Questions tagged [array]
A competition to solve a particular problem through the usage and manipulation of arrays.
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Compute cumulative means efficiently
Consider a sorted array of positive floating point numbers such as:
input = [0.22, 2.88, 6.35, 7.17, 9.15]
For each integer \$i\$ from 1 up to the last value in ...
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6
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"Signpost" puzzle from Tatham's collection
Simplified version of "Signpost" puzzle from Simon Tatham's Portable Puzzle Collection.
How the puzzle is created
We pick up randomly positive integer N ...
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Counting fading
Background
Being in a philosophical mood, I remembered one old idea. I think it is suitable for CG.
Duplicates are not found, but it's of course just a kind of totalistic cellular automaton or erosion....
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The Jaccard Index
The Jaccard index / similarity coefficient, also known as the Tanimoto index / coefficient, is a statistic used for gauging the similarity and diversity of finite sample sets. It was developed by ...
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Cosine similarity of two vectors
The cosine similarity of two vectors \$A\$ and \$B\$ is defined using their dot product and magnitude as:
\$\frac{A\cdot B}{\|A\|\|B\|}\$
Or in other terms
\$\frac{\sum_{i=1}^nA_iB_i}{\sqrt{\sum_{i=1}^...
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Make a Custom Bayer Matrix
A Bayer matrix is a threshold map used for ordered dithering that gives the illusion of having more shades of color than actually present by using a crosshatch-like pattern.
Bayer matrices are square ...
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Shortening this Code to process nested tuple even further without the use of max()
I have the code:
...
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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 ...
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Is it a valid chemical?
Non-metals typically* have a fixed number of covalent bonds in every chemical they are part of. Given the number of bonds every element requires, output whether it's possible to construct a single ...
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Is it traversable?
Imagine that a list of integers describes the heights of some two-dimensional terrain as seen from the side.
Stamina: [ 4 4 4 4 4 4 3 3 3 3 2 2 2 - ]
O
...
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Guessing on straws
Dedicated to Martin Gardner, taken from his book
Background
In the old days, the Slavs had a divination method for finding out whether a girl would get married. The girl would clutch six straws in her ...
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Counting Letters in a String
Write a program or function that takes in a string and outputs a count of each modern English alphabet letter in the string, case-insensitive.
Input: A string consisting of printable ASCII characters (...
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votes
24
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String with the smallest sum of ASCII values
Description
In this challenge, you need to write a function that takes in a list of strings and returns the smallest string based on their ASCII value. You should assume that the input list contains ...
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votes
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Voronoi-Lloyd ASCII art [closed]
Voronoi diagram is a partition of a plane (or part of plane) into regions close to each of a given set of objects ("seeds").
Here we’ll be dealing with discrete arrays or even rather with ...
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Shortest Code to Find the Smallest Missing Positive Integer
Description
Given an unsorted array of integers, find the smallest positive integer that does not appear in the array. Your task is to write the shortest code possible to solve this problem.
Input
A ...
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votes
6
answers
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Number Clusters
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 \$...
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Find the largest sum of any contiguous subarray of the array [duplicate]
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 ...
user116868
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Arbitrary Apple Dilemma
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 ...
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votes
8
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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 ...
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16
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Form a subset that is a continuous range
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:
...
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Keep elements in sequence that have a letter repeated at least 3 times
Challenge:
Given the input array l with a list of strings, only keep the elements in the sequence that have a letter that's repeated at least 3 times. Like ...
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Create \$n\$ sublists with the powers of two (1, 2, 4, 8, 16...)
Challenge:
Given the input number n. It should give me nested sublists of n layers with the power of two numbers for each level. ...
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18
votes
22
answers
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Generate recursive "arrays" up to a certain depth
Given a positive integer n.
Generate a JSON array (can be a string, or your language's built-in JSON representation as long as we can get valid JSON, (your code ...
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CGAC2022 Day 8: Fen The Wicked, Part 2
Part of Code Golf Advent Calendar 2022 event. See the linked meta post for details.
Fen is a magician Elf. He can cast spells on an array of numbers to produce another number or array of numbers.
One ...
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CGAC2022 Day 7: Fen The Wicked
Part of Code Golf Advent Calendar 2022 event. See the linked meta post for details.
Fen is a magician Elf. He can cast spells on an array of numbers to produce another number or array of numbers.
One ...
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votes
6
answers
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Conversions Galore!
Imagine that there are \$n\$ different types of objects \$O_1,O_2,O_3,\ldots,O_n\$ and they each have a conversion factor \$k_1,k_2,k_3,\ldots,k_n\$. You can, for any \$1\le i\le n\$, convert \$k_i\$ ...
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What is the longest trampoline?
In this challenge we are going to consider lists of integers such that for every member \$x\$ at index \$i\$ then the indexes \$i+x\$ and \$i-x\$ have the value \$x+1\$ or are out of bounds for the ...
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votes
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answers
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Construct a diverse array
Given an integer \$ n \ge 1 \$, your task is to output an array \$ a \$ consisting of \$ n^2 + 1 \$ integers, such that all possible pairs of integers \$ (x, y) \$ satisfying \$ 1 \le x, y \le n \$ ...
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Longest alternating subsequence
inspired by Longest Increasing Substring
Task
Given a list of non-negative integers, output the length of its longest alternating subsequence.
An alternating sequence is a sequence of numbers which ...
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Repeat Values In Array
Given two arrays of non-negative integers \$A = [A_1,A_2,\ldots,A_n]\$ and \$R = [R_1,R_2,\ldots,R_n]\$ which are equal in length, return an array which has the element \$A_1\$ repeated \$R_1\$ times, ...
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Is this a refinement? [duplicate]
A partition of a list \$A\$ is a way of splitting \$A\$ up into smaller parts, concretely it is list of lists that when concatenated gives back \$A\$.
For example ...
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Reconstruct Matrix from its diagonals
Given the diagonals of a matrix, reconstruct the original matrix.
The diagonals parallel to the major diagonal (the main diagonals) will be given.
Diagonals: ...
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Optimally pop all the bubbles
In a given 2d grid of positive integers (representing different types of "bubbles"), there are one of two actions that you can do each "step". You can either:
Pop an island (a ...
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Multiply numbers by their depth
Given a ragged list, we can define an element's depth as the number of arrays above it, or the amount that it is nested.
For example, with the list ...
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votes
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Tile stacking with ■ and □
In this challenge you will receive as input a list of binary lists. The list represents a game board with each element representing a location on the board. The list at each location represents the ...
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23
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Add in the blanks
In this challenge you will be given a list of positive integers which represents some range of integers which has been truncated for display. Your job is to find the missing bits and insert ellipses ...
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votes
12
answers
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Get multi-dimensional indices in a list
Given a matrix of non-negative numbers (of arbitrary dimension) and a number, get all multi-dimensional indices of the number in that list.
For example, let's say we have the list ...
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Word stays a word after taking away a letter
This is a repost of this challenge
Challenge
There is an old, popular riddle:
Find an English word with 8 letters that, taken away one letter, creates a new valid word. Repeat that until there are ...
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votes
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Pairs at every distance
Given a list \$X\$ of 2 or more integers, output whether, for all \$n\$ such that \$0 \leq n < length(X)-2\$, there exists a pair of equal integers in \$X\$ separated by exactly \$n\$ elements.
In ...
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Flood fill by distance
Say I have a grid with some obstacles:
----
| X |
| |
|XX |
| |
----
I can fill this with numbers, as distance from the top left corner. But, because ...
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Check a mushroom forest
In this challenge you will receive a list of pairs of non-negative integers representing a mushroom forest. Each pair represents a mushroom whose center is at that horizontal coordinate. The only ...
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How tall are the mushrooms?
In this challenge you will receive a list of non-negative integers. Each one represents a mushroom with a cap of that radius centered at that location. So a 0 ...
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Find the walls!
This is a simpler variant of my previous challenge Don't touch the walls!, as suggested by Jonah.
Given a multi-dimensional rectangular array of integers between 0 and 9, output all the elements ...
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Extend a matrix in all directions
Given a multidimensional, rectangular array and a list of dimensions, such as:
[ [1, 2],
[3, 4] ]
[3, 4]
Your challenge is to extend the matrix to the ...
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Can the 🐸 visit all the 🪷?
In this challenge you will be simulating a frog jumping from lily-pad to lily-pad in a pond. A frog's jump distance is uniquely determined by the size of the lily pad it jumps from. So for example ...
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Don't touch the walls!
Given a multi-dimensional rectangular array of non-negative integers, pad it with the minimal number of zeroes so that only zeroes are "touching the edges" of the array, in every dimension.
...
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Scribble Pad for Nerds
aka. implement an easier version of 05ab1e's canvas element.
Description
The canvas element is used to draw ASCII lines on the screen.
The (easier version of the) canvas element takes a list of ...
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Figure out the least amount of duplicate data to fill a quota [closed]
You are given 100 arrays/sets of 5-8 numbers between 1-20. If you combine all the arrays you will always get at least one of each number (1-20), so don't worry about an "unsolvable" case. ...
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Alternating sums of multidimensional arrays
Given a multidimensional array, find the recursive alternating sum. An alternating sum is simply the sum of an array, where every other item (starting with the second) is negated. For example, the ...
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