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Challenges

Code challenges of all types. For questions about golfing, bowling, etc, use Q&A. For questions about this community, use Meta. To get feedback on a challenge before posting it, use Sandbox.

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71%
+3 −0
Convert integer to English

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...

3 answers  ·  posted 2y ago by celtschk‭  ·  last activity 2y ago by Moshi‭

71%
+3 −0
Find good coalitions

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...

2 answers  ·  posted 2y ago by celtschk‭  ·  last activity 2y ago by Moshi‭

81%
+7 −0
Truthify an array

Jelly has an atom called untruth, which when given indices, creates an array with 1s at those places: [2,4] → [0,1,0,1]. You are required to perform the inverse of this. Given a 2D boolean array, ...

10 answers  ·  posted 3y ago by Razetime‭  ·  last activity 2y ago by General Sebast1an‭

84%
+9 −0
Obligatory Quine Challenge

Rules Using your language of choice, golf a quine. A quine is a non-empty computer program which takes no input and produces a copy of its own source code as its only output. No cheating -- ...

9 answers  ·  posted 3y ago by ATaco‭  ·  last activity 2y ago by General Sebast1an‭

71%
+3 −0
Encode and decode floating point integers

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. ...

2 answers  ·  posted 2y ago by celtschk‭  ·  last activity 2y ago by General Sebast1an‭

66%
+2 −0
Define a mathematical expression in English

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...

1 answer  ·  posted 2y ago by General Sebast1an‭  ·  edited 2y ago by General Sebast1an‭

77%
+5 −0
Recreate the Stack Overflow logo

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: ...

2 answers  ·  posted 2y ago by General Sebast1an‭  ·  last activity 2y ago by Anonymous‭

75%
+4 −0
The Ludic Numbers

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...

3 answers  ·  posted 2y ago by Razetime‭  ·  last activity 2y ago by General Sebast1an‭

77%
+5 −0
Decode periodic decimal fractions

Rational numbers in decimal representation can have an infinite periodic part. One common way to write this down is to repeat the periodic digits and then add three dots. Numbers without those thre...

2 answers  ·  posted 2y ago by celtschk‭  ·  edited 2y ago by General Sebast1an‭

66%
+2 −0
Reverse your quine

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...

4 answers  ·  posted 2y ago by General Sebast1an‭  ·  last activity 2y ago by celtschk‭

66%
+2 −0
Expand a polynomial

Challenge Given the roots of a polynomial (that is, the $x$ values where the polynomial evaluates to zero), as an array of real numbers, return the polynomial's coefficients. That is, given real ...

4 answers  ·  posted 2y ago by Moshi‭  ·  last activity 2y ago by Moshi‭

71%
+3 −0
Abbreviate everything

Challenge Make a program that takes input of a string and abbreviate it. All letters of an abbreviation are capitalized, so keep that in mind. Whitespace, numbers and non-English characters ar...

3 answers  ·  posted 2y ago by General Sebast1an‭  ·  last activity 2y ago by Hakerh400‭

85%
+10 −0
Create an Alphabet Diamond

Challenge Output the following text: A ABA ABCBA ABCDCBA ABCDEDCBA ...

11 answers  ·  posted 3y ago by dzaima‭  ·  last activity 2y ago by General Sebast1an‭

60%
+1 −0
Getting perfect squares, differently

Create a program that gets all perfect squares starting from 0 or 1 without using any methods of multiplication (repetitive addition) and exponentiation (repetitive multiplication). Output them for...

7 answers  ·  posted 2y ago by General Sebast1an‭  ·  last activity 2y ago by General Sebast1an‭

75%
+4 −0
When The Ternary Is Balance

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 ...

3 answers  ·  posted 2y ago by Razetime‭  ·  last activity 2y ago by Moshi‭

71%
+3 −0
My house is destroyed! Can you make me one?

Background A House of I I went on an adventure Grabbed resources and making deeds Like start to work on the materials To build the shelter I need It was a marvelous one At least in the eyes ...

10 answers  ·  posted 2y ago by General Sebast1an‭  ·  last activity 2y ago by Quintec‭

88%
+13 −0
Output 256 in many different ways

Challenge Write as many functions, programs, or snippets of code, that result in 256. Your score is the number of separate solutions submitted in an answer. The challenge? The characters used in ...

12 answers  ·  posted 3y ago by dzaima‭  ·  last activity 2y ago by snail_‭

81%
+7 −0
In The Jailhouse Now

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 ╔╦╗ ╠╬╣ ...

6 answers  ·  posted 2y ago by Shaggy‭  ·  last activity 2y ago by snail_‭

75%
+4 −0
Tile pyramids on top of each other!

The task Given a positive integer as input, output tiled pyramids of this height. How? Let's say the inputted integer was n. From there, we output n lines of output, each having: A decreasing...

9 answers  ·  posted 3y ago by Dion‭  ·  last activity 2y ago by A username‭

71%
+3 −0
Multiply two strings

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 ...

6 answers  ·  posted 2y ago by celtschk‭  ·  last activity 2y ago by Hakerh400‭

75%
+4 −0
Generate Lewis Caroll's Jabberwocky

The task is to generate the text of Lewis Caroll's Jabberwocky. The text, quoted from Wikipedia, is as follows (I've replaced a non-ASCII character with ASCII, otherwise it's direct copy&paste...

4 answers  ·  posted 3y ago by celtschk‭  ·  last activity 2y ago by General Sebast1an‭

80%
+6 −0
Beaver Code Decryption

Credit This challenge is taken with permission from https://www.mysterytwisterc3.org/en/challenges/level-1/beaver-code Description The encryption method is as follows: The plaintext is divided ...

6 answers  ·  posted 3y ago by rak1507‭  ·  last activity 2y ago by Shaggy‭

77%
+5 −0
Ratio limits of fibonacci-like series

Definition $F_{n}\left(0\right)=0$ $F_{n}\left(1\right)=1$ $F_{n}\left(x\right)=n\cdot F_{n}\left(x-1\right)+F_{n}\left(x-2\right)$ For example: $F_{1}=\left[0,1,1,2,3,5,8,13,21,34,55,89...\ri...

3 answers  ·  posted 3y ago by rak1507‭  ·  edited 2y ago by General Sebast1an‭

60%
+1 −0
A chunk of symbols is a calculation

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; ! ...

1 answer  ·  posted 2y ago by General Sebast1an‭  ·  edited 2y ago by General Sebast1an‭

80%
+6 −0
Is it a near-anagram?

Two words are anagrams of each other if the letters of one can be reordered to spell the other; e.g. ADOBE and ABODE are anagrams. An alternate way of describing it is that both words contain the s...

5 answers  ·  posted 3y ago by snail_‭  ·  edited 2y ago by General Sebast1an‭

71%
+3 −0
Longest Increasing Subsequence

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...

4 answers  ·  posted 3y ago by Quintec‭  ·  edited 2y ago by General Sebast1an‭

75%
+4 −0
Win a War (or at least a few battles)

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...

2 answers  ·  posted 3y ago by Quintec‭  ·  edited 2y ago by General Sebast1an‭

71%
+3 −0
The Camelot Wheel

Given a musical key, output its number and letter on the Camelot Wheel (shown below). Input A musical key as a string, as shown on the wheel. The words "Sharp" and "Flat" may be replaced with s...

2 answers  ·  posted 3y ago by Quintec‭  ·  edited 2y ago by General Sebast1an‭

80%
+6 −0
Juggler sequences

A Juggler sequence is a sequence that begins with a positive integer $a_0$ and each subsequent term is calculated as: $$a_{k+1} = \begin{cases} \left \lfloor a_k ^ \frac 1 2 \right \rfloor, &...

9 answers  ·  posted 3y ago by caird coinheringaahing‭  ·  last activity 2y ago by Shaggy‭

66%
+2 −0
Golf me a polygonal loader

CGCC Sandbox, Codidact Sandbox Given three positive integers as input, animate an ascii-art polygonal loading symbol on the screen. Intro Using the first input $n$, Take one the following regul...

1 answer  ·  posted 3y ago by Razetime‭  ·  edited 2y ago by General Sebast1an‭

71%
+3 −0
Towering Cistercian Representation

SE Sandbox Link, Codidact Sandbox Link Inspired by this video. Given a positive integer, draw its Cistercian representation as ascii art. The Challenge Cistercian numerals are a decimal-based...

1 answer  ·  posted 3y ago by Razetime‭  ·  edited 2y ago by General Sebast1an‭

77%
+5 −0
Shuffle a subset of a list

Idea shamelessly stolen from caird and rak1507 Shuffle a subset of a list of unique, positive integers with uniform randomness, given the indices of that subset. For example, given the list $[A, B...

4 answers  ·  posted 2y ago by user‭  ·  edited 2y ago by General Sebast1an‭

80%
+6 −0
Versatile self-printer

Using your languages of choice, golf a quine - a non-empty program taking no input and only outputting its source. Here, the win condition is your quine working in the most languages. It should be...

1 answer  ·  posted 2y ago by AndrewTheCodegolfer‭  ·  last activity 2y ago by General Sebast1an‭

77%
+5 −0
Are they abundant, deficient or perfect?

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...

8 answers  ·  posted 2y ago by caird coinheringaahing‭  ·  last activity 2y ago by General Sebast1an‭

84%
+9 −0
Length of a Sumac Sequence

Heavily based on this closed challenge from SE. Description A Sumac sequence starts with two non-zero integers $t_1$ and $t_2.$ The next term, $t_3 = t_1 - t_2$ More generally, $t_n = t_{n-2} ...

9 answers  ·  posted 3y ago by Razetime‭  ·  edited 2y ago by General Sebast1an‭

77%
+5 −0
Guess the language! (Cops' Thread)

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...

16 answers  ·  posted 2y ago by AndrewTheCodegolfer‭  ·  last activity 2y ago by Shaggy‭

71%
+3 −0
Guess the language! (Robbers' Thread)

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...

12 answers  ·  posted 2y ago by AndrewTheCodegolfer‭  ·  last activity 2y ago by m90‭

81%
+7 −0
Backspace an array

Challenge Given an array consisting of positive integers and 0s, return it with 0s acting like backspaces. Leading backspaces do nothing, and more backspaces than elements also does nothing. Cre...

6 answers  ·  posted 2y ago by rak1507‭  ·  last activity 2y ago by Shaggy‭

77%
+5 −0
Gamer Meme Creator

Challenge You will be given a string and an ascii art as input. The string must be placed above the ascii art, and centered based on its longest line. The text BOTTOM TEXT must be placed below...

4 answers  ·  posted 2y ago by Razetime‭  ·  last activity 2y ago by user‭

71%
+3 −0
Three Number Monte

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...

2 answers  ·  posted 2y ago by Quintec‭  ·  last activity 2y ago by Moshi‭

77%
+5 −0
Add two negabinary integers

About Negabinary Negabinary means base negative two (-2). That is, the $n$th place value is determined by $(-2)^n$. Negabinary numbers can be evaluated just like any other base system. For exampl...

3 answers  ·  posted 2y ago by Moshi‭  ·  last activity 2y ago by Shaggy‭

60%
+1 −0
Recreate the Server Fault logo

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...

0 answers  ·  posted 2y ago by General Sebast1an‭

77%
+5 −0
Create a Sudoku

Write the shortest program that takes no input and outputs a Sudoku solution. For reference, a Sudoku solution is a 9x9 grid of digits where each column, each row and each of the nine 3x3 grids th...

4 answers  ·  posted 2y ago by AndrewTheCodegolfer‭  ·  last activity 2y ago by Shaggy‭

81%
+7 −0
Evaluation order of an APL n-train

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) ...

7 answers  ·  posted 2y ago by rak1507‭  ·  last activity 2y ago by Shaggy‭

77%
+5 −0
Longest parallel lines

Note: This challenge was underspecified and bad, and as such I would not encourage answering it in the future. Challenge You will be given a single 2D boolean array $M$. You may take its dimensi...

1 answer  ·  posted 3y ago by rak1507‭  ·  edited 2y ago by rak1507‭

87%
+12 −0
Print the Great Numeric Pyramid

Print or return this exact text: 0 0 0 0 1 0 0 1 1 0 0 1 2 1 0 ...

5 answers  ·  posted 3y ago by Sisyphus‭  ·  last activity 3y ago by Marshall Lochbaum‭

71%
+3 −0
Really Cool Numbers

Define a cool number as a number whose proper divisors (all except for the number itself) have an integral mean. Define a really cool number as a number whose divisors (including itself) are all co...

3 answers  ·  posted 3y ago by Quintec‭  ·  last activity 3y ago by user‭

75%
+4 −0
Calculate a person's age

Challenge Given a date with day, month and year, calculate how old a person born on that day would be today. Input can be in any reasonable format(params, array, date object). Input will never b...

0 answers  ·  posted 3y ago by Razetime‭

83%
+8 −0
Integer to Roman numeral

The task is to take a decimal integer as input and print the corresponding Roman numeral with capital letters. The program must handle all positive integer numbers between 1 and 1000. Input can be...

3 answers  ·  posted 3y ago by Lundin‭  ·  last activity 3y ago by Lundin‭