# All Questions

77 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
2k views

### Complement a POSIX Extended Regular Expression

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: ...
652 views

### Topologically distinct ways of dissecting a square into rectangles

I was asked by OEIS contributor Andrew Howroyd to post a Code Golf Challenge to extend OEIS sequence A049021. Would be super great to get a couple more terms for [...] A049021. Kind of thing [...] ...
811 views

### Totally Cubular

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 ...
350 views

### Compare Dowker Knotation

Dowker notation is a common way of representing mathematical knots. Dowker notation can be derived from a knot diagram in the following way (based on the description from the wikipedium): We will ...
469 views

### Acyclic orientations of an n-dimensional cube

The goal of this challenge is to check and extend the OEIS sequence A334248: Number of distinct acyclic orientations of the edges of an n-dimensional cube. Take an n-dimensional cube (if n=1, this is ...
323 views

### Fix Brain-Flak push-pop redundancy

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

### Play Thud! (Dwarf Edition)

Key links: Troll question Chat room Game Controller Interface Dwarf league table ...
456 views

### The knight's next tour

We've all heard of the Knight's Tour puzzle: find a route for a knight that passes through all the squares on a chess board. But let's be honest, it's a little bit boring. So, let's give the knight a ...
291 views

### Play Thud! (Troll Edition)

Key Links Dwarf question Chat room Game Controller Interface Troll league table ...
227 views

### Help me prove the Four Color Theorem!

This is not just another challenge asking you to color random maps... In this challenge, you are asked to write a program that is actually used in the formal proof of the Four Color Theorem. First I ...
371 views

### Cyclic Polyglot Challenge (Cops)

Cyclic Polyglot Challenge This is the cops thread. You can find the robbers thread here. Cyclic Polyglot A N-element cyclic polyglot is a complete program that can be run in N different languages. ...
875 views

### Find a Glider Synthesis (Game of Life)

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. ...
513 views

### Simulate a Game of Quagmire

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 generate ...
790 views

### Delivery Robots and Destroyer Drones

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 ...
262 views

### Golfing Expressions

We can write mathematical expressions using the standard math operators (,),+,...
513 views

Sandbox Finding radicals of arbitrary ideals in rings is hard! However, it's a doable task in polynomial rings, since they are Noetherian (all ideals are finitely generated) Background A quick ...
333 views

### Tips for Golfing in SQLite?

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 ...
615 views

### Up 12 at 4 it's

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 ...
100 views

### NP-complete reduction: (grid-)Hamiltonian circuit

Background Hamiltonian circuit problem is a decision problem which asks whether a given graph has a Hamiltonian circuit, i.e. a cycle that visits every vertex exactly once. This problem is one of the ...
169 views

### Cover positions with snakes of same 'colour'

Imagine a grid where the origin square $(0,0)$ is at the top left of the screen, and positive $x$ is rightwards whereas positive $y$ is downwards. Coloured squares are at various positions on ...
347 views

### Morpion solitaire

Morpion solitaire This is a game that I remember having learnt from my grandparents in my childhood. Initially I didn't know the name. G B has found it to be Join Five (or less ambiguously - Morpion ...
388 views

### Don't break the bridges!

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

### Fraction Frenzy!

EDIT: I'm getting a lot of comments about this not terminating - I will give the "correct answer" tag to either the first person who gives me FF(3) (as in provides ...
454 views

### Total Derangement (Difficulty Level: Hard)

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

### mini SPICE solver

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 ...
488 views

### Chaining autograms

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. ...
468 views

### Write a FAST word equation solver

This question is similar to Write a word equation solver by David Frank but different in three important ways: (1) David asked for just the first solution found, and I am asking for all the solutions. ...
222 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 ...
357 views

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 ...
374 views

### The N Queens Problem, but with Fairy Chess Pieces

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 ...
838 views

### Find a dual graph

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 ...
650 views

### Encode a steganographic encoder into a package

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 ...
593 views

### Printing the Cracker Barrel Game

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

### Generate Loopy puzzles

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 ...
1k views

### Simple chess bot

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 ...
212 views

### Leave a wake of dead cells behind you

Conway's Game of Life is a well known cellular automaton "played" on an infinite grid, filled with cells that are either alive or dead. Once given an initial state, the board evolves ...
436 views

### Goldbach's Comet

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 ...
409 views

### Get ERC-20 token balance

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 ...
219 views

### Find the smallest triangle encompassing the specified polygon

Input: An integer N which represents the polygon's vertices and a list of their x and y coordinates. Expected output: The smallest difference possible between the area of the(not necessarily convex) ...
322 views

### Code Golf: BlackJack - best moves

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 ...
175 views

### Implement FBLint

(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 ...
282 views

### Generate net puzzles

An acyclical grid is a mapping of an acyclical graph (that is, a tree) where each node has no more than four edges onto a toroidal rectangular grid such that each cell of the grid is occupied by a ...
78 views

Find the moves that bring a chess squad to a given destination. You control a chess squad consisting of a king and several other pieces, on a larger chess board. Your army is placed so that no piece ...
326 views

### What is the simplest reversible circuit that computes conjugacy of transpositions?

Reversible computation refers to computation in which little or no information is deleted. Reversible computation a major component of quantum computation, and reversible computation is potentially ...
188 views

### Simulate Alpha Decay

Alpha Decay is a kind of radiation decay where every time the atom "decays", it loses a helium nucleus (an alpha particle). This means that an atom loses 2 protons and 2 neutrons each time. ...
226 views

### Further golfing this C# code from Scramble words while preserving their outlines

I'll start off by saying I checked and checked again that this question should be on topic. I will also clearly state that this is a tips question about further golfing a certain set of code not a ...
248 views

### Yet another digit insertion problem

Given a positive number $n$ we call another (not same as n) positive number $m$ good if we insert same digits in both n and m and the resulting fractional value is same. m/n = m_{\text{...
272 views

### Count the length of head movement

Once upon a time I wanted to order custom tokens for a board game. They say they can do it, and then they present me their price list. I was confused because they charge per inch of head movement, and ...