Questions tagged [code-golf]
Code-golf is a competition to solve a particular problem in the fewest bytes of source code.
10,094
questions
28
votes
22answers
4k views
Speed of Lobsters
From the subreddit r/SpeedOfLobsters:
Edit the text of an image to create a new phrase
This meme format/style is pretty self-explanatory. Simply have a browse through the subreddit if you need more ...
-1
votes
0answers
82 views
The Changing Quine [duplicate]
the goal here is to make a proper quine that outputs its source code and changes the source code to another quine that does the same thing.
after some runs, which doesn't have to be two, the source ...
21
votes
32answers
1k views
Print a conversion table for (un)signed bytes
Your task: Print or return a conversion table with every byte from 00 to ff's value as an unsigned integer, to its value as a ...
41
votes
11answers
5k views
The first published picture of the Mandelbrot set
Here’s the picture of the first published picture of the Mandelbrot set.
Use the fewest bytes possible to write a program or function that outputs the following.
A trailing new line is permitted. ...
17
votes
13answers
3k views
+100
Landau logarithm
Related: Landau's function (OEIS A000793)
Background
Landau's function \$g(n)\$ is defined as the largest order of permutation of \$n\$ elements, which is equal to \$\max(\operatorname{lcm}(a_1,a_2,\...
2
votes
0answers
97 views
Compute the minimal and maximal subset of a set of sets [closed]
Let S be a set of sets, for example S = {{A},{B},{A,B}}. A maximal subset, Max, is an element of S such that no other set in S ...
7
votes
5answers
590 views
Does this JavaScript function support keyword arguments?
JavaScript has no direct support for keyword arguments, but it supports argument object destructuring. It is standard to use a destructed final argument for keyword arguments. Here is an example:
<...
14
votes
8answers
2k views
Is my triangle on the lattice?
Write a program or function which takes three positive integers \$a, b, c\$ and returns/outputs one value if there is, and a different value if there isn't, a triangle on the square lattice, whose ...
3
votes
0answers
327 views
Solve a Cubic Equation [closed]
Input
Your program will take in the integer coefficients of the equation \$ax^3+bx^2+cx+d=0\$ as inputs (a, b, c, and d).
Output
All real solutions of the input equation, with an accuracy of at ...
9
votes
1answer
264 views
Win a KQ vs K endgame
Win a K vs KQ endgame
Summary
The goal of this challenge is to create a program or function which will win a Chess game with a King and Queen against a lone King. The user will specify three squares, ...
20
votes
5answers
726 views
The Caged Circles
This problem will have you analyzing circles drawn on the grid, with the gridlines drawn at integer values of \$x\$ and \$y\$.
Let \$\varepsilon\$ be a very small number (think, \$\varepsilon = 0.0001\...
8
votes
3answers
465 views
Validating a Battleship board
Do you know the game Battleship? Well, I want to play with my little brother, but before we can begin we need to set up our ships on the board. This is your input.
Now, we need to check that the ships ...
3
votes
2answers
345 views
Minimal Pairing
Your program should take two lists, where each entry (a positive integer) represents the number of members of some group, as input. These lists will have the same sum but may have different lengths.
...
17
votes
13answers
630 views
Sub-string Extractor with Specific Keywords
Challenge
The goal of this challenge is to make a function that takes an input string, a start keyword and a end keyword. The output extracted result is from (but excluded) the given start keyword to (...
20
votes
19answers
3k views
Draw an ASCII hexagon of side length n
Given a positive integer \$n\$ output an ASCII hexagon with diagonal side length \$n\$, as pictured (note there are \$2n\$ _ characters on the top edge)
Examples:
\$...
27
votes
10answers
2k views
Help Stack Exchange transpose tables
Stack Exchange doesn't know how to transpose tables. Let's help.
Given a markdown table, transpose it.
Input assumptions:
There will be at least two rows (including header) and two columns
Either all ...
13
votes
20answers
1k views
Linear integer function generator
Inspired by a recent challenge involving Fibonacci numbers in which OEIS was mentioned, I would like to present a challenge of creating a function that generates a wide array of different linear ...
22
votes
18answers
964 views
Interpret Interval Notation
Interval notation is a way to write complicated range bounds more conveniently and concisely than writing an inequality. The challenge, should you choose to accept it, is to write a program or ...
18
votes
5answers
1k views
Find a sequence in the binary digits of π
Given a binary sequence of finite length, find the starting position where this sequence first appears in the binary digits of π (after the decimal). You can assume that an answer exists for any input ...
11
votes
5answers
563 views
Ellipsoid surface area
Related: Ellipse circumference
Introduction
An ellipsoid (Wikipedia / MathWorld) is a 3D object analogous to an ellipse on 2D. Its shape is defined by three principal semi-axes \$a,b,c\$:
$$ \frac{x^2}...
24
votes
13answers
4k views
How long till Halley's Comet returns?
Halley's Comet is the only comet that may appear (i.e. become visible to the naked eye on Earth) twice in a human lifetime. The orbital period of Halley's Comet is not constant: it has varied between ...
13
votes
11answers
1k views
Golfing Advent of Code 2020, Day 3
I thought it'd be interesting to turn AoC day 3 puzzle into a Golfing Challenge, so here it is.
Task
Find the number of # you'd encounter in an 11x11 grid (...
17
votes
17answers
2k views
Vandalizing Marquees
A marquee is a low-tech board that allows customizable letters. For example, here is a marquee:
SALE ON SNEAKERS
However, someone might come along and vandalize it ...
8
votes
13answers
366 views
Von Neumann Neighborhood
Your goal is to make a function that takes the coordinates of a cell in 2D space and a distance \$r\$ and returns the coordinates of all cells in the input coordinate's von Neumann neighborhood of ...
6
votes
15answers
786 views
Prime generating function
Background
The Python code
((((((((n%35)^11)*195)|53)&181)+n)%168)*n)+83
produces 74 distinct primes for \$0 \le n \le 73\$. This code also works in Java. The ...
23
votes
14answers
2k views
Pascal's Fibonacci Triangle
What do you get when you cross Pascal's Triangle and the Fibonacci sequence? Well, that's what you have to find out!
Task
Create a triangle that looks like this:
...
20
votes
27answers
962 views
Partial sums of the Kempner series
The Kempner series is a series that sums the inverse of all positive integers that don't contain a "9" in their base-10 representations (i.e., \$\frac{1}{1} + \frac{1}{2} + \frac{1}{3} + .. +...
23
votes
12answers
1k views
Bedevil your hangman opponent
Task
You are playing Hangman, and your opponent uses a simple but effective strategy: Each turn, from the remaining letters, they guess the letter that appears most frequently across all possible ...
16
votes
14answers
1k views
Split a number in every way possible way within a threshold
Task
Given a positive integer number and a threshold, split into every possible way without generating any numbers above the threshold.
Examples
Input: 15008
Threshold: 400
Valid Output:
...
2
votes
1answer
134 views
Twist on words to numbers [closed]
The Goal
The goal of this question is to put a twist on this question. Your answer should be able to convert an array of words associated with integers into those integers. As an extra challenge, ...
30
votes
2answers
1k views
Golf the smallest sphere!
Inspired by this challenge, as well as a problem I've been working on
Problem:
Given a non-empty set of points in 3D space, find the diameter of the smallest sphere ...
13
votes
7answers
618 views
Generalised Taxicab Numbers
\$\newcommand{T}[1]{\text{Ta}(#1)} \newcommand{Ta}[3]{\text{Ta}_{#2}^{#3}(#1)} \T n\$ is a function which returns the smallest positive integer which can be expressed as the sum of 2 positive integer ...
asked Dec 28 '20 at 20:33
caird coinheringaahing
22.4k5 gold badges53 silver badges159 bronze badges
24
votes
25answers
2k views
Based Palindromes
A palindromic number, as a refresher, is any number which reads the same forward as backwards. However, what about palindromes in other bases?
Input
Any integer b ...
17
votes
16answers
4k views
I don't like curry
I don't like curry. Help me reverse the effects of this evil question - Make me some curry - by uncurrying functions.
Task
Given a blackbox curried function, output its uncurried equivalent.
The ...
23
votes
2answers
1k views
Eye test - How many squares are in this picture?
The picture:
Sick of the same old grid where the answer is simply a square pyramidal number?
Accept the challenge and write a program that given a positive integer \$n\$ counts how many squares are ...
11
votes
17answers
1k views
Polynomial Laplace transform
This is a repost of this challenge, intended to revamp it for looser I/O formats and updated rules
You are to write a program which takes an integer polynomial in \$t\$ as input and outputs the ...
asked Dec 25 '20 at 22:55
caird coinheringaahing
22.4k5 gold badges53 silver badges159 bronze badges
6
votes
3answers
333 views
Golf me a polygonal loader
Codidact post, CGCC Sandbox, Codidact Sandbox
Given three positive integers as input, animate an ascii-art polygonal loading symbol on the screen.
Intro
You will be given three inputs, \$n\$, \$l\$, ...
4
votes
5answers
177 views
Strobogrammatic Numbers [duplicate]
Strobogrammatic Numbers
Definition
A number which is rotationally symmetrical, i.e., it'll appear the same when rotated by 180 deg in the plane of your screen. The following figure illustrates it ...
27
votes
37answers
2k views
Jelly's Untruth
Jelly has an "untruth" atom: Ṭ. This takes a non-empty array of positive integers and returns a Boolean array with 1s at the indexes in the input. For ...
13
votes
8answers
1k views
How Many Atoms?
How Many Atoms?
Write the shortest code that when given a chemical formula as input, outputs the total number of atoms in the formula.
Input
A chemical formula in any reasonable format. Each chemical ...
37
votes
31answers
4k views
Find the “Bittiest” Number [closed]
The Challenge
Given a list of integers, the "bittiest" number among them is the one with the most bits on - that is, the largest amount of bits set to 1.
Write a function (or a program) that ...
25
votes
21answers
992 views
Generate newspaper page number sets
A newspaper is made of several sheets; for the purposes of this question, each sheet of newsprint holds four pages of the final newspaper. Here is an example of three sheets of newsprint making up a ...
10
votes
10answers
722 views
Find the number of ways to climb a stairway
Challenge:
Find the number of ways to climb some stairs with n steps and with some limitations. You should be able to run the tests below on TIO https://tio.run/ without timing out. – 60 seconds. (...
8
votes
8answers
182 views
Squarefree Palindromes [closed]
Create the shortest function, program, or expression that calculates a sequence of squarefree palindromic numbers.
A squarefree number is one which is not evenly divisible by a square number (i.e. ...
23
votes
9answers
853 views
Animal-Alphabetical Sequence
The Animal-Alphabetical Sequence is an infinite string of letters built accordingly to the following procedure:
Start with the letter A;
Replace each letter with ...
15
votes
4answers
897 views
(Almost) Solve Fermat's Last Theorem
It's a well-known fact that Fermat's Last Theorem is true. More specifically, that for any integer \$n \gt 2\$, there are no three integers \$a, b, c\$ such that
$$a^n + b^n = c^n$$
However, there are ...
asked Dec 17 '20 at 21:49
caird coinheringaahing
22.4k5 gold badges53 silver badges159 bronze badges
13
votes
12answers
865 views
Compute the Redwolf Checksum™ of some data
I will preface this by saying that I made this for fun; I have absolutely no formal knowledge on cryptography or error correction. Do not use this algorithm in anything remotely important.
I was kind ...
-1
votes
2answers
115 views
increment a binary number without arithmetic manipulations [closed]
Input: binary string
Output: binary string that represents the binary input + 1
Example: Given 10111 as an input, output 11000
...
0
votes
1answer
99 views
Convert all the newlines in a file from \r\n to \n [duplicate]
Inspired by what I'm doing at work right now.
Your program should take one parameter, the path to the file
It should convert all the windows style newlines (\r\n) to unix style (\n) and write the ...
28
votes
28answers
2k views
Ken Iverson’s Favourite APL Expression?
Ken Iverson, 1920–2020
Let's implement his favourite expression:
Given a row of Pascal's triangle, compute the next row.
This can for example be computed by taking the input padded with a zero on the ...
