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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 ...
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...
This is somewhat of a [proof-golf]-like [cops-and-robbers]. This is the cops' thread; the robbers' thread is here Sections: Cops Scoring What is a rewrite rule? An example An example of...
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 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...
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...
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...
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 ...
DC is a reverse-Polish calculator REPL that is available on most Linux distributions. In reverse-Polish notation, you can push values to a stack and then pop those values back off to perform operat...
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, although there is significant overlap. ...
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 ...
This is somewhat of a [proof-golf]-like [cops-and-robbers]. This is the robbers' thread; the cops' thread can be found here. Sections: Robbers Determining a winner Robbers The cops wil...
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 points, output one that is separated from its nearest neighbour by the largest distance. Input 3 distinct points (that is, no 2 points are in the same position). Each point is a pair o...
You work at a beach. In the afternoon, the sun gets quite hot and beachgoers want to be shaded. So you put out umbrellas. When you put out umbrellas you want to shade the entire beach, with as few ...
The Universal Crossword has a set of guidelines for crossword puzzle submissions. In this challenge we are going to be concerned with their rules for hidden word themes. A hidden word clue consis...
Given a list of non-negative integers the function $f$ replaces every integer with the number of identical integers preceding it (not necessarily contiguously). So f [1,1,2,2,1,3,3] = [1,2,1,2,3,1...
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...
The Challenge Your job is to, given input positive non-zero integer $n$, output an ASCII representation of the tiled Fibonacci squares up to the $n$th number of the Fibonacci sequence. Rules Inp...
Given a single character, which is a valid Roman numeral, output its value. Values There are 7 valid single character Roman numerals, with the following values: Character Value I...
Your mission for today, should you choose to accept it, is to write a simple 12-hour clock calculator. Your input will always be in the form of arg op arg, where op is either + or -, and arg is eit...
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...
In this challenge you will take an Irish word and a personal pronoun and create the possessive pronoun construction combining the two. For example sé, madra becomes a mhadra. Translated to English...
At my job we have to sometimes lay out materials. Materials come in large long rolls and are cut into smaller pieces when being laid out. When we order the rolls we draw up a layout document which...
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...
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 number $n \geq 3$ as input output the smallest number $k$ such that the modular residues of $k$ by the first $n$ primes is exactly $\{-1,0,1\}$. That is there is a prime in the first $n$ p...
$N$ vessels initially contain $3$ stones each. What is the probability of having at least $3$ stones in the first vessel after moving a uniformly random selection from the first vessel to the secon...
import requests import json import numpy as np import base64 import cv2 Replace this with the actual image path you want to test image_path = 'H_L_.jpg' Read and preprocess the image image ...
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 (...
The probability of rolling every number from 1 to 6 with $N$ six-sided dice. Input A positive integer $N$. Your code must work for inputs up to and including 10, but may crash, error, or give ...
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,...
You work in a kitchen which has a peculiar rule. When you mix something into a pot you must always add at least one new ingredient. So you can add pasta, oil, salt then pesto, but not pasta, pesto...
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...
An $n$-polyomino is a connected subset of the square tiling consisting of $n$ squares. We will not require that polyominos be simply connected, that is they can have holes. We will say a $n$-polyo...
You are a low-level censor working for the Ministry of Media Accuracy. Part of your job is to make sure that certain words don't appear in publications. Every morning you get a fresh stack of next...
Suggest a word from a word list, given a string. Motivation Imagine typing a word one letter at a time, and seeing a suggested word after each letter is typed. At first the suggested word is simp...
Task Given a list of numbers $X$ produce a second list of numbers $Y$ such that $Y_i$ is the length of the longest common prefix of $X$ and $X$ with the first $i$ elements removed. For example if...
This is a language specific challenge, for HTML only. Your answer is the content of a self contained HTML file, that when opened in a web browser gives a plain black page. Requirements The HTM...
Simple challenge: Read a byte, swap bit 7 with 0, 6 with 1, 5 with 2 and 4 with 3 and then output the byte. For example the byte 0b1001'1100 would turn into 0b0011'1001. Rules: Shortest code wi...
Find the shortest representation of an integer in generalised Roman numerals. Since there is more than one way to generalise, only the following definition applies to this challenge. Definition T...
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 ...
An polyomino is a non-empty connected subset of the square tiling consisting of squares joined along their edges. We will not require that polyominos be simply connected, that is they can have hole...
In this challenge you will take a number $n$ and a string $X$ of length $\geq n$, and produce a regular expression which matches all strings that are withing $n$ character substitutions of $X$. Sp...
Given a sequence of letters, omit those with the highest or lowest pop count. Terminology The pop count or population count of a binary string is the number of 1s in it. For this challenge, the ...
A chequer board (also spelt "checker board" in some places) is an 8 by 8 grid of squares alternating between 2 colours. Check whether a provided pattern could be a region of a chequer board. The c...
Given an integer $N$ in balanced quinary, output the first $N$ characters of your source code if $N$ is positive, or the last $-N$ characters of your source code if $N$ is negative. Terminology ...
Your task is to write a program $p$ which outputs a string $s$ with the same length as $p$, where $s \neq p$. If I remove the $n$th byte from your program to get program $q$, then either $q$ outpu...
Given a hinged tetromino, give it a unique, consistent label independent of location, rotation, and reflection. Tetrominoes A tetromino is a connected subset of the square tiling, composed of 4 s...
Task You are going to take three strings as input $A$, $B$ and $X$. And your goal is to determine if there exists a third string $S$ such that both $A$ and $B$ can be formed by iteratively removin...
