Rosetta Code:Village Pump/Suggest a programming task: Difference between revisions
Rosetta Code:Village Pump/Suggest a programming task (view source)
Revision as of 01:53, 1 August 2023
, 9 months ago→Media files
| (111 intermediate revisions by 37 users not shown) | |||
Line 1:
{{#set:is contribution page=true}}[[Category:Requesting Content]]So
you want to see a problem solved? If you're not comfortable creating the task page yourself, feel free to edit this page, and describe the problem below.
(To edit this page, click the "edit" tab at the top.)
You also might want to check out the [[:Category:Draft Programming Tasks|draft tasks]] to see if someone has already suggested one and partially produced the page; if so, just help them out by supplying what's needed to take the page from draft to full task.
When making a request, please place it in the [[#Unsorted|Unsorted]] section.
Also, feel free to review the others that are already here; help sort them into the other categories, based on the category descriptions.
(If we need another category or two, you can create them.)
=Incomplete=
* c++ console command line app Name/fantasyname/itemname/etc generators, that takes input from the keyboard and appends them to text files, then all the text files are read and every combination of item is then dumped to a new text file.
==General==
* Benchmarks
Line 20 ⟶ 29:
** Calculate number of [Sundays|Mondays|Tuesdays|Wednesdays|Thursdays|Fridays|Saturdays] in a given month or year
** Display a date in various formats
** Something with [http://terrancalendar.com the Terran Computational Calendar] (and contribute to [https://github.com/terrancalendar/terrancalendar their Github project])
** Calculate yesterday's date
* Show creation, element insertion, element removal and enumeration of a "set" type that enforces constraints as described [[Talk:Symmetric difference#Set_type|here]]. (An invariant analog would be nice as well.)
* The [[:Category:Object oriented|Object oriented category]] is missing a lot of the basics like [[calling a method]].
Line 29 ⟶ 40:
* an encryption program
** What sort of encryption? We've already got tasks for using SSL connections (e.g., [[Client-Authenticated HTTPS Request]]) so maybe you're after message-level encryption? Perhaps a simple [[wp:Data Encryption Standard|DES]] implementation would be apt. (The advantage of that is that it is not particularly strong itself, and so doesn't run close to the legal issues in this area, but points the way towards real production encryption.) –[[User:Dkf|Donal Fellows]] 09:17, 20 January 2010 (UTC)
** See Playfair below --[[User:Brnikat|Brnikat]] ([[User talk:Brnikat|talk]]) 15:09, 10 July 2015 (UTC)
* Monads
* Coroutines/[[Generator]]s
Line 62 ⟶ 74:
* Zipping sequences (calculating their [[wp:Convolution (computer science)|convolution]]) and unzipping
* cat & tee: copy input to output, copy input to multiple outputs. I'm not sure of the best name for these tasks ("IO/cat" & "IO/tee"? "copy input to output"?). [[Input loop]] has some solutions that implement the first, but it doesn't explicitly say what should be done with input, and some solutions to `cat` and `tee` may not use loops (which is what's interesting about these tasks).
* We should maybe double check whether we are missing any tasks corresponding to algorithms listed at http://algo-visualizer.jasonpark.me/
* Images: Reading, modifying, and writing either a .PNG/.JPG or other common image type. (Currently, there's bitmap and PPM stuff, but this task is for somethign more practical.)
* It would be good to have an implementation of the Nelder-Mead gradient descent algorithm. https://en.wikipedia.org/wiki/Nelder-Mead_method This would be a good candidate for a generic driver (eg:c++ template class) accepting a function and returning the parameter(s) that map to the functions (apparent) minimum. --[[User:Bitrat|Bitrat]] 14:10, 17 January 2019 (UTC)
*A program which prints out 'Rainbow' to the screen, with each character being one color of the rainbow.
==Games==
* Connect Four (or more) with variable and standard game board (6 rows, 7 columns)
*:- but watch for trade mark violations etc --[[User:Paddy3118|Paddy3118]] 17:33, 29 April 2009 (UTC)
Line 81 ⟶ 103:
::::You are both right, here is a link to a java implementation of pacman [http://zetcode.com/tutorials/javagamestutorial/pacman/]
* Implement a program that generates a random [[wp:Chess960 starting position|Chess960 starting position]]--[[User:Grondilu|Grondilu]] ([[User talk:Grondilu|talk]]) 23:56, 18 April 2014 (UTC)
* What about the [[wp:Nim|Nim]] game and the variations found on its wiki page?
:See [[User:DanBron/Game of Nim]] for history... --[[User:Paddy3118|Paddy3118]] ([[User talk:Paddy3118|talk]]) 05:57, 22 May 2015 (UTC)
* Annotate a crossword diagram given in the format
<pre>
......#......
.#.#.#.#.#.#.
.......#.....
.#.###.#.#.#.
.....#.......
##.#.#.#.###.
...#.....#...
.###.#.#.#.##
.......#.....
.#.#.#.###.#.
.....#.......
.#.#.#.#.#.#.
......#......
</pre>
and produce a diagram with the numbers in place and a skeleton set of clues in this format
<pre>
|--------------------------------------|
|1 | |2 | |3 | |##|4 |5 | |6 | |7 |
| | | | | | |##| | | | | | |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
| |##| |##| |##|8 |##| |##| |##| |
| |##| |##| |##| |##| |##| |##| |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
| |##| |##|##|##| |##| |##| |##| |
| |##| |##|##|##| |##| |##| |##| |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
|11| | | |12|##|13| | | | | | |
| | | | | |##| | | | | | | |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
|##|##| |##| |##| |##| |##|##|##| |
|##|##| |##| |##| |##| |##|##|##| |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
|14| | |##|15| | | | |##|16| | |
| | | |##| | | | | |##| | | |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
| |##|##|##| |##| |##| |##| |##|##|
| |##|##|##| |##| |##| |##| |##|##|
|--+--+--+--+--+--+--+--+--+--+--+--+--|
|17| |18| | | | |##|19| | | |20|
| | | | | | | |##| | | | | |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
| |##| |##| |##| |##|##|##| |##| |
| |##| |##| |##| |##|##|##| |##| |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
|21| | | | |##|22| |23| | | | |
| | | | | |##| | | | | | | |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
| |##| |##| |##| |##| |##| |##| |
| |##| |##| |##| |##| |##| |##| |
|--+--+--+--+--+--+--+--+--+--+--+--+--|
|24| | | | | |##|25| | | | | |
| | | | | | |##| | | | | | |
|--------------------------------------|
Across
1 (6)
4 (6)
9 (7)
10 (5)
11 (5)
13 (7)
14 (3)
15 (5)
16 (3)
17 (7)
19 (5)
21 (5)
22 (7)
24 (6)
25 (6)
Down
1 (5)
2 (7)
3 (7)
5 (9)
6 (5)
7 (7)
8 (11)
12 (9)
14 (7)
16 (7)
18 (5)
20 (5)
23 (3)
</pre>
where the bracket numbers are the lengths of the corresponding solutions.
A much harder task would be, given a set of simple definition type clues and the language used, solve the crossword.
--[[User:Brnikat|Brnikat]] ([[User talk:Brnikat|talk]]) 15:03, 10 July 2015 (UTC)
* Implement a [[wp:Wa-Tor|Wa-Tor]] population dynamics simulator. --[[User:Cgibbons|Cgibbons]] 22:22, 3 Apr 2023 (UTC)
::Python implementation: [https://scipython.com/blog/wa-tor-world/]
===Database / Network===
Line 89 ⟶ 211:
=== Data structures and algorithms ===
* Implement a finite state machine that verifies that a string contains a valid binary number. This is already done [https://sites.google.com/site/opensourceconstriubtions/ettl-martin-1/articles/how-to-determine-a-string-represents-a-binary-number-using-a-finite-state-machine here].
* Implement [http://de.wikipedia.org/wiki/Duff%E2%80%99s_Device Duff's Device] in your programming language.
: It seems to be specific to C/C++ and would it be best practice or just some kind of optimisation? --[[User:Paddy3118|Paddy3118]] ([[User talk:Paddy3118|talk]]) 17:54, 20 May 2014 (UTC)
* canonical huffman code
* Include-in : test wether a list is a part of another one, ie if each element of the first list is an element of the second one
Line 125 ⟶ 250:
* [[wp:Burrows-Wheeler transform|Burrows-Wheeler transform]]
* [[wp:Move-to-front transform|Move-to-front transform]]
: Done as [[Move-to-front algorithm]] --[[User:Paddy3118|Paddy3118]] ([[User talk:Paddy3118|talk]]) 20:21, 20 May 2014 (UTC)
* [[wp:Cartesian tree|Cartesian tree]] construction [[User:qu1j0t3]]
* [[wp:Trie|Prefix Tree]]
Line 170 ⟶ 296:
===Mathematical Operations===
* Task: bAckermann. The idea is to take the Ackermann function and find the sequence of all possible calls to the function sorted by number of recursions. The output would begin:
A(0,n) , A(1,0) , A(1,1) , A(2,0) , A(1,2) , A(1,3) , A(1,4) , A(1,5) , A(2,1) , A(1,6) , A(3,0) , A(1,7) , ...
:Conjecture: R(x+z,y)>R(x,y) and R(x,y+z)>R(x,y) for all positive integer z and all positive integer x where R is the function returning the number of recursions in the corresponding call to the Ackermann function. Can anyone prove this conjecture? -[[User:Zelah|Zelah]] ([[User talk:Zelah|talk]]) 02:34, 7 May 2014 (UTC)
* Write a programm in our programming language, that showns the numerical limits of all available datatypes for numbers. The limits of datatypes could be max number, min number, bit precission, decimal precission, etc.
* [[Convert a decimal number to fraction ]]Convert a decimal number to fraction.
Line 195 ⟶ 324:
* Perform basic mathematical operations (+,*,/,-) for numbers represented as strings.[https://github.com/danmar/cppcheck/blob/master/lib/mathlib.h Here] is a sample implementation in C++.
* Implement the longest increasing subsequence algorithm in your programming language. [http://www.algorithmist.com/index.php/Longest_Increasing_Subsequence Here] is an implementation in C and C++.
* [http://en.wikipedia.org/wiki/Fermat_primality_test Fermat primality test]
* Implement a function in your programming language that prints numbers in [http://en.wikipedia.org/wiki/Engineering_notation Engineering_notation]. A C# implementation is already [http://stackoverflow.com/a/808295 available].
* [http://en.wikipedia.org/wiki/Arithmetic_shift Arithmetic shift] - Many languages lack operators like C's << and >>. The goal for the task would be to build the function shift(n,s) where n and s are both signed integers; n is the number to be shifted and s is the number of positions (negative for left; positive for right). So shift(5,-2) would yield the same result as 5<<2. --[[User:Mappo|Mappo]] 19 Nov. 2014
:: See [[Bitwise operations]]. --[[User:Paddy3118|Paddy3118]] ([[User talk:Paddy3118|talk]]) 17:40, 19 November 2014 (UTC)
:::Looks like he wants it re-implemented even if the language already covers it. --[[User:Mwn3d|Mwn3d]] ([[User talk:Mwn3d|talk]]) 17:56, 19 November 2014 (UTC)
===Color Spaces===
Line 225 ⟶ 359:
==Implementation-specific==
* Show how your language supports separation of interface or specification from implementation.
==Language-specific==
Add a sample Makefile to demonstrate how to build a dummy executable for several programming languages (distinguish between several platforms: Linux,Windows,etc)
Line 233 ⟶ 369:
==Project level==
Which project, RC ? --[[User:Hajo|Hajo]] ([[User talk:Hajo|talk]]) 07:20, 21 November 2014 (UTC)
If possible, find ways to break these into smaller tasks
which can ultimately be assembled into the final project.
===Self-hosting compiler===
* Self-hosting compiler. Now it is a draft task. If this task is too large then I could break it up into smaller pieces. An example of a subtask that might be good is to translate functions expressed in language A into functions expressed in language B for languages A and B that have notions of functions. More specific would be to translate a Scheme-like syntax for functions into your language's syntax for functions. -[[User:Zelah|Zelah]] ([[User talk:Zelah|talk]]) 02:43, 7 May 2014 (UTC)
===Super Simple p2p network===
: Could be done with FIFOs for streams, and a constant number of clients. Needs to be more specific regarding what it does. --[[User:Short Circuit|Short Circuit]] 22:28, 6 December 2007 (MST)
:: probably means some thing like this <nowiki>http://ansuz.sooke.bc.ca/software/molester/molester</nowiki>. To make it suitable for rc the restrictions need to be spelt out - i.e. fixing the protocol and discovery mechanisms [[User:Rahul|Rahul]] 20:24, 7 October 2008 (UTC)
===A table-based native code assembler===
implement a table-based native code (macro?) assembler in various HLLs
Line 284 ⟶ 428:
===Chat Server, Client and Gateway===
I'll get started on a demo of this and proper write up over the next couple weeks.
There's already a [[Chat server]] task, but it doesn't really specify a protocol.
Most implementations seem to be pretty straightforward, query the client for a nick, then announce all messages to everyone.
The chat server I'd propose is slightly more complicated, but not as complex as IRC.
I'll work on a more clear protocol spec, but at a minimum changing of nicks and private messages, some others that will come up I'm sure (more features would be permitted, but a minimum and compatible protocol for the later projects).
The second project is a Chat Client, it would hide the protocol (similar to IRC clients) so that the user can simply type messages, pm people via something like `/pm rabuf Hey, going to the movie tonight?`. Filtering messages received from the server that the user doesn't need (like PING/PONG messages), or optionally killlists to hide messages from annoying people. This could be split into 2+ projects. A simple CLI, this would look like the result of telnetting into the current chat servers. Hides the protocol, user simply sees prompts for a name at the start, and a prompt for messages. A more complex CLI version using something like ncurses or slang to build a more featureful UI (separate panel for PMs, text input in a panel at the bottom, etc.). And a GUI client
(ideally, each language would have one `client` core that people build these
UI wrappers around).
The third part is what [[IRC Gateway]] is proposing now, but simplified. Connect two servers, announce messages between them or extend the protocol of the servers to allow gateways to be special. Announce messages as rabuf if the user is local, rabuf@rosettacode if they're from the other side of the gateway, etc. This is mainly to address what I (personally, nothing against the task, but it's potentially very easy or ludicrously hard) see as a problem in the IRC Gateway task. In the TCL version the code is largley provided by an existing library, in languages lacking such a library one would need to be made or found. Potentially allow PMs across the gateway `/pm rabuf@rosettacode Yo!`.
Line 295 ⟶ 444:
--[[User:Rabuf|Rabuf]] ([[User talk:Rabuf|talk]]) 20:47, 5 November 2013 (UTC)
==Unsorted==
I am trying to write the following instructions in Pharo or SmallTalk:
- a linked list with tests
- a simple program equivalent of javadoc system that generates a mini javadoc like html file for a class passed as argument.
Place new items here, if it's unclear where they belong.
=== Count Consonants ===
Create a program to count consonants in a string input by the user using the ASCII character set.
The program must only count the letters that are not vowels. It should not count white space, punctuation, control characters, or numeric digits.
For instance, and Ada solution is:
<lang Ada>
with Ada.Text_IO; use Ada.Text_IO;
procedure Main is
subtype letter is Character with
Static_Predicate => letter in 'A' .. 'Z' | 'a' .. 'z';
subtype Vowel is Character with
Static_Predicate => Vowel in 'A' | 'E' | 'I' | 'O' | 'U' |
'a' | 'e' | 'i' | 'o' | 'u';
subtype consonant is character with
dynamic_predicate => consonant in letter and then consonant not in vowel;
Input : String(1..1024);
length : natural;
consonant_count : Natural := 0;
begin
Put("Enter a string: ");
Get_Line(Item => Input, Last => length);
-- count consonants
for char of input(1..length) loop
if char in consonant then
consonant_count := consonant_count + 1;
end if;
end loop;
New_Line;
Put_Line(Input(1..Length));
Put_Line("contains" & consonant_count'image & " consonants.");
end Main;
</lang>
See also https://rosettacode.org/wiki/Count_how_many_vowels_and_consonants_occur_in_a_string.
[[user:wherrera|wherrera]]
=== Multiple Mice ===
If 2 or more USB mice (or trackballs / trackpads) are connected to the system, read the input of each separately (for multiple mouse pointers or for multiplayer game input).
=== Colorwheel ===
description
* [https://stackoverflow.com/questions/4235072/what-is-the-math-behind-the-colour-wheel SO]
Versions:
* [https://commons.wikimedia.org/wiki/File:HLSColorSpace.png continous]
* discrete: circle is divided into n sectors varying in hue. Each sector is divided into m levels along radial dimension varying in lightnes, like [https://theblog.adobe.com/the-power-of-the-palette-why-color-is-key-in-data-visualization-and-how-to-use-it/ here]
=== Operators polymorphism ===
For many OO programming languages we need simple examples of [http://en.wikipedia.org/wiki/Operator_overloading operator overloading] and (if applicable to language) examples how to create new operators.--[[User:Zmi007|Zmi007]] ([[User talk:Zmi007|talk]]) 10:31, 16 April 2015 (UTC)
Not only OO languages. Algol68 allows operator overloading and creation of new operators. For instance
<lang ALGOL68>
OP FACTORIAL = (INT n) INT :
IF n < 1 THEN 1 ELSE
INT fact:= 1;
FOR i FROM 2 TO n DO fact TIMESAB i OD;
fact
FI;
OP * = (CHAR c, INT n) []CHAR :
( [n]CHAR result := HEAP [n] CHAR;
FOR i TO n DO result[i]:=c OD;
result
);
print ((FACTORIAL 5, newline));
print (("X" * 6, newline))
</lang>
Output:
<lang>
+120
XXXXXX
</lang>
[[User:Brnikat|Brnikat]] ([[User talk:Brnikat|talk]]) 11:58, 10 July 2015 (UTC)
=== Simple OCR ===
("optical character recognition") - Find text (or numbers) in pictures,
for example comics (like Dilbert), or screenshots. <br>
WRT "simple", we restrict this to chars of known fonts,
e.g. by giving the program some picture(s) with known text-samples. --13:07, 13 December 2014 (UTC)
=== Page-splitter ===
A bot for splitting pages into sub-pages.
If possible, with only a single captcha-check.<br>
E.g. I moved some entries from [[99_Bottles_of_Beer]] to separate pages, <br>
to organize them into groups of languages per subpage, <br>
see [[:Category:99_Bottles_of_Beer]].
The Page-splitter should be able to automate such tasks. --[[User:Hajo|Hajo]] ([[User talk:Hajo|talk]]) 07:20, 21 November 2014 (UTC)
=== Reversible random bit generator ===
Implement a random bit generator that can be run forward and backward.
When run backward it produces bits in reverse order.
I suggest using a maximal period minimal cost linear hybrid cellular automaton utilizing rules 90 and 150. -[[User:Zelah|Zelah]] ([[User talk:Zelah|talk]]) 02:35, 7 May 2014 (UTC)
=== Duff's Device ===
Implement [http://en.wikipedia.org/wiki/Duff%27s_device Duff's Device] or a near equivalent [[User:Axtens|Axtens]] ([[User talk:Axtens|talk]]) 03:27, 26 April 2014 (UTC)
===Bank Routing Number Validator===
All banks are assigned one or more 9-digit routing numbers (aka. transit routing number) that are self checking according to this algorithm.
From the left, multiply each digit by a corresponding weight (3,7,1,3,7,1,3,7,1) and add all products.
If the sum ends in zero, the number is a valid routing number.
Try it for 121000248 - it should sum up to 60.
Also try it on the 9-digit routing number found at the bottom of your checking account)
===Clipboard Manipulation===
Display the clipboard content & Write new content to the clipboard
===Minilight===
A minimal global illumination renderer http://www.hxa.name/minilight/
===Random RC task===
Select a random task or draft task from RC, filtering out the non-task pages
**Possibly done as a variation on [[Rosetta Code/Find unimplemented tasks]]?
:See [http://irclog.perlgeek.de/rosettacode/2011-11-21#i_4737091 this IRC discussion] for more information -- [[User:Eriksiers|Erik Siers]] 05:46, 21 November 2011 (UTC)
=== Noises ===
* Perlin Noise, Simplex Noise, Worley Noise implementations
http://en.wikipedia.org/wiki/Perlin_noise
Line 326 ⟶ 577:
* Perlin Noise, Simplex Noise, Worley Noise implementations for tiling system in video games or other media
Using mutexes or semaphores to conduct thread safe and robust read and writes from a circular buffer.
===Henderson Escher Picture Language===
[http://www.ecs.soton.ac.uk/%7Eph/funcgeo.pdf PDF] as made famous by [http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-15.html#%_sec_2.2.4 SICP Section 2.2.4] [http://groups.csail.mit.edu/mac/classes/6.001/abelson-sussman-lectures/ Video, Lecture 3a].
Here is an [http://www.frank-buss.de/lisp/functional.html implementation in Lisp] by Frank Buss. --[[User:Alanning|Alanning]] 04:00, 27 May 2011 (UTC)
===Phonecode===
Given a list of words, and a telephone number, find all possible encodings of that telephone number by words. This task has already been used in a few comparative studies of language performance and productivity, for example [http://page.mi.fu-berlin.de/prechelt/Biblio/jccpprtTR.pdf]
: Thanks so much for that link! I had read the paper some time ago but I probably have the link on an old hard drive somewhere...
: You have to remember though, that the aims of RC are ''very'' different to the authors of that paper and any task would have to be written for RC. If anyone has the number to a cold-calling firm, we could find the most appropriate phrase for their number ;-) or maybe not. --[[User:Paddy3118|Paddy3118]] 08:15, 7 May 2011 (UTC)
:: Here's an easy one. The phone number to the White House [http://www.whitehouse.gov/contact switch board]: 202-456-1414. Nothing specific or political intended here; it's just a published, public number. I do like the task idea, though. --[[User:Short Circuit|Michael Mol]] 13:15, 8 May 2011 (UTC)
===Weather Routing===
The weather routing problem has the following parts:
<ul>
<li> a predicted surface wind direction and speed, at increments of longitude, latitude, and time</li>
<li> an expected surface current direction and speed, at increments of longitude, latitude, and time</li>
<li> 'polar data' describing maximum speed of a sailboat at points of sail for a given speed of wind over water</li>
<li> regions for sailing (the open ocean) and not (the land, shallows, restricted areas, etc.)</li>
<li> a starting location and time, and a destination</li>
</ul>
Given the above information and a specific path, progress along path and therefore arrival time are determined. The weather routing problem, conversely, is to determine the path which results in the earliest arrival time.
[[User:JimTheriot|JimTheriot]] ([[User talk:JimTheriot|talk]]) 00:33, 8 July 2015 (UTC)
===Project Euler problems===
* I suggest implementations of various maze generation algorithms, such as Recursive Division or Prim's Algorithm. A website that already does this for Python can be found here: [http://weblog.jamisbuck.org/search?q=maze+generation http://weblog.jamisbuck.org]--[[User:Intercoder|Intercoder]] 12:57, 7 March 2011 (UTC)
Line 491 ⟶ 759:
* Draw a Pythagoras Tree ( http://fsharpnews.blogspot.it/2009/05/pythagoras-tree.html http://en.wikipedia.org/wiki/Pythagoras_tree_%28fractal%29 )
* Linear regression [[User:Wei2912|Wei2912]] ([[User talk:Wei2912|talk]]) 14:38, 6 June 2014 (UTC)
=== Playfair encryption and decryption ===
This is a specific example of the encryption problem mentioned in the general section. Playfair is a simple 25-character bigram alphabetic cipher which was still being used by the military in WW1. The task is to use a given keyword or phrase to generate a key which is used to encrypt a plain text and then to decrypt the corresponding cypher text. As only 25 different letters can be used, one must be chosen '''not''' to be used in the plaintext, substituting a valid character as needed to maintain unambiguity of the message. As adjacent identical letters can not be present in the plaintext before encryption, one or more dummy characters must be inserted between them. The plaintext must be padded to an even number of characters before encryption.
I don't yet have a suggested plaintext which trips all the above special conditions but will produce one, along with a pass phrase, the corresponding key and the cipher text.
[[User:Brnikat|Brnikat]] ([[User talk:Brnikat|talk]]) 11:16, 10 July 2015 (UTC)
:There is already a draft task [[Playfair_cipher]] --[[User:AndiPersti|Andreas Perstinger]] ([[User talk:AndiPersti|talk]]) 05:32, 11 July 2015 (UTC)
=== ICMP Ping ===
Send an ICMP ping to some local resource, such as the current default gateway or even just 127.0.0.1 or ::1, and display information about the response or the absence of the response.
=== Generate a Regular Expression for a Range of Integers ===
Write a function that, given the integers 0 <= ''min'' < = ''max'', returns a regular expression that will match the decimal representation of any integer in the range [''min'', ''max'']. You may assume there are no thousand-separators, leading 0's, or other problematic characters in the string to be processed. You may also assume the caller of your function will prepend/append appropriate anchors (e.g., ^, $, or \b) depending on need, so don't include them. Don't use \d as an alias for [0-9] since \d can match weird unicode characters on some systems.
'''Example''':
''min'' = 1
''max'' = 31
f(''min'', ''max'') = [1-9]|[1-2][0-9]|3[0-1] /* possible result */
f(''min'', ''max'') = [1-9]|[12][0-9]|3[01] /* equally-valid alternate result */
'''Example''':
''min'' = 91
''max'' = 417
f(''min'', ''max'') = 9[1-9]|[1-3][0-9]{2}|4(0[0-9]|1[0-7]) /* possible result */
f(''min'', ''max'') = 9[1-9]|[1-3][0-9][0-9]|4(0[0-9]|1[0-7]) /* equally-valid alternate result */
Hint: Use a recursive, divide-and-conquer approach. You will have to handle cases where max contains more digits than min.
Bonus: support ranges containing negative integers.
=== Weighted Random ===
Pick a random item from a list of dozen items, where each item has different weight (rarity). If the language permits, the list should be made in a way that makes it easy to add new items without having to adjust the weights of the other items.
Gaming example: random treasure generation in roguelikes. I've found that this is extremely awkward to do in some languages, and simple in others.
=== Partitioning ===
Task for "partition an integer into X primes". For example, partition 19 into 3 primes could return 3+5+11.
<br>
-----
<br>
This request was just created today.
See the Rosetta Code task:
:* [http://rosettacode.org/wiki/Partition_an_integer_X_into_N_primes '''Partition an integer X into N primes'''].
-- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 03:48, 3 March 2017 (UTC)
=== Bron-Kerbosch algorithm ===
Implement any of the variants of the [[wp:Bron-Kerbosch_algorithm|Bron-Kerbosch algorithm]] for finding maximal cliques (maximal complete subgraphs) in an undirected graph.
This should likely be sorted under 1.2.2.1, Graph algorithms.
=== Radix-50 encoding and decoding ===
[[wp:DEC_Radix-50|Radix-50]] is a method of encoding a restricted character set, used by DEC to store compiler labels and filenames. Each 16-bit word stores three characters encoded as char1*40*40 + char2*40 + char3. The name Radix-50 comes from 50(octal) = 40(decimal).
Challenge:
* encode up to three characters into a single word, indicate what you do with invalid characters
* decode a single word into three characters, indicate what you do with invalid data (word>=40*40*40)
* encode a string, indicate what you do with invalid characters
* decode to a string, indicate what you do with invalid data (word>=40*40*40)
The character set to be used is:
" ABCDEFGHIJKLMNOPQRSTUVWXYZ$?%0123456789"
[[User:Jgh|Jgh]] ([[User talk:Jgh|talk]]) 17:14, 15 May 2020 (UTC)
:That sounds like a good idea for a task which will particularly appeal to the 'old timers' amongst us. Why don't you create a draft task for it and add an implementation to start the ball rolling.
[[User:PureFox|PureFox]] ([[User talk:PureFox|talk]]) 08:14, 17 May 2020 (UTC)
=== Modulo operation ===
The table [[wp:Modulo_operation#In_programming_languages]] deserves to be somewhere on this site, with additional information and features.
In my own docs (for Phix) I have this (as a suggestion for the kind of info I think would be useful):
x,y: -9,-4 -9,+4 +9,-4 +9,+4
remainder(x,y): -1 -1 +1 +1
mod(x,y): -1 +3 -3 +1 -- (matches C's % operator)
I was thinking there could be checkboxes to filter the list to languages that can and cannot get the results you need/prefer, have an infix operator (or two), work on integers and floating point values or not, and probably something about precedence and associativity. Also the availability of a divmod function, and whether native/bigint/gmp wrappers all agree.
A table would clearly be better than a long list of individual entries, I know we can do sorting ([[Rosetta_Code/Count_examples/Full_list|eg]]), I don't know whether filtering is possible. --[[User:Petelomax|Pete Lomax]] ([[User talk:Petelomax|talk]]) 08:06, 29 March 2021 (UTC)
=== Media files ===
Determine the duration of an audio or video file. Extract a thumbnail from a video file. --[[User:Petelomax|Petelomax]] ([[User talk:Petelomax|talk]]) 01:53, 1 August 2023 (UTC)
==Insufficient information==
| |||