instruction stringlengths 34 53.1k |
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Part of Code Golf Advent Calendar 2022 event. See the linked meta post for details.
Santa and the Elves are secretly preparing for a new tourist train service, called "North Pole Railroads". The train will travel through various sightseeing spots near the North Pole.
As a part of this project, they want to know how ma... |
Scientists have made contact with a parallel universe. Just one problem: They write math differently. Help the scientists make a program that can convert normal math expressions to their equivalent in alternate universe math. The connection through the portal is bad so your code needs to be as short as possible
Given a... |
Given two non-zero 16-bit integers a and b, decide the smallest number of shift operations needed to turn a into b. A shift is one of the following (big-endian) operations:
shl (shift left): move all bits to the left, adding a 0x0 bit to the right.
shr (shift right): move all bytes to the right, adding a 0x0 bit to th... |
Background
Here in the UK1, these are the income tax rules:
You get a personal allowance (untaxed) of up to £12,570:
If you earn less than £100,000, you get the full £12,570 as personal allowance
For every £2 over £100,000, your personal allowance goes down by £1
After the personal allowance, the next £37,700 is ta... |
Presumably everybody here knows that for the legacy BIOS, the tiniest bootable disk image is 512 bytes (the lower bound is due to the 2-byte magic at offset 510), and there is a bootsector demoscene where people try to fit the entire demo into the 510 bytes of usable space.
Now that the BIOS is being superseded by UEFI... |
Part of the Code Golf Advent Calendar 2022 event. See the linked meta post for details.
As a Christmas gift, you were given a toy solar system. In this toy, all the orbits are circular and happen in the same plane. Each planet starts at a fixed location, has a fixed circumference orbit, and moves at a fixed speed (all... |
According to MDN, every WebSocket message is sent as one or more frames. Your job is to extract the payload given a (masked) client-to-server text frame. The steps to extract the payload is as follows:
ignore byte 1; read byte 2
if it is 254, skip the next 2 bytes
if it is 255, skip the next 8 bytes,
otherwise, conti... |
Objective
Given a permutation of 4 distinct items, classify the permutation by the normal subgroup(s) it belongs.
Input/Output Format
You gotta choose the followings as the hyperparameters for your submission:
The 4 distinct items.
The permutation serving as the identity permutation.
The input format is to accept a... |
Task
Provide two programs/functions A and B (not necessarily in the same language) with the following properties:
Either program, when given its own source code as input, produces an accepting output.
Either program, when given the other program's source code as input, produces a rejecting output.
It doesn't matter w... |
The Riemann R function is as follows:
$$R (x)=\sum _{n=1}^{\infty } \frac{\mu (n) \text{li}\left(x^{1/n}\right)}{n}.$$
This uses the Möbius function as well as the logarithmic integral.
From Wikipedia, the Möbius function is defined so that for any positive integer \$n\$, \$μ(n)\$ is the sum of the primitive nth roots... |
The Prime Signature of a number is the list of the exponents of the prime factors of a number, sorted in descending order (exponents of 0 are ignored). Inspired by Combo Class's "The Magnificent Patterns of Prime Signatures" video.
For example, the prime factorization of 6860 is 2 * 2 * 5 * 7 * 7 * 7, or 2^2 + 5^1 + 7^... |
Title is an homage to this classic challenge
In Pip, the Scalar data type encompasses strings and numbers. A Scalar value is truthy in most cases. It is falsey only if:
It is the empty string ""; or
It is some representation of the number zero.
A Scalar is considered to be a representation of zero if:
It consists of... |
Last time you were required to write program that output a file, such that no byte is same as original file. The request meant to let everyone carry part of information, but it ends up that everyone carry same info to reduce their storage... This challenge is similar.
Write at most 1024 programs that output at least 85... |
Introduction
The \$RADD(n)\$ operation is defined as the sum of \$n + [\$ the number whose decimal representation are the decimal digits of \$n\$ in reverse order \$]\$, see A004086. After reversal, trailing zeros are lost. See Reverse-Then-Add Sequence and A056964.
Not all numbers can be represented as the result of a... |
We're going to turn ascii art versions of polygons into their equivalent GeoJSON.
The ASCII shape language
The input ASCII language only has 3 possible characters:
* signifies a vertex
- signifies a horizontal line
| signifies a vertical line
A * will never be directly adjacent to another * (but may be diagonal to on... |
Fastest code is a scoring method on this site where the goal is to write code that is as fast as possible.
From the tag wiki:
The winner of a fastest-code challenge is determined by the runtime performance of the submissions. For fairness, all submissions should be benchmarked on the same machine, which usually means ... |
Introduction
Our goal is to efficiently find the maximum of a large amount of (redundant) data.
We define the outer product of vectors \$A\$ and \$B\$ as a matrix containing the products of all entries of \$A\$ with each entry of \$B\$. (see outer Product)
$$
A\otimes B := A\cdot B^T = \left(\begin{array}{rrr}
A(1)\cdo... |
The standard way to round numbers is to choose the nearest whole value, if the initial value is exactly halfway between two values, i.e. there is a tie, then you choose the larger one.
However where I work we round in a different way. Everything is measured in powers of two. So wholes, halves, quarters, eights, sixte... |
Given a word list, find all sets of five words of five letters each, such that the words of each set have 25 distinct letters in total.
This challenge was inspired by this video by Matt Parker.
Testcases
Use this file if you want to test your code against the English vocabulary. Sample output sets:
["fjord", "vibex", ... |
Given two rectangles, which are possibly not in the orthogonal direction, find the area of their intersection.
Input
You may take the rectangles as input in one of the following ways:
The coordinates of the four vertices of the rectangle. These coordinates are guaranteed to represent a rectangle.
The coordinates of t... |
Inverse function of this challenge
To (properly) multiply an string by an integer, you split the string into characters, repeat each character a number of times equal to the integer, and then stick the characters back together. If the integer is negative, we use its absolute value in the first step, and then reverse t... |
I just discovered this site and this is my first question, I hope I'm doing it correctly.
The challenge is the following, you must write a code that prints all the prime numbers of \$n\$ digits. Since this problem is computationally complicated, I think that one way to simplify it is to give a number \$m\$ that will be... |
Consider a list of subject, grade pairs. E.g.
[("Latin", "A"), ("French", "A*"), ("Math", "B"), ("Latin", "A*")]
The task is to return the same list but with each subject given at most once. Where a subject occurred more than once originally, the returned list should have the highest grade for that subject.
Using th... |
I have this problem where I listen to so much music that I can never remember what songs are called. But even if I remember the lyrics, I won't always know the song's name. But lucky for me, there's a pretty neat formula to determine¹ the title of a song just based on its lyrics.
I'll define the way a song title can be... |
Wren is a small, fast, class-based concurrent scripting language. Does anyone have any tips for this language?
Please make sure to post 1 tip per answer, and don't post answers like "remove whitespace".
|
Given as input a positive nonzero integer n >= 10 and a sequence of digits 0-9 (which may be taken as a string or a list), find the first contiguous subsequence of digits in the sequence that sums to n and output the start and end indexes. You may use zero- or one-based indexing. If no such subsequence exists, your pro... |
Given a list of lists of positive integers, output a subset of them so their union forms a continuous non-empty range with no numbers missing. For example, consider this input:
[
[1, 2, 3, 5],
[2, 4, 6],
[7, 9, 11]
]
The union of the first 2 forms a continuous sequence: [1, 2, 3, 4, 5, 6] with no numbers miss... |
Related
Now you have some dice which you may roll several times. You need a uniform random integer between 1 and \$n\$, inclusive. Show a method that rolls the fewest times and behaves as an \$n\$-sided dice.
Alternative question: Given a set \$S\$ and \$n\$, pick the fewest elements from \$S\$(each element can be pick... |
Consider:
c=(a,b)=>(+a||0)+(+b||0)
Yes, it is not good to solve it like that. But I want to shorten it even more. If a is a string and b is a string, then return 0. If one is a number, return it (floats and intergers). And if both inputs are numbers, then return the sum (if either string can be cast to a number, treat... |
Intro
The Tetris Guidelines specify what RNG is needed for the piece selection to be called a Tetris game, called the Random Generator.
Yes, that's the actual name ("Random Generator").
In essence, it acts like a bag without replacement: You can draw pieces out of the bag, but you cannot draw the same piece from the ba... |
Write a function that takes an ASCII-printable-only (all charcodes ∈ [32..126]) string input x and provides an ASCII-printable-only output string f(x), such that for every x
f(f(x))=x
f(x) is all-numeric (all charcodes ∈ [48..57]) iff x is not all-numeric
You can assume input is not empty and never provide empty outp... |
Inspired by the title of the Toggle some bits and get a square challenge.
In that challenge you output how many bits should be toggled, in order for the base-10 representation of the binary to become a square number.
Challenge:
In this challenge, you'll be given a bit-matrix \$M\$ and an integer \$n\$ as inputs.
Output... |
In chess, fork means to target two pieces with just one piece, and one of the best pieces for forking is the knight.
In this challenge, you will be given three coordinates in a to h and 1 to 8 (like a8 or e7) format. The first and second coordinates are for two other random pieces, and the third is the knight's coordin... |
A Shift matrix is a binary matrix with one superdiagonal or subdiagonal formed by only ones, everything else is a zero.
A superdiagonal/subdiagonal is a diagonal parallel to the main diagonal, which is not the main diagonal, i.e. all entries \$a_{ij}\$ where \$i=j+k\$ and \$k \neq 0\$.
The main diagonal is defined to b... |
Sometimes I feel like the conversation is going down the wrong path and take it upon myself to steer it in another direction. And this conversation is going wrong real fast, so I need to change the subject in as few characters as possible.1
Task
Given a list of sentences, return the sentences ordered such that each sen... |
Let's solve the same task as in this challenge but faster!
Input: a non-empty string containing letters a-z
Output: the length of a longest (contiguous) substring in which all letters are different
Time and space complexity: O(n).
The number of letters in the alphabet is 26, or O(1). Make sure you understand how your l... |
Context
So the Dutch "Ministerie van Binnenlandse Zaken en Koninkrijksrelaties" (NL) - "Ministry of the Interior and Kingdom Relations" (EN) recently released the source code of their digid-app.
They have some goofy code in there, which led to mockery and memes on reddit
Source code of the offending method can be found... |
Alternatively: That one challenge I forgot I had in the sandbox and is about stuff from Discrete Mathematics I learned like 5-6 months ago and kinda don't remember
Given a path of vertices that form a cycle on a graph, output a simple version of the cycle. That is, if a vertex appears twice, snip out the part in betwee... |
Challenge
To quote Wikipedia:
An octave-repeating scale can be represented as a circular arrangement
of pitch classes, ordered by increasing (or decreasing) pitch class. For instance, the increasing C major scale is C–D–E–F–G–A–B–[C], with the bracket indicating that the last note is an octave higher than the first no... |
Inspired by a challenge from the OUCC 2022 Seniors competition.
Background
Two teams are playing "capture the flag". They take turns invading each other's base and capturing their opposing team's flag in the shortest amount of time. The attacking players each have one soft ball they can throw at the defenders. Teams ge... |
Given a matrix of positive integers, output whether it's possible to generate it by starting with an empty1 matrix of the same dimensions and repeatedly filling a whole row or a whole column with the same value, overwriting any values already written.
Example
The following matrix:
$$\begin{pmatrix}1&1&1\\2&3&4\\2&3&4\e... |
Introduction
An abstract syntax tree (AST) is a tree of tokens that shows their connection to each other and syntactical meaning. They are commonly used in compilers and static analysis tools, as parsing a language into an AST helps remove any ambiguity and can be helpful for optimizations. Many ASTs are large and comp... |
2fuck is a simple 2D variation on brainfuck. Like traditional brainfuck, there is an 1D memory tape that extends 30000 bytes to the right from its beginning, consisting of values between 0 and 255.
Arithmetic should wrap around, adding 1 to 255 sets the cell to 0, and moving right from memory cell 29999 should move the... |
You are on a plane filled with boxes, and you get a sequence of movements, say "up right right down left":
You move up, pushing all boxes in front of you away:
You move right, right and down, getting
and finally left. This time you only push one box rather than infinite boxes:
At the end, there are 4 spaces.
Given ... |
Introduction
In the prisoner's dilemma, two partners in crime are being interrogated, and have the choice to either betray their partner or stay silent.
If both prisoners betray each other, they both get 2 years in prison.
If neither betrays (both stay silent), they both get 1 year in prison.
If only one betrays and t... |
In a certain chatroom, we like making acronym jokes about the build tool we use called sbt. While it usually stands for "Scala Build Tool", we aim to come up with all sorts of meanings, such as:
Stupid Brick Teeth
Sussy Baka Training
Shady Blue Tourists
Seriously Big Toes
Silly Bear Topics
Salacious Bacon Tripod
Syrin... |
Alternatively: Now you're checking with portals!
Inspired this challenge
I am somewhat of a self-declared Chess Anarchist. That means that when I play chess, en passant is forced (else the brick gets used), double check is mate (and pasta), and all sorts of new pieces and squares are added to the game.
One such piece i... |
Bingo
Bingo is a numbers game where players match randomly drawn numbers to the numbers on their cards. Each bingo card is a square grid with 25 spaces, and the columns of the grid are labeled with letters such as "B", "I", "N", "G", "O". The letters help to identify the number range in each column, for example, the "B... |
Output the numbers 1-16 (or any other set of 16 distinct items). Then, repeatedly, output a random value chosen uniformly from the last 16 items outputted.
After the same item is printed 16 times in a row, halt.
If a number appears multiple times in the last 16 values, it should have proportionally more chance to be ch... |
Introduction
In the United States, national elections are normally held on the first Tuesday after the first Monday in November.
Challenge
Write a program that takes a Year as integer, and a pair of (day of week as character and ordinal as integer) and output the date as "yyyy-mm-dd"
Remember, the second pair is after... |
You work at a bakery, and every day you make pastries. You make 100 of each of several different types. However customers are less predictable. Some days they order all of one kind of pastry and you run out, some days they order hardly any and you have some left over. So your boss has made up a chart which tells you ho... |
Given a list of countries in alphabetical order, put them in the same order as they are given in the song "Yakko's World".
Specifically, you are given the following list of countries* exactly:
Abu Dhabi, Afghanistan, Albania, Algeria, Algiers, Angola, Argentina, Australia, Austria, Bahamas, Bahrain, Bangladesh, Barbado... |
For a given positive integer, try to find out the smallest possible rotation resulted by rotating it 0 or more bits.
For example, when the given number is 177, whose binary representation is \$10110001_{(2)}\$:
\$ 10110001_{(2)}=177 \$
\$ 01100011_{(2)}=99 \$
\$ 11000110_{(2)}=198 \$
\$ 10001101_{(2)}=141 \$
\$ 00011... |
In this challenge you will be tasked with implementing a sequence of natural numbers such that:
Each number appears a natural number of times
No two numbers appear the same number of times
No two numbers appear in the sequence next to each other more than once.
For some examples, the sequence
1,2,3,1,4,5,1,6,7,1,8,9,... |
Your task
Given a integer input, \$ n \$ (such that \$ n > 1 \$), decide whether it can be written as the sum of (at least 2) consecutive square numbers.
Test cases
Truthy:
Input Explanation
5 1 + 4
13 4 + 9
14 1 + 4 + 9
25 9 + 16
29 4 + 9 + 16
30 1 + 4 + 9 + 16
41 16 + 25
50 9 + 16 + ... |
Your function must accept 2 strings which are correct numbers. It needs to sum them up (without rounding and floating point errors) and return the result (which is also a correct number) without any leading zeros in the integer part, trailing zeros in the decimal part and without minus if the answer is 0 i.e. -0 is not... |
Task
Write a polyglot in two languages that when run, outputs the name of the language it is run in. Additionally, this program must also output the other language's name if the source code is reversed
Example:
Program ABC in language foo outputs foo. ABC in language bar outputs bar. CBA in language foo outputs bar, an... |
Suppose we have a sequence \$P\$. Every element \$P_n\$ represents the distance between the \$n^{th}\$ prime number and the average of the next two prime numbers.
For example, \$P_1\$ would be the distance between the first prime number (2) and the average of the next two prime numbers (3 and 5), so
\$P_1 = \frac{3+5}{... |
Given as input a list of positive integers, your task is to determine if every integer present has exactly two neighbors in the list. The neighbors of a integer \$x\$ are the distinct integers that appear next to an \$x\$ anywhere in the list. For example in the list:
[1,3,4,4,3,2,1]
The number 3 has 3 neighbors 1, 4... |
The city defines a dog as any living entity with four legs and a tail. So raccoons, bears, mountain lions, mice, these are all just different sizes of dog.
Given an ASCII-art image of an animal, determine if that animal is a dog.
Rules
An animal is a dog if it has four legs and a tail.
The foot of a leg starts with one... |
There is a 1x1x1 cube placed on a infinite grid of 1x1 squares. The cube is painted on every side, so it leaves a mark on the grid when it moves.
The sides of the cube are colored 6 distinct colors, re-presentable with any 6 distinct values. A 7th value represents a blank space.
The cube can roll around the grid. Ever... |
Traditionally when you compare two strings you use lexicographical comparison. That can be described by the recursive algorithm:
$$
f(x, y)=
\left\{\begin{array}[rr] \\
\mathrm{EQ} & \mathrm{if}\,\mid x\mid=0\,\mathrm{and}\,\mid y\mid=0 \\
\mathrm{GT} & \mathrm{if}\,\mid x\mid>0\,\mathrm{and}\,\mid y\mid=0 \\
\mathrm{L... |
The task is to count the number of disjoint 11 blocks in a 64-bit word, using the minimum number of straight-line instructions. That is, how many nonoverlapping neighbored pairs of 1-bits can be found.
Examples
(imagine leading zeros to fill up to 64 bits)
Input Output
111111 3
1110111 2
111100... |
Yesterday, as part of a IQ-style test, I got this interesting question:
The time on a 24-hour clock is 11:43. What is the least number of minutes I should wait before the same digits are on the screen again (in any valid 24-hour time order)?
The answer's 91 minutes, if you were wondering!
This stuck in my mind, and ... |
I have encountered this type of puzzle, that usually involves apples, several times. It goes as follows:
There is a certain number of apples in a basket. Ava takes a third of the apples. Bob takes a quarter of the apples that are left. Finally, Dennis takes one-sixth of the apples left. In the end, there are 10 leftov... |
Given an atomic number in the inclusive range [1,118], write the shortest program/function that outputs one of {2,8,18} if the element with that atomic number follows the duplet, octet, or 18-electron rule, respectively.
Notes
The Octet/Duplet/18-electron rule is a rule of thumb that describes how many electrons is ne... |
It can be proven that there's exactly one string of infinite length that remain same after base64 encoding Vm0wd2QyUXlVWGxWV0d4V1YwZ...
Given a position, output the character on that position.
Your program would be run on AMD Ryzen 5 5500U@4GHz given 4GB memory and 1 minute (may decrease if RAM turns out to be hard lim... |
Your task is to generate an emoticon of three characters, the first character being one eye, the second the mouth, and the third another eye. Each eye is a random one of these characters: $'*+-;O^`ox~, and the mouth is a random one of these: ,-._coux.
Each eye and the mouth must be on the same general level. These eyes... |
plorcly borglar is a "mod" created by jan Misali for the constructed language toki pona that makes words sound funny.
It involves substituting the 14 toki pona letters for funnier versions plus 2 extra rules. The substitutions are:
toki pona letter
plorcly borglar letter
m
bl
n
gl
p
b
t
pl
k
cl
s
scr... |
Ptolemy's Almagest contains a table of chords that effectively served as the world's only comprehensive trigonometric table for over a millennium. In modern form it looks like this:
\begin{array}{|l|rrr|rrr|}
\hline
{}\,\,\,\,\,\,\,\,\,\, \tfrac12 & 0 & 31 & 25 & 1 & 2 & 50 \\
{}\,\,\,\,\,\,\, 1 & 1 & 2 & 50 & 1 & 2 &... |
Given a base as input, output all pan-digital numbers. A number is pan-digital if it includes every digit in that base at least once, possibly multiple times. Every number is considered to contain an infinite number of leading 0s.
sequence rules apply. Given a base, you may either:
Given an index, output the n-th pan-... |
Write a program that, for any \$n\$, generates a triangle made of hexagons as shown, \$2^n\$ to a side. The colors are to be determined as follows.
We may give the triangle barycentric coordinates so that every hexagon is described by a triple \$(x,y,z)\$ with \$x+y+z=2^n-1\$. (The three corners will be \$(2^n-1,0,0)\$... |
A Latin square of order n is text which is arranged as a square of n lines by n columns, contains n different characters, and each character appears once in each line and column. For example, here is a Latin square of order 9:
Code gOlf
ode gOlfC
de gOlfCo
e gOlfCod
gOlfCode
gOlfCode
OlfCode g
lfCode gO
fCode gOl
M... |
You are the treasurer and you have received information that a counterfeit coin has entered the treasury. All you know is that the counterfeit coin is lighter than the original.
Knowing how many coins you have in total and using only a balance scale, you need to determine the minimum number of weighings to determine wh... |
Let's say you are given an integer array. Create a function to determine the largest sum of any array's adjacent subarrays. For instance, the contiguous subarray with the largest sum is [4, -1, 2, 1] in the array [-2, 1, -3, 4, -1, 2, 1, -5, 4].
You can employ a variant of Kadane's algorithm to resolve this issue. The ... |
You are given a matrix of size m x n where each cell can contain either 1 or 0. You need to find the largest square submatrix that contains only 1's. The output should be the area of the largest square submatrix.
For example, given the following matrix:
1 0 1 1 1
1 0 1 1 1
1 1 1 1 1
1 0 0 1 0
The largest square submat... |
Write a program that takes an undirected graph and finds the minimum cut, i.e., the set of edges that, if removed, would disconnect the graph into two or more connected components. The program should have a time complexity of \$O(n^2m)\$, where n is the number of vertices and m is the number of edges in the graph.
One ... |
Define the (unnormalised) Willmore energy of a surface as the integral of squared mean curvature over it:
$$W=\int_SH^2\,dA$$
For surfaces topologically equivalent to a sphere \$W\ge4\pi\$, and \$W=4\pi\$ iff it is actually a sphere. Thus the energy quantifies how spherical a surface is.
In September 2020 I asked on Ma... |
proposed by @Adám in chat
Given an even number of finite points return a line \$y=mx+b\$ that evenly splits the points on both sides.
Specs
Take a list of distinct points \$(x,y)\$ (or a list of x-coordinates and a list of y-coordinates), output a possible \$(m,b)\$ pair
Half of the points should be true for \$y>mx+b\... |
This challenge is simple: Take a path to an png image file as input and overwrite that file with a copy of itself rotated 90 degrees clockwise. You may assume that the file has dimensions of 128x128 pixels. You may not use image metadata modifications (like Exif) to rotate the image; the pixels themselves must be trans... |
Description
The Gameboy stores tiles as 2 bit-per-pixel 8x8 images, thus 16 bytes. Every two bytes is a complete row with all of the Low-bits of each pixel in the first byte, and all of the High-bits of each pixel in the second.
Input
Input will be exactly 16 bytes, received through Standard IO in one of the following... |
Your function must accept one string and return the opposite
The opposite string is a string where all characters go in reverse order, all letters are replaced with the opposite mirror letter from the English alphabet and are changed in case, and all digits are replaced with opposite mirror digits
opposite mirror for l... |
Given an ASCII art with simple closed paths using | and - (pipes and dashes), output a random point inside the boundary.
Eg. given:
---- ----
| |- --- => |12|- ---
| | | | |345| |6|
----- --- ----- ---
Any point 1-6 should have an equal probability of being printed.
Specs
T... |
Let a counting tree be a rooted tree in which every node is labeled with the number of descendants it has.
We can represent such trees as ragged lists with each node being represented by a list containing its label followed by its children. For example the following is a counting tree:
[5,[2,[0],[0]],[0],[0]]
However ... |
There are multiple ways to represent a 3D rotation. The most intuitive way is the rotation matrix –
$$A=\begin{bmatrix}A_{11}&A_{12}&A_{13}\\A_{21}&A_{22}&A_{23}\\A_{31}&A_{32}&A_{33}\end{bmatrix}$$
rotates a point \$p=(x,y,z)^T\$ by left-multiplication: \$p'=Ap\$. This is however inefficient since a 3D rotation has on... |
Every odd degree polynomial has at least one real root. However this root does not have to be a rational number so your task is to output a sequence of rational numbers that approximates it.
Rules
Your input is an odd degree polynomial \$f\$ with integer coefficients in any reasonable format.
You must output a sequen... |
Your task is to create a program or function, that when given an input list of nonnegative integers of length \$l \ge 2\$ and a nonnegative integer \$c\$ where \$2 \le c \le l\$, group the list into \$c\$ "clusters." What this means is, the average (population) variance* of all the groups should be as low as possible.
... |
It can be easily proven using Hall's marriage theorem that given fixed \$n\$ and \$k<n/2\$, there is an injective (one-to-one) function from all \$n\$-bit strings with \$k\$ ones to \$n\$-bit strings with \$k+1\$ ones such that an input and its corresponding output differ by exactly one bit. For example, with \$n=5,k=2... |
It is well-known that a 3D rotation can always be represented by a quaternion. It is less well-known that a 4D rotation can always be represented by two quaternions, sending a point \$p=(a,b,c,d)^T\$ represented as the quaternion \$a+bi+cj+dk\$ to the point \$p'=xpy\$ for an appropriate choice of unit quaternions \$x,y... |
Given a list of fractions, group them so that each group sums to a whole number. This should be done in such a way to maximize the number of non-empty groups.
You may assume a solution exists. Order does not matter, both for the groups and their contents. You may output in any order.
Test Cases
Fractions
Groups
... |
The ubiquitous Catalan numbers \$C_n\$ count the number of Dyck paths, sequences of up-steps and down-steps of length \$2n\$ that start and end on a horizontal line and never go below said line. Many other interesting sequences can be defined as the number of Dyck paths satisfying given conditions, of which the Fine se... |
I was playing with the Fibonacci sequence in binary like so (note that the binary representations are written here from smallest bit to largest bit):
1 1
1 1
01 2
11 3
101 5
0001 ... |
In Haskell (and probably some other languages or something) zip is a function which takes two lists, and produces a list of tuples by pairing elements at the same index:
zip [1,2,3] [6,5,4] = [(1,6),(2,5),(3,4)]
If there are extra elements on one of the input lists those are trimmed off and don't appear in the result:... |
There is a building with an infinite number of floors and you are the only passenger in an elevator which can lift an infinite number of people. You are going home, but before the elevator gets to your floor, the elevator stops at another floor to allow people to enter the elevator and input their destination floors. Y... |
An intriguing MathsSE question asked if there were large N-queens solutions where no three queens lie on a line. That question's body included the unique 4×4 solution up to symmetries
. Q . .
. . . Q
Q . . .
. . Q .
and noted that there are no solutions for 5×5 to 7×7 because of knight lines. However, joriki over ther... |
I'm trying to shorten a bash solution to a Code Golf challenge, which requires an output of true or false. I've managed to condense the key piece of the code down to a substring check, to determine if the provided argument, $1, is a substring of a particular hard-coded fixed string, of the form:
[[ FIXEDSTRING = *$1* ]... |
Specifically, this references JavaScript, a programming language that happens to be one you can run on StackExchange/StackOverflow. However, you may use any programming language to do this challenge. This is not actual JS golfing, but merely a "code-golfable" challenge. Actual complete parsing of JS is not needed.
An e... |
I'm working from home and the heat of my laptop on my lap is the only thing keeping me warm. I have a Dell G3 Laptop with an NVidia GEForce GTX CPU.
I have tried writing a rust program with 5 threads that calculates and prints the Fibonacci sequence in an infinite unthrottled loop, but that only gave a bit of warmth, a... |
Given a non-empty string (or an integer, or a list/array if you prefer) composed exclusively of digits in the range [1-9], your task is to write a function (or a whole program) that applies a "Match-3 type of rule" from left to right and outputs the resulting string, like this :
[parameter] "12223" -> [returned value] ... |
Strangely never asked before, this question pertains to the generation of a list of prime numbers within a given range using the shortest possible code. Several algorithms, such as the Sieve of Eratosthenes and trial division, are known to be effective for this purpose, but require significant code length. Is there an ... |
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