Questions tagged [code-golf]
Code-golf is a competition to solve a particular problem in the fewest bytes of source code. If you want to score by characters instead of bytes, please state this explicitly in the challenge. If source code length is not the primary scoring criterion, consider using another tag instead.
9,080
questions
11
votes
6answers
438 views
Billiard balls collision
Given the 2-dimensional positions and velocities of a pair of billiard balls right before impact, calculate their velocities after a perfectly elastic collision. The balls are assumed to be ideal ...
5
votes
24answers
449 views
Talk interpreter
"Talk" is a baroquified accumulator-based language that is created in response to Dennis's quote on talk.tryitonline.net.
...
14
votes
21answers
557 views
Tex Quotes(UVa 272)
Given a string, replace all left-double-quotes into two backticks and all right-double-quotes into two single-quotes.
Left-quotes means the quotes that starts a quote. Right-quotes means the quotes ...
8
votes
7answers
212 views
Church Subtraction
Church Subtraction
Lambda calculus has always been a fascination of mine and the emergent behaviors of passing functions into each other is delightfully complex. Church numerals are representations ...
5
votes
6answers
448 views
The Knight's estate
And then the King said: You fought bravely, Knight, and your deed will not be forgotten for centuries. For your valor I grant you this castle and the lands around it. Things rush me, and I can not ...
21
votes
10answers
923 views
Nothing like a good ol' game of ModTen
Disclaimer: ModTen is a fictional card game which was created for the sole purpose of this challenge.
The rules of ModTen
ModTen is played with a standard 52-card deck. Because the full rules are ...
11
votes
54answers
2k views
Round towards zero
This is a simple task. Given a positive or negative real number, round it to the next whole integer closer to zero.
The challenge
Take input through any reasonable form (stdin, function, etc.) of ...
17
votes
30answers
2k views
Numbers Decrease while Letters Increase
Randomly inspired by Numbers Increase While Letters Decrease
Given a list of mixed letters and integers (e.g., ['a', 2, 3, 'b']) increase the letters by one ...
10
votes
13answers
1k views
Irish Snap: Variant Rules
Introduction
Recently, me and a couple of my friends decided to play some cards, and one of them suggested the game 'Irish Snap', which was the inspiration for this challenge. However, I later learnt ...
52
votes
14answers
6k views
Who was president of the USA?
Challenge
Write a program that takes as input a day from April 30, 1789 to August 21, 2019 and returns as output who was president of the USA that day.
Notes
For the list of US presidents, the ...
14
votes
21answers
1k views
Start from ones
Given a strictly positive integer n, follow these steps:
Create an array A with n 1s.
If A only has one element, terminate. Otherwise, starting from the first element, replace each pair of A with its ...
16
votes
4answers
2k views
Fancy String Replace
let S, a and b each represent a string
Goal: Write a standard string replace function where ...
8
votes
4answers
288 views
Weigh your words!
The challenge
Given two strings, each of length up to 30, consisting of printable ASCII characters (codes \$[32, 126]\$), put them onto a balance scale in the fewest bytes of code! This consists of ...
6
votes
23answers
380 views
caN it be acrOnymised? [duplicate]
The Typical Way to Make an Acronym Out of a Phrase Is to Take the First Letter of Each Word: TTWMAOPITFLEW. howeveR, sometimEs, you can make an acronym of random ...
32
votes
19answers
6k views
Church Booleans
Church booleans
A Church boolean is a function that returns x for true and y for false where ...
53
votes
50answers
10k views
How much code would a codegolf golf if a codegolf could golf code?
Write a function or program that takes two words as input and outputs variants of the popular English tongue-twister "How much wood would a woodchuck chuck if a woodchuck could chuck wood?".
The ...
3
votes
2answers
247 views
Identical grids
You’re given two \$r×c\$ grids. Each cell contains either 0 or 1. What are the minimum number of swaps (between horizontally and vertically adjacent cell elements, no wrapping i.e no swapping between ...
12
votes
1answer
293 views
Write a radiation-hardened irradiator
The task is to write a radiation-hardened irradiator. What do I mean by that, exactly?
An irradiator is a program that, when given a string as input, will output all possible versions of the string ...
21
votes
60answers
8k views
!I!n!s!e!r!t! !n!b!e!t!w!e!e!n!
Posted from here.
This challenge is highly "distilled" from this question. Special thanks to @Akababa!
In this task, you should insert an exclamation mark at the start of the string and after every ...
19
votes
9answers
2k views
Levenshtein Neighbours
Most square numbers have at least 1 different square number with which their Levenshtein distance is exactly 1. For a given square \$x\$, each square that meets this condition is called a Levenshtein ...
-1
votes
0answers
110 views
A prescribed time length [closed]
Challenge
Write a program that takes as input an integer 1 <= n <= 50 and returns a text string of length n stating a time in the English language.
Example
Input: 20 Output: "It's six thirty-...
28
votes
29answers
2k views
The Lucky House
There's a minigame in Super Mario 3D World known as the Lucky House. It consists of a slot machine with 4 blocks.
Each block may be one of 5 different icons (Flower, Leaf, Bell, Cherry or Boomerang) ...
26
votes
29answers
2k views
Output with the same length always
With challenges like Output with the same length as the code and Create output twice the length of the code, I thought of a separate, but similar challenge.
The task is to produce an output. It can ...
9
votes
0answers
146 views
Decompose Commutators
A theorem in this paper1 states that every integral n-by-n matrix M over the integers with trace M = 0 is a commutator, that means there are two integral matrices A,B of the same size ...
24
votes
14answers
7k views
Build a mob of suspiciously happy lenny faces ( ͡° ͜ʖ ͡°)
I was going through a bizarre thread on Reddit, and came across this:
( ͡°( ͡° ͜ʖ( ͡° ͜ʖ ͡°)ʖ ͡°) ͡°)
It's representing a group of people smiling somewhat suspiciously.
(In the challenge below ...
-5
votes
2answers
122 views
Elimination ordering
Your task is to remove smallest amount elements from a list, so the most elements are on their corresponding place. The element is on it's corresponding place, when it's value is equal to it's ...
-4
votes
0answers
151 views
Smallest self-hosting golfing language [closed]
Implement a golfing language that is implemented in itself. Formally speaking: The original compiler O (an executable file assumed to be implemented in other language X), when given its own source ...
4
votes
8answers
205 views
Shortest Program To Find Lowest Common Ancestor of Two Nodes in a Binary Tree
Any two separate nodes in a binary tree have a common ancestor, which is the root of a binary tree. The lowest common ancestor(LCA) is thus defined as the node that is furthest from the root and that ...
2
votes
20answers
501 views
Number in overlapping range
You are given two integers between lets say 1 and 12, one and two
and a integer between lets say 0 and 4 which is called ...
10
votes
1answer
208 views
Interpreter for number theory, modulo n
A sentence of number theory (for our purposes) is a sequence of the following symbols:
0 and ' (successor) - successor means <...
27
votes
31answers
2k views
Output the list of musical notes
This task is simple: Write a program or function that outputs the list of all musical notes (using English note names) from A♭ to G♯.
All notes without a name consisting of a single letter (i.e. ...
15
votes
17answers
4k views
Attacking the Hydra
Instead of being a skillful warrior capable of slaying Hydras (see here and here), this time you are a warrior that has no prior knowledge on how to kill one or which weapons to use against the ...
9
votes
7answers
968 views
An array battle with odd secret powers
Here is a relatively simple two dimensional array challenge.
Imagine a battlefield of 625 foot soldiers. You command the odd troops, but unfortunately the strength of the even troops overwhelms you. ...
10
votes
33answers
979 views
Chunk + Enumerate a list of digits
I have a list of decimal digits:
4, 4, 4, 7, 7, 9, 9, 9, 9, 2, 2, 2, 4, 4
The list of decimal digits are known as items. We can form "chunks" from these items by ...
20
votes
12answers
2k views
Lípínguapua dopo Pêpê
Língua do Pê, or P Language, is a language game spoken in Brazil and Portugal with Portuguese. It is also known in other languages, such as Dutch and Afrikaans. (Wikipedia)
There are some dialects in ...
32
votes
21answers
5k views
Telephone number in spoken words
Goal
Write a program or function that translates a numerical telephone number into text that makes it easy to say. When digits are repeated, they should be read as "double n" or "triple n".
...
10
votes
7answers
231 views
Crossing sequences
Crossing Sequences
Given a list of positive integers A, call it an increasing sequence if each element is greater than or equal to the previous one; and call it a ...
15
votes
18answers
2k views
Simplification of numbers
How, you can’t remember the 6 or 7-digit phone number that appeared on the TV screen for a second?! Using the special technique described below, you will turn into a walking phonebook!
Obviously, the ...
32
votes
33answers
6k views
Is this n-speak?
Inspired by Is it double speak?, I devised a harder challenge. Given a string, determine if the string is n-speak, for any \$n\geq 2\$.
N-speak is defined by repeating each letter \$n\$ times. With \$...
1
vote
5answers
194 views
Print an array as a table [closed]
Write a program that prints an associative array (key-value) to a table.
Requirements
Standard loopholes are forbidden
Please include a link to an online interpreter and the byte count in the ...
30
votes
34answers
7k views
The cat ate your input again!
Create a cat program, a.k.a a program that takes an input and prints it.
...Except, the program will randomly take characters away from your input and print that instead.
Each character in the input ...
0
votes
1answer
210 views
The Practice of Programming
At 1998, Brian Kernighan, while working on the book "The Practice of Programming", wanted to demonstrate realisation of regular expression engine. But struggled to find small engine, that cod could ...
18
votes
7answers
3k views
Y2K… in 2019?
It's August 10th, 2019, but your task still involves Y2K. Weird, right?
Create a program that prints itself, with a two digit number appended to it. The first time you run it, it should append 00 to ...
5
votes
7answers
290 views
Bucket interpreter
Create a program that interprets the programming language Bucket.
Bucket works on two buckets: the first can hold A and the second can hold B units of liquid. The things you can do with these buckets ...
19
votes
25answers
3k views
Write an interpreter for *
The task is simple. Write an interpreter for the language *.
Here's a bigger link to the wiki.
There are only three valid * programs:
* Prints "Hello World"
<...
5
votes
7answers
191 views
Dropsort with a Twist
This is my first attempt at a Code Golf question. If it needs obvious edits, please feel free to make them.
Below is a description of the basic Dropsort algorithm.
Dropsort is run on a list of ...
43
votes
15answers
4k views
Does this Foo machine halt?
Determining whether a Turing machine halts is well known to be undecidable, but that's not necessarily true for simpler machines.
A Foo machine is a machine with a finite tape, where each cell on the ...
1
vote
0answers
146 views
Self-Contained Generator Function (JavaScript) [closed]
Create a function that takes in a generator function as its only parameter, and returns an object that can be used as both as a generator and a generator function for said generator. The idea is to be ...
7
votes
6answers
227 views
Help me sub-divide a time signature
This challenge is based on a video in which Andrew Huang discusses unusual time signatures...
https://www.youtube.com/watch?v=JQk-1IXRfew
In it, he advises that you can understand time signatures by ...
21
votes
14answers
5k views
Look mom! I made my own (Base 10) numeral system! [closed]
We've all done it, well, maybe not, but making your own alien language and numbering system is a staple of especially fantasy writing, but is mostly just a fun activity.
The task is simple, take two ...
