# Posts tagged math

Challenge Given an array in any suitable format, create a frequency table for it. i.e: Pair each unique element with the number of times it appears in the array. You can return the frequency tabl...

Challenge A Niven number is a positive integer which is divisible by the sum of its digits. For example, 81 -> 8+1=9 -> 81%9=0. Your task is to find the first n Niven numbers, given n. Te...

Multiply complex numbers. 2 space-seperated ones will be input, as follows: (update: you can replace i with j or some other symbol if needed) a+bi -a+bi a-bi -a-bi where a and b are integers ...

Get ready for a comparatively dry question - this is intended to be one of the "the"s of the code-golfing dictionary. Create a program which inputs a base 10 non-negative whole number (without lea...

In this challenge, add 2 integers, but if both the integers are 2, output 5. Shortest code in each language wins! Example ungolfed program in Python 3.x def add(x, y): if x == 2 and y == 2: ...

Goldbach's Conjecture states that every even whole number greater than 2 is the sum of 2 prime numbers. Your task is to return those 2 prime numbers, given an even whole number as input. There are ...

Background Check out this video on the Collatz conjecture, also known as A006577. If you don't know what this is, we're given an equation of $3x + 1$, and it is applied this way: If $x$ is odd...

Challenge A catalogue type challenge that simply asks: Given an integer n (where n>=0) as input return a truthy value if n is a perfect square or a falsey value if not. Rules You may take...

Challenge Make a program that takes input of 3 non-negative integers: a result and 2 other values that once calculated results to the 3rd value. The program must figure out how to get the 2 fir...

Challenge Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + ... + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input va...

Challenge A simple challenge: Given a two-dimensional matrix (an array of arrays) of real numbers, compute the determinant. The determinant of a matrix is a mathematical construct used in many ap...

Background Inspired by this challenge that is also a mathematical English translator. Challenge Write a program that translates a mathematical expression using English with the following specifi...

Challenge Given the roots of a polynomial (that is, the $x$ values where the polynomial evaluates to zero), as an array of real numbers, return the polynomial's coefficients. That is, given real ...

Create a program that gets all perfect squares starting from 0 or 1 without using any methods of multiplication (repetitive addition) and exponentiation (repetitive multiplication). Output them for...

Challenge Create a program that takes input of a string and outputs an integer using the following calculation system: The string can only contain +, -, *, /, ^, ! (or a different character; ! ...

A Juggler sequence is a sequence that begins with a positive integer $a_0$ and each subsequent term is calculated as: $$a_{k+1} = \begin{cases} \left \lfloor a_k ^ \frac 1 2 \right \rfloor, &...

Abundant numbers are numbers which are less than their proper divisor sum. For example $18$ is abundant as $1 + 2 + 3 + 6 + 9 = 21 > 18$ Deficient numbers are numbers which are greater than the...

Heavily based on this closed challenge from SE. Description A Sumac sequence starts with two non-zero integers $t_1$ and $t_2.$ The next term, $t_3 = t_1 - t_2$ More generally, $t_n = t_{n-2} ...

About Negabinary Negabinary means base negative two (-2). That is, the $n$th place value is determined by $(-2)^n$. Negabinary numbers can be evaluated just like any other base system. For exampl...

Define a cool number as a number whose proper divisors (all except for the number itself) have an integral mean. Define a really cool number as a number whose divisors (including itself) are all co...