# What is the Sandbox?

This "Sandbox" is a place where Code Golf users can get feedback on prospective challenges they wish to post to the main page. This is useful because writing a clear and fully specified challenge on the first try can be difficult. There is a much better chance of your challenge being well received if you post it in the Sandbox first.

To post to the Sandbox, scroll to the bottom of this page or click on the "Add Proposal" link below, and click "Answer This Question". Click "OK" when it asks if you really want to add another answer. Write your challenge just as you would when actually posting it. You may also add some notes about specific things you would like to clarify before posting it. Other users will help you improve your challenge by rating and discussing it. When you think your challenge is ready for the public, go ahead and post it, replace the post here with a link to the challenge and delete it.

See the Sandbox FAQ for more information on how to use the Sandbox.

## Get the Sandbox Viewer to view the sandbox more easily

To add an inline tag to a proposal use shortcut link syntax with a prefix: [tag:king-of-the-hill]

## 2995 Answers

Your task is to print the Champernowne constant (A033307) indefinitely.

There must be no spaces in your output and the solution with the fewest bytes wins!

• 1. The Cham-whatever constant has infinitely many digits, making this challenge the same as this – Leaky Nun Aug 4 '16 at 18:23
• 2. Duplicate. – Leaky Nun Aug 4 '16 at 18:25
• @LeakyNun To prevent this being a duplicate could the challenge be "Print the Champernowne constant in base n", where the input is the base? – ASCIIThenANSI Aug 5 '16 at 14:35
• Also, this question isn't self contained. If you were to post an acceptably modified version of this, please explain what this constant/sequence is within the question itself, even if there is a link – MildlyMilquetoast Jan 20 '17 at 1:03

# Left and Right

Given an input string, in ASCII, output ")|]" as many times as the case-insensitive word "right" appears in input, and output "(|[" as many times as the case-insensitive word "left" appears in input. The order is irrelevant. If and only if no occurences of these words are in input, output "X|X". Spacing between items is optional

This is , less bytes is best

Test cases:

input -> output
RightRightighteftleft -> (|[ )|] )|], or some other ordering
this doesn't contain either word -> X|X
LEfT, LeFT, leFT, righT -> (|[ (|[ (|[ )|]
(|[ -> X|X


# Enterprise Quality Code!

## Summary of this challenge

Print (to make it more fair when competing with another language changing the output method could be a trivial way to golf) the first N Prime numbers. Your score will be the sum of the byte counts of all entries which no one has been able to golf down (by removing one or more characters and rearrange the program). If you golf down someones program, post it as another submission.

You may not golf your own programs once submitted.

This is not a dupe because it significantly changes the scoring method. Writing code which allows a single byte to be golfed off will cost the whole of the score. Also as this is a challenge the winner is likely going to have high scores across a multitude of languages. It is likely that scores will be incredibly near 30k for each language. This limit allows a more interesting competition as it prevents submissions of exponentially large lengths.

### Back-story and explanation

At Pretty Good consultants there is a focus on writing "quality" verbose code that is sufficiently engineered. Your boss has decided to test you on your skills.

Consider the set of all programming languages in existence before the posting of this challenge. For this challenge there will technically be one individual "winner" in each language, however the boss will give a promotion accepted tick mark to only one answer based on your score.
The goal of this challenge is to receive an integer N strictly smaller than 2^16-1 and print the first N prime numbers (in less than 24 hours) separated by your platforms choice of new line. OEIS sequence A000040 in as many bytes as possible in as many languages as possible. However, note that others vying for the promotion will try to "help" you by golfing down your score.

Sample output for an input 11

2
3
5
7
11
13
17
19
23
29
31


## How to participate

Pick any language X, but please avoid selecting a language which is just another version or derivative of another answer. If there is no existing answer in language X than you will write a program (which must fit into a single post) that solves this challenge. The length in bytes of the source (in any reasonable preexisting textual encoding) will be added to your score. You must avoid using any unnecessary characters for reasons that will soon become apparent.

If language X already has been used to answer this question, then you must answer using any permutation of any proper subset of the characters used in the shortest answer (I.E take the shortest X answer and remove some (>=1) characters and optionally rearrange the resulting code). The previous holder of the shortest X answer will lose all of the bytes provided by his answer from his score, and the number of bytes of your submission will now be added to your score. The number of bytes golfed off gets "lost" forever.

Clarifications shamelessly lifted adapted from this challenge

### Rules for Languages

Languages used should be distinctly different. A language is different iff:

• It is not a different version of another language (Java 7, Java 8)
• They must not be derived from another language (Branf*** versus Alphf***)
• One language may not be a subset or superset or trivial of the other one (e.g. hq9+ versus hq9+b).

HQ9+ wouldnt be a language anyway, but please be judicious when selecting a language, if you have any clarifications on a language that may be significantly different from an existing answer please ping me and we can work it out.

• If anyone knows how to make a scoreboard for this I will be much obliged – Rohan Jhunjhunwala Aug 20 '16 at 17:28
• So the highest score wins, overall (from all your still-valid answers). And when you outgolf somebody, they lose their points, you gain your points, but do you get the points that they lost? – Rɪᴋᴇʀ Aug 20 '16 at 17:42
• @EasterlyIrk the way I had it planned out is that the amount of bytes golfed off is forever lost. I don't know if thats fair but that essentially prevents people from "profiting" off of ridiculous answers that were not fortified against being golfed. – Rohan Jhunjhunwala Aug 20 '16 at 17:49
• Yeah, that's what I figured. You might want to clarify that a bit though. I really like the idea. – Rɪᴋᴇʀ Aug 20 '16 at 17:52
• @EasterlyIrk clarifications added, let me know if this is ready for main – Rohan Jhunjhunwala Aug 20 '16 at 17:59
• It might be ready, but you should wait for somebody else to also give input. – Rɪᴋᴇʀ Aug 20 '16 at 18:01
• All right sounds good – Rohan Jhunjhunwala Aug 20 '16 at 18:04
• 1. So basically the accepted answer goes to the shortest answer in Unary? 2. The tags code-golf and code-bowling are mutually exclusive. This isn't really either. – Peter Taylor Aug 20 '16 at 19:49
• @PeterTaylor please read the whole thing. The answer must fit within 30k – Rohan Jhunjhunwala Aug 20 '16 at 20:02
• If someone can write a brainf*** program that is only about 6 chars long or so than they deserve the accept tick – Rohan Jhunjhunwala Aug 20 '16 at 20:03
• @RohanJhunjhunwala Golunar wins – Rɪᴋᴇʀ Aug 20 '16 at 22:07
• @EasterlyIrk lol thats actually just a compressed form of Brainf*** it probably wouldn't score that well – Rohan Jhunjhunwala Aug 20 '16 at 23:15
• @PeterTaylor essentially I restrict answers to fit in one post which means the best score for a single language is slightly under 30 characters – Rohan Jhunjhunwala Aug 20 '16 at 23:15
• I find the intro confusing. I didn't understand what the challenge is broadly about until reading to the end. Can you cleanly state the challenge at the beginning, and move the details later? – xnor Aug 21 '16 at 0:42
• @trichoplax the overall winner with the highest score summed up over all of their answer posts will receive the tick on their highest scored post. It doesn't really matter which post in particular (as long as it is a post of the winner) receives the tick, but it makes sense to tick off the highest scoring post. – Rohan Jhunjhunwala Aug 21 '16 at 12:44

Find all paths in a matrix maze.

A maze is represented as a two-dimensional array of 0s and 1s. Zero indicates a closed door and one indicates an open door. An example representation of maze is given below.

0100
0010
1101


to avoid loops input square matrix should not contain a square of once like

111      11
101  or  11
111


Write an application either in Java,C,C++,Python,C# or Javascript. It takes as input a maze(mxn array) and prints out all the possible ways out.

• No database should be used.

• Yes...Way out is any edge containing 1.

• Enter from any edges of the maze

• Exit from any edges of the maze

• Should not enter and exit from the same door

• Move can be one unit distance either top/bottom/left/right/diagonal

For the above maze, one possible way out is: [0,1] -> [1,2] -> [2,3] i.e you start at [0,1] and then move to [1,2] and then to [2,3]. There are other possible ways as you can see.

• Probable dupes: One, Two – Emigna Sep 8 '16 at 15:10
• Also, restricting challenges to specific languages are frowned upon. An objective winning criterion is also needed. – Emigna Sep 8 '16 at 15:10
• @Emigna, No Actually, here we need to find all the paths not the shortest path or straight path and here we can also traverse diagonal in the matrix. – Ali786 Sep 8 '16 at 15:15
• okay will add few more languages that I know so that I can evaluate ... – Ali786 Sep 8 '16 at 15:16
• 1. "Handle error cases like a production application" is not a clear requirement. Different production applications have different standards for how to handle errors. 2. "prints out all the possible ways out" runs into trouble when there's an infinite number, and I don't see any guarantee that there won't be loops. 3. The example doesn't make the input format very clear. What's the non-rectangular border for? 4. Path-finding with a trivial input format is definitely a dupe of at least one previous question. – Peter Taylor Sep 8 '16 at 15:31
• @PeterTaylor, I have modified my question, can you plz check once. – Ali786 Sep 8 '16 at 16:04

# Quine tree

Inspired by that really weird quine challenge

For this challenge, you must construct a quine tree, which is a thing I made up, specifically an infinite binary tree.

How a quine tree works:

A quine tree has infinite nodes.

• Each node is associated with a program

• Let X, Y, Z, be the programming languages. This program is a polyglot in X and Y. In all but the root node, it is also a polyglot in Z. Note the

• see below for more details

• Each node has exactly two children

• Every node but the root has a parent. Their parent has the node as a child (obviously).

Programs:

• When a node's program is run in X, it produces the program of the first child of that node.
• When run in Y, it produces the program of the second child of that node.
• The programs produced must be different (node foo's program, cannot have the same output in X and Y. This output must also be different than the nodes program).
• If not the root node, when run in Z, it produces the parent of the node.

## Example

Imagine that we have the (fake) programming languages Hello, World, and Foobaz. Say the root node is $QQ$QQ$;: • when run in Hello, perhaps it produces $QQ$QQ$;;
• When this is run with Hello again, perhaps produces $QQ$QQ$;;; • When this is run with World, perhaps produces $QQ$QQ$;;Q
• Both these programs must produce, run in Foobaz, $QQ$QQ$;; (Output of root node run in Hello) • when run in World, perhaps it produces $QQ$QQ$;Q
• When this is run with Hello, perhaps produces $QQ$QQ$;Q; • When this is run with World again, perhaps produces $QQ$QQ$;QQ
• Both these programs must produce, run in Foobaz, $QQ$QQ$;Q (Output of root node run in World) • Both these programs, run in Foobaz, must produce $QQ$QQ$; (root program).
• This seems like a really interesting challenge. I'm not sure how possible it is, though! Substitution languages like /// might be easiest to solve this in. – wizzwizz4 May 27 '17 at 8:20

# The only differences that matter

## Cops' task

Write two programs (or functions) A and B in the same version of the same programming language. They also should be called in the same way, meaning you can't write one program and one function. Each should accept an integer n and output the term n of a different integer sequence on OEIS.

You should reveal a substring of each of A and B. Call them PA and PB. If one instance of PA is replaced by PB from A, it should become B. That means every byte except the reveal part in A and B should be exactly the same. You also reveal the lengths of A and B, and the two OEIS sequences. You don't reveal the programming language you use.

Your answer is cracked if a robber finds two programs A' and B' that also print the elements in the two integer sequences respectively, where A' is no longer than A, and A' with one instance of PA replaced by PB is also B'. They don't have to be the same with your original A and B. And they don't have to be in the same programming language as yours, as long as they are in the same programming language themselves.

If your answer isn't cracked 7 days after you post the answer, you can reveal your language and the original A and B and mark the answer safe, and it will be immune to future crack. Your answer can still be cracked if you don't do it.

Your score is max(len(A)+len(PA)*5, len(B)+len(PB)*5). The safe answer posted before a certain date with the minimum score wins.

For example, if your two programs are The first program and The second program, you can reveal first and second. Your score is 18 + 6*5 = 48. And a robber can crack your answer by <<first>> <<second>> if they work. But you can also reveal first pro and second pro to prevent this crack.

Please post your answer using this template:

# <length of PA> / <length of A> bytes, <length of PB> / <length of B> bytes, score <score>, <open / safe / cracked>

Part of program A (outputing [<OEIS number>](<OEIS link>)):

<code of PA>

Part of program B (outputing [<OEIS number>](<OEIS link>)):

<code of PB>

<any other explanations>


## Robbers' task

(To do.)

• Do robbers have to produce the same program, or any program? – Nathan Merrill Oct 28 '16 at 14:47
• There are two tricky edge cases around character encodings which the question needs to address. 1. It talks about substrings of A and B, saying that every byte except the revealed ones must be the same. If A and B differ in one Unicode codepoint, such that in UTF-8 they differ in only one byte but it's part of a three-byte sequence, can I post just that one byte as PA/PB or must I post the three-byte sequence? (I.e. are the substrings operating on the bytes or on the codepoints?) – Peter Taylor Oct 28 '16 at 20:57
• 2. If my program is in APL using an 8-bit encoding, do robbers answering in a language other than APL have to have the same bytes in the part of their file corresponding to PA/PB or the same Unicode codepoints? – Peter Taylor Oct 28 '16 at 20:57
• @NathanMerrill Any program. – jimmy23013 Oct 28 '16 at 21:05
• @PeterTaylor I'm considering requiring every program to be in printable ASCII (and tabs and newlines), as some special characters effectively banned many languages. But I'm not sure about newlines, which have the \r problem. – jimmy23013 Oct 28 '16 at 21:09
• Maybe I'll just say \r\n is counted one byte in this challenge, and is interchangeable with \n. But the programs in one submission must use only \n or only \r\n. – jimmy23013 Oct 28 '16 at 21:13
• An example would make this easier to understand, – xnor Oct 29 '16 at 6:08
• I'm skeptical about having the programming language be a free variable. If a cop writes an answer using a verbose language, a robber can comment out all the visible parts and stuff a terse language answer into the cracks. – feersum Oct 29 '16 at 11:24
• @feersum But that's the whole point of all the requirements. If you comment out all the visible parts, both your programs usually should output the same thing. But I realized it's easy to have some workarounds in languages such as Befunge. I may try to find a way to ban them, or just abandon this post. – jimmy23013 Oct 31 '16 at 0:59

# Translation Polyglot

Your task is to write a program which runs in two distinct programming languages to translate text. Input should be translated between each language i.e. running your code in Code Language A translates from language 1 to 2, while running your code in Code Language B translates from language 2 to 1.

Rules:

• Code Languages must be distinct, two versions of the same language are disallowed
• Your code may be a full program or function
• Your code must take one string (or nearest equivalent) as input. Input may be user input, function arguments, or other reasonable form
• Output may be a function return, output to STDOUT, or other reasonable form. I do not care about trailing newlines or spaces
• Your code may translate from/to any language on the official language list on Wikipedia. List the languages in your answer
• To accomplish your goal, you may use prebuilt language tanslation dictionaries such as the ones found here.
• If you read your dictionary as an external file, only the code to read in the file (f = open("dictionary.txt", 'r') in Python) counts towards your byte count. If your dictionary is hardcoded in, only count the bytes required to make it syntatically valid code (s="word1_in_english word1_in_french ..." would be 4 (s="")). Essentially, do not include the dictionary as part of your submissions byte count.
• The dictionary you use must have been created before this post (including sandbox time). You may not modifiy the dictionary in any way.
• Any built-in translation tools are disallowed. Built-in dictionaries are ok, but whatever code used to import them into your code must be included in the byte count

This is code golf, so shortest answer in bytes wins.

• wait... Are you actually asking for machine translation? Seems very difficult. Haven't you ever seen bad translator? If it actually is machine translation, this won't work, because of the different resolution of the languages (like converting a jpg to a png and expecting the same quality back) – Destructible Lemon Nov 1 '16 at 4:11
• It's really just value lookup. I'm not asking people to to make their own dictionary, just use a pre-built and accept whatever it translates – wnnmaw Nov 1 '16 at 13:45
• But that doesn't really satisfy Language A produces output O from input I, while running in Language B produces output I from input O. – Destructible Lemon Nov 1 '16 at 22:04
• Ah, now I see the source of confusion. Updated text to require basic translation, not symmetric translation – wnnmaw Nov 2 '16 at 11:53
• Also I don't think translation is objective enough for code golf... – Destructible Lemon Nov 3 '16 at 5:30

# What in the heck just happened?

I want you to write a program that will bleep out the H-word, regardless of where it occurs, whether it is inside of another word or a stand-alone word, whether capitalized or not.

## Input and Output

The inputs and outputs of your program may be any of the following: an array of characters, a string, or any other standard data structure which does the job. However, the output must match the case of the input.

## Samples:

In the format of Input: Output
A Shell gas station : A Sheck gas station
Hell is a very bad place to be. : Heck is a very bad place to be.
Ella fell and Nelly dug a well. : Ella fell and Nelly dug a well.
Chellsea Thell bought shells. : Checksea Theck bought shecks.


Standard loopholes apply, and the entry submitted by [insert date here] with the lowest number of bytes as defined by the Meta will win.

• I can't say for sure, as I don't have an exact reference, but I'm pretty sure a simple find and replace challenge has been done before. – ATaco Feb 13 '17 at 0:19
• "Hell" and "heck" are both "H-words", so you need to be clearer. Also, I feel like this is a duplicate. Though these are milder swear words, I think someone did one with swear words in general and it got deleted. If you're going to make a find/replace challenge, it's simple enough to make it about something else. – mbomb007 Feb 13 '17 at 0:19
• Ah, I see. So, are you saying I should change what's being replaced or what my idea is? – Drew Christensen Feb 14 '17 at 0:50

# Google Logo in Conway's Game of Life

Conway's Game of Life base challenges are always fun so here is a new one.

This is Google's Logo (if you have not somehow seen it):

The font is called Product Sans. Your job is to replicate this logo (no color of course) in 800x439px just like the image (just the letters).

Have fun! This is a popularity contest so the most votes wins. :D Good luck. Of course, this may not be possible but, you never know until you try.

Usual rules apply.

Inspired by this.

• "looks like" isn't a tight enough specification for a challenge. – user45941 May 29 '17 at 21:20
• Also consider some method besides first-past-the-post, that winning criteria doesn't really work well with this site. – FryAmTheEggman May 30 '17 at 0:22
• So the answer could replicate it at the 0th generation? – Peter Taylor May 30 '17 at 10:48
• @PeterTaylor Good point – arodebaugh May 30 '17 at 13:14
• @FryAmTheEggman Popularity contest? – arodebaugh May 30 '17 at 13:14
• @Mego Also good point – arodebaugh May 30 '17 at 13:15
• OK I updated stuff maybe it will make this challenge better – arodebaugh May 30 '17 at 13:16
• 1. I don't see how the change you've made addresses my previous point. 2. Pop-con is barely any better than fastest-gun-in-the-west. 3. It's possible to test whether this is possible or not (I highly doubt it) by running the CA backwards. – Peter Taylor May 30 '17 at 16:09

# The 2017 Loader contest

Here's a thing: Let's do the bignum bakeoff again.

Because why not.

### What to do

Write a program in less than 256 characters that outputs the biggest number you can.
Yep, that's it. Biggest return value wins.

We'll run the program on a VM with infinite memory. (How do we do this?)

### Rules

• 256 chars max, excluding whitespace
• Different leagues for each language
• Output however you want
• No explicitly printing numbers until your loop runs out. Print the number you generate directly. {1}
• Program must terminate
• No implementation-dependent shenanigans.
• Implementation-independent shenanigans is encouraged.
• ints are infinite.
• Program must return the same number every time
• Submission must include the approximate return value in any suitable googological notation.
• Whitespace is space, tab, newline, formfeed, and return
• BrainF***: Whitespace is all non-[]+-<> characters

{1} Allowed ways to return: printf("%d", num); return num;, etc.
Banned ways to return: for(;num>0;num--)printf("99999");, etc.

### This is not a dupe of...

This because you can put any characters you want, not just non-digits; because we're hard-limiting the characters.

### Suggested rules

• No floats: float double long double, etc
• No strings or chars
• No bitfeilds
• No looking at Command-line args

Next year's contest will be named after this year's winner, for no particular reason.

http://djm.cc/bignum-rules-posted.txt

### Sandbox

• How do you even test these programs?
• What other rules should we have?
• You don't actually explain the rules of the challenge, we would have to go to that link to find out what we are supposed to do. Aside from that, I think this has a lot of problems with your typing restrictions if these are not limited to C, but limiting it to C wouldn't really fit the spirit of the site. I think you may want to rethink how you want to approach this question. – FryAmTheEggman May 29 '17 at 16:43
• @FryAmTheEggman "Typing restrictions"? (Added proper instructions) – SIGSTACKFAULT May 29 '17 at 16:45
• Your post doesn't describe how people win. Is it by the largest possible number? Anyway, the problems are things like not counting whitespace, which can easily result in degenerate answers, as well as things like I/O streams and whatnot. All of your extra rules seem entirely based around C with no regard for other languages, which will not go well. – FryAmTheEggman May 29 '17 at 16:48
• In answer to "Because why not": because it will be closed as a dupe. – Peter Taylor May 29 '17 at 17:59
• Here's a couple of rules I would consider. 1. Program must generate the same result every time (e.g. not based on timer, probability, or the like). 2. Submissions should include, if not the exact resulting number, at least a best estimate, in scientific notation if need be. – Computronium May 30 '17 at 18:32
• Scientific notation? People will post answers that far, far exceed that. In fact, Mathematica, 22: Fold[Power,2~Range~9999] It's 2^3^4^...^9999. That's not being represented anytime soon. – CalculatorFeline May 31 '17 at 3:31
• This is a duplicate, and is also going to come down a lot to whether or not you allow programs that exceed the computational capacity of any existing computer. (If you require programs to work on a physical computer, the best they can possibly do is to use the entirety of memory as a counter and print out 9s over and over again. If you don't, the answers can easily be large enough that you need to use notation invented specifically for describing the number, because all other notations are not enough.) – user62131 May 31 '17 at 22:40
• If your code can simulate a Turing machine, it becomes hard to judge who the winner is, and whether an answer is valid at all. – anatolyg Jun 1 '17 at 20:35
• Re your latest edit: you're wrong. The question it's a dupe of also has a hard limit to the number of characters; in fact it's a harder one, but the best answers could be copied with slight tweaking to take advantage of the extra space. And the digit restriction turned out not to be a serious problem: the winning answer would gain extremely little from being able to use digits. – Peter Taylor Jun 2 '17 at 9:07

# Golf Cubically code code-challengefgitw

Your task is to optimize Cubically source code using one or more optimizations in this post.

How this challenge works:

• You will choose one or more optimizations below and write a program (in the language of your choice) that performs those optimizations on a Cubically program.
• Your program will take a Cubically program as input using any allowed input methods, and output a Cubically program using any allowed output methods.
• The first answer to successfully perform all optimizations wins!

# Optimizations

### 1. Face turn arguments

Before a face turn is performed, the interpreter calculates turns = turns mod 4. So R5 would be equivalent to R1 which is equivalent to R, R7 is equivalent to R3 which is equivalent to R', etc. Also note that R11111 is equivalent to R5, and R22 is equivalent to nothing at all.

Performing this optimization will mean evaluating all arguments to an R, L, U, D, M, E, or S command and shortening them as much as possible.

Test cases:

Relevant code -> Optimization
R11           -> R2
R1            -> R
L33           -> L2
U22           ->
D222          -> D2
M11111        -> M
E00001        -> E
S9            -> S


### 2. Repeated face turn

When multiple calls to the same face turn command are present right next to each other, they can clearly be golfed. For example, R2R1 is equivalent to R3. UUU is equivalent to U3. F2F2F2F2 is equivalent F8.

Test cases:

Relevant code -> optimization
R2R2R2        -> R6            (R2 if you also choose optimization 1)
LLL           -> L3
UU            -> UU or U2
D3D2D1        -> D6            (D2 if you also choose optimization 1)


### 3. "Set notepad to" commands

There are some commands that, instead of adding to/subtracting from/multiplying by/dividing by the notepad, just assign to it. Here are all such commands:

_^=<>⊕«»·|:


When called with multiple arguments, since each argument calls the command separately, only the final argument is relevant. So =123 is equivalent to =3, _00000 is equivalent to _0, and :12345678987654321 is equivalent to 1.

Test cases:

Relevant code -> Optimization
_333          -> _3
=12321        -> =1
+54321        -> +54321
:55           -> :5
/55           -> /55


### 4. Repeated non-face-turn commands

When multiple face turn commands are present right by each other, their arguments can simply be added together. Commands do not act this way. While R2 calls R with 2, =2 calls = with the face sum of the front face (face index 2).

To perform this optimization, when multiple commands outside of RLUDFBMES appear next to each other, simply remove the duplicated commands without removing the arguments.

Relevant code -> Optimization
_1_1_1_1      -> _1111         (_1 if you also choose optimization 3)
%11%22%33     -> %112233       (%3 if you also choose optimization 3)
+12345+67+8   -> +12345678


### 5. Nonexistent commands

Go check out the Cubically commands page and you'll see that there are plenty of characters that are not commands. For example, there are no commands that are lowercase letters.

To perform this optimization, remove all nonexistent commands and their arguments from the Cubically source. If the commands also have arguments, you must remove the arguments so that they are not passed to the previous command.

Test cases:

Relevant code -> Optimization
moo cow moo   ->
moo2cow2moo   ->
misteR2 FOO   -> R2F
FEAR ME.      -> ERME
u1U2u3U4u5U6  -> U2U4U6   (nothing if you also choose optimization 1, U12 if you also choose optimization 2)


There are lots of implicit commands in Cubically (RLUDFBMES()$~&E!), but there are plenty that need to be called with arguments. So %%%% is equivalent to nothing at all while %%2%% is equivalent to %2. Test cases: Relevant code -> Optimization %%%% ->  ->  ++2++2++2 -> +2+2+2 (+222 if you also choose optimization 4) +++>--<- -> Not Brainf**k, sorry! (:P)  # Sandbox I'll add more optimizations later. • Clarification on R123: That's the same as R6 and R2, not R3, right? Digits are summed, there are multidigit numbers? That would be better to specify – isaacg Aug 17 '17 at 20:13 • A few things: first, I can't find the tag "fgitw", is there a typo? Second, does optimization 1 require handling F and B as well, or just the currently listed ones? Third, in optimization 3 most of the listed commands seem invalid because the notepad is used in calculation and then overwritten with the output; for example =11 is not the same as =1 in most circumstances. In fact, I think only _: are valid. Fourth, is the winning answer one which performs all optimizations in a single program, or one which contains a separate program for each optimization? – Kamil Drakari Aug 18 '17 at 18:03 # Proper Kerning Kerning is the adjustment of spacing between pairs of letters in order to obtain an aesthetic result. When kerning is applied automatically by a program (typically whatever editor you're using), it is said to be automatic. There are two types of automatic kerning. The one used in this challenge is metric kerning. With metric kerning, the amount of space between pairs of letters is dictated by the kerning tables found in the font file. Given a TrueType font file, output the kerning values for each mapping in the kerning table for ASCII characters 48 - 122 inclusive. ## Example calibri.ttf l="A" r="C" v="-15" l="A" r="G" v="-15" l="A" r="J" v="23" l="A" r="O" v="-23" l="A" r="Q" v="-23" l="A" r="T" v="-160" l="A" r="U" v="-32" l="A" r="V" v="-89" l="A" r="W" v="-80" l="A" r="Y" v="-150" l="A" r="t" v="-52" l="A" r="v" v="-38" l="A" r="y" v="-41" l="A" r="?" v="-68" l="B" r="A" v="-20" l="B" r="T" v="-48" l="B" r="V" v="-25" l="B" r="W" v="-24" l="B" r="X" v="-44" l="B" r="Y" v="-57" l="B" r="Z" v="-20" l="B" r="f" v="-20" l="B" r="t" v="-20" l="B" r="v" v="-20" l="B" r="x" v="-15" l="B" r="y" v="-20" l="C" r="G" v="-18" l="C" r="J" v="12" l="C" r="O" v="-18" l="C" r="Q" v="-18" l="C" r="T" v="10" l="D" r="A" v="-30" l="D" r="J" v="-22" l="D" r="T" v="-23" l="D" r="V" v="-24" l="D" r="W" v="-14" l="D" r="X" v="-31" l="D" r="Y" v="-39" l="D" r="Z" v="-22" l="E" r="A" v="-22" l="E" r="C" v="-24" l="E" r="G" v="-24" l="E" r="O" v="-32" l="E" r="Q" v="-32" l="E" r="S" v="-20" l="E" r="Z" v="-10" l="E" r="a" v="-34" l="E" r="c" v="-28" l="E" r="d" v="-30" l="E" r="e" v="-37" l="E" r="f" v="-64" l="E" r="o" v="-37" l="E" r="q" v="-30" l="E" r="t" v="-24" l="E" r="v" v="-48" l="E" r="w" v="-34" l="E" r="y" v="-48" l="F" r="A" v="-115" l="F" r="C" v="-18" l="F" r="G" v="-18" l="F" r="J" v="-109" l="F" r="O" v="-18" l="F" r="Q" v="-18" l="F" r="S" v="-29" l="F" r="X" v="-22" l="F" r="Z" v="-11" l="F" r="a" v="-55" l="F" r="c" v="-28" l="F" r="d" v="-20" l="F" r="e" v="-30" l="F" r="o" v="-28" l="F" r="q" v="-20" l="F" r="s" v="-35" l="G" r="T" v="-10" l="G" r="V" v="-10" l="G" r="W" v="-9" l="G" r="Y" v="-30" l="G" r="v" v="-29" l="G" r="w" v="-22" l="G" r="x" v="-14" l="G" r="y" v="-30" l="J" r="A" v="-35" l="J" r="X" v="-20" l="K" r="C" v="-78" l="K" r="G" v="-80" l="K" r="O" v="-97" l="K" r="Q" v="-97" l="K" r="S" v="-18" l="K" r="U" v="-29" l="K" r="W" v="-34" l="K" r="a" v="-34" l="K" r="c" v="-40" l="K" r="d" v="-33" l="K" r="e" v="-37" l="K" r="f" v="-25" l="K" r="m" v="-32" l="K" r="n" v="-32" l="K" r="o" v="-37" l="K" r="p" v="-32" l="K" r="q" v="-33" l="K" r="r" v="-32" l="K" r="s" v="-18" l="K" r="t" v="-38" l="K" r="u" v="-32" l="K" r="v" v="-101" l="K" r="w" v="-95" l="K" r="y" v="-85" l="L" r="C" v="-22" l="L" r="G" v="-47" l="L" r="J" v="25" l="L" r="O" v="-45" l="L" r="Q" v="-45" l="L" r="T" v="-150" l="L" r="U" v="-44" l="L" r="V" v="-147" l="L" r="W" v="-118" l="L" r="Y" v="-167" l="L" r="f" v="-23" l="L" r="t" v="-38" l="L" r="v" v="-78" l="L" r="w" v="-72" l="L" r="y" v="-79" l="O" r="A" v="-23" l="O" r="J" v="-27" l="O" r="T" v="-55" l="O" r="V" v="-25" l="O" r="W" v="-22" l="O" r="X" v="-64" l="O" r="Y" v="-55" l="O" r="Z" v="-38" l="O" r="x" v="-12" l="O" r="z" v="-10" l="P" r="A" v="-151" l="P" r="J" v="-140" l="P" r="T" v="-9" l="P" r="V" v="-10" l="P" r="X" v="-35" l="P" r="Y" v="-11" l="P" r="Z" v="-29" l="P" r="a" v="-44" l="P" r="c" v="-43" l="P" r="d" v="-34" l="P" r="e" v="-41" l="P" r="f" v="12" l="P" r="o" v="-41" l="P" r="q" v="-34" l="P" r="s" v="-32" l="P" r="t" v="12" l="P" r="y" v="12" l="Q" r="J" v="41" l="Q" r="T" v="-47" l="Q" r="V" v="-25" l="Q" r="W" v="-12" l="Q" r="X" v="12" l="Q" r="Y" v="-46" l="Q" r="g" v="59" l="Q" r="j" v="79" l="Q" r="x" v="31" l="Q" r=";" v="60" l="Q" r="]" v="32" l="R" r="C" v="-18" l="R" r="G" v="-19" l="R" r="O" v="-20" l="R" r="Q" v="-20" l="R" r="S" v="-27" l="R" r="T" v="-20" l="R" r="V" v="-28" l="R" r="W" v="-18" l="R" r="Y" v="-30" l="R" r="e" v="-36" l="R" r="o" v="-42" l="R" r="v" v="-26" l="R" r="w" v="-33" l="R" r="y" v="-33" l="S" r="A" v="-15" l="S" r="J" v="-9" l="S" r="T" v="-14" l="S" r="V" v="-14" l="S" r="W" v="-15" l="S" r="X" v="-13" l="S" r="Y" v="-20" l="S" r="v" v="-23" l="S" r="w" v="-17" l="S" r="y" v="-25" l="T" r="A" v="-160" l="T" r="C" v="-42" l="T" r="G" v="-59" l="T" r="J" v="-65" l="T" r="O" v="-58" l="T" r="Q" v="-58" l="T" r="S" v="-10" l="T" r="T" v="28" l="T" r="a" v="-160" l="T" r="c" v="-177" l="T" r="d" v="-147" l="T" r="e" v="-182" l="T" r="g" v="-151" l="T" r="m" v="-127" l="T" r="n" v="-127" l="T" r="o" v="-182" l="T" r="p" v="-127" l="T" r="q" v="-147" l="T" r="r" v="-127" l="T" r="s" v="-153" l="T" r="u" v="-127" l="T" r="v" v="-92" l="T" r="w" v="-86" l="T" r="x" v="-90" l="T" r="y" v="-93" l="T" r="z" v="-142" l="T" r=";" v="-114" l="T" r=":" v="-134" l="U" r="A" v="-45" l="U" r="J" v="-40" l="V" r="A" v="-96" l="V" r="C" v="-18" l="V" r="G" v="-25" l="V" r="J" v="-80" l="V" r="O" v="-27" l="V" r="Q" v="-27" l="V" r="S" v="-12" l="V" r="V" v="9" l="V" r="a" v="-114" l="V" r="c" v="-103" l="V" r="d" v="-87" l="V" r="e" v="-102" l="V" r="g" v="-100" l="V" r="m" v="-50" l="V" r="n" v="-50" l="V" r="o" v="-86" l="V" r="p" v="-50" l="V" r="q" v="-87" l="V" r="r" v="-50" l="V" r="s" v="-90" l="V" r="u" v="-50" l="V" r="y" v="-35" l="V" r="z" v="-82" l="V" r=";" v="-108" l="V" r=":" v="-73" l="W" r="A" v="-93" l="W" r="C" v="-22" l="W" r="G" v="-22" l="W" r="J" v="-88" l="W" r="O" v="-22" l="W" r="Q" v="-22" l="W" r="S" v="-10" l="W" r="X" v="-13" l="W" r="a" v="-71" l="W" r="c" v="-78" l="W" r="d" v="-72" l="W" r="e" v="-75" l="W" r="g" v="-54" l="W" r="m" v="-60" l="W" r="n" v="-60" l="W" r="o" v="-86" l="W" r="p" v="-60" l="W" r="q" v="-72" l="W" r="r" v="-60" l="W" r="s" v="-73" l="W" r="u" v="-60" l="W" r="v" v="-34" l="W" r="y" v="-53" l="W" r=";" v="-156" l="X" r="C" v="-57" l="X" r="G" v="-65" l="X" r="O" v="-57" l="X" r="Q" v="-57" l="X" r="S" v="-20" l="X" r="d" v="-44" l="X" r="e" v="-39" l="X" r="g" v="-9" l="X" r="o" v="-38" l="X" r="q" v="-44" l="X" r="t" v="-31" l="X" r="u" v="-38" l="X" r="v" v="-55" l="X" r="w" v="-49" l="X" r="y" v="-43" l="Y" r="A" v="-152" l="Y" r="C" v="-67" l="Y" r="G" v="-67" l="Y" r="J" v="-112" l="Y" r="O" v="-66" l="Y" r="Q" v="-66" l="Y" r="S" v="-17" l="Y" r="Z" v="-10" l="Y" r="a" v="-134" l="Y" r="c" v="-159" l="Y" r="d" v="-131" l="Y" r="e" v="-147" l="Y" r="f" v="-62" l="Y" r="g" v="-142" l="Y" r="i" v="-32" l="Y" r="j" v="-49" l="Y" r="m" v="-94" l="Y" r="n" v="-94" l="Y" r="o" v="-153" l="Y" r="p" v="-94" l="Y" r="q" v="-131" l="Y" r="r" v="-94" l="Y" r="s" v="-115" l="Y" r="t" v="-44" l="Y" r="u" v="-94" l="Y" r="v" v="-69" l="Y" r="w" v="-62" l="Y" r="x" v="-70" l="Y" r="y" v="-65" l="Y" r="z" v="-100" l="Y" r=";" v="-138" l="Y" r=":" v="-154" l="Z" r="A" v="-11" l="Z" r="C" v="-25" l="Z" r="G" v="-24" l="Z" r="O" v="-24" l="Z" r="Q" v="-24" l="Z" r="W" v="-7" l="Z" r="Y" v="-7" l="Z" r="a" v="-10" l="Z" r="c" v="-12" l="Z" r="d" v="-18" l="Z" r="e" v="-31" l="Z" r="o" v="-29" l="Z" r="q" v="-18" l="Z" r="v" v="-45" l="Z" r="w" v="-38" l="Z" r="y" v="-37" l="a" r="f" v="-12" l="a" r="t" v="-19" l="a" r="v" v="-34" l="a" r="w" v="-14" l="a" r="x" v="-19" l="a" r="y" v="-38" l="b" r="f" v="-17" l="b" r="s" v="-10" l="b" r="t" v="-9" l="b" r="v" v="-10" l="b" r="w" v="-10" l="b" r="x" v="-41" l="b" r="y" v="-10" l="b" r="z" v="-28" l="c" r="a" v="-17" l="c" r="o" v="-17" l="e" r="f" v="-18" l="e" r="t" v="-11" l="e" r="v" v="-10" l="e" r="w" v="-10" l="e" r="x" v="-31" l="e" r="y" v="-13" l="e" r="z" v="-20" l="f" r="a" v="-40" l="f" r="c" v="-45" l="f" r="d" v="-53" l="f" r="e" v="-51" l="f" r="f" v="-20" l="f" r="g" v="-60" l="f" r="o" v="-43" l="f" r="q" v="-53" l="f" r="s" v="-27" l="f" r="v" v="13" l="f" r="w" v="6" l="f" r="y" v="10" l="f" r="z" v="-20" l="g" r="a" v="-38" l="g" r="c" v="-12" l="g" r="d" v="-19" l="g" r="e" v="-17" l="g" r="g" v="19" l="g" r="o" v="-14" l="g" r="q" v="-19" l="g" r="t" v="-31" l="h" r="f" v="-12" l="h" r="t" v="-19" l="h" r="v" v="-34" l="h" r="w" v="-14" l="h" r="x" v="-19" l="h" r="y" v="-38" l="k" r="a" v="-35" l="k" r="c" v="-48" l="k" r="d" v="-56" l="k" r="e" v="-66" l="k" r="o" v="-69" l="k" r="q" v="-56" l="k" r="s" v="-19" l="k" r="t" v="-10" l="k" r="u" v="-26" l="m" r="f" v="-12" l="m" r="t" v="-19" l="m" r="v" v="-34" l="m" r="w" v="-14" l="m" r="x" v="-19" l="m" r="y" v="-38" l="n" r="f" v="-12" l="n" r="t" v="-19" l="n" r="v" v="-34" l="n" r="w" v="-14" l="n" r="x" v="-19" l="n" r="y" v="-38" l="o" r="v" v="-9" l="o" r="w" v="-8" l="o" r="x" v="-40" l="o" r="y" v="-11" l="o" r="z" v="-27" l="p" r="f" v="-17" l="p" r="s" v="-10" l="p" r="t" v="-9" l="p" r="v" v="-10" l="p" r="w" v="-10" l="p" r="x" v="-41" l="p" r="y" v="-10" l="p" r="z" v="-28" l="q" r="g" v="10" l="r" r="a" v="-42" l="r" r="c" v="-30" l="r" r="d" v="-28" l="r" r="e" v="-27" l="r" r="g" v="-28" l="r" r="o" v="-33" l="r" r="q" v="-28" l="r" r="s" v="-35" l="r" r="v" v="19" l="r" r="w" v="11" l="r" r="y" v="10" l="s" r="f" v="-19" l="s" r="t" v="-23" l="s" r="v" v="-31" l="s" r="w" v="-10" l="s" r="x" v="-22" l="s" r="y" v="-37" l="s" r="z" v="-18" l="t" r="a" v="-25" l="t" r="c" v="-25" l="t" r="d" v="-23" l="t" r="e" v="-22" l="t" r="o" v="-20" l="t" r="q" v="-23" l="t" r="t" v="-29" l="v" r="a" v="-30" l="v" r="c" v="-25" l="v" r="d" v="-20" l="v" r="e" v="-20" l="v" r="f" v="11" l="v" r="g" v="-28" l="v" r="o" v="-19" l="v" r="q" v="-20" l="v" r="s" v="-9" l="v" r="t" v="10" l="v" r="v" v="12" l="v" r="w" v="12" l="v" r="y" v="12" l="v" r="z" v="-26" l="w" r="a" v="-23" l="w" r="c" v="-20" l="w" r="d" v="-18" l="w" r="e" v="-18" l="w" r="f" v="6" l="w" r="g" v="-18" l="w" r="o" v="-19" l="w" r="q" v="-18" l="w" r="s" v="-18" l="w" r="t" v="4" l="w" r="v" v="12" l="w" r="w" v="8" l="w" r="y" v="12" l="w" r="z" v="-17" l="x" r="a" v="-37" l="x" r="c" v="-46" l="x" r="d" v="-44" l="x" r="e" v="-54" l="x" r="o" v="-55" l="x" r="q" v="-44" l="x" r="s" v="-12" l="x" r="t" v="6" l="x" r="u" v="-20" l="y" r="a" v="-31" l="y" r="c" v="-26" l="y" r="d" v="-24" l="y" r="e" v="-25" l="y" r="f" v="10" l="y" r="g" v="-26" l="y" r="o" v="-24" l="y" r="q" v="-24" l="y" r="s" v="-19" l="y" r="t" v="10" l="y" r="v" v="12" l="y" r="w" v="8" l="y" r="y" v="10" l="y" r="z" v="-17" l="z" r="a" v="-34" l="z" r="c" v="-45" l="z" r="d" v="-46" l="z" r="e" v="-46" l="z" r="f" v="-10" l="z" r="g" v="-17" l="z" r="o" v="-45" l="z" r="q" v="-46" l="z" r="s" v="-22" l="z" r="u" v="-10" l="z" r="v" v="-18" l="z" r="w" v="-22" l="z" r="y" v="-18"  ## Scoring This is , so the shortest answer (in bytes) wins. ### Meta I know this challenge is going to need a lot of work before it's ready for main. Please hold criticisms for now. Helpful ideas and thoughts are welcome. • I'm not sure that the problem is well defined. There's a reason it's called font hinting: the rendering application is free to take it into account or not, or even to apply more complex logic. E.g. some fonts have multiple sets of font hints for different contexts. There are other complex issues. A font can have Latin and Cyrillic letters and define hints for kerning between pairs of Latin and pairs of Cyrillic but not between Latin and Cyrillic; however, some letters may have identical glyphs, so a judgement on whether the kerning is "correct" might be ambiguous. Then there's antialiasing. – Peter Taylor May 24 '17 at 6:15 • @PeterTaylor Good notes. I will likely restrict the character set. I just wanted to start getting ideas down in the sandbox. – Poke May 24 '17 at 6:51 • Very ambiguous. – anna328p May 25 '17 at 17:48 • @Mendeleev It's not done yet. I'm aware it's ambiguous. – Poke May 26 '17 at 16:10 • Looking at developer.apple.com/fonts/TrueType-Reference-Manual/RM06/… I can see a number of issues to address. 16- vs 32-bit entries? Should multiple tables be combined or printed separately? All tables or only tables with certain coverage values? Which of the four defined formats need to be supported? Do you have a test case which covers glyph index differing from codepoint? – Peter Taylor Sep 16 '17 at 17:28 • @PeterTaylor I have a proof of concept that I wrote (it's the reason I have taken so long to update this) and I'm planning to address all of your questions. Thanks for doing a bit of research to help me out, though :] – Poke Sep 16 '17 at 18:57 • Downvoter, why? – Poke Oct 4 '17 at 21:03 Six Flags over HTTP Let's say you need to transmit six boolean flags in a URL string. Obviously you could do it with six ones or zeroes, but you want better compression. With a little math you can pack them into two characters using 0-7 octal. How about mapping all six to a single ASCII character? Here we have a problem: you are not allowed to use , / ? : @ & = +$ # or space. Now the range of printable ASCII no longer has 64 valid characters in a row.

In Javascript (or another language that can run from a web page, if any), what is the shortest code for a pair of functions to encode and decode this data, between an array of six booleans and a single character?

• -1 language restriction, most languages have HTTP libraries so I think any language should be allowed – ASCII-only Sep 24 '17 at 13:11
• This challenge could be improved by rephrasing it to: "Write a bijective function between an array of six booleans and a single printable character excluding the characters ,/?:@&=+$# ". Mentioning that the encoder and decoder should be separate programs/functions would be helpful. Also, may the encoder and decoder share code? – fireflame241 Sep 24 '17 at 22:08 # Count letter frequency Inspired by question Tweetable hash function challenge, you should take the English dictionary used there and produce a program or function that outputs the the absolute and relative frequency of each character. It is CASE SENSITIVE and the APOSTROPHE is also accountable as a real letter. Example of a valid output format (but with stupid guessing values): A 5566 20% ... Z 60 0.2% a 27000 30% ... z 120 0.01% ' 450 3.5%  It is , but no answer will be accepted. Wanna know shortest script for each language. • -1 (01) Don't rely on another challenge to define yours; include all the information we need in your write-up. (02) Make an effort to come up with some actual test cases - do you honestly expect us to verify our solutions against "stupid guessing values"? – Shaggy Sep 30 '17 at 0:55 # Is it a perfect loop? test-batterydecision-problem Your task is to take a GIF or an animated image in any reasonable format as input (including taking the file name of a GIF in the current directory), and output whether it is a "perfect loop" - that is, the frames transition seamlessly from the end to the start, and a human cannot notice where it starts and ends at first glance. Return or print a truthy value if it is a perfect loop, otherwise print or return a falsy value. ## Scoring Winners will be determined from the percentage of test cases they get correct. In the event of a tie, highest votes wins. You can view test cases at https://ghostbin.com/paste/m3yaw. Show your score against the test cases when you post. ## Input If you are not taking input in a GIF, please provide a program that will convert a GIF to your desired format. Images corresponding to a truthy value have been taken from /r/perfectloops and for falsy test cases, /r/almostperfectloops and /r/gifs. ## Restrictions • Hard coding is not allowed (violates standard loophole 1 and 2). • You must provide consistent results for the same GIF (no randomness) • Remember, this is not , so byte count is not needed in your solution. Just post the language name and add the percentage correct when I comment. • I'm not sure it's as simple as comparing the first to the last frame, if it is we'd have duplicate frames. is this challenge allowing HTTP requests? – tuskiomi Oct 17 '17 at 21:15 • If hashing the inputs is not allowed, then you should clearly define what constitutes a “perfect loop”. It's not good to extrapolate from a handful of test cases where the pass/fail cases are very similar. – japh Oct 18 '17 at 14:31 # Highest code size∕output ratio to generate a large executable section inside an elf file. Your challenge is to create the shortest code in your language of choice or the tools of your choice (like objcopy) that will create an elf file with a the executable section as large as possible. I mean that if I extract the.text section of the elf binary, the resulting extracted file should be at least 90% of the elf binary. # Requirements • The program should takes the desired section size as input. • The .text section name needs to corresponds to the executable section. • The type of the .text section should bePROGBITSand it should contains instructions. • The elf file should have a .shstrtab section. • The .text section should be readable and writable. • The target architecture should be Pnacl or armelv7 or x86_64. • The elf file should be valid and pass Google nacl’s validation whitelist in order to be loaded (but I don´t care if the sandbox segfault). If you have no idea about what Google native client is, just create a script that call the patched version of binutils from the nacl_sdk, or make sure the elf file is valid and can be executed on Linux. Of course, you normally can’t use a compiler because it would takes too much computational years in order to finish. # Winner The answer with the highest code size∕program output ratio. • Why not make scoring output size / code size? – anna328p Apr 4 '17 at 3:49 • Make it a code-challenge – anna328p Apr 4 '17 at 3:49 • This is essentially the same challenge as this one, and would be closed as a duplicate. Although it's not exactly the same, some answers to the previous question would require very little modification and answers to this question would also require very little modification to be answers to the other one. – Peter Taylor Apr 4 '17 at 8:37 • @Alt-F4 : it was a code challenge. – user2284570 Apr 4 '17 at 21:52 • @PeterTaylor : they were no answer to the previous question. In order to be closed as a duplicate the target needs to be already answered. You known it was closed an unclear, so please suggest change to make this answer clearer. – user2284570 Apr 4 '17 at 21:54 • Huh? It's open and has 15 answers. – Peter Taylor Apr 4 '17 at 22:09 • @PeterTaylor sorry, I thought to an another question that was closed as unclear and didn’t take time to read your link. In that case NO, the aim is to not use the compiler in order to actually build the file. This normally can’t be done with a compiler or an assembler. – user2284570 Apr 4 '17 at 22:16 • Can't it? Why not? – wizzwizz4 Dec 16 '17 at 19:55 • Wait... shortest code that generate any program? Or what? Don't think this is a good idea... – user202729 Jan 6 '18 at 12:10 # Removing a Letter adds a Letter Your program should output nothing when unaltered, however, when any single character is removed it should have an output length of 1. This extends to any number of characters being removed from the program, as long as there is, at minimum, a single character remaining. For example, if my program were abcdefg, it should output nothing if unaltered. However, if I were to remove a and d from this program to get bcefg, it should output any two printable characters that represent 16 bytes of information (2 characters for 2 characters removed). • So if bcefg outputs (00,AA,etc...) this is valid. Taking this further, if we were to remove all but the letter g we'd need an output of 6 characters. • So if g outputs ('000000','@$^%@(',etc...) this is valid.

Your program must function for all possible combinations of removals that are possible, that is to say each single letter in your program should be a valid program.

# Rules

• You may "lock" pieces of the code, each locked byte counts for 2-bytes instead of 1-byte.
• Locked bytes will never be removed.
• For instance, if my program was abcdefg and bcd is locked, the shortest program we'll get is abcd,bcde,bcdf and bcdg.
• If bcd was locked in abcdefg it'd be 10 bytes, not 7.
• The program may output any byte to represent 1 removed character, N-bytes for N removed chars in the code itself.
• The rule only leads to totally locked code – l4m2 Mar 13 '18 at 0:13
• @l4m2 hah. I disagree. – Magic Octopus Urn Mar 13 '18 at 0:58
• But more constructively, increase the penalty? Limit locked chars? – Magic Octopus Urn Mar 13 '18 at 1:04
• Maybe require an unlocked percent? – l4m2 Apr 6 '18 at 10:52

Sandbox:

Is this question already available (duplicate)?

Are things too vague?

Does providing the example help or hinder?

# Tidy the Pantry (easy)

I hate grocery shopping, particularly the part where I put groceries away--so I'm calling upon the collective hive-mind to handle that.

## Challenge

Your challenge is to take a 1D-list of groceries and a 2D pantry as input; and output an newly assorted pantry. The two variables can be of your type choice, and in any order, but please specify what item types your program requires (e.g. string, array, etc.).

## Rules & Additional info.

### Scoring

• This is code golf, so the shortest answer in bytes wins

### Rules

• The pantry should be ordered alphabetically (A - Z, left to right, top to bottom)
• For simplicity, the pantry is case-insensitive
• The pantry must retain its horizontal size (but trailing newlines are optional)
• "Pockets" (empty spaces) should be filled between items (i.e. only the last item is allowed to have a trailing pocket)
• If the pantry is too small for the incoming groceries, then the pantry must replace older items (Z being the oldest, A the youngest)
• Z from groceries is younger than A in pantry
• Standard loopholes are forbidden

## Examples ([ and ] are used for readability)

Input (4x4 pantry):

[A][A][ ][ ]
[ ][ ][B][ ]
[C][ ][ ][ ]
[ ][ ][ ][D]

AAD


Output:

[A][A][A][A]
[B][C][D][D]
[ ][ ][ ][ ]
[ ][ ][ ][ ]


Input (2x2 pantry):

[A][B]
[C][D]

XYZ


Output:

[A][X]
[Y][Z]


# JavaScript ES6 (989 bytes)

// (String, String) -> String
let organise = (pantry, groceries) => {
let n = pantry.split("\n").sort((a, b) => b.length - a.length); // used at the end of the function for horizontal sizing
n = n[0].length;

pantry = pantry
.replace(/\W/g, "") // get rid of all non-alphanumeric characters
.split("");         // turn the string into an array

// we need the properties of the new array
// so the extra pantry = pantry is needed
pantry = pantry
.slice(0, pantry.length - groceries.length) // go ahead and remove the last overlapping elements
.concat(groceries)                          // add the groceries to the pantry
.join("")                                   // turn into a string
.split("")                                  // turn into an array
.sort()                                     // sort the array
.join("");                                  // turn into a string

return pantry.replace(RegExp((.{${n}}), 'g'), "$1\n");
};

/** Testing below **/

console.log("Test #2:\n" + organise(
AJCHDJE
JJ   JA
ASD
OOQ I U
Q     W
R,

'AHJBCJHDHHATTGEH'
))

## Test Cases:

### Test #1, 4x4 pantry

TVCX <- pantry
ABCD
ATDJ
UAIK

XYXY <- groceries
----
AAAB <- expected output
CCDD
IJKT
XYXY


### Test #2, 7x6 pantry

AJCHDJE
JJ   JA
ASD
OOQ I U
Q     W
R

AHJBCJHDHHATTGEH
-------
AAAAABC
CDDDEGH
HHHHJJT
T


### Test #3, 10x10 pantry

AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA

ZZZZZZZZZZZZZZZZZZZZ
----------
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
AAAAAAAAAA
ZZZZZZZZZZ
ZZZZZZZZZZ


# Test #4, 16x16 pantry pantry

ASDFGHJKLZXCVBNM
QJKAJ  KAKSJD  J
KJASDKFHI YOIER
W   OSDOFJ    DK
E PPPASP     AS
R
TASD
YAAAAAAAAAAAA
U          JHOLK
IIAUSHODUYOAISUO
OASD  AUSODI
PIASND JUASJNOIJ
A ASJDH PPOIO
QHIAIUSOIUOOO
WYYAIUSNNAJSDASD
EAISDUUIOPJPIJPJ
ROQPEWIHRNXCAISD

QWERTYUIOP
----------------
AAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAA
ABCCDDDDDDDDDDDD
DDDEEEEEFFFGHHHH
HHHIIIIIIIIIIIII
IIIIIIJJJJJJJJJJ
JJJJJJKKKKKKKKLL
MNNNNNNOOOOOOOOO
OOOOOOOOOOPPPPPP
PPPPPPQQQQRRRRRS
SSSSSSSSSSSSSSSS
SSSTTUUUUUUUUUUU
UVWWY


# Test #5, 2x2 pantry

HE
LO

[no groceries]
--
HE
LO

• why divide the program score? – RedClover Feb 26 '18 at 19:03
• I recommend you do count by bytes otherwise someone is just going to encode their entire program in Chinese characters and win. – HyperNeutrino Feb 26 '18 at 19:09
• @labela--gotoa To get a golfed score (smaller programs get a smaller score), should I change it? – Ephellon Dantzler Feb 26 '18 at 19:13
• @EphellonDantzler I don't understand why not just normal scoring...? – RedClover Feb 26 '18 at 19:14
• LOL, that's why I set in in Sandbox first @labela--gotoa – Ephellon Dantzler Feb 26 '18 at 19:16
• Some notes on your reference implementation: 1 It appears far too soon in the challenge. 2 It's not 1768 bytes. 3 You need to ungolf it and make it readable or it's not much use. 4 As it's JS, create a Snippet for it. 5 Is it necessary? It seems to be thrown in there to try to patch over any holes in the challenge spec. – Shaggy Feb 26 '18 at 23:17

# Interpret pseudocode

Wikipedia says pseudocode

is intended for human reading rather than machine reading.

and

A program in pseudocode is not an executable program.

I don't care.

Make a pseudocode interpreter that can run pseudocode that fits the rules described below*. This is based on the IB pseudocode guide, but it is simplified quite a bit to make it fit for the challenge.

# Pseudocode specifications

This is a simplified pseudocode to make the challenge less tedious. The pseudocode language has no strings, no arrays, no classes, no methods, and no variables other than integers.

## Basic syntax

Comments that start at // and end at a newline (like java one-line comments). // is not necessarily followed by a space, and the comment may be empty. Example:

A = 2 + 3 // I can't write five because my keyboard is broken


Statements are separated by newlines. Lines may be empty (without statements). The exact number of spaces doesn't matter, and spaces are not required. The language is case sensitive.

## Variables

All variables are global, and can be accessed anywhere. They do not need to be declared. To keep things simple, all variables can be assumed to be integers. All variable names are UPPERCASE, and consist only of letters. Your program should at least handle integers from -256 to 256. A wider range is not a requirement.

Variables are assigned values using this syntax:

VARIABLE = Expression


Where VARIABLE can be any uppercase name and expression can be any integer expression, as discussed below.

Examples:

A = 5
B = A + 3
NUMBER = A * B


## Expressions

An expression can be:

• An integer, like 42
• A variable, like NUMBER
• A binary operation on two other expressions, like NUMBER + 5. There are only four operations: +, -, *, /. Division rounds integers down.

Expressions can be surrounded by parentheses to indicate that they need to be evaluated first. To keep things simple, all expressions are evaluated from left to right no matter what the operations are (unless there are parentheses that specify otherwise), so

A = 2 - RM * 9 + 3 / NUMBER
B = 1 + 2 * (3 - 4) / 6


is equivalent to

A = (((2 - RM) * 9) + 3) / NUMBER
B = ((1 + 2) * (3 - 4)) / 6


## Boolean expressions

Boolean expressions can compare two expressions using == (equality), != (not equal to), < (less than), and > (greater than). They are only used for control flow, as discussed below (there are no boolean variables).

## Control flow

There are four types of control flow. They can be infinitely nested in all combinations.

### If

if (booleanExpression) then
// statements (discussed below)
endif


### If-else

if (booleanExpression) then
// statements (discussed below)
else
// other statements
endif


### Loop while

loop while (booleanExpression)
// do stuff
endloop


Where booleanExpressions are boolean expressions. The ifs work the same as in normal programming languages. The while loop is a simple while loop.

The booleanExpressions will always be surrounded by (). The pseudocode is very flexible with spaces, and any number of spaces is valid.

### Loop for

loop VARIABLE from Expression1 to Expression2
// things to do over and over again
end loop


Where Expression1 and Expression2 are expressions that are evaluated before the loop begins and their values are stored until the loop finishes. The content of the loop is executed for every integer from the result of Expression1 to that of Expression1, inclusive. At every iteration, the index variable (VARIABLE in this case) is updated.

Example:

loop I from 3 to 5
output(I)
endloop


Outputs:

3
4
5


## Statements

### Output

output(Expression) outputs the evaluated expression. It's like println in programming languages. So:

output(1+1)


prints 2, followed by a newline.

output() with no arguments should print a newline.

### Other statements

If the interpreter encounters any other statement that looks like a method call with no arguments, it should pretend it's executing it. For example,

lightsoff()
gohome()


should print (together with a newline):

executing lightsoff
executing gohome


In other words, executing [Method name] should be printed. All statements will be lowercase and will consist entirely of letters.

Keywords cannot be statements. You do not have to deal with the following (it will not appear in the pseudocode): - if() - endif() - loop() - while() - etc.

However, statements that start with keywords are valid. For example, loophole() should print executing loophole, even though loop() itself is not valid.

# Challenge rules

• Your program should take a string as input. It can also take something equivalent, like an array of characters. But you can't take an array of strings; your program must itself separate the lines and tokens. You can also take a file as input.
• Your program should print the output of the pseudocode in any reasonable form.
• No standard loopholes.
• There are no restrictions on what your program should do when given invalid pseudocode.
• This is code golf. The shortest code in bytes wins.

# 1

A = 3
output(A) // prints 3
B = 4 + A * 2
output(B)
helloworld()
output(A + B + 1 * 3)


Should give:

3
14
executing helloworld
54


# 2

loop NUM from 2 to 20 // cycle through possible prime numbers
COUNT = 0
loop DIV from 2 to NUM // cycle through possible divisors
if(NUM/DIV*DIV == NUM) then // if the number is exactly divisible
COUNT = COUNT + 1
endif
endloop
if (COUNT == 2) then // if number is prime
output(NUM)
endif
endloop


Should give:

2
3
5
7
11
13
17
19


# 3

Tricky cases that your interpreter should handle:

// empty comment:
//
// empty line:

// more comment testing // ///
////

if     (3<4) then
endoftheworld() // a statement
ifff()
endifnot()
// endif in a comment doesn't count
endif
// loops can be empty:
loop I from 0 to 10
endloop
output(I) // variables are global
if(1<2)
if(3<4) // nesting is ok
ok()
endif
endif
// spacing doesn't matter:
output   (2+   8   - 1   )
loop             while(2<1)
neverhappened()
endloop


Should output:

executing endoftheworld
executing ifff
executing endifnot
10
excecuting ok
9


*Technically, once pseudocode follows rules as strict as those described here, it is arguably not pseudocode anymore. Wikipedia says it's called skeleton code.

Any suggestions?

I double-checked all the specifications, but if anything seems reasonably unclear, please let me know.

• Actually that's because the challenge is uninteresting. – Xwtek May 3 '18 at 2:11
• @Akangka thanks for the feedback. How do you think it could be made more interesting? – Reinis Mazeiks May 3 '18 at 16:47
• Unfortunately, there is nothing to improve. You have to find other challenge. Also, it is not pseudo-code. – Xwtek May 4 '18 at 3:03
• @Ok, thanks. I'll try to think of something. Also, read the *note. :) – Reinis Mazeiks May 5 '18 at 19:39

# Common Logic Gates

Given positive integer n, make a common n-to-1 gate with fewest input, i.e. make a function f: {0,1}k ↦ {0,1} with smallest k that, for each function g: {0,1}n ↦ {0,1}, there exists {ak}, such that each element ai in the sequence map to one of 0, 1, x1, x2, x3, ..., xn, satisfying that, for each {xn}, g(x1, x2, x3, ..., xn) = f(a1, a2, a3, ..., an).

Samples:

To make a common 1-to-1 gate, your circuit must take at least 2 input:

f(A,B) = A XOR B


For a buffer gate (g = x1 ↦ x1), let A=0 and B=Input (a1 = 0, a2 = x1); for a not gate (g = x1 ↦ ¬x1) , let A=1 and B=Input (a1 = 1, a2 = x1).

Alternatively, you can use f(A,B) = A AND NOT B. For a buffer gate, let B=0 and A=Input; for a not gate, let A=1 and B=Input.

To make a common 2-to-1 gate, the circuit must take at least 4 input bits: (The two inputs are represented as a and b)

f(A,B,C,D) = ((A AND B) OR (C AND NOT B)) XOR D

(ab)
00 01 10 11 A B C D
0  0  0  1  a b 0 0
0  0  1  0  0 b a 0
0  1  1  0  a a a b
0  1  1  1  1 b a 0
1  0  0  0  1 b a 1
1  0  0  1  0 a 1 b
1  1  0  1  0 b a 1
1  1  1  0  a b 0 1


Output can be an boolean expression with reasonable logic gates, or just the output corresponding to all possible input of the n-to-1 function f (the truth table of f). If there are more than one possible functions, you can output any of them.

Shortest code in bytes win.

Code that matches the requirement:

function solve(n) { // n positive int
var res = [], tmp=[], inmap=[], need=[];
for (var i=1; ; i++) {
for (var _res=0; _res<2**(2**i); _res++) {
var valid = 1;
for (var j=0; j<2**i; j++)
tmp[j] = Math.floor(_res/2**j)%2;
for (var _need=0; _need<2**(2**n); _need++) {
for (var j=0; j<2**n; j++)
need[j] = Math.floor(_need/2**j)%2;
var valid2 = 0;
for (var _inmap=0; _inmap<(n+2)**i; _inmap++) {
var valid3 = 1;
for (var j=0; j<i; j++)
inmap[j] = Math.floor(_inmap/(n+2)**j)%(n+2) - 1;
for (var j=0; j<2**n; j++) {
var bits = 0;
for (var k=0; k<i; k++) {
if (inmap[k]==-1 || (inmap[k] && (j>>(inmap[k]-1))%2))
bits |= 1 << k;
}
if (tmp[bits] != need[j])
valid3 = 0;
}
valid2 |= valid3;
}
if (!valid2) valid = 0;
}
if (valid)
res.push (tmp.slice());
}
if (res.length)
return res[AnyNonNegativeIntegerLessThan(res.length)];
// binary index input
}
}

function AnyNonNegativeIntegerLessThan(x) { if(R>=x) throw ("end"); return R;}
for (R=0; ; R++) { console.log (solve(1)); }

• You don't define what an n-to-1 gate is anywhere in your question. – Wheat Wizard Mar 27 '18 at 1:00
• @user202729 @user56656 n-to-1 gate means a gate with n input and 1 output. common n-to-1 logic gate mean a logic gate that can be used to replace any n-to-1 gate with some proper wiring. You can treat a logic gate as a ROM(so you can decide for each input what the output is) – l4m2 Mar 27 '18 at 1:15
• Output gates or ROM – l4m2 Mar 27 '18 at 1:25
• You should put the definitions in the challenge. "that can be used to replace any n-to-1 gate with some proper wiring" is still not very clear, you should define more carefully what you mean by proper wiring. – Wheat Wizard Mar 27 '18 at 3:22
• I assume you mean functions g: {0,1}^n -> {0,1}, right? Why do you specify x_0 and x_-1? Shouldn't x just be a vector with indices 1,2,3,...,n? – flawr Mar 27 '18 at 14:07
• Is {a_k} just a subset of {1,2,3,...,n}? Or can we have a_1=a_2=a_3=1 for example? – flawr Mar 27 '18 at 14:09
• {a_k} seems not a multiset. It should be an array or say a sequence of numbers – l4m2 Mar 27 '18 at 14:43
• So you're asking for something which outputs answers to codegolf.stackexchange.com/q/24983/194 ? – Peter Taylor Mar 28 '18 at 11:33
• @PeterTaylor No. it requires to use NAND gate to make up one circult that do the thing. Also 24983 is a 1-of-4 (74LS153), not a 4-to-1 gate common 2-to-1 – l4m2 Mar 28 '18 at 12:41
• (+) Any reason for downvoting? Downvoting in the sandbox indicates that the challenge is incomplete, if you don't leave a comment the OP can't know what is wrong. – user202729 Mar 29 '18 at 4:48
• @user202729, there are already comments indicating that this question is going to attract close votes as unclear if it's posted to main in the current state. – Peter Taylor Mar 29 '18 at 10:59
• @user56656 Are the issues fixed now? – user202729 Mar 31 '18 at 15:16
• @flawr Are the issues fixed now? – user202729 Mar 31 '18 at 15:16
• No I still think the explanation is quite bad and the notation is not very clear – flawr Mar 31 '18 at 16:15
• A reference implementation is no substitute for a clear specification. The first paragraph is where you need to focus your efforts. – Peter Taylor Mar 31 '18 at 19:32

# Is the program 32 or 64 bits?

Assignment is simple to explain: write the shortest code you need to determine whether an executable binary program supplied as parameter is 32 or 64 bits.

If there is a different kind of bitness, you can also do for it, but is not mandatory.

What I really don't want is telling me you support other bitnesses and after I get 32 or 64 as a result.

Valid outputs for 32:

32
32bit
32bits
32 bit
32 bits


The same pattern for 64.

No accepted answer.

• I think you're missing a word somewhere in the region of "determine supplied" – Kamil Drakari Apr 4 '18 at 19:43
• @KamilDrakari thanks. – sergiol Apr 4 '18 at 19:53
• Executable on Windows or Linux machine? What if (... maybe ...) the program is a valid executable for both "bitness" but do different things? – user202729 Apr 5 '18 at 1:30
• Of the output formats you allow, I think the first one will result in the shortest code in every single language. Because of this, you might as well just specify that the output should be the number 32 or the number 64. – Nathaniel Apr 5 '18 at 8:03
• This made me wonder what to do about shell scripts, which are executable programs, but require another file to interpret them and as such aren't 32-bit or 64-bit per se. Maybe it would be best to specify "executable binary file" to not have to deal with that mess. – Angs Apr 5 '18 at 11:22
• @Angs: Thanks. Changed. – sergiol Apr 5 '18 at 11:27
• @user202729: I don't care. Windows, Linux, Mac, whatever, ... – sergiol Apr 5 '18 at 11:28
• @Nathaniel: It is intentional. If you have a language feature called bitness(program) returning 32bits you do not need to waste more bytes removing the bits part! – sergiol Apr 5 '18 at 11:30
• The word "challenge" is not really true, at least for ELF. It's absolutely trivial. – Peter Taylor Apr 6 '18 at 20:20
• @PeterTaylor : Changed, thanks. – sergiol Apr 6 '18 at 21:20
• The real "challenge" is to know the executable file format, so this becomes more of a puzzle than a challenge. And for puzzles, people can just copy others' solution and port to other languages. // Consider having some popular file format in the challenge itself so people don't have to look up them? – user202729 Apr 7 '18 at 11:19
• @user202729: My initial idea was to ask only for Windows .exe files but I changed my mind because it was too limiting. Without such restrictions the question becomes multi-platform. – sergiol Apr 7 '18 at 11:38

## The challenge

• Write a Discord bot with a single command, !oldest, that gives the oldest user in the server that the command that was run in.

• Gracefully failing in DM channels is not required.

• Assume the bot's token is this invalid token: MjM4NDk0NzU2NTIxMzc3Nzky.CunGFQ.wUILz7z6HoJzVeq6pyHPmVgQgV4.
If the token is compressed in the program, provide instructions on how to change it so I can test it.

## Sample discord.py implementation

import discord
client = discord.Client()
@client.event
async def on_message(M):
if(M.content=="!oldest"):
N=sorted([x.id for x in M.server.members])[1]
await client.send_message(M.channel, str(M.server.get_member(N)))
client.run("MjM4NDk0NzU2NTIxMzc3Nzky.CunGFQ.wUILz7z6HoJzVeq6pyHPmVgQgV4")

1. Get a list of every user in the server
2. Sort their snowflake IDs
3. Print the username and discriminator of the member with the smallest ID.

No API for your language? Have fun.

Standard loopholes forbidden, etc, etc.

Shortest code in bytes wins.

# Sandbox

I originally posted this question on the main site, but I deleted it, as it turns out I'm bad at writing these. Please forgive me.

• I'm sure I've seen this already, but with comments saying that it needed a lot more information to be self-contained. It still needs a lot more information to be self-contained. – Peter Taylor May 5 '18 at 11:11
• Yep. I've edited the question to clarify. – SIGSTACKFAULT May 5 '18 at 12:35
• Are you talking about discord servers? Other than form the example this is not clear at all. What is a DM channel? What is a token in this context? – flawr May 5 '18 at 13:02
• A: Clarify that you're talking about Discord B: When you make a challenge that requires a library does that mean I can use a library that conveniently has the command you're asking of? – IQuick 143 May 6 '18 at 2:12

# Divide two strings

One day, I saw the challenge to multiply two strings and I thought I might be able to do one better.

That challenge was fake. It was elementwise maximum. It was not real multiplication. So I set out to make something real. Real division between two strings.

I quickly realized that this would make an amazing challenge, as the algorithm was surprisingly complex and interesting to implement.

I then realized that it was actually easily reduced into a mere few operations. I'm still doing the challenge, though.

Enough with the backstory. Let's go.

## Method

To divide two strings, do the following, where x is the first string and y the second:

• If x does not contain y, return a space and a period concatenated to x.
• For example, testx and blah would become .textx, with a space at the beginning.
• Otherwise, return every occurrence of y in x, a period, then y divided by x with every occurrence of y removed, with all the periods removed.
• For example, eestestst and est would become estest.est.

## Challenge

Write a program or function that, given two strings via standard input, returns the first string divided by the second.

You may assume that neither input string contains a space, newline or period, and that the operation does not require more than 10 layers of recursion.

## Test cases

test, es => es. es
test, blah =>  .test
okayye, y => yy. y
testes, es => eses. es
battat, at => atat. at
see, es =>  .see
see, e => ee. e
same, same => same.
aabb, ab => ab.ab
eestestst, est => estest.est
aheahahe, aheah => aheah.aheah ah


## Scoring

As this is , the submission with the least amount of bytes wins.

# Sandbox questions

• Is this a duplicate?
• Have I missed anything?
• Does anything need further explaining?
• Is there an issue with the concept of the challenge?
• What for aabb / ab? – l4m2 Jun 1 '18 at 12:42
• okayye, y => yy. okay typo? – l4m2 Jun 1 '18 at 12:42
• The test case battat, at => atat. by seems like it should be battat, at => atat. bt instead. – Kamil Drakari Jun 1 '18 at 13:47
• It seems odd to me that when no characters are matched the output format is {matched characters (empty)}<space>.{unmatched characters} while the format when there are matches becomes {matched characters}.<space>{unmatched characters}. I would much rather see consistent ordering of the . and <space> – Kamil Drakari Jun 1 '18 at 13:50
• @KamilDrakari 2 / 4 is 0.5, not .05, when 4 is not contained within 2 at all. Thus it makes no sense for test / blah to be . test when blah is not contained within test. We treat a space essentially like a zero would be with normal numbers. – LyricLy Jun 1 '18 at 22:15
• @LyricLy 6/4 is 1.5 not 1.05. If you're treating space as 0 then there shouldn't be any space after the dot in any of the test cases. – Kamil Drakari Jun 1 '18 at 22:58
• @KamilDrakari Actually, you're right. I was entirely mistaken because you get a fraction from 1 / remainder, not original number / remainder. Meaning this entire thing is wrong and I need to figure out a good replacement for 1 in string form. – LyricLy Jun 2 '18 at 3:32
• Fixed the issues. – LyricLy Jun 2 '18 at 3:50
• I accept downvotes, but I'd appreciate suggestions on how to improve the idea, or at least an explanation of what's wrong with it, so I know why I shouldn't post it. – LyricLy Jun 2 '18 at 8:18

# Introduction

I recently came across an oral exam where the candidates were asked to find a logical circuit than can negate 3 inputs A,B,C using only two NOT gates.

The question also specified that such a circuit is unique up to removal of useless gates and reordering inputs/outputs. The candidates were asked to prove this assertion by writing a piece of code that generates all such circuits.

# Challenge

No inputs whatsoever are given.

The program must output all logical circuits using unlimited AND and OR gates but only two NOT gates which take in three inputs which map to three outputs. The outputs should be the negation of each input.

The outputted circuits should not have any redundant/trivial gates (gates that always output the same thing) or unused gates (whose output doesn't influence the outcome).

The program should use as little precalculated data as possible.

Output format is left up to the coders.

The winner will be determined by overall simplicity -- low run time and code elegance. It is not an objective criterion.

# Example Input and Output

Input:

N/A

Output:

R    = (A & B) | (A & C) | (B & C)
notR = !R
S    = (notR & (A | B | C)) | (A & B & C)
notS = !S

notA = (notR & notS) | (notR & S & (B | C)) | (R & notS & (B & C))
notB = (notR & notS) | (notR & S & (A | C)) | (R & notS & (A & C))
notC = (notR & notS) | (notR & S & (A | B)) | (R & notS & (A & B))

• Example output and proof of existence are provided here – John Do Jun 17 '18 at 9:22
• "It is not an objective criterion." Then it is not an on-topic question. – Peter Taylor Jun 19 '18 at 8:49

# Two functions with same input/output, with largest difference in bytes.

This challenge is a terrible idea. Don't try submitting it or anything similar!

Provide two functions with the largest difference in bytes. (These two functions will be referred to in bold italics to distinguish them from built-in functions available in your language in the rules below.)

Rules:

1. Both functions must take an input and must produce an output. The input to and output from both functions must be identical.

2. Both functions must be explicitly named. The function names must have the same byte count.

3. You may not define any other functions.

4. If you use a built-in function your language provides, it must be used with the same number of parameters in each of the functions.

5. You may use string/numeric literals or any built-in constants, but you must use exactly the same ones in both functions.

6. You can define variables, must you must use the same variable names in both functions.

7. You can use comments, no-ops, and the equivalent, but they must be the same in both functions.

8. Both functions must contain the same amount of whitespace (or equivalently, don't count whitespace at all.)

9. You can import libraries/packages and the equivalent, as long as you import the same ones for both functions.

10. You can use pre-processor directives as long as they are the same for both functions.

If any of these rules mean your language cannot compete, so be it.

Not really sure how to tag this. A little bit of and .

• I don't think this is a good idea. {Main downvote} – user202729 Jul 12 '18 at 16:26
• Give up. E.g. in APL, ⊢ and ⊢⊢⊢⊢⊢⊢⊢⊢⊢ do the same. – Adám Jul 12 '18 at 16:26
• @Adám, with those rules, it'd be something like f←⊢ and g←⊢(⊢(⊢(⊢(...)))) due to rules #2 and #3. The same thing still applies to OP: give up! – Zacharý Jul 12 '18 at 16:36
• Thank you. I am happy to give up! – ngm Jul 12 '18 at 16:56
• @Zacharý I intended them to be dyadic, but whatever… – Adám Jul 12 '18 at 17:18
• "Both functions must take an input", which I assume would restrict the functions to monadic. – Zacharý Jul 12 '18 at 17:39

Quiet QR

Your mission, should you choose to accept it is to infiltrate the top secret HQ of the Big Bad Evil Guy (TM) and extract information on their latest evil scheme saved in the file Plan.txt.

The target PC is isolated from any and all network connections, and you can't physically connect anything to it. The server room is equipped with sound sensors that will detect key presses.

Your tools are restricted to a mobile phone equipped with a QR code reader. Your recommended course of action is to write a code on the target machine that will display the file content as QR code.

You are to complete the mission with the least number of keystrokes as to minimise the sound generated by the mechanical keyboard.
It is advisable not to use languages that require unicode characters as entering one character will require multiple key presses (Eg:þ = Alt+0254) is considered 5 keystrokes.

You are to assume that the machine will have its terminal open and ready for input at the root directory of the system (C:\> or /).

All programming languages can be accessed directly from root folder. The target file is on the root folder.

Javascript is available as command line executable named js usable as (js filename) and prints output.

Image viewer is called view and usable as (view imagefile) [Extension is not needed]

Possible ways of output:

1. An image containing the QR code

2. ASCII art depicting the QR code using characters like █ ▄▀

3. Or any form readable by any standard-issue QR code reader

4. Other formats of 2D barcodes are accepted on the condition of being readable by a standard reader.

Example Solution for batch file:

copy con a.bat
open file Plan.txt
echo █ ▄▀
^Z
a


=59 keystrokes.

The symbols are 4 keystrokes each:

• ▀ Alt+991

• █ Alt+987

• ▄ Alt+988

^Z as Ctrl+z and is considered 2 ketstrokes (F6 is considered one).
New lines and spaces are one keystroke each.
Capital letters are 2 strokes (Shift+c).
CAPITAL words are one keystroke added to the length of the word (Shift+capital).
No need to clean the screen at the end because the evidence will be erased by a Micro-EMP device that will disable the machine.

• Why not just have a question to turn text into a QR code? The keystroke golfing just seems to complicate things – Jo King Jul 18 '18 at 11:54
• @JoKing The premise of the challenge is to extract information from a pc with the least keystrokes. – workoverflow Jul 22 '18 at 9:06
• In that case, what operating system is the PC? What type of QR code do you want (alphanumeric or byte?)? Can you add a link or explain an algorithm to generate you type of QR code (questions should be self-contained)? How big can the input be (100 bytes? 1kb?), and what characters can it contain? – Jo King Jul 22 '18 at 9:15
• You may assume that the PC have an open terminal window ready for input in whatever OS you'd want (Bash, PowerShell, Command prompt,.....) The QR code must be able to encode alphanumeric+punctuation text in the file Plan.txt – workoverflow Jul 24 '18 at 10:29

# Projective related points

Points A, B, C, D and A′, B′, C′, D′ are related by a projective transformation if their cross ratios are equal.

Given A, B, C, D four ordered points on a line, their cross ratio is defined as:

$\displaystyle\frac{distance(A,C)\times distance(B,D)}{distance(A,D)\times distance(B,C)}$,

where $distance(A,C)$ is the Euclidean distance between points A and C.

## Challenge

Given a set of eight points, say if yes or no the set can be splited into two subgroups (each subgroup with four points) where the two subgroups are related by a projective transformation.

## Input

A set of 8 points, each point defined by its Cartesian coordinates (integer coordinates).

## Output

Either a specific true output (true, 1, yes, ...) or a specific false output (false, 0, no, ...).

## Example

{(10,100),(25,100),(2,63),(2,33),(31,100),(2,13),(2,3),(17,100)} --> true
with subgroups:
{(10,100),(25,100),(31,100),(17,100)}
and
{(2,63),(2,33),(2,13),(2,3)}

{(45,54),(8,23),(8,8),(8,29),(27,30),(15,14),(9,6),(8,15)} --> true
with subgroups:
{(8,23),(8,8),(8,29),(8,15)}
and
{(45,54),(27,30),(15,14),(9,6)}


## Hint (no need to use division or square root)

In order to avoid floating points, you can use the fact that points A, B, C, D and A′, B′, C′, D′ are related by a projective transformation implies:

$distance^2(A,C)\times distance^2(B,D)\times distance^2(A',D')\times distance^2(B',C')$

equals

$distance^2(A',C')\times distance^2(B',D')\times distance^2(A,D)\times distance^2(B,C)$

## Rules

• The input and output can be given in any convenient format.
• No need to output the two subgroups.
• No need to handle the case when at least two points in the set are the same.
• No need to check the fact that the four points in each subgroup are aligned.
• In your submission, please state the true and the false values.
• Either a full program or a function are acceptable. If a function, you can return the output rather than printing it.
• If possible, please include a link to an on-line testing environment so other people can try out your code!
• Standard loopholes are forbidden.
• This is so all usual golfing rules apply, and the shortest code (in bytes) wins.
• As with most problems involving floating point comparisons, I think you should include a large-ish number of test cases and require that submissions pass all of those cases. That way people can be sure their submissions are sufficiently accurate. – FryAmTheEggman Jul 13 '18 at 20:40
• @FryAmTheEggman In fact there is a way to work only with integers, I'll add a hint. – mdahmoune Jul 16 '18 at 10:53
• I had totally missed that the input would always be integers. Cary on, but I still recommend including at least several test cases to make users more able to be sure their submission works without having to find edge cases on their own. – FryAmTheEggman Jul 16 '18 at 14:35
• @FryAmTheEggman Ok I'll add more examples. – mdahmoune Jul 16 '18 at 15:55
• Is the cross ratio $\overline{AC}\times\frac{\overline{BD}}{\overline{AD}}\times\overline{BC}$ or $\frac{\overline{AC}\times\overline{BD}}{\overline{AD}\times\overline{BC}}$? – wastl Jul 18 '18 at 11:31
• @wastl it's the second one, thanks for the remark, I just updated the formula. – mdahmoune Jul 18 '18 at 11:39

A function to traverse an array and re-generate the same array

We take an array, then write a function that will traverse the array and generate the array in a format given in the example below.

For example, given the array:

Array

(

[0] => Array
( [name] => Tom
[age] => 32
[key] => Array
( [0] => abc
[1] => def
[2] => efg
)
)
[1] => Array
( [name] => Jim
[age] => 30
[key] => Array
( [0] => abc
[1] => def
[2] => efg
)
[address] => Array
( [0] => Array
( [state] => CA
[country] => US
)
[1] => Array
( [state] => NY
[country] => US
)
)
)
)


Output should be:

User: 0
name: Tom
age: 32
key:
0: abc
1: def
2: efg
User: 1
name: Jim
age: 30
key:
0: abc
1: def
2: efg
address:
0:
state: CA
country: US
1:
state: NY
country: US


Challenge rules:

• You can assume array can be multidimensional
• The array can also be array of cars, schools, districts etc.
• The preferred output is in json format
• Indentation for the output is a simple json format

code-golf

The function will be tested with any sort of multidimensional arrays for speed of execution

• Can you give a quick explanation of how you generated the array? For example, where does Name come from, and what are the rules behind indentation? – Jo King Aug 9 '18 at 6:17
• The array just contains User details which will include the Name, Age, Address etc. – Mochesane Aug 9 '18 at 6:45
• Hi! Welcome to PPCG. We usually require challenges to be a bit more precisely defined, to avoid ambiguity. For eg., you mention " generate the array in a format given in the example below", and the rules say "the preferred output is in json format" - but the format in the example is not JSON (and has some possible issues, for eg. address not being indented). Also, the post says "array" throughout, but what you're actually working with looks like a nested hashmap/dictionary structure. – sundar - Reinstate Monica Aug 12 '18 at 11:46
• Finally, you've mentioned code-golf, but also that the answers will be tested for speed of execution - do you intend code-golf (number of bytes) to be the primary winning criterion and the speed of execution the tie-breaker? Or do you mean all answers have to transform a particular large input within a certain time (say 1 minute) to be valid? In the latter case, it would be useful to specify what the large, multidimensional input will be, and what the maximum time of execution allowed is. – sundar - Reinstate Monica Aug 12 '18 at 11:46

# Pyramid of Bots

In this game, your bot is trying to get as high off the ground as possible. However, it can only stand on top of other bots, which are trying to get higher, too!

## Overview

Your bot should be a Javascript function. It's return value should tell the program if the bot should move left, move right, or jump. Every bot starts out on a 2 dimensional grid, with a width and height set by (botCount * 2) + 1. Bots are placed on either side of the center space, and every other bot is spaced 1 apart from any other bot. They all start at y=0, and far left is x=0.

## Gravity

If there is no bot on top of your bot, it can return the value jump. When a bot jumps, it moves 1 square up. If at any point in time there is nothing under the bot, it moves down 1. A bot cannot return jump if nothing is under it. If your bot is on top of another bot which moves left, your bot will fall.

## Function params

Your function has 3 parameters: dirs, height, and map. The array dirs contains four boolean values, representing if there is a bot or arena border: below, to left, to right, above. The parameter height is an array with 2 elements: your height, current winner's height. The map array contains the height/width of the array, and then the amount of turns left in the game.

## Running the game

In one game, the bot function will be run 800 times. Each of these is a turn. Your bot should return jump, or a direction. The bot can only move in a direction if there is no bot currently there. The two directions are left and right. Standard loopholes are not allowed (when are they ever allowed??), and the bot who wins the most out of 1000 games is the winner.

• I don't see the strategy in this. There's no way for a bot to reliably move up. No bot will stand still, so you literally have to guess whether or not an adjacent bot will move under you, and then hope that they move up while other adjacent bots move under. – Nathan Merrill Aug 27 '18 at 16:21

# My Ribosomes Got a Firmware Upgrade

So all of the Apple iBosomes in my body have been updated to RibOS 4.0 now… while I appreciate the additional optimizations that were added, unfortunately for me they've dropped support for the legacy mRNA API.

So since my RNA Polymerase library still needs to return strings in the format AUUCGGUCAAAGU for the code still using it, I'll need to add some code to the getBasePairs() method to translate it from the new API.

# Challenge

• Your input will be a string in base64 (because codons are exactly 6 bits) representing the genome.
• You should output a string with the equivalent RNA base pair sequence:
• 00 becomes A.
• 01 becomes G.
• 10 becomes C.
• 11 becomes U.
• All languages are allowed.
• Your I/O must be in these exact string formats, even if they're small enough to encode as integers.
• The shortest answer in bytes wins.
• Are you asking for a method that does a base64 to base4 conversion and pretty-prints the result? – Jonathan Frech Sep 18 '18 at 21:15
• @JonathanFrech Kinda, I guess. – Nissa Sep 18 '18 at 21:17
• So using lax I/O I can take the input as an integer and output four unique values like this? – Jonathan Frech Sep 18 '18 at 21:21
• @JonathanFrech wasn't what I had in mind; I'll edit the proposal once I finish the essay I'm working on right now. – Nissa Sep 18 '18 at 21:26