Questions tagged [math]

The challenge involves mathematics in some central way. Also consider using more specific tags, listed in the tag wiki info.

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Calculate Standard Deviation

Challenge Given a list of numbers, calculate the population standard deviation of the list. Use the following equation to calculate population standard deviation: Input The input will a list of ...
Beta Decay's user avatar
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21 votes
22 answers
2k views

Sum the diagonals

Take a matrix of positive integers as input, and output the individual sums of the elements on the diagonal lines through the matrix. You shall only count the lines that goes diagonally down and to ...
Stewie Griffin's user avatar
21 votes
9 answers
5k views

Implement Rijndael's S-box

Rijndael's S-box is a frequently used operation in AES encryption and decryption. It is typically implemented as a 256-byte lookup table. That's fast, but means you need to enumerate a 256-byte ...
Keith Randall's user avatar
21 votes
12 answers
3k views

Calculate Landau's function

Landau's function \$g(n)\$ (OEIS A000793) gives the maximum order of an element of the symmetric group \$S_n\$. Here, the order of a permutation \$\pi\$ is the smallest positive integer \$k\$ such ...
Daniel Schepler's user avatar
21 votes
16 answers
2k views

Verify Eigenpairs

In this challenge, you will be given a square matrix A, a vector v, and a scalar λ. You will ...
hyper-neutrino's user avatar
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21 votes
18 answers
5k views

Convince me Gabriel's Horn is possible

From Wikipedia, Gabriel's Horn is a particular geometric figure that has infinite surface area but finite volume. I discovered this definition in this Vsauce's video (starting at 0:22) where I took ...
ihavenoidea's user avatar
  • 1,219
21 votes
5 answers
688 views

Thar she blows!

Arrr... Ahoy there, me maties! Unfurl tha' mainsail! Full to starboard! Ah, feel th' wind in yer hair! Right, me hearties... I be needin' a bit of yer codin' skills! Me crew are a li'l more ...
Eliseo D'Annunzio's user avatar
20 votes
14 answers
1k views

Output N in base -10

Challenge: In the programming language of your choice, accept an integer as input in base 10, and output it in the negadecimal notation, which is also known as base -10 Example algorithm: This is ...
Offtkp's user avatar
  • 3,062
20 votes
2 answers
816 views

Lean golf: Pascal vs. Fibonacci

The Pascal's triangle and the Fibonacci sequence have an interesting connection: Source: Math is Fun - Pascal's triangle Your job is to prove this property in Lean theorem prover (Lean 3 + mathlib). ...
Bubbler's user avatar
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20 votes
21 answers
3k views

Implement the Torian

The Torian, \$x!x\$, of a non-negative integer \$x\$ can be recursively defined as $$ x!0 = x \\ x!n = \prod^x_{i=1} i!(n-1) = 1!(n-1) \times 2!(n-1) \times \cdots \times x!(n-1) $$ The Torian is then ...
caird coinheringaahin g's user avatar
20 votes
11 answers
2k views

What's next, Achilles?

Powerful numbers are positive integers such that, when expressed as a prime factorisation: $$a = p_1^{e_1} \times p_2^{e_2} \times p_3^{e_3} \cdots \times p_k^{e_k}$$ all exponents \$e_1, e_2, ...\$ ...
caird coinheringaahin g's user avatar
20 votes
4 answers
529 views

Locally invert a Polynomial

Challenge Given a polynomial \$p\$ with real coefficients of order \$1\$ and degree \$n\$, find another polynomial \$q\$ of degree at most \$n\$ such that \$(p∘q)(X) = p(q(X)) \equiv X \mod X^{n+1}\$, ...
flawr's user avatar
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19 votes
26 answers
2k views

Triangle Area Side Side Side [closed]

Given three sides of a triangle, print area of this triangle. Test cases: In: 2,3,4 Out: 2.90473750965556 In: ...
chyanog's user avatar
  • 1,286
19 votes
16 answers
1k views

(RGS 4/5) Inverting matrices modulo m

Task Given an integer matrix M and a modulus m, find an inverse of M modulo ...
RGS's user avatar
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19 votes
39 answers
2k views

Print the tetration

Tetration, represented as \${}^ba\$, is repeated exponentiation. For example, \${}^32\$ is \$2^{2^2}\$, which is \$16\$. Given two numbers \$a\$ and \$b\$, print \${}^ba\$. Test cases ...
Oliver Ni's user avatar
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19 votes
6 answers
995 views

Kolakoski-like self-referencing sequences

This is how the Kolakoski sequence (OEIS A000002) is defined: The Kolakoski sequence is a sequence that contains 1 and 2, and ...
Erik the Outgolfer's user avatar
19 votes
18 answers
2k views

Hypercube elements

Write a function or program that outputs the number of each type of element (vertex, edge, face, etc.) of an N-dimensional hypercube. As an example, the 3 dimensional cube has 1 cell (i.e. 1 3-...
Fatalize's user avatar
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18 votes
4 answers
2k views

Laver table computations and an algorithm that is not known to terminate in ZFC

The Laver tables provide examples of programs which have not been shown to terminate in the standard axiomatic system of mathematics ZFC but which do terminate when one assumes very large cardinal ...
Joseph Van Name's user avatar
18 votes
22 answers
1k views

Output diagonal positions of me squared

Given a number n, Output an ordered list of 1-based indices falling on either of the diagonals of an n*n square matrix. ...
sergiol's user avatar
  • 3,398
18 votes
11 answers
2k views

Find numbers within the Copeland–Erdős constant

Background The Copeland–Erdős constant is the concatenation of "0." with the base 10 representations of the prime numbers in order. Its value is ...
Luis Mendo's user avatar
  • 104k
18 votes
8 answers
649 views

Convert between balanced bases!

Balanced bases: Balanced bases are essentially the same as normal bases, except that digits can be positive or negative, while in normal bases digits can only be positive. From here on, balanced ...
clismique's user avatar
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18 votes
9 answers
1k views

How long does it take to paint a stick?

(Based on this Math.SE problem, which also provides some graphics) I have a stick which looks kinda like this: I want it to look kinda like this: I'm not an expert painter, however, so before I ...
PhiNotPi's user avatar
  • 29k
18 votes
5 answers
1k views

Jordan Decomposition

Important note: Because this challenge only applies to square matrices, any time I use the term "matrix", it is assumed that I am referring to a square matrix. I am leaving off the "...
user avatar
17 votes
27 answers
555 views

\$n\$-perfect numbers

A positive integer \$x\$ is an \$n\$-perfect number if \$\sigma(x) = nx\$, where \$\sigma(x)\$ is the divisor sum function. For example, \$120\$ is a \$3\$-perfect number because its divisors sum to \$...
caird coinheringaahin g's user avatar
17 votes
23 answers
2k views

Enumerate Derangements

Given some positive integer \$n\$ generate all derangements of \$n\$ objects. Details A derangement is a permutation with no fixed point. (This means in every derangement number \$i\$ cannot be in ...
flawr's user avatar
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17 votes
12 answers
2k views

Strict partitions of a positive integer

OEIS A000009 counts the number of strict partitions of the integers. A strict partition of a nonnegative integer n is a set of positive integers (so no repetition ...
lirtosiast's user avatar
  • 21.4k
17 votes
10 answers
538 views

Ascending matrix

The "ascending matrix" is an infinite matrix of whole numbers (0 included) in which any element is the smallest available element which has not been previously used on the respective row and column: <...
adrianton3's user avatar
16 votes
3 answers
375 views

Solving less-than inequalities with positive integers

Write a program or function that takes in a nonempty list of mathematical inequalities that use the less than operator (<). Each line in the list will have the ...
Calvin's Hobbies's user avatar
16 votes
6 answers
1k views

Simulate any 1D cellular automaton

The Challenge You are to write a complete program that takes seven numbers from STDIN, and prints the two dimensional history of the cellular automaton (CA) to STDOUT. This is code golf. Input ...
PhiNotPi's user avatar
  • 29k
16 votes
4 answers
1k views

An optimization challenge with strange coins

You have n coins which each weigh either -1 or 1. Each is labelled from 0 to n-1 so you can ...
user avatar
16 votes
16 answers
3k views

Test if given number is a Keith number

Since Fibonacci numbers and sequences seems like a popular subject for code golf I thought that it might be a fun challenge to code golf with Keith numbers. So I propose a challenge that is to create ...
Smetad Anarkist's user avatar
16 votes
47 answers
2k views

Alternating Sign Sequence

Introduction The sign of a number is either a +, or a - for every non-zero integer. Zero itself is signless (...
Adnan's user avatar
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15 votes
36 answers
4k views

Generate Sexy Primes

Sexy Primes are pairs of numbers \$(n, n+6)\$ such as \$n\$ and \$n+6\$ are both prime You need to create a function which will take an integer, check for sexy primes from 0 to that integer, and ...
Rohit's user avatar
  • 263
15 votes
5 answers
568 views

Visualize a Difference Pyramid

A difference pyramid is a pyramid where each new diagonal is the absolute value of the differences between the elements of the last diagonal. For example, if we start with the array ...
DJMcMayhem's user avatar
  • 58.9k
15 votes
7 answers
3k views

Draw the Sierpinski Arrowhead Curve

Introduction The Sierpinski Arrowhead Curve is a curve that's limit is Sierpinski's Triangle. It first starts like this: _ / \ Then, each line is replaced with a ...
Oliver Ni's user avatar
  • 10.6k
15 votes
15 answers
1k views

Fun With Permutations

Who doesn't absolutely love permutations, right? I know, they are amazing––so much fun! Well, why not take this fun and make it funner? Here's the challenge: Given an input in the exact form: ...
Daniel's user avatar
  • 6,693
15 votes
14 answers
3k views

Compute the first N digits of e

Challenge Write a program to compute the the first N (<= 10^3) digits of e. Your program should take an integer N as input. Input: 100 Output: ...
Quixotic's user avatar
  • 2,359
15 votes
4 answers
428 views

Counting Abelian groups of a given size

Background Last time, we counted groups of a given size, which is a non-trivial problem. This time, we'll only count Abelian groups, i.e., groups with a commutative operation. Formally, a group (G, ∗) ...
Dennis's user avatar
  • 210k
14 votes
15 answers
1k views

Dihedral group D4 composition with custom labels

The dihedral group \$D_4\$ is the symmetry group of the square, that is the moves that transform a square to itself via rotations and reflections. It consists of 8 elements: rotations by 0, 90, 180, ...
xnor's user avatar
  • 144k
14 votes
7 answers
950 views

Molar masses of compounds

Task Write a program that takes in a compound made solely of elements with an atomic number less than or equal to 92 (Uranium), and outputs the molar mass of the compound in ...
es1024's user avatar
  • 9,165
14 votes
37 answers
3k views

N numbers closest to zero staying balanced

Objective: Given a positive integer n: If n is odd, output the list of n numbers closest to ...
Conor O'Brien's user avatar
14 votes
10 answers
2k views

Find a fraction's position in the Stern-Brocot tree

The Stern-Brocot tree is a binary tree of fractions where each fraction is acquired by adding the numerators and denominators of the two fractions neighbouring it in the levels above. It is generated ...
Joe Z.'s user avatar
  • 34.7k
14 votes
12 answers
7k views

3 and 5 Litre Jug Puzzle

You may have seen this one in Die Hard: With a Vengeance... This question is based on the famous 3 and 5 Litre Jug Puzzle, but with a slightly different slant. Golf up some code that when given an ...
Eliseo D'Annunzio's user avatar
13 votes
6 answers
712 views

Ellipsoid surface area

Related: Ellipse circumference Introduction An ellipsoid (Wikipedia / MathWorld) is a 3D object analogous to an ellipse on 2D. Its shape is defined by three principal semi-axes \$a,b,c\$: $$ \frac{x^2}...
Bubbler's user avatar
  • 73.8k
13 votes
4 answers
1k views

How NOT to reduce fractions

Reducing fractions the wrong way In this code-golf challenge you have to find fractions that can be reduced the wrong way but still end up in the same number. Note: reducing fractions the wrong way ...
flawr's user avatar
  • 43.7k
13 votes
9 answers
2k views

Calculate the Kronecker Product

Related, but very different. In the examples below, \$A\$ and \$B\$ will be \$2\times2\$ matrices, and the matrices are one-indexed. A Kronecker product has the following properties: ...
Stewie Griffin's user avatar
13 votes
3 answers
992 views

Implement a Graphing Calculator

There have been many questions involving calculators; however, it does not appear that any involve implementing a graphing calculator. The Challenge You are to write a complete program that takes ...
PhiNotPi's user avatar
  • 29k
12 votes
18 answers
1k views

Polynomial Laplace transform

This is a repost of this challenge, intended to revamp it for looser I/O formats and updated rules You are to write a program which takes an integer polynomial in \$t\$ as input and outputs the ...
caird coinheringaahin g's user avatar
12 votes
7 answers
4k views

Shortest Program to Solve a Quartic Equation

Write the shortest program to solve a quartic equation. A quartic equation is a polynomial equation of the form: \$ax^4 + bx^3 + cx^2 + dx + e=0\$ A solution for \$x\$ is a number such that the above ...
Ali Caglayan's user avatar
12 votes
6 answers
622 views

Implement Multiplicative Fuzzy Logic

Inspired by this excellent challenge (from which the bulk of this text is blatantly duct-taped) – and my highschool philosophy project... I define the following operators: Fuzzy Conjunction a ×F b is ...
Adám's user avatar
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