Questions tagged [code-golf]
Code-golf is a competition to solve a particular problem in the fewest bytes of source code.
10,531
questions
1
vote
0answers
133 views
FreeCell stack moving [closed]
Rule of FreeCell only allows to move one card each time, but it's possible to move a few using empty free cells and columns.
Each time, one card in a free cell or at top of a column can be moved to an ...
11
votes
3answers
367 views
Maximal hexagonal dot pattern
Challenge
Imagine a hexagonal grid as shown below. Let's call such a grid has size \$n\$ if it has \$n\$ dots on one side. The following is one of size 3:
...
9
votes
0answers
132 views
Calculate the integer square root of a matrix
Let \$A\$ be a square matrix that is at least \$2 \times 2\$ where each element is an integer. \$A^2 = A \times A\$ will then have the same dimensions as \$A\$, and will have integer elements. For ...
3
votes
0answers
122 views
Flatten a parabola keeping the distances between points along the curve constant
Background
Math SE's HNQ How to straighten a parabola? has 4,000+ views, ~60 up votes, 16 bookmarks and six answers so far and has a related companion HNQ in Mathematica SE How to straighten a curve? ...
4
votes
1answer
113 views
Calculate the (n x “super”)factorial [duplicate]
Introduction
Factorials are one of the most frequently used examples to show how a programming language works.
A factorial, denoted \$n!\$, is \$1⋅2⋅3⋅…⋅(n-2)⋅(n-1)⋅n\$.
There is also the ...
18
votes
7answers
794 views
+100
Enlarge ASCII art, Mark II
Related
Given a piece of ascii art and a factor to enlarge it by, which will always be an odd number >1, replace each character with the corresponding ascii-art, resized to fit on a grid the size ...
5
votes
5answers
165 views
Potential nonzero entries in an irregular sequence
Background
A338268 is a sequence related to a challenge by Peter Kagey. It defines a two-parameter function \$T(n,k)\$, which counts the number of integer sequences \$b_1, \cdots, b_t\$ where \$b_1 + \...
17
votes
14answers
1k views
Unfold a list using a function
Task
Haskell's and Scala's standard libraries have an unfold function that builds a list from an initial state s and a function <...
4
votes
2answers
144 views
The Roly-Poly, Square-Wheeled Quine
Code-Golf caddy Eddie Brackets was getting tired of quine challenges, which appeared to be much too easy for the grand poobahs. He has this idea to spice up things and is sending quines to the car ...
11
votes
1answer
219 views
We all know how to SKI, but can you BCKW?
Background
Lambda calculus is a model of computation using lambda terms.
A variable \$x\$ is a lambda term.
If \$E\$ is a lambda term, the lambda abstraction \$\lambda x. E\$ is a lambda term.
If \$...
13
votes
11answers
2k views
+50
How many Sets are there?
This is similar in concept to this challenge, but that is pretty restrictive on input and output and I think opening up these restrictions would lead to a completely different set of solutions that ...
7
votes
5answers
219 views
Will Alice win in this Stick Bomber game?
Background
Stick Bomber is a two-player game I just made up. Initially, some sticks are placed in one or more groups, and the sticks in each group are laid out in a straight line. So a configuration ...
6
votes
6answers
457 views
Group binary shapes together
Consider the following binary matrix:
$$\begin{matrix}
1 & 0 & 1 \\
1 & 0 & 0 \\
0 & 1 & 1
\end{matrix}$$
The (1-indexed) co-ordinates of the \$1\$s here are \$(1,1), (1,3), (2,...
27
votes
6answers
4k views
I'm a lizard, cut here!
Write an \$n\$-bytes program \$AB\$ such that:
it outputs an integer \$x,\ 0\lt x\lt n\$;
both its \$x\$-byte prefix \$A\$ and \$(n-x)\$-byte suffix \$B\$, when run as programs, output \$AB\$.
\$A, ...
14
votes
18answers
1k views
Compare positions of integers in this sequence
A001057 is one way to represent an integer as a natural number. It lists them according to the following pattern:
0, 1, -1, 2, -2, 3, -3, 4, -4, ...
In this ...
12
votes
22answers
2k views
Park, Lake, Santa Fe [closed]
Given a long multi-sentence string, the goal is the count the occurrences of the following words: park, lake, ...
3
votes
2answers
169 views
A Suitable Mission — The Professor's Revenge
Summer Klerance turned in her term assignment for this challenge. Her professor was miffed (but also amused) when he overheard a disgruntled classmate of Summer's saying she got her answers by ...
14
votes
23answers
2k views
Make an array of 128 bit integers
Given an input value \$n\$, construct an array of \$n\$ random 128 bit (unsigned) integers. The integers should be uniformly random.
Your code can use any in built random number generation function ...
7
votes
23answers
747 views
Index and return 3 characters
The challenge is simple: Read 3 letters from a system input¹ and convert them to numbers (A-1, B-2, C-3...Z-26)². Print each of those numbers in the order the ...
14
votes
4answers
1k views
Are you a probabilist or a physicist?
Hermite polynomials refer to two sequences of polynomials:
The "probabilist's Hermite polynomials", given by
$${He}_n(x) = (-1)^n e ^ \frac {x^2} 2 \frac {d^n} {dx^n} e ^ {-\frac {x^2} 2}$$
...
19
votes
5answers
776 views
What if function application was right-associative?
Background
In Haskell and many other functional languages, function application f(x) is simply written as f x. Also, this form ...
16
votes
3answers
654 views
Sliding Dice in a Dish
We have 3 dice in a square dish. The dish is 8 units wide and tall and each die is 3 units wide and tall. The dice are facing up each with a different number on their top face.
...
9
votes
20answers
1k views
+100
Third Stirling numbers of the second kind
\$\left\{ n \atop k \right\}\$ or \$S(n, k)\$ is a way of referring to the Stirling numbers of the second kind, the number of ways to partition a set of \$n\$ items into \$k\$ non-empty subsets. For ...
6
votes
3answers
275 views
Hexagonal section numbers
Introduction
Let's draw some regular hexagons formed by hexagonal tiles, marking the vertices of the tiles with dots. Then we will count the number of dots.
...
19
votes
7answers
2k views
Is this a Jordan matrix?
Background
A Jordan matrix is a block-diagonal matrix where each block on the diagonal has the structure of
$$
\begin{bmatrix}
\lambda & 1 & 0 & \cdots & 0 \\
0 &...
8
votes
7answers
414 views
A Suitable Mission
Summer Klerance, a senior in college, is what her teachers refer to as GBL*. Students in her probability class have been assigned individual problems to work on and turn in as part of their final ...
19
votes
21answers
2k views
Longest Zero Sum Sub-array
Given an array of integers. Find out its longest sub-array (contiguous subsequence) whose sum is 0.
The sub-array for output may be an empty array.
Input
Input an array of integers.
Output
Output the ...
23
votes
7answers
2k views
Happy Birthday… caird coinheringaahing? ChartZ Belatedly?
When this question was posted, it was caird coinheringaahing's birthday! (source: 1, 2, 3, 4) (It was also World Emoji Day.)
As a bit of some CGCC lore, caird's name came from a Jelly answer by Dennis ...
6
votes
6answers
354 views
Blinking Lighthouses – Founder's Day Upgrade
To celebrate the island's next Founder's Day, colored filters (fuchsia, chartreuse, and aquamarine*) have been installed in every lighthouse. All lighthouses begin operation with their fuchsia filter,...
8
votes
3answers
399 views
Possible numbers on a broken screen
A screen consisted of some LED segments like such:
_ _ _ _ _
|_|_|..._|_|_|
|_|_| _|_|_|
However, some of the LEDs are broken, and it's possible that only ...
14
votes
7answers
705 views
Polyagony layout (mode 3/3,6)
Background
Polyagony is a family of hypothetical esolangs where the source code is laid out on a specifically shaped board before running it. It's similar to Hexagony, but various uniform tilings can ...
19
votes
5answers
2k views
KEYBOARD FOR MONKE!
Flavortext
So...this is awkward. It seems I accidentally turned into a monkey last night after eating one too many banana sundaes. This has made many things inconvenient, especially typing. You see, ...
17
votes
40answers
2k views
Which character to change (Cops)
Robbers Thread
Cops, your task is to chose a program that prints a string (you can choose).
Although, if you change 1 character in your code, it should print another string.
But there's a twist: You ...
5
votes
3answers
138 views
Is this an ordinal transform? [duplicate]
Related: What's my telephone number? which asks to calculate the terms of A000085, the number of possible ordinal transforms of length n.
Background
Ordinal transform is a transformation on an integer ...
28
votes
21answers
4k views
It almost works (Cops' Thread)
Robbers' Thread
Your challenge is to find an existing challenge, and implement it in a way such that certain inputs fail. At least one input must not produce the correct output (use the other ...
0
votes
0answers
46 views
Simple Maze Generator [duplicate]
Introduction
Some time ago I found interesting one-liner for C64 and book (300 pages!) only about this programm
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
which ...
18
votes
16answers
2k views
Implement the Torian
The Torian, \$x!x\$, of a non-negative integer \$x\$ can be recursively defined as
$$
x!0 = x \\
x!n = \prod^x_{i=1} i!(n-1) = 1!(n-1) \times 2!(n-1) \times \cdots \times x!(n-1)
$$
The Torian is then ...
8
votes
4answers
177 views
Hamiltonian levencycle of 1-dup permutations
The word "levencycle" is inspired by cyclic levenquine challenge.
Definitions
A 1-dup permutation of order \$n\$ is some permutation of \$1, \cdots, n\$ plus one duplicate number in the ...
24
votes
8answers
2k views
Blinking Lighthouses
Lighthouses on an island have blink codes that let ships know which lighthouse they are seeing. Input should be strings of S and L. Here is a (Python) example of codes for 4 lighthouses as a list of ...
11
votes
2answers
243 views
Classify a graph
Challenge
Given a graph (a structure consisting of nodes and vertices), classify it according to a few categories.
Specifically, you will be given an unweighted directed graph, which is a set of nodes ...
14
votes
6answers
1k views
Most Valuable Circle Chords
This challenge was inspired by this tweet.
Idea
Consider a circle with n evenly spaced dots around the perimeter, where each dot has a postive integer value:
Now ...
7
votes
23answers
3k views
9
votes
2answers
295 views
Greatest Common Gaussian Divisor
Gaussian integers are complex numbers \$x+yi\$ such that \$x\$ and \$y\$ are both integers, and \$i^2 = -1\$. The norm of a Gaussian integer \$N(x+yi)\$ is defined as \$x^2 + y^2 = |x+yi|^2\$. It is ...
36
votes
13answers
2k views
Maximum number of squares touched by a line segment
Consider a square grid on the plane, with unit spacing. A line segment of integer length \$L\$ is dropped at an arbitrary position with arbitrary orientation. The segment is said to "touch" ...
24
votes
16answers
1k views
r flag my Vyxal
Vyxal is a stack-based language, meaning that everything operates by popping and pushing values onto a stack. It has a bunch of useful flags, one of which is r.
...
11
votes
2answers
260 views
Number of distinct shadow transforms
Background
Shadow transform of a 0-based integer sequence \$a(n)\$ is another 0-based integer sequence \$s(n)\$ defined with the following equation:
$$
s(n) = \sum_{i=0}^{n-1}{(1 \text{ if } n \text{ ...
19
votes
10answers
1k views
Ploughed fields via moduli
Let \$R, C\$ be positive integers and let \$0 < s \leq 1\$. Consider the \$R \times C\$ matrix \$\mathbf M\$ defined as
\begin{equation}
M(i,j) = \frac{\mathrm{mod}\,(j, i^s)}{R^s}, \quad i = 1, \...
15
votes
2answers
248 views
Packing Cuboid Boxes into the Shortest Stretchy Truck
You are a package handler for Big CompanyTM and your job is to load boxes into a truck. These are special, stretchy trucks: their length can be adjusted at will. But stretching trucks are expensive, ...
13
votes
14answers
3k views
Roll up a D&D character, with options
I'd like to roll up the ability scores for my Dungeons and Dragons character. But I'd also like them to be balanced (and slightly better than average).
Typically, a character's stats are created by ...
28
votes
23answers
2k views
Recursive Z-matrix
Originally from a CMC I proposed for the last BMG event
Challenge
Given a non-negative integer \$n\$, create a 2D array of size \$2^n × 2^n\$ which is generated in the following manner:
Divide the ...
