Posts by AndrewTheCodegolfer
Your challenge today is to golf a program to interpret something Turing-complete. You may use any Turing-complete system for this so long as it is not the source language of the challenge - even a...
COPS THREAD A famous cops-and-robbers challenge whose source shall remain unnamed is brought to Codidact. You are a robber. Your goal is to find answers on this link which haven't been cracked an...
Interpreting the challenge too literally If the challenge asks that you print the nth prime given input n, a program printing the nth prime given input n isn't allowed.
ROBBERS' THREAD A famous cops-and-robbers challenge whose source shall remain unnamed is brought to Codidact. You are a cop. You should write a program in a "famous" (has an English Wikipedia/Eso...
Languages with free online interpreters are free This includes all languages currently on tio.run, for example.
Platform specific languages are free if there is a free implementation on another platform (or of the platform which the lang is native to) Although Batch is exclusive to Windows, Windows can be p...
Free access must not be finite There has to be a time-unlimited, free way to run the language in question.
I have proposed that we shouldn't use nonfree languages to compete in cops-and-robbers challenges, but this proposal needs some demarcation. Matlab, Stata, LabVIEW all have finite free trials. Bat...
Storing information in the platform specs We should disallow requiring the program to be run on some platform to store information for the challenge. An extreme example would be Nullary, in which ...
My thoughts on the matter Does randomness need to be uniform? Nope, although it has to follow the specifications of the challenge (but if the challenge is too demanding with its randomness yo...
Image output may be a pixel shader A pixel shader inputs x,y coordinates of a pixel and prints the color of a pixel (scalar for grayscale, tuple for full color, bool for binary...). Relevant for S...
Programs/functions may use the presence/absence of output as a bool
Numerical I/O may be given as a character code Input 64 may be given as @ instead. This mostly exists for languages like Brainfuck that only take input through character codes.
Multiple URL shorteners in a web-based challenge In challenges which require fetching data from the Internet, URL shorteners can be problematic. This is because: shorteners made after the cha...
Functions may take multiple arguments with currying For some languages like Haskell this is almost a necessity, as only one-argument functions exist and multi-argument functions are implemented wi...
Empty answers to questions requiring an interpreter In particular, "simulating" a machine on this very machine by accepting the initial state as the simulation's initial state and returning t...
Bypassing source restrictions by storing data in the file name In some languages, like Pxem, programs are usually stored in the file name and the file's contents are irrelevant. On Somewhere Else,...
Using the lack of features in a language to trivialize the problem For example, in a challenge which requires your program to check if it is connected to the internet, using Brainfuck to always pr...
Optimizing specifically for the given test cases Applies to "code-speeding" or fastest-code where your program must run as quickly as possible, as well as compression challenges. Obviously, there ...
Abusing native number types It's common to restrict inputs, outputs, intermediate algorithm values, etc. to fit into the native number type of the language. This can be a problem for languages li...
Regexes may output via the list of matched strings (capture group 0)
Functions may return bools via the presence/absence of an error Crashing to mean false and not crashing to return true. Another branch of the exit code answer.
Programs may take input from prompts from the GUI For Mathematica, JS, Matlab, et. al. this is the closest thing they have to STDIN.
Using inconsistent I/O An example would be a program whose only two outputs given some input can be 2 and 11. The program is print(11): claiming that it outputs in unary for some outputs and in de...
Using a non-free (beer) language on a cops-and-robbers challenge For a discussion on what counts as "free", see this post. Cops-and-robbers challenges have two components: a cop posts a program o...
