All Questions
261
questions
35
votes
35
answers
7k
views
Random Golf of the Day #1: Shuffle an Array
About the Series
I will be running a little series of code-golf challenges revolving around the theme of randomness. This will basically be a 9-Hole Golf Course, but spread out over several questions....
- 197k
39
votes
54
answers
4k
views
Boustrophedonise
Related but very different.
A boustrophedon is a text where every other line of writing is flipped or reversed, with reversed letters.
In this challenge, we will just reverse every other line, but ...
- 30.9k
39
votes
53
answers
11k
views
Determine the depth of an array
A simple challenge for your Monday evening (well, or Tuesday morning in the other half of the world...)
You're given as input a nested, potentially ragged array of positive integers:
...
- 197k
28
votes
47
answers
4k
views
Shortest power set implementation
Problem definition
Print out the powerset of a given set. For example:
[1, 2, 3] => [[], [1], [2], [3], [1, 2], [1, 3], [2, 3], [1, 2, 3]]
Each element is to ...
- 381
26
votes
31
answers
3k
views
Different Way Forward
Given a list of integers produce a Forward Difference at a specified order/depth.
For the list of integers:
(10, 18, -12, 4, 8, -3, -5, 67, 9, 14)
The Forward ...
- 12.2k
48
votes
16
answers
6k
views
Zigzagify a Matrix
As part of its compression algorithm, the JPEG standard unrolls a matrix into a vector along antidiagonals of alternating direction:
Your task is to take a matrix (not necessarily square) and return ...
- 197k
37
votes
39
answers
4k
views
Determinant of an Integer Matrix
Given a square integer matrix as input, output the determinant of the matrix.
Rules
You may assume that all elements in the matrix, the determinant of the matrix, and the total number of elements in ...
user45941
11
votes
25
answers
3k
views
Cartesian product of a list with itself n times
When given a a list of values and a positive integer n, your code should output the cartesian product of the list with itself n ...
- 447
69
votes
62
answers
4k
views
Count trailing truths
Inspired by, and in memory of, my dear friend and colleague,
Dan Baronet, 1956 – 2016. R.I.P.
He found the shortest possible APL solution to this task:
Task
Given a Boolean list, count the number of ...
- 30.9k
69
votes
61
answers
7k
views
N-dimensional N^N array filled with N
In: Enough memory and a positive integer N
Out: N-dimensional N^N array filled with N, where N^N means N terms of N-by-N-by-N-by...
Examples:
1: [1] ...
- 30.9k
32
votes
46
answers
8k
views
Mode (most common element) of a list
Write a snippet to calculate the mode (most common number) of a list of positive integers.
For example, the mode of
d = [4,3,1,0,6,1,6,4,4,0,3,1,7,7,3,4,1,1,2,8]
...
- 709
27
votes
27
answers
3k
views
Diamondize a Matrix
Given a matrix, output a representation of the matrix where the top left element is on top, the anti-diagonal is the central row and the bottom right element is at the bottom.
For example, consider ...
- 39.2k
21
votes
16
answers
2k
views
Discrete Convolution or Polynomial Multiplication
Given two non empty lists of integers, your submission should calculate and return the discrete convolution of the two. Interestingly, if you consider the list elements as coefficients of polynomials, ...
- 43.9k
17
votes
105
answers
8k
views
Turn an integer n into a list containing it n times [closed]
Given an integer n as input, return a list containing n, repeated n times. For example, the ...
- 425
42
votes
45
answers
4k
views
Skip like a rabbit!
Given a list of non-negative integers in any reasonable format, iterate over it, skipping as many elements as every integer you step on says.
Here is a worked example:
...
- 40.6k