# All Questions

10,644 questions
93 views

### Write the shortest O(n^2) sorting algorithm

Write a sorting algorithm for a list of integers that has an average performance of O(n^2). Your score is the amount of characters your source code has. A lower score is better. RULES: The ...
517 views

### Prime parity peregrination

The purpose of this challenge is to graphically depict a walk on the plane, where the direction of each step $k$ is determined by the primality of $k$ and the parity of its binary expansion: ...
3k views

### Golf the smallest circle!

The problem: Given a non-empty set of points in the Cartesian plane, find the smallest circle that encloses them all (Wikipedia link). This problem is trivial if the number of points is three or ...
247 views

### Output the nth 'boring' number

There are 9 main types of numbers, if you categorise them by the properties of their factors. Many numbers fall into at least one of these categories, but a few don't. The categories are as follows: ...
97 views

### Letter Boxed, part 2: this time, solve it

This challenge is a sequel to Letter Boxed Validator. The New York Times has a daily online game called Letter Boxed (the link is behind a paywall; the game is also described here), presented on a ...
192 views

### Inverse-quotes-quine, inverted (pt. 2)

Based on a comment by Jo King on my previous question (called 'Inverse-quotes-quine'), I present this new question. The rules are similar, but just, the opposite: If your program is run normally, all ...
2k views

### Analog is Obtuse!

An analog clock has 2 hands*: Hour and minute. These hands circle the clock's face as time goes by. Each full rotation of the minute hand results in 1/12th of a rotation of the hour hand. 2 full ...
185 views

### Number conversion [on hold]

Assume that there is a number a. In every conversion of that number, the number can either convert itself to its value plus the value of one of its digits, or ...
3k views

### Alphabet completion rate

Introduction How much of the English alphabet does a given string use? The previous sentence uses 77%. It has 20 unique letters (howmucftenglisapbdvr), and 20/26 ≃ 0.77. Challenge For an input ...
83 views

### How can I change following function not to use flag? [on hold]

I am trying to see how to improve following code....need to somehow not use the flag and still return null in case not dirty. ...
2k views

### Inverse-quotes-quine

The prospect of this challenge is: If your program is run normally, all of the code in the speech marks (" - double quotes) should be printed. If your program is ...
107 views

### Fastest way to iterate over sublattice of discrete lattice

I need to construct a functor that iterates over the linear representation of a sub-lattice of size $d_x,d_y,d_z,d_q$ embedded in a lattice of size $n_x,n_y,n_z,n_q$. The sub-lattice corner is ...
3k views

### Is my Rep in Stack-Exchange Form?

Premise: Your reputation is in Stack-Exchange Form if it can be represented by decomposing your medal counts (gold, silver, and bronze counted separately) into their base-10 digits and joining them ...
786 views

### Find the diameter of a word graph

Introduction A popular word puzzle is to convert one word into another via a series of steps which replace only one letter and which always result in a valid word. For example, BAG can be converted ...
6k views

### Impossible darts scores

I was surprised to not find this asked already, though there is a great question on darts checkouts: Darts meets Codegolf Your challenge is to calculate which scores are not possible with 'n' darts ...
175 views

### Convert a string containing integers to list of integers

What is the shortest way to convert a string containing integers separated by spaces to a list of integers? input : "-3 1 5 8 10" output : [-3, 1, 5, 8, 10] I regularly face this situation and I ...
2k views

### Find the C-factor of a vote

In this challenge you will be determining how controversial a vote is, given an array of other votes, by figuring out a number called the C-factor. What is the C-factor, you ask? Well, imagine you've ...
317 views

### Distributing parliament seats

Introduction In a general election, one would like to calculate a constant price per parliament seat. This means that for N >= 0 seats to be distributed and a ...
82 views

### Flow of materials from A to B with constraint [closed]

I have been struggling with this problem and haven't been able to figure out the solution. By solution, I mean the problem modelling, defining and structuring it, and then writing a program to solve ...
4k views

### Count All Possible Unique Combinations of Letters in a Word

You are given a string, which will contain ordinary a-z characters. (You can assume this will always be the case in any test, and assume that all letters will be lowercase as well). You must ...
928 views

### Subtract the Folded Matrix

Challenge: Given an NxN matrix where $N\geq2$ and one of eight distinct 'folding options', output a 2D array/list with the subtracted values. The eight folding options are: left-to-right; right-to-...
5k views

### Cut the gold chain

A traveler needs to stay for n days in a hotel outside town. He is out of cash and his credit card is expired. But he has a gold chain with n links. The rule in this hotel is that residents should ...
145 views

### Hello Random World? [closed]

Write a program that outputs each character of the string "Hello Random World" with a one second interval, and each character should be randomly generated within [a-A z-Z] range (any lower/upper ...
306 views

### Print the total length of all “quoted” characters

Rules In this challenge, I'm going to redefine the definition of "quotes" a bit. Quotation marks (AKA quotes) are any identical characters used in pairs in various writing systems to set off direct ...
2k views

### Print 'A' 1000 times with BrainFuck

What is the best BrainFuck code (in terms of code size) to print 'A' 1000 times ? My approach is: set 'A' to p[0] set 255 to p[1] to display 255 'A', 3 times set 235 to p[1] to display 235 'A' This ...
179 views

### Reroute the Path

Given a grid of directions and a start and end position, determine the minimum number of substitutions in the direction grid that needs to be made to complete the path between the two points. The grid ...
2k views

### Print the new site header

The new site header has some bits of source code from various questions as the background. Here are the first 3 lines: ...
1k views

### Fill the maze with a wall-following Snake until it gets stuck

Make a snake fill any maze (until it gets stuck). The snake The snake starts at a given starting point, pointing EAST. It moves by always having a wall or a part of its body immediately to the LEFT ...
2k views

### First occurrence in the Sixers sequence

The Sixers sequence is a name that can be given to sequence A087409. I learned about this sequence in a Numberphile video, and it can be constructed as follows: First, take the multiples of 6, ...
107 views

### Pandemic Outbreak Calculator [closed]

In the board game Pandemic, an outbreak occurs when a city contains more than 3 disease cubes. When the outbreak occurs, any disease cubes in the city in excess of 3 are removed, and each city ...
422 views

### FizzBuzz but time-based

Make a program that outputs the number of seconds from the beginning of today (00:00:00 of the day you run it) to the second you ran it. However, if this number is divisible by three, print ...
182 views

### The year counter is here [closed]

Create a program that, given an integer N, outputs the number of years we have to get to N A.D. or how many years it has been since N A.D, as a string or int. For example, given 2014, the program ...
237 views

### Partition and Restructure

Given two contiguous shapes of the same area, determine the optimal way to divide the first shape into a minimum number of contiguous segments such that they can be rearranged to form the second shape....
510 views

### The anti-narcissist

The narcissist is a program which, given its own source as input, prints a truthy value and, given anything other than that, prints a falsey value. Today, we're reversing this. Create a program that, ...
9k views

### Print the phrase “And she said, 'But that's his.'” using only the alphabet

Print the phrase And she said, 'But that's his.' using only the following characters: ...
72 views

### Obfuscate the “Hello, world!” program [duplicate]

Create a "Hello, world!" program which is heavily obfuscated. You can use whichever language you want, so long as it has a common "Hello, world!" program which is clearly identifiable as a "Hello, ...
8k views

### New Site Design!

Unless you have a userscript that modifies the site's design (or even if so), you should have noticed that we have our site design! (It's November now) So, to celebrate, let's make a program that ...
371 views

### Who can escape the Nonary Game?

The Nonary Game is a fictional game played in the video game trilogy of the same name. Your goal is to find how many players (at best) can escape a given game, in as few bytes of code as possible. ...
5k views

### Nth term of Van Eck Sequence

Output the Nth term of the Van Eck Sequence. Van Eck Sequence is defined as: Starts with 0. If the last term is the first occurrence of that term the next term is 0. If the last term has occurred ...
609 views

### An OEIS polyglot

This is an answer-chaining challenge relating to the OEIS. Oh, the justification for this is because a company needs one program to print out their OEIS sequences real bad and they have every ...
186 views

### Alphabet without the alphabet [duplicate]

You are tasked with displaying the string "ABCDEFGHIJKLMNOPQRSTUVWXYZ" and only that, except for trailing newlines if they're unavoidable. You must not output any homoglyphic characters like Cyrillic ...
5k views

### Parsing text written the millitext font

Reading the text of the millitext font There is a font here that fits each character into a single, 1x5 pixel block. It does this (assuming you're using an LCD screen) by using the RGB channels of ...
223 views

### Generate Aheui Number

Make a Number Expression is related : actually, it is also about Aheui. But it just made number expression, but this made real Aheui code. Aheui is esolang written in only Korean character. Because ...
12k views

### Print “N NE E SE S SW W NW”

This seems almost trivial, but since after some effort I was not able to beat the literal solution in J, I thought it might make a decent challenge (though, to be clear, this is not a J-specific ...
4k views

### That's not my X, its Y is too Z

This challenge is inspired by a series of young children's books by Fiona Watt and Rachel Wells, which I've recently been enjoying with my daughter. In each book a mouse (illustrated, but not part ...
152 views

### Find longest consecutive characters in 2D array

Challenge Given a 2D array, find the length and direction of all the longest consecutive characters. If there are ties, output every possible winning combination in any order, (winners can overlap ...
2k views

### Make Gimbap cutter

Gimbap(김밥) is Korean food, somewhat looks like sushi roll. Here is Korean emoticon represent Gimbap : @)))))))))) Your quest is make ASCII Gimbap cutter. Rule ...
3k views

### ASCII Meme Arrow Generator

Specifications Given a number n, output an ASCII "meme arrow" (greater-than symbol, >) of size ...