Here's a challenge: make a randomized integer generator in any programming language without the use of a pre-defined method (i.e. Math.random();)
Rules:
Any programming language
Must be usable offline (haha, people who use curl!)
Interaction with hardware is acceptable
Must be tested with comp...
Challenge
In this challenge, you are to code in any language a program that will take a string and replace certain characters within it with different characters.
Input
[string] [char1] [char2]
string will be an indefinite line of characters surrounded by quotation mars, such as "Hello, Wor...
As you should (hopefully) know, a radiation hardened quine is a quine that you can remove any one character from and still print its original, pre-modified source. The thing is, with most of these you can only remove one character; otherwise everything breaks down. This is where this comes in; yo...
Introduction
Some ASCII characters are just so expensive these days...
To save money you've decided to write a program that encodes expensive characters using inexpensive ones.
However, character prices change frequently and you don't want to modify your program every time you need to encode o...
The ] nests the string one level deeper in an array, like [[q q q q w w w e e \n]]
Then, the single character input is split into an array like [q \n]
The double-nesting of the first array is currently needed because the "single character" input still has the newline attached (I don't have a chop operator yet).
The = (string equality) distributes pairwise over the arrays, comparing the q with [q q q q w w w e e \n] and the \n with nothing.
The language has something called the active modifier list. Each time a modifier (like the | reduce) is used, the modifier reduce is pushed onto that list.
No, they are not treated as operators. They are things that take operators (like + or *) and apply them in different ways. Reduce, for example, applies addition to an array to add together the elements of the array.
Then, when on operator + comes up, the program looks through the list to determine which modifiers are applicable, and puts those onto a selected modifier list.
I have a concept called the "footprint" that describes the number and type of operands that an operator accepts.
Addition has a [0,0] footprint since it's just two numbers. Something else may have a [1] footprint that means it can operate on a single 1-dimensional array.
Each modifier has its own footprint, like reduces [-1], for any single array of any size.
In the end, double-reduction addition has a footprint of [[-1],[-1],[0,0]]
@PhiNotPi The term I'm familiar with for that concept is "signature". The signature of a function defines the number and types of arguments, as well as the return type.
So, a single object is pops off the stack. Then, it gets fed through a recursive function that divides it into smaller objects if, say, that object had been marked as the subject of a foreach loop.
Then the individual objects are fed into another recursive function, where it detects that a modifier is in use, applies said modifier, and then recurses with a [[-1],[0,0]] footprint/signature.
Which, after being feed back through those two recursive functions again, becomes a [[0,0]] signature. When that is fed through the first recursive function, it makes sure that both operands are scalars by division+recursion. Once they are broken down into individual pieces, they are fed through the second recursive function again, which detects that there are no modifiers left, and performs the calculation. The result is then fed back up through the recursive chain.
All of which is invoked by a nice &performop(\&add); which allows direct compilation of the golfing language to Perl.
If I decided to add an input operator i that automatically chomps the newline, I could shorten the "count occurances of character" solution down to _ci=|+
GolfScript places the input on the stack, CJam doesn't. While CJam's approach always adds a byte to your count, GolfScript's approach is really annoying when undesired.
Yo @Dennis (and @Doorknob if you're awake!), it seems to be unclear whether our defaults for functions vs. programs can be assumed when the OP says "program," like for this question. Thoughts?
@Dennis Right, but based on the wording he doesn't seem to be enforcing programs only; it seems more like an ambiguous word choice. Do you know what I mean?
Composite Number Sequences
Inspired by this question
Given a positive integer n, your code must output the first n composite numbers.
Input / Output
You may write a program or a function. Input is through STDIN or function argument and output is to STDOUT, or function return value.
Output ca...
@AlexA. If you ask me, he might have excluded functions unintentionally, but he still excluded them. No way to tell for sure without waiting for an answer from the OP.
@Maltysen I'm not claiming that Pyth is an entirely stack-based language. With *2d something like cJam of GolfScript would have to push that as a code block.
@AlexA. (I'm about to go to sleep) Even I've been guilty of accidentally saying "Your program must..." in a challenge without intending to exclude functions. Currently, from my challenge-writing experience, if you say "the program" anywhere in your post then functions are automatically out, but I would really prefer something less... pedantic.
(Especially since newcomers are unlikely to know this rule.)
@AlexA. The other problem with that letter replacement challenge is that the specification says that the input string is "surrounded by quotation marks", which most people seem to have ignored.
@orlp I don't know. I interpreted it as the input being with quotes, the output without. The examples certainly suggest that this was the expectation. But the description does not make it entirely clear. And it looks like others interpreted it differently.
@orlp Yeah, I doubt that the OP did that on purpose. In any case, it looks like we have a bunch of answers that all interpret the requirements differently. Which is unfortunate.
@orlp I much prefer challenges where the "meat" of it is finding good solutions, and not on parsing weird input or producing painful output formats. Or on dealing with boundary/error cases. I often pass on those challenges entirely. And I know nothing about pokemons. :)
Is this number a prime?
code-golf math primes
Believe it or not, we do not yet have a code golf challenge for a simple primality test. While it may not be the most interesting challenge, particularly for "usual" languages, it can be nontrivial in many languages.
Rosetta code features lists by ...
@orlp Actually, my initial CJam implementation of your idea for the composite challenge is 18 bytes, which is the same as the one I already had. Dennis could probably reduce it to about half the size...
Is a point inside a polygon?
Given the polygon with 2 < N < 11 sides, on 2D plane, find out if a given point is inside the polygon.
The input can be an array of points in x, y, each determining a vertex, or by a string in format X Y x1 y1 x2 y2 ... xN yN (you may choose other separator). The X ...
Literal Fourier Transform (or Fouriest Numbers?)
(inspired by this Saturday Morning Breakfast Cereal comic)
It's called a fourier tranform when you take a number and convert it to the base system where it will have more fours, thus making it "fourier". If you pick the base with the most four...
Introduction
Today's my birthday (really!) and sadly I've had to organise my own party. Well, now you know, couldn't you at least make the cake?
Challenge
Given an integer n as input, write a full program to output a birthday cake with n candles on.
Output
A piece of cake with one candle on ...
Restricting to just programs requires explicitly requiring "full program" rather than just "program"
If the question requests a program, this can still be answered with a function. This allows for the fact that many people state "program" without thinking, not intending to exclude functions.
Fo...
Note: After trying this myself, I soon realized what a mistake this was. Therfore, I am modifying the rules a bit.
The minimum required functionality:
Character classes (., \w, \W, etc.)
Multipliers (+, *, and ?)
Simple capture groups
Your challenge is to implement PCRE in the language...
pop-con idea:
Your task is to write programs under 10 bytes (or 20 bytes, or flexible, or chaining and increasing, I'll decide later) in different languages, which take no input and all output the same thing.
Voting criteria:
Answers with more languages are better.
The shorter the the longest...
Example:
Write a function which returns number passed into it as an argument.
Solution:
f=x=>x
What is its length?
Is it 4 as a length of the lambda x=>x only or 6 as a length of whole statement with assignment?
What if there are 2 functions?
g=x=>x/2
f=x=>g(x)+g(x)
The top half (above the giant dividing line) take the source and compiles it to Perl, which, for the most part, is simple substitution of + with &performop(\&add); etc.
Then, below the dividing line, is all of the meat of calculations.
The "compiled" source code has a ton of subroutines in it, for each of the operators.
And so, by making a list of operations, like &performop(\&add);&performop(\&mult); I can call those subroutines in the order needed to perform those operations.
A lot of non-trivial graphical questions seem to get most of the answers with more verbose languages. (Things like this are possible with Pyth and CJam.) I think it would be cool to have a golf language like Pyth or CJam, but with a "mode change" operation that changes between different modes (default, mathematics, image processing, etc.) and then all commands/variables/stuff would be single characters in that mode.
So say D is default and M is maths, you have a program like p"Hello, World"Mp23Dp"hdjd" where the program starts in default, switches to maths mode and then back to default
And p in default is print while in maths it's say, factorise
I guess this could be done as a mod for Pyth or CJam. For CJam, it would be a normal instruction. For Pyth I'd say when the parser encounters the "mode change" command it would change any subsequent commands to another mode (the mode command is never actually executed, it just changes compiler mode).
Talking of that, @isaacg I think Pyth needs an equivalent to pass in Python. The only equivalent is K0 or J0, which seems a bit long for a golfing language
Pyth, 19 bytes
Late entry but after finding .d0 in the docs last night I decided to give it a go.
DCNK.d0W<-.d0KNJ1))
Defines a function which loops until the time elapsed is N seconds.
Try it here.
Implement Simple Regex Character Classes
This task is about writing a very basic Regex tester, that only has to deal with simple Character Classes (ex: [abc], [a-z]). Shorthand Character Classes (ex: \d, \w), dot, anchors, quantifiers and all other awesome Regex features will be ignored.
Input
...
Here's a challenge: make a randomized integer generator in any programming language without the use of a pre-defined method (i.e. Math.random();)
Rules:
Any programming language
Must be usable offline (haha, people who use curl!)
Interaction with hardware is acceptable
Must be tested with comp...
Challenge
In this challenge, you are to code in any language a program that will take a string and replace certain characters within it with different characters.
Input
[string] [char1] [char2]
string will be an indefinite line of characters surrounded by quotation mars, such as "Hello, Wor...
Introduction
Some ASCII characters are just so expensive these days...
To save money you've decided to write a program that encodes expensive characters using inexpensive ones.
However, character prices change frequently and you don't want to modify your program every time you need to encode o...
Composite Number Sequences
Inspired by this question
Given a positive integer n, your code must output the first n composite numbers.
Input / Output
You may write a program or a function. Input is through STDIN or function argument and output is to STDOUT, or function return value.
Output ca...
Pyth, 46 bytes
Encoder, 22 bytes
@smfql{Td^<Szd4S4-Cw48
Decoder, 24 bytes
C+48xsmfql{Td^<sS{zd4S4z
Is this number a prime?
code-golf math primes
Believe it or not, we do not yet have a code golf challenge for a simple primality test. While it may not be the most interesting challenge, particularly for "usual" languages, it can be nontrivial in many languages.
Rosetta code features lists by ...
Is a point inside a polygon?
Given the polygon with 2 < N < 11 sides, on 2D plane, find out if a given point is inside the polygon.
The input can be an array of points in x, y, each determining a vertex, or by a string in format X Y x1 y1 x2 y2 ... xN yN (you may choose other separator). The X ...
Literal Fourier Transform (or Fouriest Numbers?)
(inspired by this Saturday Morning Breakfast Cereal comic)
It's called a fourier tranform when you take a number and convert it to the base system where it will have more fours, thus making it "fourier". If you pick the base with the most four...
Introduction
Today's my birthday (really!) and sadly I've had to organise my own party. Well, now you know, couldn't you at least make the cake?
Challenge
Given an integer n as input, write a full program to output a birthday cake with n candles on.
Output
A piece of cake with one candle on ...
Restricting to just programs requires explicitly requiring "full program" rather than just "program"
If the question requests a program, this can still be answered with a function. This allows for the fact that many people state "program" without thinking, not intending to exclude functions.
Fo...
Note: After trying this myself, I soon realized what a mistake this was. Therfore, I am modifying the rules a bit.
The minimum required functionality:
Character classes (., \w, \W, etc.)
Multipliers (+, *, and ?)
Simple capture groups
Your challenge is to implement PCRE in the language...
pop-con idea:
Your task is to write programs under 10 bytes (or 20 bytes, or flexible, or chaining and increasing, I'll decide later) in different languages, which take no input and all output the same thing.
Voting criteria:
Answers with more languages are better.
The shorter the the longest...
Example:
Write a function which returns number passed into it as an argument.
Solution:
f=x=>x
What is its length?
Is it 4 as a length of the lambda x=>x only or 6 as a length of whole statement with assignment?
What if there are 2 functions?
g=x=>x/2
f=x=>g(x)+g(x)
Implement Simple Regex Character Classes
This task is about writing a very basic Regex tester, that only has to deal with simple Character Classes (ex: [abc], [a-z]). Shorthand Character Classes (ex: \d, \w), dot, anchors, quantifiers and all other awesome Regex features will be ignored.
Input
...
