Posts tagged code-golf
Challenge Given a date with day, month and year, calculate how old a person born on that day would be today. Input can be in any reasonable format (params, array, date object). Input will never ...
Write a function $f$ which takes rational numbers and gives binary fractions (rational numbers whose denominator is a power of two) which is bijective and preserves order. That means: Different...
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...
Does a number have balanced numbers of distinct digits? That is, do the number's digits appear with equal frequency? Input A positive integer N. N will have no leading zeroes. Output An ...
Write code that takes a positive integer and outputs the awkward ordinal name from the test cases. Notice that these are not the conventional ordinal names. Input A positive integer from the te...
We have many questions about how to golf in a specific programming language. These result in tips that apply only to that language or closely related languages. What advice do you have on golfing ...
What tips do you have for saving bytes in Rust? Please post one tip per answer for ease of voting and commenting.
Introduction What is the Caesar shift cipher (ROT$n$)? It's basically a cipher sequence that changes a letter's value from the number chosen. If we use ROT1 on "games", we get "hbnft". The basic i...
Challenge Write a program that takes in a number greater than or equal to 0 and outputs its representation in hexadecimal (base 16). Examples 0 => 0 1 => 1 10 => A 15 ...
Definition $F_{n}\left(0\right)=0$ $F_{n}\left(1\right)=1$ $F_{n}\left(x\right)=n\cdot F_{n}\left(x-1\right)+F_{n}\left(x-2\right)$ For example: $F_{1}=\left[0,1,1,2,3,5,8,13,21,34,55,89...\ri...
Challenge Given an array of numbers return the cumulative count of each item. This is the number of times an item has occurred so far. Examples [1,1,2,2,2,1,1,1,3,3] -> [1,2,1,2,3,3,4,5,1,2]...
Recently I asked for tips on improving some code-golf of mine. The code was supposed to output every third value of the Fibonacci sequence starting with 2: 2,8,34,144,610,2584,10946,46368,196418,...
Given two binary strings $A$ and $B$ such that $A$ is an anagram of $B$, output a third binary string $S$ such that both $A$ and $B$ can be created by iterated removals of the substring $10101$ fro...
Challenge Cause the currently running program to receive the SIGSEGV signal (on Linux or other *nix systems) as fast as possible. What it does with the signal doesn't matter as long as it receives...
Background While we do have a "Hello, World!" challenge, we still don't have one regarding input. So let's do one! Challenge Create a program that takes an input (not as a function argument) the...
If you have any tips for golfing in Python, add them as answers to this post.
Lean is an interactive theorem prover and a functional programming language created in 2013. What tips do you have for golfing in Lean? Tips should be specific to Lean ("remove comments" is not an...
The task is to take a decimal integer as input and print the corresponding Roman numeral with capital letters. The program must handle all positive integer numbers between 1 and 1000. Input can be...
Introduction The classic "Hello, World" challenge. What more can I say? Rules Program takes no input. Program outputs Hello, World! with an optional trailing newline. No other output is accep...
Goal Print the modular multiplicative inverse with a modulus of 65536 (or a higher exponent of 2) for odd numbers 1-97. Example output Print these values (or an extension of them): 1 43691 52...
Input is a number, you have to decide if it is part of the mandelbrot set or not, after at least 16 iterations. This is done by applying this formula: $z_n = z_{n-1}^2 + c$ repeatedly. $c$ is the ...
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 ...
Inspiration: Leetcode's [3Sum] linkLink on CG&CC Problem Given an array nums of n (not necessarily distinct) integers, and given a target number target, return an array of all of the unique...
Given an positive integer $n$, return the least positive integer $k$ such that the $k$th partial sum of the harmonic series is greater than or equal to $n$. For example, if $n = 2$, then $k = 4$, b...
The goal of this challenge is simple: given a ratio of whole numbers, output a 50-character long progress bar representing the ratio. Rules Input Your program must take two numbers as input. T...
Given 3 positive integers, indicate whether they are Borromean coprimes. Definition 3 positive integers are called Borromean coprimes if both of the following are true: Their greatest common d...
Consider a type of hexadecimal colour code that supports shorthand for both greyscale and colour: A 6 digit code is interpreted as 2 digits for red, followed by 2 for green, then 2 for blue. A ...
Task Given an IP address as a string, find its IP address class. For reference, here is a table: Class Leadingbits Numberof networks Addressesper network Total addressesin class Start...
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: ...
The challenge is to write as short a source as possible, where the English alphabet (in alphabetical order from top to bottom) "abcdefghijklmnopqrstuvwxyz" is a sub-sequence of the source code. Th...
Given a positive integer, count its odd digits. Input An integer from 1 to 999,999,999, inclusive, in any of the following formats: A number (such as an integer or floating point number), li...
Given a string of Roman numerals, decide whether it forms a valid Roman number. If not, output the substring that proves this, from the list of 50 strings described below. Relevant fact This chal...
Given a positive integer, indicate whether it is the product of its proper divisors. Integers equal to the product of their proper divisors can be found on the Online Encyclopedia of Integer Seque...
Output the Nth number in the list of Fibonacci numbers that have no consecutive digits. Input A non-negative integer (if you treat the Fibonacci numbers as zero-indexed) or a positive integer (...
Given an integer from 1 to 1000, indicate whether it is a centered hexagonal number[1] (also known as a hex number). What is a hex number? The hex numbers can be visualised as follows: On a he...
Looping counter Create an infinite loop that outputs lines of asterisks, with each line containing one more asterisk. Instead of the asterisk, any printable, non-whitespace character can be used. ...
Does a positive integer have a substring as a factor? Input A positive integer. Output One of 2 distinct values to indicate whether the input has a factor that is a strict substring of it...
Given a hexomino, indicate whether it is a net of a cube. Input A 6 by 6 grid containing exactly 6 filled squares. The 6 filled squares will be in a single edge connected set (a hexomino). Th...
