All Questions

Introduction Decide whether a Hexagony program composed solely of the characters .)_|\/><@ will halt using least bytes. Challenge Hexagony is a language ...

Background As noted in the PPCG challenge Compress a maximal discrepancy-2 sequence – which inspired this challenge – the authors of the paper Computer-Aided Proof of Erdős Discrepancy Properties ...

Input is an r by c matrix of non-negative integers (you may input r and c as other parameters if this helps with golf). This may be inputted as a 2D array or, if you prefer, a 1D array (though taking ...

Trigonometry has LOTS of identities. So many that you can expand most functions into sines and cosines of a few values. The task here is to do that in the fewest bytes possible. Identity list Well, ...

Given a POSIX Extended Regular Expression as input, output its complement (also a POSIX ERE). If the given regular expression matches a string, its complement should not match it, and the regex: ...

A simple graph is toroidal if it can be drawn on the surface of a torus without any edges intersecting. Your task is to take a simple undirected graph via any reasonable method (adjacency matrix, ...

(This is part 1 in a two-part challenge.) Your task is to solve a Hexasweep puzzle. A Hexasweep puzzle is set out on a grid of diamonds arranged in hexagonal shapes, of which the board looks like a ...

Does anybody have tips for golfing in Erlang? I'm looking for specific things that can be applied to Erlang, not any language. I know we already have tips for Elixir, but that is different. As usual,...

I recently ordered some new and colorful tiles to replace my boring old white tiling for my kitchen. However, when the tiles arrived, they were all in a weird shape! Therefore, I need a program to ...

I'm attempting to solve a programming golf style programming puzzle. I need to write an 18 character phrase in Chef in less than 32 "lines" of code. In this case, a line counts as an ingredient or an ...

For the purposes of this challenge, we define a postfix regex dialect with alphabet {1, 0} and the following operations: 1 and <...

Create a program or function to unjumble a 9x9x9 cube of digits by rotating individual 3x3 cubes within it. This is similar to (but, I suspect, a bit harder than) my Flippin' Squares question. Input ...

Background Due to some unfortunate accident during coding you are now teleported and stranded on an alien planet. You really hope that the locals will be helpful and point to the general direction of ...

Program your robots to deliver packages in a warehouse infested with destroyer drones. Avoid the drones and get your packages to the right place as fast as you can. Delivery Robots There are ...

The challenge How well can you gerrymander North Carolina into 13 voting districts? In this challenge, you use the following files to draw different maps for Republicans and Democrats. File 1: ...

Shocking news: Dr. Mad J Scientist has released a proof of P = NP to the world. But the proof is nonconstructive, and she's keeping the algorithm to herself. Worry not. Without even looking at her ...

Challenge Summary In summary, the challenge is to provide the glider synthesis for a Game of Life configuration, which is your input. What does this mean? Well, firstly, let me explain a few terms. ...

SPICE is an electrical circuit simulation program originating from UC Berkeley. Your goal is to implement a minimalistic version which can solve for the nodal voltages and branch currents of a circuit ...

Background Many moons ago, in a galaxy much like our own, a young BrainSteel attempted to invent a board game. He believed that he, too, could find an amazingly simple set of rules that would ...

A theorem in this paper1 states that every integral n-by-n matrix M over the integers with trace M = 0 is a commutator, that means there are two integral matrices A,B of the same size ...

Brain-Flak is a stack-based esoteric language with eight commands: ...

Given a list of case-insensitive ASCII letter strings ("words"), output whether the entire list can be found on some four-by-four configuration ("board") of letter squares, in which no square can be ...

I was looking for this page to help me enhance my first answer with SQLite, but I couldnt find one. So here we are! What general tips do you have for golfing in SQLite? I'm looking for ideas that can ...

Introduction On BBC Radio 2, on Saturdays there's a show hosted by Tony Blackburn called Pick of the Pops. Here, Tony selects a random week from a random year (in the range 1960-1989), and plays the ...

This is the third in a series of puzzles that I will be posting every Monday at Midnight PST, and the final variant of "Take It or Leave It". The first puzzle is located Here The second puzzle is ...

Challenge Your challenge is simply to write a program in the language of your choosing that when run, determines the highest possible score for a board of Scrabble - For the sake of this challenge, a ...

The problem: Write a function which, given a cycle length n and a number of cycles m, where 'm' is within ...

The Challenge I was looking into small code examples for a specific language as a small tutorial and came accross a simplified Blackjack that should be implemented. In this Challenge you will have to ...

One of the cool features introduced in the C++11 standard is the ability to declare a template parameter as being variadic; i.e. that parameter represents a sequence of an arbitrary number of ...

In honor of recent news of Google developing a keyboard for iPhone... Your input (for simplicity, all input is case sensitive): Location of standard dictionary file. File format is 1 valid word per ...

Revised formatting and instructions Given a list of moves for a Cracker Barrel peg board game, or as @Steveverrill stated, Peg Triangle Solitaire: ...

I recently saw this language in a challenge and it's awesome. Does anyone have some tips for golfing in it?

Scratch is a visual programming language. For the sake of counting bytes, Scratch is usually written in scratchblocks2 syntax. Post tips that specifically apply to Scratch or scratchblocks2.

The game of xiangqi, also known as Chinese chess, is a chess-like game popular in China, Vietnam, Taiwan, and other East Asian countries. The colours of the two sides in xiangqi are red and black. ...

Fairy Chess is a sort of generalized chess that allows unconventional pieces. The eight queens puzzle is a classic problem where you have to put 8 queens on a chess board such that no two queens ...

This is thematically similar to Generate keyboard shortcuts for a menu, but its actually a pretty different challenge. Let's take PHPStorm's menu as an example: ...

Write a program that takes one integer input n and one format letter and outputs n autograms in the format This sentence contains ? "A"s, ? "B"s ... and ? "Z"s. ...

About Hangul As I'm Korean, I'm really proud of Korean character, Hangul(한글). Hangul is artificial character made by King Sejong the great, 4th king of Joseon dynasty, at 1443. Because today(...

Back to back challenges I guess. Hopefully this one is more clear than the last. Background I was playing around with Goldbach's conjecture, and decided to plot evens (on the x-axis) vs the number ...

Ethereum is a blockchain platform. It has its own native cryptocurrency, ether, but in this challenge, we'll be focusing on its ability to run smart contracts. The ERC-20 standard describes an ...

Normally, I'd open with some flavor text here about being bored and/or lazy but looking through the stack-exchange-api questions that would be far from original. So instead I'm going to open with a ...

Introduction: You are a worker, who is in charge of managing a set of bridges, connecting a square grid of "nodes": ...

A dual graph is defined such that for every "face" in a graph G, there is a corresponding vertex in the dual graph, and for every edge on the graph ...

Subleq is a programming language with only one instruction. Each instruction contains 3 parameters. Code and data space is the same. How it works: A B C A, B and ...

(FB, or Functional-Basic, as found here Interpret Functional-Basic) Task Implement a linting program for FB, similar to JSLint for JavaScript. Error types Invalid identifier Identifiers can only ...

Introduction By steganography we mean hiding a message along an existing text or image so the result would be unsuspicious of the existence of the original message. This challenge is about hiding ...

Loopy is a puzzle game from the collection of Simon Tatham. The previous link contains a javascript implementation of a Loopy puzzle generator. I suggest everybody who wants to attempt this challenge ...

Inspired by this Implement simple chess bot (with console or GUI) that has following features: [Pseudo-]graphically showing the board; Accepting user moves and making their own moves; Playing by ...

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 ...

A radiation-hardened quine can take a hit and stay standing, but nobody ever said that the quine can't be a wuss about it. For this challenge, you should write a quine that: If no characters are ...