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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Generate Pascal's triangle
Pascal's triangle is generated by starting with a 1 on the first row. On subsequent rows, the number is determined by the sum of the two numbers directly above it to the left and right.
To ...
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Collatz Conjecture (OEIS A006577)
This is the Collatz Conjecture (OEIS A006577):
Start with an integer n > 1.
Repeat the following steps:
If n is even, divide it by 2.
If n is odd, multiply it by 3 and add 1.
It is proven that ...
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Greatest Common Divisor
Your task is to compute the greatest common divisor (GCD) of two given integers in as few bytes of code as possible.
You may write a program or function, taking input and returning output via any of ...
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Golf the Subset-Sum Problem
Task
Given a list of space-delimited integers as input, output all unique non-empty subsets of these numbers that each subset sums to 0.
Test Case
Input: ...
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Least Common Multiple
The least common multiple of a set of positive integers A is the smallest postive integer B such that, for each ...
user45941
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Sum of all integers from 1 to n
I'm honestly surprised that this hasn't been done already. If you can find an existing thread, by all means mark this as a duplicate or let me know.
Input
Your input is in the form of any positive ...
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It's Hip to be Square
Challenge
So, um, it seems that, while we have plenty of challenges that work with square numbers or numbers of other shapes, we don't have one that simply asks:
Given an integer ...
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Find the nth decimal of pi
There are already 30 challenges dedicated to pi but not a single one asks you to find the nth decimal, so...
Challenge
For any integer in the range of ...
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Josephus problem (counting out)
The challenge
Write a function that takes two positive integers \$n\$ and \$k\$ as arguments and returns the number of the last person remaining out of \$n\$ after counting out each \$k\$-th person.
...
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Find the Smoothest Number
Your challenge is to find the smoothest number over a given range. In other words, find the number whose greatest prime factor is the smallest.
A smooth number is one whose largest prime factor is ...
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XOR multiplication
You goal is to implement the operation of XOR (carryless) multiplication, defined below, in as few bytes as possible.
If we think of bitwise XOR (^) as binary ...
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Shortest terminating program whose output size exceeds Graham's number
Write the shortest possible program (length measured in bytes) satisfying the following requirements:
no input
output is to stdout
execution eventually terminates
total number of output bytes exceeds ...
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Compute the multinomial coefficient
Time for another easy challenge in which all can participate!
The multinomial theorem states:
$$(x_1 + x_2 + \cdots + x_m)^n = \sum_{k_1 + k_2 + \cdots + k_m = n} \binom n {k_1, k_2, \dots, k_m} \...
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Write a program that makes 2 + 2 = 5 [closed]
Write a program that seemingly adds the numbers 2 and 2 and outputs 5. This is an underhanded contest.
Your program cannot output any errors. Watch out for memory holes! Input is optional.
...
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Test a number for narcissism
A Narcissistic Number is a number which is the sum of its own digits, each raised to the power of the number of digits.
For example, take \$153\$ (3 digits):
\$1^3 + 5^3 + 3^3 = 153\$
\$1634\$:
\$1^...
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Draw A Sierpinski Triangle
The Sierpinsky Triangle is a fractal created by taking a triangle, decreasing the height and width by 1/2, creating 3 copies of the resulting triangle, and place them such each triangle touches the ...
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Balanced Ternary Converter
Credits for the challenge idea go to @AndrewPiliser. His original proposal in the sandbox was abandoned and since he has not been active here for several months, I have taken over the challenge.
...
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All your bijective base are belong to us
Background
A bijective base b numeration, where b is a positive integer, is a bijective positional notation that makes use of b symbols with associated values of 1 to b.
Unlike its non-bijective ...
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Print the N-bonacci sequence
This isn't very widely known, but what we call the Fibonacci sequence, AKA
1, 1, 2, 3, 5, 8, 13, 21, 34...
is actually called the Duonacci sequence. This is ...
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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
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Implement hyperexponentiation/tetration without the use of '^' [closed]
The Challenge
Implement tetration (aka Power Tower or Hyperexponentiation) with the least amount of characters.
The Conditions
Don't use the 'power' operator or its equivalents (such as ...
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Advanced Calculator
You must write a program that evaluates a string that would be entered into an advanced calculator.
The program must accept input using stdin and output the correct answer. For languages that do no ...
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Generate a Kolakoski sequence [duplicate]
Definition1
A Kolakoski sequence is a self-describing infinite sequence {kn} of alternating blocks of 1's and 2's, given by the following rules:
k0 = 1
kn = the length of the (n+1)'th ...
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Four fours puzzle
The Four fours puzzle is a popular recreational mathematical puzzle that involves using exactly four 4s (and no other number) and a defined set of operations to reach every number from 0 to a given ...
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Polynomial Interpolation
Write a program that performs Polynomial Interpolation using true arbitrary precision rational numbers. The input looks like this:
f(1) = 2/3
f(2) = 4/5
f(3) = 6/7
...
You may assume that there's ...
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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 ...
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votes
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answers
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Output the sign
Given a number N, output the sign of N:
If N is positive, output 1
If N is negative, output -1
If N is 0, output 0
N will be an integer within the representable range of integers in your chosen ...
user45941
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votes
9
answers
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Golf a number bigger than TREE(3)
The function TREE(k) gives the length of the longest sequence of trees T1, T2, ... where each vertex is labelled with one of k colours, the tree Ti has at most i vertices, and no tree is a minor of ...
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Count sums of two squares
Given a non-negative number n, output the number of ways to express n as the sum of two squares of integers ...
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Reverse Polish notation
You must evaluate a string written in Reverse Polish notation and output the result.
The program must accept an input and return the output. For programming languages that do not have functions to ...
user11
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I reverse the source code, you negate the input!
Blatant rip-off of a rip-off. Go upvote those!
Your task, if you wish to accept it, is to write a program/function that outputs/returns its integer input/argument. The tricky part is that if I ...
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Zeroes at the end of a factorial
Write a program or function that finds the number of zeroes at the end of n! in base 10, where n is an input number (in any ...
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Find the number in the Champernowne constant
Introduction
In base 10, the Champernowne constant is defined by concatenating representations of successive integers. In base 10: 0.1234567891011121314151617... ...
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Calculate the partitions of N
Your challenge is simple: GIven an integer N, ouput every list of positive integers that sums to N. For example, if the input was 5, you should output
...
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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, ...
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Minimum perimeter of an area [duplicate]
Just a simple code golf function for fun, intentionally left open with few rules to see what creativity comes up.
Input: An integer representing the area of a rectangle.
Output: Two integers ...
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Multiply without multiply [closed]
Write the fastest (best big-O) and smallest multiplication algorithm for positive integers, without using multiplication operators. You are only allowed addition, subtraction, logical functions (AND, ...
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Tweetable Mathematical Art [closed]
Integer math can generate amazing patterns when laid out over a grid. Even the most basic functions can yield stunningly elaborate designs!
Your challenge
Write 3 Tweetable (meaning 140 characters ...
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One OEIS after another
As of 13/03/2018 16:45 UTC, the winner is answer #345, by Khuldraeseth na'Barya. This means the contest is officially over, but feel free to continue posting answers, just so long as they follow the ...
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Coprimes up to N
Given a number n >= 2, output all the positive integers less than n where gcd(n, k) == 1 (...
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An abundance of integers!
An Abundant number is any number where the sum of its proper divisors is greater than the original number. For example, the proper divisors of 12 are:
...
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Pseudofactorial
There is a rather curious number which shows up sometimes in math problems or riddles. The pseudofactorial(N) is the least (i.e. lowest) common multiple of the numbers 1 through N; in other words, it'...
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Calculate the Super-Logarithm
This should be a simple challenge.
Given a number \$n \ge 0\$, output the super-logarithm (or the \$\log^*\$, log-star, or iterated logarithm, which are equivalent since \$n\$ is never negative for ...
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Count the divisors of a number
Introduction
This is a very simple challenge: simply count the divisors of a number. We've had a similar but more complicated challenge before, but I'm intending this one to be entry-level.
The ...
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Multiply two numbers
Input: Two decimal integers. These can be given to the code in standard input, as arguments to the program or function, or as a list.
Output: Their product, as a decimal integer. For example, the ...
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Additive Persistence
The shortest code to pass all possibilities wins.
In mathematics, the persistence of a number measures how many times a certain operation must be applied to its digits until some certain fixed ...
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Natural construction
The natural numbers including 0 are formally defined as sets, in the following way:
Number 0 is defined as the empty set, {}
For n ≥ 0, number n+1 is defined as n ∪ {n}.
As a consequence, n = {0, 1, ...
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Generate a pair of integers from a non-negative one
You should write a program or function which takes a non-negative integer N as input and outputs or returns two integers (negative, zero or positive) ...
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Find real roots of a polynomial
Write a self-contained program which when given a polynomial and a bound will find all real roots of that polynomial to an absolute error not exceeding the bound.
Constraints
I know that Mathematica ...
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Generalized matrix trace
Inspiration.
Given (by any means):
A two-argument (or single argument consisting of a two-element list) black box function, f: ℤ+ × ℤ+ → ℤ+ (input and output are 1,...
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