end.
The "too obvious" method of creation generates a string of length N!*N. Using this as a yardstick, the task is to investigate other methods of generating superpermutations of N from 1-to-7 characters, that never generate larger superpermutations.
Show descriptions and comparisons of algorithms used here, and select the "Best" algorithm as being the one generating shorter superpermutations.
The problem of generating the shortest superpermutation for each N might be NP complete, although the minimal strings for small values of N have been found by brute -force searches.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
Reference
The Minimal Superpermutation Problem. by Nathaniel Johnston.
oeis A180632 gives 0-5 as 0, 1, 3, 9, 33, 153. 6 is thought to be 872.
Superpermutations - Numberphile. A video
Superpermutations: the maths problem solved by 4chan - Standupmaths. A video of recent (2018) mathematical progress.
New Superpermutations Discovered! Standupmaths & Numberphile.
| #Objeck | Objeck | class SuperPermutation {
@super : static : Char[];
@pos : static : Int;
@cnt : static : Int[];
function : Main(args : String[]) ~ Nil {
max := 12;
@cnt := Int->New[max];
@super := Char->New[0];
for(n := 0; n < max; n += 1;) {
"superperm({$n}) "->Print();
SuperPerm(n);
len := @super->Size() - 1;
"len = {$len}"->PrintLine();
};
}
function : native : FactSum(n : Int) ~ Int {
s := 0; x := 0; f := 1;
while(x < n) {
f *= ++x; s += f;
};
return s;
}
function : native : R(n : Int) ~ Bool {
if(n = 0) {
return false;
};
c := @super[@pos - n];
if(--@cnt[n] = 0) {
@cnt[n] := n;
if(<>R(n - 1)) {
return false;
};
};
@super[@pos++] := c;
return true;
}
function : SuperPerm(n : Int) ~ Nil {
@pos := n;
len := FactSum(n);
tmp := Char->New[len + 1];
Runtime->Copy(tmp, 0, @super, 0, @super->Size());
@super := tmp;
for(i := 0; i <= n; i += 1;) {
@cnt[i] := i;
};
for(i := 1; i <= n; i += 1;) {
@super[i - 1] := i + '0';
};
do {
r := R(n);
}
while(r);
}
}
|
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Rust | Rust |
/// Gets all divisors of a number, including itself
fn get_divisors(n: u32) -> Vec<u32> {
let mut results = Vec::new();
for i in 1..(n / 2 + 1) {
if n % i == 0 {
results.push(i);
}
}
results.push(n);
results
}
fn is_tau_number(i: u32) -> bool {
0 == i % get_divisors(i).len() as u32
}
fn main() {
println!("\nFirst 100 Tau numbers:");
let mut counter: u32 = 0;
let mut i: u32 = 1;
while counter < 100 {
if is_tau_number(i) {
print!("{:>4}", i);
counter += 1;
print!("{}", if counter % 20 == 0 { "\n" } else { "," });
}
i += 1;
}
}
|
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Sidef | Sidef | func is_tau_number(n) {
n % n.sigma0 == 0
}
say is_tau_number.first(100).join(' ') |
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Swift | Swift | import Foundation
// See https://en.wikipedia.org/wiki/Divisor_function
func divisorCount(number: Int) -> Int {
var n = number
var total = 1
// Deal with powers of 2 first
while (n & 1) == 0 {
total += 1
n >>= 1
}
// Odd prime factors up to the square root
var p = 3
while p * p <= n {
var count = 1
while n % p == 0 {
count += 1
n /= p
}
total *= count
p += 2
}
// If n > 1 then it's prime
if n > 1 {
total *= 2
}
return total
}
let limit = 100
print("The first \(limit) tau numbers are:")
var count = 0
var n = 1
while count < limit {
if n % divisorCount(number: n) == 0 {
print(String(format: "%5d", n), terminator: "")
count += 1
if count % 10 == 0 {
print()
}
}
n += 1
} |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute zero.
The Fahrenheit and Rankine scales also have the same magnitude, but different null points.
0 degrees Fahrenheit corresponds to 459.67 degrees Rankine.
0 degrees Rankine is absolute zero.
The Celsius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9.
Task
Write code that accepts a value of kelvin, converts it to values of the three other scales, and prints the result.
Example
K 21.00
C -252.15
F -421.87
R 37.80
| #C.2B.2B | C++ |
#include <iostream>
#include <iomanip>
//--------------------------------------------------------------------------------------------------
using namespace std;
//--------------------------------------------------------------------------------------------------
class converter
{
public:
converter() : KTC( 273.15f ), KTDel( 3.0f / 2.0f ), KTF( 9.0f / 5.0f ), KTNew( 33.0f / 100.0f ),
KTRank( 9.0f / 5.0f ), KTRe( 4.0f / 5.0f ), KTRom( 21.0f / 40.0f ) {}
void convert( float kelvin )
{
float cel = kelvin - KTC,
del = ( 373.15f - kelvin ) * KTDel,
fah = kelvin * KTF - 459.67f,
net = cel * KTNew,
rnk = kelvin * KTRank,
rea = cel * KTRe,
rom = cel * KTRom + 7.5f;
cout << endl << left
<< "TEMPERATURES:" << endl
<< "===============" << endl << setw( 13 )
<< "CELSIUS:" << cel << endl << setw( 13 )
<< "DELISLE:" << del << endl << setw( 13 )
<< "FAHRENHEIT:" << fah << endl << setw( 13 )
<< "KELVIN:" << kelvin << endl << setw( 13 )
<< "NEWTON:" << net << endl << setw( 13 )
<< "RANKINE:" << rnk << endl << setw( 13 )
<< "REAUMUR:" << rea << endl << setw( 13 )
<< "ROMER:" << rom << endl << endl << endl;
}
private:
const float KTRank, KTC, KTF, KTRe, KTDel, KTNew, KTRom;
};
//--------------------------------------------------------------------------------------------------
int main( int argc, char* argv[] )
{
converter con;
float k;
while( true )
{
cout << "Enter the temperature in Kelvin to convert: ";
cin >> k;
con.convert( k );
system( "pause" );
system( "cls" );
}
return 0;
}
//--------------------------------------------------------------------------------------------------
|
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #PL.2FI | PL/I | taufunc: procedure options(main);
tau: procedure(nn) returns(fixed);
declare (n, nn, tot, pf, cnt) fixed;
tot = 1;
do n=nn repeat(n/2) while(mod(n,2)=0);
tot = tot + 1;
end;
do pf=3 repeat(pf+2) while(pf*pf<=n);
do cnt=1 repeat(cnt+1) while(mod(n,pf)=0);
n = n/pf;
end;
tot = tot * cnt;
end;
if n>1 then tot = tot * 2;
return(tot);
end tau;
declare n fixed;
do n=1 to 100;
put edit(tau(n)) (F(3));
if mod(n,20)=0 then put skip;
end;
end taufunc; |
http://rosettacode.org/wiki/Tau_function | Tau function | Given a positive integer, count the number of its positive divisors.
Task
Show the result for the first 100 positive integers.
Related task
Tau number
| #PL.2FM | PL/M | 100H:
/* CP/M BDOS FUNCTIONS */
BDOS: PROCEDURE(F,A); DECLARE F BYTE, A ADDRESS; GO TO 5; END BDOS;
EXIT: PROCEDURE; GO TO 0; END EXIT;
PR$CHAR: PROCEDURE(C); DECLARE C BYTE; CALL BDOS(2,C); END PR$CHAR;
PR$STR: PROCEDURE(S); DECLARE S ADDRESS; CALL BDOS(9,S); END PR$STR;
/* PRINT BYTE IN A 3-CHAR COLUMN */
PRINT3: PROCEDURE(N);
DECLARE (N, M) BYTE;
M = 100;
DO WHILE M>0;
IF N>=M
THEN CALL PR$CHAR('0' + (N/M) MOD 10);
ELSE CALL PR$CHAR(' ');
M = M/10;
END;
END PRINT3;
/* TAU FUNCTION */
TAU: PROCEDURE(N) BYTE;
DECLARE (N, TOTAL, COUNT, P) BYTE;
TOTAL = 1;
DO WHILE NOT N;
N = SHR(N,1);
TOTAL = TOTAL + 1;
END;
P = 3;
DO WHILE P*P <= N;
COUNT = 1;
DO WHILE N MOD P = 0;
COUNT = COUNT + 1;
N = N / P;
END;
TOTAL = TOTAL * COUNT;
P = P + 2;
END;
IF N>1 THEN TOTAL = SHL(TOTAL, 1);
RETURN TOTAL;
END TAU;
/* PRINT TAU 1..100 */
DECLARE N BYTE;
DO N=1 TO 100;
CALL PRINT3(TAU(N));
IF N MOD 20=0 THEN CALL PR$STR(.(13,10,'$'));
END;
CALL EXIT;
EOF |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #Racket | Racket |
#lang racket
(require (planet neil/charterm:3:0))
(with-charterm
(void (charterm-clear-screen)))
|
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #Raku | Raku | sub clear { print qx[clear] }
clear; |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #Retro | Retro | clear |
http://rosettacode.org/wiki/Ternary_logic | Ternary logic |
This page uses content from Wikipedia. The original article was at Ternary logic. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
In logic, a three-valued logic (also trivalent, ternary, or trinary logic, sometimes abbreviated 3VL) is any of several many-valued logic systems in which there are three truth values indicating true, false and some indeterminate third value.
This is contrasted with the more commonly known bivalent logics (such as classical sentential or boolean logic) which provide only for true and false.
Conceptual form and basic ideas were initially created by Łukasiewicz, Lewis and Sulski.
These were then re-formulated by Grigore Moisil in an axiomatic algebraic form, and also extended to n-valued logics in 1945.
Example Ternary Logic Operators in Truth Tables:
not a
¬
True
False
Maybe
Maybe
False
True
a and b
∧
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
False
False
False
False
False
a or b
∨
True
Maybe
False
True
True
True
True
Maybe
True
Maybe
Maybe
False
True
Maybe
False
if a then b
⊃
True
Maybe
False
True
True
Maybe
False
Maybe
True
Maybe
Maybe
False
True
True
True
a is equivalent to b
≡
True
Maybe
False
True
True
Maybe
False
Maybe
Maybe
Maybe
Maybe
False
False
Maybe
True
Task
Define a new type that emulates ternary logic by storing data trits.
Given all the binary logic operators of the original programming language, reimplement these operators for the new Ternary logic type trit.
Generate a sampling of results using trit variables.
Kudos for actually thinking up a test case algorithm where ternary logic is intrinsically useful, optimises the test case algorithm and is preferable to binary logic.
Note: Setun (Сетунь) was a balanced ternary computer developed in 1958 at Moscow State University. The device was built under the lead of Sergei Sobolev and Nikolay Brusentsov. It was the only modern ternary computer, using three-valued ternary logic
| #Pascal | Pascal | Program TernaryLogic (output);
type
trit = (terTrue, terMayBe, terFalse);
function terNot (a: trit): trit;
begin
case a of
terTrue: terNot := terFalse;
terMayBe: terNot := terMayBe;
terFalse: terNot := terTrue;
end;
end;
function terAnd (a, b: trit): trit;
begin
terAnd := terMayBe;
if (a = terFalse) or (b = terFalse) then
terAnd := terFalse
else
if (a = terTrue) and (b = terTrue) then
terAnd := terTrue;
end;
function terOr (a, b: trit): trit;
begin
terOr := terMayBe;
if (a = terTrue) or (b = terTrue) then
terOr := terTrue
else
if (a = terFalse) and (b = terFalse) then
terOr := terFalse;
end;
function terEquals (a, b: trit): trit;
begin
if a = b then
terEquals := terTrue
else
if a <> b then
terEquals := terFalse;
if (a = terMayBe) or (b = terMayBe) then
terEquals := terMayBe;
end;
function terIfThen (a, b: trit): trit;
begin
terIfThen := terMayBe;
if (a = terTrue) or (b = terFalse) then
terIfThen := terTrue
else
if (a = terFalse) and (b = terTrue) then
terIfThen := terFalse;
end;
function terToStr(a: trit): string;
begin
case a of
terTrue: terToStr := 'True ';
terMayBe: terToStr := 'Maybe';
terFalse: terToStr := 'False';
end;
end;
begin
writeln('Ternary logic test:');
writeln;
writeln('NOT ', ' True ', ' Maybe', ' False');
writeln(' ', terToStr(terNot(terTrue)), ' ', terToStr(terNot(terMayBe)), ' ', terToStr(terNot(terFalse)));
writeln;
writeln('AND ', ' True ', ' Maybe', ' False');
writeln('True ', terToStr(terAnd(terTrue,terTrue)), ' ', terToStr(terAnd(terMayBe,terTrue)), ' ', terToStr(terAnd(terFalse,terTrue)));
writeln('Maybe ', terToStr(terAnd(terTrue,terMayBe)), ' ', terToStr(terAnd(terMayBe,terMayBe)), ' ', terToStr(terAnd(terFalse,terMayBe)));
writeln('False ', terToStr(terAnd(terTrue,terFalse)), ' ', terToStr(terAnd(terMayBe,terFalse)), ' ', terToStr(terAnd(terFalse,terFalse)));
writeln;
writeln('OR ', ' True ', ' Maybe', ' False');
writeln('True ', terToStr(terOR(terTrue,terTrue)), ' ', terToStr(terOR(terMayBe,terTrue)), ' ', terToStr(terOR(terFalse,terTrue)));
writeln('Maybe ', terToStr(terOR(terTrue,terMayBe)), ' ', terToStr(terOR(terMayBe,terMayBe)), ' ', terToStr(terOR(terFalse,terMayBe)));
writeln('False ', terToStr(terOR(terTrue,terFalse)), ' ', terToStr(terOR(terMayBe,terFalse)), ' ', terToStr(terOR(terFalse,terFalse)));
writeln;
writeln('IFTHEN', ' True ', ' Maybe', ' False');
writeln('True ', terToStr(terIfThen(terTrue,terTrue)), ' ', terToStr(terIfThen(terMayBe,terTrue)), ' ', terToStr(terIfThen(terFalse,terTrue)));
writeln('Maybe ', terToStr(terIfThen(terTrue,terMayBe)), ' ', terToStr(terIfThen(terMayBe,terMayBe)), ' ', terToStr(terIfThen(terFalse,terMayBe)));
writeln('False ', terToStr(terIfThen(terTrue,terFalse)), ' ', terToStr(terIfThen(terMayBe,terFalse)), ' ', terToStr(terIfThen(terFalse,terFalse)));
writeln;
writeln('EQUAL ', ' True ', ' Maybe', ' False');
writeln('True ', terToStr(terEquals(terTrue,terTrue)), ' ', terToStr(terEquals(terMayBe,terTrue)), ' ', terToStr(terEquals(terFalse,terTrue)));
writeln('Maybe ', terToStr(terEquals(terTrue,terMayBe)), ' ', terToStr(terEquals(terMayBe,terMayBe)), ' ', terToStr(terEquals(terFalse,terMayBe)));
writeln('False ', terToStr(terEquals(terTrue,terFalse)), ' ', terToStr(terEquals(terMayBe,terFalse)), ' ', terToStr(terEquals(terFalse,terFalse)));
writeln;
end. |
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another program can be written to parse and transform the original data into a format useful to the other. The term "Data Munging" is often used in programming circles for this task.
A request on the comp.lang.awk newsgroup led to a typical data munging task:
I have to analyse data files that have the following format:
Each row corresponds to 1 day and the field logic is: $1 is the date,
followed by 24 value/flag pairs, representing measurements at 01:00,
02:00 ... 24:00 of the respective day. In short:
<date> <val1> <flag1> <val2> <flag2> ... <val24> <flag24>
Some test data is available at:
... (nolonger available at original location)
I have to sum up the values (per day and only valid data, i.e. with
flag>0) in order to calculate the mean. That's not too difficult.
However, I also need to know what the "maximum data gap" is, i.e. the
longest period with successive invalid measurements (i.e values with
flag<=0)
The data is free to download and use and is of this format:
Data is no longer available at that link. Zipped mirror available here (offsite mirror).
1991-03-30 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1
1991-03-31 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 10.000 1 20.000 1 20.000 1 20.000 1 35.000 1 50.000 1 60.000 1 40.000 1 30.000 1 30.000 1 30.000 1 25.000 1 20.000 1 20.000 1 20.000 1 20.000 1 20.000 1 35.000 1
1991-03-31 40.000 1 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2 0.000 -2
1991-04-01 0.000 -2 13.000 1 16.000 1 21.000 1 24.000 1 22.000 1 20.000 1 18.000 1 29.000 1 44.000 1 50.000 1 43.000 1 38.000 1 27.000 1 27.000 1 24.000 1 23.000 1 18.000 1 12.000 1 13.000 1 14.000 1 15.000 1 13.000 1 10.000 1
1991-04-02 8.000 1 9.000 1 11.000 1 12.000 1 12.000 1 12.000 1 27.000 1 26.000 1 27.000 1 33.000 1 32.000 1 31.000 1 29.000 1 31.000 1 25.000 1 25.000 1 24.000 1 21.000 1 17.000 1 14.000 1 15.000 1 12.000 1 12.000 1 10.000 1
1991-04-03 10.000 1 9.000 1 10.000 1 10.000 1 9.000 1 10.000 1 15.000 1 24.000 1 28.000 1 24.000 1 18.000 1 14.000 1 12.000 1 13.000 1 14.000 1 15.000 1 14.000 1 15.000 1 13.000 1 13.000 1 13.000 1 12.000 1 10.000 1 10.000 1
Only a sample of the data showing its format is given above. The full example file may be downloaded here.
Structure your program to show statistics for each line of the file, (similar to the original Python, Perl, and AWK examples below), followed by summary statistics for the file. When showing example output just show a few line statistics and the full end summary.
| #Python | Python | import fileinput
import sys
nodata = 0; # Current run of consecutive flags<0 in lines of file
nodata_max=-1; # Max consecutive flags<0 in lines of file
nodata_maxline=[]; # ... and line number(s) where it occurs
tot_file = 0 # Sum of file data
num_file = 0 # Number of file data items with flag>0
infiles = sys.argv[1:]
for line in fileinput.input():
tot_line=0; # sum of line data
num_line=0; # number of line data items with flag>0
# extract field info
field = line.split()
date = field[0]
data = [float(f) for f in field[1::2]]
flags = [int(f) for f in field[2::2]]
for datum, flag in zip(data, flags):
if flag<1:
nodata += 1
else:
# check run of data-absent fields
if nodata_max==nodata and nodata>0:
nodata_maxline.append(date)
if nodata_max<nodata and nodata>0:
nodata_max=nodata
nodata_maxline=[date]
# re-initialise run of nodata counter
nodata=0;
# gather values for averaging
tot_line += datum
num_line += 1
# totals for the file so far
tot_file += tot_line
num_file += num_line
print "Line: %11s Reject: %2i Accept: %2i Line_tot: %10.3f Line_avg: %10.3f" % (
date,
len(data) -num_line,
num_line, tot_line,
tot_line/num_line if (num_line>0) else 0)
print ""
print "File(s) = %s" % (", ".join(infiles),)
print "Total = %10.3f" % (tot_file,)
print "Readings = %6i" % (num_file,)
print "Average = %10.3f" % (tot_file / num_file,)
print "\nMaximum run(s) of %i consecutive false readings ends at line starting with date(s): %s" % (
nodata_max, ", ".join(nodata_maxline)) |
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas | The Twelve Days of Christmas | Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | daysarray = {"first", "second", "third", "fourth", "fifth", "sixth",
"seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth"};
giftsarray = {"And a partridge in a pear tree.", "Two turtle doves",
"Three french hens", "Four calling birds", "FIVE GOLDEN RINGS",
"Six geese a-laying", "Seven swans a-swimming,",
"Eight maids a-milking", "Nine ladies dancing",
"Ten lords a-leaping", "Eleven pipers piping",
"Twelve drummers drumming"};
Do[Print[StringForm[
"On the `1` day of Christmas, my true love gave to me: `2`",
daysarray[[i]],
If[i == 1, "A partridge in a pear tree.",
Row[Reverse[Take[giftsarray, i]], ","]]]], {i, 1, 12}] |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #XPL0 | XPL0 | code ChOut=8, Attrib=69;
def Black, Blue, Green, Cyan, Red, Magenta, Brown, White, \attribute colors
Gray, LBlue, LGreen, LCyan, LRed, LMagenta, Yellow, BWhite; \EGA palette
[ChOut(6,^C); \default white on black background
Attrib(Red<<4+White); \white on red
ChOut(6,^o);
Attrib(Green<<4+Red); \red on green
ChOut(6,^l);
Attrib(Blue<<4+LGreen); \light green on blue
ChOut(6,^o);
Attrib(LRed<<4+White); \flashing white on (standard/dim) red
ChOut(6,^u);
Attrib(Cyan<<4+Black); \black on cyan
ChOut(6,^r);
] |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #zkl | zkl | fcn table(title,mode){
println("\n\e[1m%s\e[m\n bg\t fg".fmt(title));
foreach b in ([40..48].chain([100..107])){
print("%3d\t\e[%s%dm".fmt(b,mode,b));
foreach f in ([30..38].chain([90..97])){ print("\e[%dm%3d ".fmt(f,f)) }
println("\e[m");
}
}
table("normal ( ESC[22m or ESC[m )", "22;");
table("bold ( ESC[1m )", "1;");
table("faint ( ESC[2m ), not well supported", "2;");
table("italic ( ESC[3m ), not well supported", "3;");
table("underline ( ESC[4m ), support varies", "4;");
table("blink ( ESC[5m )", "5;");
table("inverted ( ESC[7m )", "7;"); |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if supported by the terminal)
| #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 FOR l=0 TO 7
20 READ c$: REM get our text for display
30 INK l: REM set the text colour
40 PRINT c$
50 NEXT l
60 PAPER 2: REM red background
70 INK 6: REM yellow forground
80 FLASH 1: REM activate flashing
90 PRINT "Flashing!": REM this will flash red and yellow (alternating inverse)
100 PAPER 7: INK 0: FLASH 0: REM normalize colours before exit
110 STOP
900 DATA "Black","Blue","Red","Magenta","Green","Cyan","Yellow","White" |
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes.
One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit.
This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
| #Haskell | Haskell | import Control.Concurrent
import Control.Concurrent.MVar
main =
do lineVar <- newEmptyMVar
countVar <- newEmptyMVar
let takeLine = takeMVar lineVar
putLine = putMVar lineVar . Just
putEOF = putMVar lineVar Nothing
takeCount = takeMVar countVar
putCount = putMVar countVar
forkIO $ writer takeLine putCount
reader putLine putEOF takeCount |
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use the term threads, others use the term tasks, while others use co-processes. This task should not be implemented using fork, spawn, or the Linux/UNIX/Win32 pipe command, as communication should be between threads, not processes.
One of the concurrent units will read from a file named "input.txt" and send the contents of that file, one line at a time, to the other concurrent unit, which will print the line it receives to standard output. The printing unit must count the number of lines it prints. After the concurrent unit reading the file sends its last line to the printing unit, the reading unit will request the number of lines printed by the printing unit. The reading unit will then print the number of lines printed by the printing unit.
This task requires two-way communication between the concurrent units. All concurrent units must cleanly terminate at the end of the program.
| #Icon_and_Unicon | Icon and Unicon | procedure main(A)
fName := A[1]|"index.txt"
p := thread produce(fName)
c := thread consume(p)
every wait(p | c)
end
procedure produce(fName)
every !open(fName)@>> # drop messages in p's outbox (blocking whenever box is full)
@>> # Signal consumer that p is done
write("count is ",<<@) # block until message in p's inbox
end
procedure consume(p)
i := 0
while write(\<<@p) do (i+:=1) # loop until empty message in p's outbox
# (blocking until each message arrives)
i@>>p # put row count into p's inbox
end |
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