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# Unanswered Questions

72 questions with no upvoted or accepted answers
0answers
1k views

### Halting Problem for Simplified Hexagony

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

### Maximal discrepancy-2 sequence with minimal entropy

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 ...
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933 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: ...
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373 views

### Is this ordinal prime?

You are given an countable ordinal $1 < r < \varepsilon_0$. Determine whether or not it is prime. If not, provide exactly two ordinals $r_0, r_1 < r$ such that $r_0r_1 = r$, following ...
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426 views

### Gerrymander North Carolina

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: ...
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415 views

### Hexasweep (part 1): The Solver

(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 ...
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509 views

### How should I tile my kitchen?

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 ...
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397 views

### How to golf string output in Chef

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 ...
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301 views

### Tips for golfing in Erlang

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,...
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631 views

### Complement of a Regex

For the purposes of this challenge, we define a postfix regex dialect with alphabet {1, 0} and the following operations: 1 and <...
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325 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 ...
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744 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. ...
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453 views

### Please parse this aLL1en language

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 ...
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707 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 ...
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153 views

### Fix Brain-Flak push-pop redundancy

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

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