Questions tagged [sorting]
This challenge is intended to be solved by sorting, ordering, or otherwise organizing some set of data.
220 questions
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Order a list by the difference of its elements
Task
Given an unsorted list of integers, order it in such a way that the absolute difference of every two adjacent elements will always be equal to 1:
\$|dx| = 1\$
There will be guaranteed one or more ...
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The steps of sorting a stack of disks on three pegs
You have a Tower of Hanoi-esque set of 3 pegs.
There is a stack of unsorted disks labelled from 1 to n (inclusive) on one of these pegs. The other two pegs are ...
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Ranking of binary trees
Let N = [0,1,2,...n-1] be the initial segment of the natural
numbers of length n, then all permutations of N can be sorted
lexicographically, starting with the identity. The index into this
sorted ...
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In what order will the downloads complete?
Background
Recently, I was installing updates on my pc with Pacman (I use arch btw) and noticed the order it downloaded files was like this
Start with the largest 4 downloads
When a download ...
- 14.4k
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How comparison-heavy is this list? [closed]
Given a list of strings in any convenient format display the amount of comparisons between individual characters that a merge sort algorithm would perform.
The merge-sort algorithm is a divide & ...
- 12.8k
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Double dequer sort
In this challenge Bubbler describes sorting a list by inserting its elements left to right into a double ended queue or "deque".
Take a number from the front of the array, and push it into ...
- 103k
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Sorting with a deque
You're given an array of positive integers. Your job is to sort them using an initially empty deque (double-ended queue) by the following procedure:
Take a number from the front of the array, and ...
- 79.3k
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Sort Number Array
Given array \$A\$ \$(a_0, a_1,... , a_n) \$ as a permutation of \$(0, 1,...,n)\$ where \$n ≥ 2\$. Sort array \$A\$ into array \$(0, 1,...,n\$) with \$2\$ caveats:
\$1\$ swap is counted when swapping ...
- 121
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Stably sort N elements in this restricted "cmov" language
The following problem is taken from the real world — but indubitably code-golf!
In this puzzle, the programming language is fixed, and your job is to write the most ...
- 837
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Iteratively sort a list
Given a list of Integers greater than zero, Sort each of the unique values in ascending order, then repeat the process on the remaining duplicate values and append.
Example:
...
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Pseudo-Quantum Bogosort [closed]
Pseudo-Quantum Bogosort
Quantum Bogosort is as follows:
Quantumly randomise the list, such that there is no way of knowing what order the list is in until it is observed. This will divide the ...
- 5,395
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votes
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How long to carry sort?
Carry sort is an \$O(n)\$ "sorting" algorithm. Here's how it works. The algorithm moves left to right along a list. As it traverses a list it "carries" a single item, the largest ...
- 103k
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"Sort" by element duplication
Inspired by one of many bugs I ran into while implementing selection sort in trilangle.
Given a non-empty list of non-negative integers, "sort" the list using the following procedure:
Find ...
- 3,863
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Change the subject
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 ...
- 12.6k
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CGAC2022 Day 17: Present Heap
Part of Code Golf Advent Calendar 2022 event. See the linked meta post for details.
Inspired by https://xkcd.com/835
In the midst of his mid-life crisis, Santa has impulsively purchased a Sports ...
- 6,098
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votes
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CGAC2022 Day 10: Help Santa sort presents!
Part of Code Golf Advent Calendar 2022 event. See the linked meta post for details.
Santa likes to sort his presents in a special way. He keeps "uninterleaving" the pile of presents into ...
- 9,528
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votes
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Fix my FizzBuzz
FizzBuzz is where a range of positive integers is taken, and numbers divisible by 3 are replaced with "Fizz", divisible by 5 with "Buzz" and divisible by 15 with "FizzBuzz&...
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Implement the slowest possible sorting algorithm that retains a fast best case [closed]
I have recently been on a quest to create really really slow sorting algorithms that make Bogosort seem like it is the best.
The task is simple: Sort an array of integers in as long average time as ...
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Sort my Cups︎︎︎︎︎︎︎︎︎︎ [closed]
I have a set of colored plastic cups. They come in four colors: green, yellow, pink, and blue. When I put them on my shelf, I like to stack them in a certain pattern. Your job is, given a list of any ...
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Magic: the Gathering - Colour Sorting
Related: Deck Names Friends or Foes Paying for Spells
The Magic: the Gathering card game has five colours of magical mana: white (W), blue (U), black (B), red (R), and green (G). Cards can be any of ...
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Sorting passengers on a plane
A few days ago I made a puzzle about moving people on an airplane. Now I am interested in the general version of this puzzle and the shortest code golf for it.
I will briefly summarise the puzzle here....
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votes
14
answers
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Sort numbers in a ragged list
Given a ragged list, e.g.
[[4, 7], [5, 3, [], [6, [2]]]]
Your challenge is to sort only the numbers in it. For example, with the above, the result would be
...
- 46.2k
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Sort musical pitches
Given an unordered list of musical pitches, write the shortest program/function (scored in bytes) to sort the list from lowest pitch to highest.
Pitches will be given in scientific pitch notation, ...
- 11.5k
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Sort every dimension
Given a multidimensional, rectangular array of nonnegative integers, sort it at every depth (lexicographically), starting from the innermost.
For example, with this array:
...
- 46.2k
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Unsort an array
Inspired by this StackOverflow post
Given a list where each element appears a maximum of 2 times, we can define it's "sortedness" as the sum of the distances between equal elements. For ...
- 50.9k
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Chunk Sort a Sequence
Your task is to input a sequence of integers and chunk sort it. You may assume the input list can always be chunked into groups of 1, 2, and 3.
Definition
Chunk sorting (a term I made up for the ...
- 4,269
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An Scalable Event Scheduler That Can Handle Billions of Events [closed]
The event scheduler is a recurrent theme in event-driven architectures: something triggers an event that needs to be checked in the future one or more times. I has particular use in trading where you ...
user108147
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Worst case of Slowsort
Background
Slowsort is an in-place, stable sorting algorithm that has worse-than-polynomial time complexity. The pseudocode for Slowsort looks like this:
...
- 79.3k
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Branchless (MIPS) assembly code for median of 3
I was trying to write a short MIPS32 code for computing the median of three registers.
The rules:
Assume that some values are pre-loaded into $t0, ...
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Recursive Stalin Sort [duplicate]
There is a "sorting" algorithm often called Stalin Sort, where instead of sorting an array, you just remove any items that are out of order. In this challenge, you'll implement part of a ...
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Largest Number with No Repeating Digit Pairs
Inspired by the problem with the same name on Puzzling SE by our very own Dmitry Kamenetsky.
You are to find the largest number that only uses every digit pair once, in a given base. For example, in ...
- 2,211
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votes
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Coordinate Connecting
Input:
Ten unique integer coordinates, between (0,0) and (100,100).
Output:
The coordinates arranged in the order/an order such ...
- 1,194
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votes
14
answers
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NESCA: New English Stroke Count Alphabet
TLDR: Sort your input according to a new English alphabet somewhat based on Chinese stroke count methods.
Background: In a Chinese glossary/index, finding terms that are contained within the book is ...
- 1,926
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votes
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Interviewer's Room
You are James and four of your friends (Bjarne, Eich, Rossum, Ada) are called for an interview. There are n interviewers, and they can each serve one person at a time, alphabetically. Each round of ...
- 3,000
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Too much lines for me! [closed]
The problem
You just got a new job, hurray! You expect to be given various interesting tasks, and be able to learn a lot in the next few months.
Good news, your boss gave you your first work this ...
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Is this a half-sort?
The problem over here introduces an new type of strings: if you split the string into equal halfs and swap the pairs, it produces the same output as sorting the string. We call that a half-sort.
...
user92069
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Help, I've mixed my week up!
My dog ate my calendar, and now my days are all mixed up. I tried putting it back together, but I keep mixing up the days of the week! I need some help putting my calendar back together, with the days ...
- 7,017
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Pendulum Encoding
Given a string as an input (which can be any acceptable/convenient format in your language), implement pendulum encoding. The test cases are split into individual items (which aren't quoted) for a ...
user92069
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votes
3
answers
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Swaps to Sort an Array
You are given an array \$A\$, which may contain duplicate elements. In each swap, you may swap the value of any two indices \$i, j\$ (i.e. switch the values of \$A_i\$ and \$A_j\$). What is the least ...
user62257
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votes
2
answers
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Two stack sorting
This challenge is inspired by the same task I read some time ago in CACM.
There are many ways to sort stuff. Most attempt to sort in as few operations as possible (= as fast as possible). However, it ...
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Roll for Initiative!
Roll for Initiative!
Introduction
In tabletop games like Dungeons and Dragons, when you begin a battle, all involved parties roll for initiative. In DnD 5e, this is ...
- 11.4k
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Sort and Table a Sentence by Word Lengths
In as few bytes as possible, sort the input, a delimited string OR list/vector/array of words, words contain printable ASCII except space (ASCII values 33-126) into a numbered list, table, or ...
- 1,926
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North Korean dictionary order
The objective
Given a string of Hangul syllables, sort the characters in North Korean dictionary order.
Introduction to Hangul syllables
Hangul(한글) is the Korean writing system invented by Sejong ...
- 7,371
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votes
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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 ...
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A quine of sorts
Given a string x, output the characters in x sorted according to the order of appearance in your source code.
Examples
...
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Write the shortest O(n^2) sorting algorithm [closed]
Write a sorting algorithm for a list of integers that has an average performance of O(n^2).
This is code-golf, so the shortest code in bytes wins.
RULES:
The characters wasted for the declaration of ...
- 531
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votes
23
answers
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Rotated Position of Integers
Challenge:
Input:
A sorted list of positive integers.
Output:
The amount of integers which are still at the exact same index, after rotating the digits in each integer its index amount of times ...
- 136k
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votes
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answers
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Arrow those variables!
Challenge
Robin likes having his variables declaration in the shape of an arrow. Here's how he does it:
Input any number of strings
Order them by ascending length
Output them ordered by the middle to ...
- 789
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Implement the Thanos sorting algorithm
The sorting algorithm goes like this:
While the list is not sorted, snap half of all items (remove them from the list). Continue until the list is sorted or only one item remains (which is sorted by ...
- 2,509
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Matrix rotation sort
Lets define a non-empty, unsorted and finite matrix with unique numbers as follow:
$$N = \begin{Bmatrix} 4&5&7\\1&3&6 \end{Bmatrix}$$
Lets define 4 matrix moves as:
↑* (up): Moves a ...
