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Given a string, convert all of its letters using ROT13, and all of its digits using ROT5. This is sometimes referred to as ROT13.5. Input A sequence of printable ASCII characters (character cod...
Challenge Make a program that takes input of 3 non-negative integers: a result and 2 other values that once calculated results to the 3rd value. The program must figure out how to get the 2 fir...
Given an integer $N$ in balanced quinary, output the first $N$ characters of your source code if $N$ is positive, or the last $-N$ characters of your source code if $N$ is negative. Terminology ...
Challenge Write a program that prints its reversed self. For example, if your code is foo() Then it'll output: )(oof Make sure that the quine is a valid one, as defined here: No cheatin...
This is a fixed output challenge. It is similar to a standard Kolmogorov complexity challenge, except you get to choose your own fixed output. Given no input, output 55 fruits. You may choose any 5...
Challenge Given an integer n>=4 as input create an ASCII art "prison door"* measuring n-1 characters wide and n characters high, using the symbols from the example below. Example ╔╦╗ ╠╬╣ ...
Given a string of printable ASCII characters, convert them all to lowercase, except not just the letters. ASCII characters that are letters have a bit in their binary representation that is 0 for ...
Given a radius R, output a text representation of a circle. Input A positive integer R (strictly greater than zero) You do not need to handle values of R greater than 32 Output A square ...
In this challenge, add 2 integers, but if both the integers are 2, output 5. Shortest code in each language wins! Example ungolfed program in Python 3.x def add(x, y): if x == 2 and y == 2: ...
Looping counter Create an infinite loop that outputs lines of asterisks, with each line containing one more asterisk. Instead of the asterisk, any printable, non-whitespace character can be used. ...
Inspired by this Rosetta Code article. Introduction Balanced Ternary is a method of representing integers using -1, 0 and 1 in base 3. Decimal 11 = (1 * 32) + (1 * 31) + (−1 * 30) = [1,1,-1] or ...
Background Check out this video on the Collatz conjecture, also known as A006577. If you don't know what this is, we're given an equation of $3x + 1$, and it is applied this way: If $x$ is odd...
Challenge A Niven number is a positive integer which is divisible by the sum of its digits. For example, 81 -> 8+1=9 -> 81%9=0. Your task is to find the first n Niven numbers, given n. Te...
Challenge Make a program that takes input of an integer that's $n > 1$ and print out a staircase using a specific character for stair basing (hashes (#) for demonstration; you can use spaces,...
Background Inspired by this challenge that is also a mathematical English translator. Challenge Write a program that translates a mathematical expression using English with the following specifi...
Make the Server Fault logo using the following criteria: The boxes' measurements: There are 3 columns of 5 boxes, with long ones at the left where the rest are regular. The following measure...
Task Print the following: ABDFHJLNPRTVXZ CABDFHJLNPRTVX ECABDFHJLNPRTV GECABDFHJLNPRT IGECABDFHJLNPR KIGECABDFHJLNP MKIGECABDFHJLN OMKIGECABDFHJL QOMKIGECABDFHJ SQOMKIGECABDFH USQOMKIGE...
Disclaimer This challenge also exists in CGCC, but if you want to compete here (too), then hop in! Challenge Recreate "99 Bottles of Beer on the Wall", using the least bytes possible. Lyrics: ...
Originally from Somewhere Else. I thought I'd continue making more drawing challenges here now that I discovered it. Make the Stack Overflow logo using the following criteria: The tray: ...
Many programming languages have the concept of keywords, special syntax items that are not just identifiers reserved by some library, but words reserved by the language itself. The challenge is to...
Description APL trains are a series of functions, that get applied to an argument in this way: (f g) x = f g x (f g h) x = (f x) g (h x) (a b c d e f) x = (a (b c (d e f))) x = a (b x) c (d x) ...
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...
Get ready for a comparatively dry question - this is intended to be one of the "the"s of the code-golfing dictionary. Create a program which inputs a base 10 non-negative whole number (without lea...
Challenge idea taken from: Eliseo D'Annunzio Task Provide code that evaluates to 0.5 numerically, i.e. the output must be recognized by your chosen language as a numeric value (Number, float, dou...
Multiply complex numbers. 2 space-seperated ones will be input, as follows: (update: you can replace i with j or some other symbol if needed) a+bi -a+bi a-bi -a-bi where a and b are integers ...
Challenge Given a list of integers >= 0 , check if all of them are equal. Tests [1,1,1,1,1] -> true [0,1,1,6,7] -> false [1] -> true [] -> undefined(you do n...
The Rules In this game, each round, every player faces off against every other player in a round robin format. In each match, players pick 3 positive integers that sum to 360. Let's say player 1 p...
As you might know, there were elections in Germany, and now the parties have to form a government coalition. Let's help them with it! A good coalition has the strict majority of seats (that is, mo...
Task I often need to find the factorial of a number or the sum of all numbers up to a number when cheating on math tests. To help me with this, your task is to write $F$, a generalized version of ...
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...
Given a string and a non-negative integer $n$, output a new string in which each character is repeated $n$ times. Test cases: "abc", 1 -> "abc" "Hello", 0 -> "" "double", 2 -> "ddo...
The Ludic Numbers are a sequence that pops up when you apply the sieve of eratosthenes to the natural numbers, completely removing the numbers every iteration. Here is how they are generated: The...
Given a non-negative integer up to $999\,999\,999$, write it in English. The input number can be in any form other than English (though you'll typically want to use the native integer type of your...
You have an army of size $n$ that you need to split up to fight $k$ battles simultaneously against an opposing army $A$. In each battle, the army with the most troops present wins - no one wins a t...
Challenge Given a string, e.g. Hello, do the following: Mirror it: Hello -> HelloolleH and create a right triangle using it as the sides: H ee l l l l o...
Abundant numbers are numbers which are less than their proper divisor sum. For example $18$ is abundant as $1 + 2 + 3 + 6 + 9 = 21 > 18$ Deficient numbers are numbers which are greater than the...
Given two strings, I define their product as follows: If any of the two strings is empty, the product is the empty string. If the second string consists of a single character, the result ...
An integer is called square-free if it is not a multiple of a perfect square other than 1. For example, 42 is square-free, but 44 is not because it is a multiple of the perfect square 4 = 2². Your...
Natural to set (set meaning an unordered collection with no duplicates, though answers may use and output lists instead) Recently I was brainstorming what a language with only (arbitrarily nested...
The task is to create a program which displays a golf score as text. It takes 2 numbers as input, separated by space or new line: The first number is the par of the specific hole. The second nu...
Imagine you have only one byte (8 bits) to store a value, but need to store values from $0$ to $4032$. Impossible, until you are also told that an error of 1/64 of the exact value does not matter. ...
Inspired by this challenge. If anyone has any suggestions for a song title I could use for the challenge title then please leave a comment. Definition We define f(x) for a given integer as the su...
Challenge Create a program that takes input of a string and outputs an integer using the following calculation system: The string can only contain +, -, *, /, ^, ! (or a different character; ! ...
Challenge Given a list of unique colour names as input, sort them in the order that they first appear in Joseph's Amazing Technicolour Dreamcoat. Example Input: green, blue, red, brown Outpu...
Given an array of numbers, output the length of the longest increasing (not necessarily contiguous) subsequence. It is guaranteed that there are no duplicates in the array. For example, if the inpu...
Introduction The classic "Hello, World" challenge. What more can I say? Rules Program takes no input. Program outputs Hello, World! with an optional trailing newline. No other output is accep...
Given an integer n, output the smallest prime such that the difference between it and the next prime is at least n. For example, if n=5, you would output 23, since the next prime is 29, and 29-23&...
A rewrite of this SE question with a simpler input format and guidelines. Challenge Deadfish uses a single accumulator, on which all commands are to be performed. It has the following commands: ...
Task Given an IP address as a string, find its IP address class. For reference, here is a table: Class Leadingbits Numberof networks Addressesper network Total addressesin class Start...
In Google Docs, the word count tool looks like this: Pages would not make sense, but your goal is to implement every other count. Definitions Words are strings of text separated by any amount ...
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