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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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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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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Mathematics is fact. Programming is not
In mathematics an exclamation mark ! often means factorial and it comes after the argument.
In programming an exclamation mark ! ...
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Programming Languages Through The Years
In this challenge, users will take turns completeing three fairly simple coding tasks in programming languages that are allowed to be progressively older.
The first answer must use a programming ...
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Hyperprogramming: N+N, N×N, N^N all in one
Write a program that takes in a number N from 1 to 9 inclusive. In its native form your program should output N+N. E.g. output 2 if N is ...
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(-a) × (-a) = a × a
We all know that \$(-a) \times (-a) = a \times a\$ (hopefully), but can you prove it?
Your task is to prove this fact using the ring axioms. What are the ring axioms? The ring axioms are a list of ...
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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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Proving that a Russian cryptographic standard is too structured
The aim of this challenge is to find an impossibly short
implementation of the following function p, in the langage of your
choosing. Here is C code implementing it ...
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Does the code terminate?
This is a code golf challenge I thought of with a mathematical bent. The challenge is to write the shortest code possible such that it is an open question whether or not the code terminates. An ...
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Mandelbrot image in every language
I always used a Mandelbrot image as the 'graphical' version of Hello World in any graphical application I got my hands on. Now it's your guys' turn.
Language must be capable of graphical output or ...
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The Colors in Our Stars
Write a program that takes in a string or text file whose first line has the form
width height
and each subsequent line has the form
...
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When does (x == x+2)? [closed]
The challenge: Define x in such a way that the expression (x == x+2) would evaluate to true.
I tagged the question with C, but ...
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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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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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Hard code golf: Regex for divisibility by 7
Matthias Goergens has a 25,604-character (down from the original 63,993-character) regex to match numbers divisible by 7, but that includes a lot of fluff: redundant parentheses, distribution (...
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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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Calculate the number of primes up to n
π(n) is the number of primes less than or equal to n.
Input: a natural number, n.
Output: π(n).
Scoring: This is a fastest-code challenge. Score will be the sum of times for the score cases. I ...
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Yo boy, must it sum
Every positive integer can be expressed as the sum of at most three palindromic positive integers in any base b≥5. Cilleruelo et al., 2017
A positive integer is palindromic in a given base if ...
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How lit is this mountain? 🔥
A mountain is defined to be a set of line segments whose first point has coordinates (0,a) where a > 0, and whose last point ...
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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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Factorial in haiku!
Task
Create a program that calculates the factorial of a number using no built-in factorial functions. Easy? The catch is that you must write your entire program (including testing it) in haiku form.
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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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9 Hole Challenge [closed]
The 9 Hole Challenge
9 code golfing challenges of varying difficulty.
Penalties for using the same language more than once.
The question will be updated with pars, hole champions and trophy winners....
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Calculate a square and a square root!
You must make a polyglot that outputs the square of the input in one language and the square root of the input in another. The shortest answer in bytes wins!
You must have a precision of at least 3 ...
user58826
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How many steps does it take from n to 1 by subtracting the greatest divisor?
Inspired by this question over at Mathematics.
The Problem
Let n be a natural number ≥ 2. Take the biggest divisor of ...
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Little Chandler is sad. Draw him a cloud to cheer him up
Little Chandler is sad. Draw him a cloud to cheer him up.
Note: Drawing a cloud won't actually cheer him up.
A circle can be defined as a 3-tuple (x,y,r) where <...
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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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Count without 3
Background
When I was in elementary school, we used to play a game in math class that goes as follows.
All kids sit in a big circle and take turns counting, starting from 1.
However, the following ...
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Superstitious hotel elevator
Description
Here's a very superstitious hotel elevator in Shanghai:
It avoids the number 13, because ...
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Conway's Monster
This challenge is in honor of mathematician John Conway who passed away April 11, 2020 due to COVID-19. He was famous for coming up with the Game of Life cellular automaton and many other mathematical ...
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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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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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Dennis numbers 2.0
PPCG user and elected mod, @Dennis just became the second ever user to earn over 100k rep!
This is a totally original idea, that I did not get from anybody else, but let's make a challenge based off ...
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The vanilla factorial challenge
Task
Given a non-negative integer \$n\$, evaluate the factorial \$n!\$.
The factorial is defined as follows:
$$
n!=\begin{cases}1 & n=0\\n\times(n-1)!&n>0\end{cases}
$$
Rules
All default I/...
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Golf a transcendental number
Definitions
An algebraic number is a number that is a zero of a non-zero polynomial with integer coefficients. For example, the square root of 2 is algebraic, ...
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Multiplicative persistence
Multiplicative Persistence
Multiply all the digits in a number
Repeat until you have a single digit left
As explained by Numberphile:
Numberphile "What's special about 277777788888899?"
...
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Program that adds all natural numbers and yields -1/12 [closed]
As you might know there is a mathematical fun-fact that if you add all natural numbers you end up with... -1/12 (see Wikipedia here).
Of course this is very strange result and can not be obtained by ...
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Illustrate the Least Common Multiple
Given two positive integers, \$A\$ and \$B\$, illustrate their least common multiple by outputting two lines of dashes (-) with length \$\text{lcm}\$\$(A, B)\$ ...
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Help me with differential calculus!
I love programming and know every language, but I suck at math. Unfortunately, my school requires that computers students must take a year of calculus. There's a test next week, and I don't know any ...
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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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Detect heat waves
Background
The Royal Netherlands Meteorological Institute defines a heat wave* as a series of at least 5 consecutive days of ≥25°C weather (“summery weather”), such that at least 3 of those days are ≥...
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The Snail in the Well
Background
There's a common riddle that goes something like this:
A snail is at the bottom of a 30 foot well. Every day the snail is able to climb up 3 feet. At night when they sleep, they slide ...
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Quiche Lorraine [closed]
Since it was Pi day recently, I have noticed a number of challenges that ask you to calculate pi.
Of course, a quiche lorraine is not quite a pie (you can claim a Bonus Score¹ of +1 if you guessed ...
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Product over a range
Your task is simple: given two integers \$a\$ and \$b\$, output \$\Pi[a,b]\$; that is, the product of the range between \$a\$ and \$b\$. You may take \$a\$ and \$b\$ in any reasonable format, whether ...
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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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Bringing a pair of integers to equality
This was inspired by a math problem I saw somewhere on the internet but do not remember where (UPDATE: The original problem was found on the math riddles subreddit with a proof provided that it is ...
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Divide a number by 3 without using *, /, +, -, % operators [closed]
Quoting this question on SO (Spoiler alert!):
This question has been asked in an Oracle interview.
How would you divide a number by 3 without using *, /, +, -, %,
operators?
The number ...
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Is my triangle right?
Given a, b, c the length of the three sides of a triangle, say if the triangle is right-angled (i.e. has one angle equal to 90 degrees) or not.
Input
Three positive ...
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Moving modest minimum
Inspired by a question over at Stack Overflow. The title here is entirely my fault.
The challenge
Given a list of positive integers containing at least two entries, replace each number by the ...
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Multiply with restricted operations
There's a 500 rep unofficial bounty for beating the current best answer.
Goal
Your goal is to multiply two numbers using only a very limited set of arithmetic operations and variable assignment.
...
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