All Questions
13,899
questions
10
votes
5
answers
791
views
Write a Web server quine
Write a program that accepts HTTP requests on any port of your choice above 1024, and responds to requests on any URL of your choice with its own source code. It must work with, at least, Firefox and ...
- 803
14
votes
15
answers
1k
views
Just another traffic jam!
One lane is closed, the vehicles have to thread their way in according to the zip-lock system: One car from one lane, the next car from the other lane, always taking turns.
Input: Two vehicle queues, ...
- 1,600
0
votes
21
answers
807
views
How Many Paint Tins Do I Need?
Task
Take in 3 inputs. The length of the wall, the height of the wall and the coverage of the paint. Output how many tins of paint are required.
Output
Since there's no way to purchase ...
- 539
15
votes
14
answers
3k
views
Which skill to train?
Story (skip, if you prefer the naked task): You need five skills for an imaginary sport: Speed, strength, endurance, accuracy and tactics. If you achieve a score in each of these disciplines, you can ...
- 1,600
4
votes
1
answer
168
views
Convert real numbers between factoradic and positive integer bases
This prompt asked you to convert back and forth to factoradic, but is very limited in scope (only decimal integers from 0 to 10!-1). Your task in this challenge is to reach just a bit further and ...
- 149
-3
votes
1
answer
201
views
Bingo Cards SVG Code [duplicate]
Generate the contents of an SVG file containing 6 bingo cards. Winner is the one that uses the shortest code. A qualifying answer has an output that can be directly pasted in a blank to get the ...
- 161
4
votes
2
answers
727
views
Shortest C code to display argv in-order
I recently tried to produce the shortest C code possible to display all its command line arguments (which are stored in argv).
I ended with a relatively small piece of code, and I was wondering if ...
- 153
7
votes
1
answer
235
views
Tips for Golfing in Vyxal 3
The reason for this question is because I made a deadlineless bounty and I need a tips question to link in the bounty
Vyxal 3 is the third major version of the Vyxal golfing language. As it is ...
- 32.5k
19
votes
38
answers
3k
views
Print the Christmas alphabet
Write a program to print or return one of these strings verbatim:
abcdefghijkmnopqrstuvwxyz
ABCDEFGHIJKMNOPQRSTUVWXYZ
Notice that there is no L.
- 803
1
vote
0
answers
118
views
Produce a secure block cipher round function (1 bit round key; 7 bit message)
We need to produce a block cipher round function with a 1 bit round key size and a 7 bit message size with the highest level of cryptographic security according to our measure of security.
...
- 391
17
votes
34
answers
2k
views
Rudin-Shapiro sequence
The Rudin-Shapiro sequence is a sequence of \$1\$s and \$-1\$s defined as follows: \$r_n = (-1)^{u_n}\$, where \$u_n\$ is the number of occurrences of (possibly overlapping) \$11\$ in the binary ...
- 46.5k
15
votes
2
answers
2k
views
Shortest Algorithm* That Generates a Harlequin Pattern
What is the shortest sequence of moves that, from the solved state of the cube, creates a pattern that meets the following criteria:
6 colors on each face
at most 2 facelets of the same color
no ...
- 293
0
votes
0
answers
68
views
Write a checker quine [duplicate]
Write a program that takes a string as input and returns truthy if the string is the same as the source code, falsy otherwise. The usual restrictions on quines apply.
- 803
9
votes
3
answers
531
views
Get the Bible verse
Write a program that accesses Project Gutenberg's KJV Bible, either from a file called pg10.txt in the working directory or in any other way that is typical for the ...
- 803
-2
votes
4
answers
180
views
Answer a Loaded Question (with Lojban!) [closed]
A loaded question is something like 'Have you stopped swearing?' in which both yes and no answers mean that I have swore, meaning it is impossible to answer the question if I haven't swore.
However, ...
- 143
18
votes
9
answers
1k
views
Limited letter renderer: BIOPD
There have of course been challenges to render ASCII art fonts here and there. This challenge doesn't add anything to those. In contrary, it subtracts from them for a good reason. If you allow all ...
- 1,600
13
votes
21
answers
4k
views
German pharmacy payment
Your task is to calculate the amount you have to pay for prescribed medication at a pharmacy in Germany. The amount is simply based on the full price of the item, which will be your input. It is a ...
- 4,899
-11
votes
2
answers
303
views
Bingo Cards PDF
Write code to generate a PDF file containing 6 bingo cards. Winner is the one that uses the shortest code and needs no actions except for installing a library and running the code. (No Save As PDF). ...
- 161
15
votes
13
answers
1k
views
Golf Transmission
As in, the 5 speed transmission from the original VW Golf GTI.
Print the transmission pattern in as few bytes as possible.
Yes I know this isn't what it actually looks like but the GTI 5 speed shift ...
- 1,850
14
votes
22
answers
2k
views
Decode the date in Christmas Eve format
This is the inverse of "Encode the date in Christmas Eve format."
Write a program that takes as input the string Christmas, possibly followed by ...
- 803
10
votes
36
answers
3k
views
7
votes
2
answers
303
views
How many twisted corners?
Your challenge is to output the number of twisted corners given a 2x2 Rubik's Cube scramble.
For the purpose of this challenge, twisted corners are defined as corners where the colour of the top/...
- 8,463
17
votes
21
answers
2k
views
Monotone sequence beatitude
Provided that the input is a monotone sequence of three or more integers:
Output -2 if the sequence strictly decreases. Example: [7,4,3,2]
Output -1 if the ...
- 5,447
11
votes
8
answers
2k
views
Add two natural numbers
Given two natural numbers (less than 100) as input print the sequence of intermediate results obtained when computing the sum of the two numbers using only the following operations1:
...
- 5,677
7
votes
1
answer
251
views
Literate Programming in Base 26
Your task is to convert non-empty strings - between strings using the 26 letters, and programs, which are strings of bytes, where each byte has 256 possible values. You should use the same codepage ...
- 9,682
5
votes
9
answers
1k
views
Print the banned characters based on the most common characters
This is an answer-chaining post, so in this challenge every answer (except the first answer) depends on the previous answer.
The goal of this challenge is to output the restricted characters. The ...
- 3,087
10
votes
6
answers
616
views
Robinson Schensted correspondence
[The explanations of the algorithm come from here. I recommend reading it for a beautiful description of the algorithm.]
This challenge is to implement the Robinson Schensted correspondence.
Input
A ...
- 1,812
6
votes
1
answer
200
views
Determine if a Spider Solitaire game is stale
Let's introduce a simplified variant of the well known Spider Solitaire.
From Wikipedia:
The main purpose of the game is to remove all cards from the table, assembling them in the tableau before ...
- 12.2k
13
votes
17
answers
3k
views
Make Code Printing X without X
The challenge is simple: write a program which takes in some non-empty string \$n\$ consisting of only uppercase and lowercase ASCII letters, and outputs the code for a program (in the same language) ...
- 7,061
32
votes
33
answers
6k
views
aaabbabbc⠀⠀⠀⠀⠀⠀
One element of the list aa, ab, ba, bb, c has been removed, and the remainder shuffled and joined with no separator. Find the missing element.
For example, if the ...
- 14.7k
4
votes
3
answers
370
views
Is there a shortest code to format string
Code Golf Challenge
Given a string of 10 characters:
'abcdefghij'
I want to format it in this pattern and print it in the console in a minimum number of characters:
...
- 43
9
votes
8
answers
657
views
Produce the shortest suffix for an (almost) arbitrary string
I encountered some silly code from a game and I figured this would actually turn into a fun golfing problem, so:
Given any ASCII string in the limited char range specified below.
Append as few ...
- 199
17
votes
12
answers
1k
views
Encode the input to exclude a given character (part 1)
Your task is to write 2 functions/programs. They may share code.
The first function must, given a string and a character, output a new string that does not contain that character.
The second function ...
- 11.8k
6
votes
4
answers
584
views
Sum of the sum of all possible subsets raised to power k
You are given an array A of non-negative integers. You can pick any non-empty subset, S from the array A. The score of a subset S is the sum of the elements in S raised to the power of K, i.e. for a ...
- 79
16
votes
19
answers
2k
views
Find the fairest partition of a list
Given a list of positive integers, partition the list into two sublists such that the absolute value of the difference of the sums over the two sublists is minimal.
The output of the program should be ...
- 5,677
6
votes
4
answers
253
views
Positions on the Pickleball Court
My doubles pickleball group often has five people. Four are playing and one is awaiting the next game. We can represent the state of the game with a string of five characters like abCde. This ...
- 231
12
votes
6
answers
2k
views
Sine using square root [closed]
Given input \$x \in \left\{0,3,6,...,90\right\}\$, output \$\sin\left(x°\right)\$ using integer and \$+ - \times \div ( ) \sqrt{\cdot}\$(square root), e.g. \$\sin(45°)=\sqrt{1\div 2}\$.
Flexible ...
- 20.4k
12
votes
5
answers
1k
views
The too-short urinal problem
The well-known Urinal Protocol states that each person that takes a urinal will take the one furthest from any other taken urinal. But this fails to account for short urinals; in many cases, a person ...
- 5,212
14
votes
9
answers
2k
views
Seat gangs as far as possible
Imagine there are \$n\$ people \$\{a_1, a_2, \ldots, a_n\}\$ who enter a room in order and sit down in \$n\$ seats, arranged in a row. Each of these people belong to some gang, indicated by an integer ...
- 7,061
4
votes
5
answers
149
views
Base consecutive k-frequency counter [closed]
Given a base \$k\$ as well as two indices (also passed in base \$k\$, call them \$s\$ and \$e\$) return a list containing a frequency count of all base-\$k\$ digits occurring between \$s\$ and \$e\$ ...
-1
votes
1
answer
249
views
It's Just Simple Math! [duplicate]
Task
Your boss is on another crusade for 'efficiency.' He wants to encourage the use of numbers with fewer syllables, so that they're easier to discuss in meetings. If you want to take some time off ...
- 539
19
votes
27
answers
3k
views
Restricted Meta-Cat
Your challenge, should you choose to accept it, is to write a program in a language of your choice that, when given a string (limited to printable ASCII) as input, outputs a new program in the same ...
- 5,212
19
votes
35
answers
2k
views
Compute the conjugate of a partition
We will think of a partition as a sequence of non-increasing integers.
For a given partition into \$n_1, n_2, \dots, n_k\$ with \$n_1 \geq n_2 \dots n_{k-1} \geq n_k = n\$ we write it out with \$n_i\$...
- 1,812
17
votes
14
answers
2k
views
Finding the power sandwich version 2
Introduction
This question is inspired by this great question.
Challenge
Given a number \$N>0\$, output the largest integer \$a^b\$ that is smaller or equal to \$N\$, and the smallest integer \$c^d\...
6
votes
0
answers
242
views
Shortest CSS selector to select ALL html elements, without using asterisk *
What is the shortest selector (by character count) to select ALL html elements on a web page, without using asterisk (*)? Some examples are the following:
...
- 161
13
votes
10
answers
1k
views
Directional Run Length Decoding
We all know run-length decoding: A list of character-length pairs expands to a string of that many characters, so A1B4C2 expands to ...
- 5,212
-6
votes
1
answer
256
views
The longest "Hello World!" program [closed]
I was seen multiple shortest "Hello World!" program, but this is the longest program.
The Rules
Each submission must be a full program.
This must be non-interpreted language (for example, ...
15
votes
19
answers
2k
views
Last Week Day Of The Month
Introduction
This challenge was inspired by a seemingly simple task requested at work that couldn't easily be done in Microsoft Teams. At least not from what we could find!
Task
Your task, if you ...
- 539
14
votes
16
answers
2k
views
Finding the power sandwich
Introduction
Finding the closest power to a number is a common enough problem. But what if you need both the next-highest and next-lowest power? In this challenge you must find the closest powers to a ...
- 149
10
votes
6
answers
360
views
Hermite interpolation
We already have a challenge for polynomial interpolation: given a list of points, output the coefficients of the polynomial that passes through them.
Hermite interpolation is a generalization of ...
- 46.5k