Questions tagged [array]
A competition to solve a particular problem through the usage and manipulation of arrays.
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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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Write a (simplified) BitCycle interpreter
Implement a function or program that can run simplified BitCycle code. The functions you must implement are:
<^>v: Change the direction of a bit to the ...
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center a matrix [closed]
The words "center a" probably give flashbacks to any decent HTML developer. Luckily, we are not working with divs, we are working with matrices.
Given a matrix where w=h, and given a "...
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Euler characteristic of a binary matrix
A binary matrix represents a shape in the plane. 1 means a unit square at that position. 0 means nothing. The background is <...
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Unshuffle my poker chips
This part is somewhat detached from the actual array manipulation side of the challenge, scroll down for an explanation that is much more array-based
You've been learning how to shuffle poker chips ...
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Is Wally there?
Inpired by recent Stand-up Maths' video.
Task
Wrapping a list x can be seen as inserting "line-breaks" into x every <...
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Get the trends of an array
For our purposes, a trend is a contiguous subsequence of an array that falls into one of three categories:
increasing, e.g. [1,2,3,10,239]
decreasing, e.g. ...
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Convert J brackets back to 2-D list
Let's say we have a 2-D list, like the following one:
\$
\begin{bmatrix}
\color{red}{1} & \color{red}{2} & \color{red}{3} & \color{red}{4} \\
\color{blue}{5} & \color{blue}{6} & \...
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Shuffle an array, a little bit
Given some input array a = [a1, a2, ..., an] and a positive integer k, shuffle the input array ...
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Damerau-Damerau distance
Given a list of the integers from \$1\$ to some \$n\$, give the minimum number of adjacent swaps required to put the list in ascending order.
You will receive a list as input and should output a non-...
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Find the J twin
For a 2 dimensional array we will define the elements in either the first row or the last column to be the largest "J-Bracket" of the array. For example in the following array elements in ...
- 84.4k
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Removed J-brackets
For a 2 dimensional array we will call the elements in either the first row or the last column the "J-Bracket" of the array. For example in the following array elements in the J-bracket are ...
- 84.4k
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Fourth Time's the Triple Tap
The sci-fi shooter Destiny 2 contains guns which have the ability to regenerate ammunition directly into the magazine if, and only if x (precision) shots are landed ...
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Recreate Minecraft's lighting
Minecraft has a fairly unique lighting system. Each block's light value is either one less than the brightest one surrounding it, or it is a light source itself. Your task is to write a method that ...
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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
...
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Complex permutation
Given an array of integers as input(including negative integers), find all (can include duplicates) permutations that do not have the same number next to each other, then print them all out.
If no ...
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Zip uneven lists
In this challenge you will take two lists as input and you will zip them. The zip can be defined with this recursive expression:
\$
\mathrm{zip}(a,b) = \begin{cases}
\left[\,\,\right] & a = \left[...
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11
votes
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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, ...
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Repeat List Until Longer
The Challenge
The challenge is simple: given an input list a and another list b, repeat a ...
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5
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The Nineteenth Bakery [duplicate]
Yes, this is very similar to this question. However, that concerns infinite linked lists, and you do not need to handle out of bounds indexes in that question.
You are in a strange city, looking for ...
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What was my Wordle play?
Task
Given a winning Wordle play results (clues), the target ("secret") word and a list of words, output a possible sequence of words leading to such results.
The words in the list will be ...
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Fill in the next numbers
Given a list of integers, output a list where the \$ i \$th element of the list equals the first number in the input list which is \$ \ge i \$, until there are no such numbers.
For example, if the ...
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Lexicographically Smallest Decreasing Integer Partition
For a given number n, output an strictly decreasing array whose sum is n and its lexicographical order is the smallest for any ...
- 3,031
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votes
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Crate art stacking
Your task is, given a array of numbers, that is strictly increasing, output the crate stack. The input is an array of positive integers which represents which layer has how many crates there are. So ...
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Is it a tower permutation?
A tower is made out of layers, each one being one unit shorter than the one below it. Every layer is completely on top of the previous layer. For example, here is a tower along with it's height map:
<...
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Wiggle the tower
Your input is the height map of a tower. The tower is made out of layers, each one being one unit shorter than the one below it. Every layer is completely on top of the previous layer. For example <...
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10
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Pretty print my arrays
I like to pretty print multidimensional arrays, like this:
[ [ [1, 2, 3],
[4, 5, 6] ],
[ [7, 8, 9],
[6, 4, 2] ] ]
But it's a pain to do by hand and it'd ...
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Smallest maximal rectangle in a skyline
A skyline is an array of positive integers where each integer represents how tall a building is. For example, if we had the array [1,3,4,2,5,3,3] this would be the ...
- 6,645
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votes
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"Defuse" the bombs
You've been hired by a bomb defusing company to perform some "controlled" demolition of un-exploded ordnance. You are given a list of bombs represented by non-negative integers.
...
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Simulating Bombs
More advanced version of this
The aim of this puzzle is to simulate the impact of the shock wave of bombs on a square grid. The grid initially contains cells labelled ...
- 3,031
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votes
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answers
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Heart Point Generator
It's mentioned last time that, in Hearts,
Each round every player gets a non-negative amount of points. The sum of the points is 26, and at least one player gets 13 or more points.
Actually, it's ...
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Largest rectangle in a skyline
A skyline is an array of positive integers where each integer represents how tall a building is. For example, if we had the array [1,3,4,2,5,3,3] this would be the ...
- 6,645
23
votes
9
answers
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Generate all groupings
Let's define a grouping as a flat list, which is either:
just 0
2 groupings followed by the literal integer 2
3 groupings ...
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Rolling a ball over a list
Starting with a binary list (just 1s and 0s) we are going to roll a ball over it. The ball has a position and a direction. At ...
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votes
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Can I wall glitch to there?
Background
In a 2d game that I play, each screen is a 2d grid of tiles with walls and walkable tiles, with the player only able to travel on walkable tiles, and being stopped by walls. When the player ...
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Cubax Folding Game
Your task is to solve a new puzzle called Cubax. This toy is actually a Chinese puzzle whose expected “final” state is a simple cube. During the festivities, Cubax unfolded, because it cannot move ...
- 3,031
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votes
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Retaining Water
Your task is to check the volume of water in a pool. Your have to create a program that takes in a input that is represented by an 10 by 10 grid of integers, with ...
- 3,031
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votes
6
answers
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Check if a matrix is Zarankiewicz-maximal
My final-year project at the National University of Singapore is on Zarankiewicz's problem:
What is the maximum number of 1s in an \$m×n\$ binary matrix (\$m\$ rows and \$n\$ columns) with no \$a×b\$ ...
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votes
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Bracket Depth List
Challenge
Your challenge is simple, calculate the depth of each matching brackets in the given input e.g. (()()(()))->...
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votes
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How many laps around the permutation?
Your input is an array of numbers: a permutation of \$\{1, 2 \dots n\}\$ for some integer \$n \geq 2\$.
How many times must you repeat this list before you can "pick out" the numbers \$[1, 2 ...
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Solve Rubik's Clock
Rubik's Clock is a round(ish) puzzle with two flat sides. On each side, front and back, there are 9 clock faces, arranged on a 3x3 grid. In addition, there are 4 pegs (switches) in between the clock ...
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Is there a stable way to stack these?
If we have a binary matrix then we will say that a \$1\$ is stable if it is in the bottom row or it is directly adjacent to a \$1\$ which is stable.
In other words there must be a path to the bottom ...
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One pair or fewer
Given a list of positive integers, give the longest contiguous sublist which contains at most 1 pair of identical items. In the case of a tie return any of the solutions.
This is code-golf so the ...
- 84.4k
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Animate finding the middle (hypercube edition)
1d version
Given a multidimensional array of positive integers where all dimensions are the same length, animate finding the centre of it.
Simply output the array, then remove the first and last items ...
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SuperSquares NxN
Given an integer N from 1-9, you must print an NxN grid of NxN boxes that print alternating 1s and Ns, with each box having an alternating starting integer.
Examples
...
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Print a NxN integer involute
Given an integer \$N\$, you must print a \$N\times N\$ integer involute with the numbers increasing in a clockwise rotation. You can start with either 0 or 1 at the top left, increasing as you move ...
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Count the ways to transform
A rigid transformation of a square array is a mapping from square arrays of a certain size to square arrays of the same size, which rearranges the elements of the array such that the distance to each ...
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Squishy vectors
If we have a list of integers we can "squish" one of them by:
decrementing it
replacing adjacent values with its new value
For example in this list:
...
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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:
...
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Build a list from a depth map
You will be given as input a non-empty list of positive integers. For example:
[1,2,2,2,1]
You want to produce a ragged list as output which has this as its "...
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