Sandbox for Proposed Challenges

Question

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

Sandbox FAQ

Posting

To post to the sandbox, scroll to the bottom of this page 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, though you can optionally add a title at the top. 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, and replace the post here with a link to the challenge and delete the sandbox post.

Discussion

The purpose of the sandbox is to give and receive feedback on posts. If you want to, feel free to give feedback to any posts you see here. Important things to comment about can include:

• Parts of the challenge you found unclear
• Comments addressing specific points mentioned in the proposal
• Problems that could make the challenge uninteresting or unfit for the site

You don't need any qualifications to review sandbox posts. The target audience of most of these challenges is code golfers like you, so anything you find unclear will probably be unclear to others.

If you think one of your posts requires more feedback, but it's been ignored, you can ask for feedback in The Nineteenth Byte. It's not only allowed, but highly recommended! Be patient and try not to nag people though, you might have to ask multiple times.

It is recommended to leave your posts in the sandbox for at least several days, and until it receives upvotes and any feedback has been addressed.

Other

Search the sandbox / Browse your pending proposals

The sandbox works best if you sort posts by active.

To add an inline tag to a proposal, use shortcut link syntax with a prefix: [tag:king-of-the-hill]. To search for posts with a certain tag, include the name in quotes: "king-of-the-hill".

Answer 1

Google search result short summary

string fastest-code search

Intro

When you search in google, it always shows you a result with a sample text from the found webpage.

For example if you search for "Madonna greatest vinyl", google will show you one line link, and below a short excerpt from that found webpage:

Madonna Greatest Hits Records, LPs, Vinyl and CDs
Madonna - Greatest Hits Volume 2, Madonna, Greatest Hits ... vinyl Is Fully Restored To As Near New Condition As Possible. Shipping & Multiple Order D..

Task

Imagine yourself you work for google and you have to write a program/function which takes in:

• a string containing many words (the webpage content)
• list of searched words (at least 3)

and returns the shortest excerpt of given string (webpage) containing all searched words.

Example

Given this webpage content:

This document describes Session Initiation Protocol (SIP), an application-layer
 control (signaling) protocol for creating, modifying, and terminating
 sessions with one or more participants. These sessions include 
 Internet telephone calls, multimedia distribution, and multimedia conferences.

and these searched words:

calls, sessions, internet

the program should return:

sessions include Internet telephone calls

, as this is the shortest substring containing all 3 searched words. Note that one more substring contains these 3 words, it is "sessions with one or more participants. These sessions include Internet telephone calls", but it is longer, so it was discarded.

Rules

• If the string is empty, return empty string
• If all searched words are not found in given string, return empty string
• Search is ignoring letters case
• At least 3 words need to be specified for searching
• The returned string may contain the searched words in different order than specified

Challenge

Write the fastest code. It's for google, right? Remember that repeatable strings comparison is very expensive.

Answer 2

It's 42!

This challenge is to code golf a program that proves that the next number in a pattern is 42 based on the website Actually it's 42.

In your program, the user inputs a pattern of numbers and it has to output the equation that proves that the next number is 42.

For example, the user inputs the pattern 1, 2, 3, 4, 5 the output is something like:

f(n)=9/2(n^2)−17(n)+29/2

Because f(6) = 42

Your program can output any form of an equation that makes the next value in the equation 42.

Your outputted equation must be able to also output the numbers in the original input also in the form of a variable. For example, in this equation, if you put 1 as the number input you get the number 1.

Your program cannot make any HTTP requests to APIs, in other words, all the calculations must be done in the program.

Good Luck!

Answer 3

The Mnemonic Major System

People frequently need to memorize long strings of digits, such as telephone numbers. Fortunately, the mnemonic major system, which uses sounds to represent digits, and words to represent strings of digits, can help.

• /s/ and /z/ represent the digit 0
• /t/, /d/, /θ/ and /ð/ all represent 1
• /n/ represents 2
• /m/ represents 3
• /r/ represents 4
• /l/ represents 5
• /tʃ/, /dʒ/, /ʃ/ and /ʒ/ all represent 6
• /k/ and /ɡ/ represent 7
• /f/ and /v/ represent 8
• and /p/ and /b/ represent the digit 9
• For the purpose of this challenge, the sound /ŋ/, generally written as ng, counts as 27.

All other sounds can be used to create words, but do not represent any digits. Thus, the words Code Golf represent the digits 71 758. Since the mnemonic major system is a phonetic system, silent letters do not represent any digits. Thus, the word knight represents the number 21, not 7271. The letter x is pronounced /ks/, and thus represents the digits 70. On the other hand, most double consonants are not actually pronounced separately (e.g. mummy, chicken), and represent only one digit.

Challenge

Your task is to write a program or function that takes a string of digits in any convenient format as input and returns a mnemonic representation of those digits as output. The following rules must be observed:

1. You must use real English words. Acronyms and abbreviations are not allowed. If in doubt, refer to an authoritative dictionary.

2. Whenever possible, two or more digits must be represented by a single word. If the number of digits is odd, you may choose which digit, if any, stands alone (see examples). All two-digit numbers can be represented by English words.

You may use a built-in or external dictionary to search for suitable words.

This is code golf, so the shortest solution wins.

Example Input and Output

758
golf, kale fee, key leaf

0142710
strengths, suitor nugget saw, seat run key tease

2362185
unimaginatively, gnome gin devil, enmesh native lie

Answer 4

Print the Previous Program

answer-chainingcode-challenge

Specifications:

You must print the exact text of the previous answer without ever having a sequence of more than 5 letters in a row in your program that also show up in the previous answer (prevents hardcoding). Your program must only use UTF-8 characters.

You may repeat a language; however, you may not post twice in a row and no two of your consecutive answers may be from the same language class (different versions are treated as the same language).

The first language is to print the exact text "Hello, World!"

0-byte submissions are not allowed.

By the way, this is just a draft, it might be a dupe or really closely related, and probably has more holes in it than Swiss cheese so please give me any suggestions you have. Thanks.

Also, my drafted scoring system is something like bytes / answer_num where answer_num is which answer yours is (on a time scale).

Answer 5

Display Haftseen table items - in Persian/Arabic characters

Theme : Jalali New Year 1397

Main Goal : Displaying non-ASCII characters correctly

Introduction

A typical Haftseen table consists 7 items which their names start with س (pronounced like S) and some additional items. It is set few days before the new year's day and it's kept till end of new year's holiday.

Challenge

Your program/function should display exactly 7 items from the list below :

سبزه
سرکه
سکه
سیب
سنبل
سمنو
سماق
سیر
سنجد

with right alignment, right to left typing, in an Arabic-compatible font, with each word displayed correctly, and a non-alphabetical character (,.- =+~?,newline etc) between each 2 words. The list must be displayed in a window, in terminal or similar.

Answer 6

Code - Decode

Cops:

Your task is to write a program or functon wich otuputs encrypted alphabetic input. The same program or function has to be used to encrypt and decrypt messages as the case of ROT13

You have to post in your answer:

1. Languaje and length of your program
2. The encrypted output of the input "CODE GOLF"
3. Two more examples of crypted - unencrypted strings

Example:

Bash, 30 chars

1. "CODE GOLF" <=> "PBQR TBYS"
2. "SHA" <=> "FUN"
3. "Why did the chicken cross the road? Gb trg gb gur bgure fvqr!" <=> "Jul qvq gur puvpxra pebff gur ebnq? To get to the other side!"

You may post your program code an decpription of your crypting algorithm once is considered safe. Shortest uncracked answer wins.

Example:

tr '[A-Za-z]' '[N-ZA-Mn-za-m]'

This bash command crypts and decrypts messages shifting each letter 13 positions in the alphabet.

Robbers:

Your task is to write a program or function wich otuputs encrypted alphabetic input. The same program or function has to be used to encrypt and decrypt messages as the case of ROT13

Your code has to pass test cases posted on one of the COPS post. The user who cracks most wins.

Extra bonus if your code cracks more than one answer.

cops-and-robberscryptographyencryption

Answer 7

Shortest “Hello World” for common journaled file systems.

Create a valid file system image as small as possible containing a file or a folder labeled “Hello World” with the following constraint:

• If the hello world is a regular file, it needs to not be empty.
• The file system needs to one of the following: ntfs3.1 ext3/ext4 zfs btrfs hfsplus

Please note you won’t be able to create the smallest file system with normal fomatting tool.
I mean they don’t allows to create the smallest theoriticall size.

Winner

The answer with the smallest file system

Answer 8

Real Programmers Don't Comment Their Code code-golf

(Disclaimer: I do think programmers should comment their code.)
Your task is to write code in one language that removes comments from code in another language. Both single-line and multi-line comments should be removed from your program. You may write code in one language to remove comments from the same language. Input and output may be in any format. Finally, before answering, read the rules, please.

---

Rules

1. Your program in language X must take a program in language Y as input and output the code with all comments removed. Language X may be the same as Language Y.
2. You may not use language Y if:
   • Language Y has no comments whatsoever.
   • Language Y does not have 2 or more types of comment.
3. Language Y should preferably have unusual comment behavior. (Ex.: older programming languages or Haskell)
4. You may not ignore line continuations (usually \ at the end of the line).
5. Your code may not remove anything inside a string literal.
6. Standard loopholes are disallowed.
7. I strongly encourage you, ironically, to provide an explanation if it is unclear how your code works.

---

This is code-golf, so may the best programmer with the shortest code win...

Answer 9

You've been Thunderstruck!

Background

A "fun" drinking game is based on the classical hard rock song by AC/CD: Thunderstruck. The Thunderstruck drinking game starts when the song starts. When the word "thunder" is heard, the first person starts drinking, not stopping until the word "thunder" is said again. At that point, the next person begins to drink. This continues around the circle until the song ends.

The "twist" is that in the middle of the song, there is an entire verse where thunder is not uttered once. The person who gets this part -- and thus has to drink for the longest period of time -- is said to have been thunderstruck.

Challenge

Input: An Integer number of players.

Output: Which player got thunderstruck

Example

Input:  1
Output: 1

Input:  2
Output: 1

Input:  3
Output: 3

Rules

Here are the rules:

• Assume that the number of players always is a positive integer.
• Output should always give a positive integer.
• You are not allowed to hardcode the number of times before the "solo" / long verse. Meaning your code has to find the longest part without the word thunderstruck, on its own.
• Use the following lyrics for thunderstruck
• Shortest code wins.

Answer 10

Description

Find the number of '1's in a binary number of any length. (Variable name up to you)

Output

You should output or print an integer/number/string which reflects the number of '1's that were counted.

Example

10101100 should return 4

Sandbox

I'm new here, so I don't know if this has been asked before. I searched but I could only find one other similar question, however that required the answer to be in binary, and was somewhat different in terms of the inputs.

My question seems very short and lacking details, but I don't know how to expand further on such a simple challenge.

Any other ways I could improve on my first post in this Stack Exchange?

Answer 11

Add numbers without math functions.

In this challenge, you must take an input that can take at least 10 numbers separated by commas and add them together without addition, subtraction, multiplication, and division symbols. Least bytes win. Normal code golf rules apply.

Examples:

Input:

1,2,3,4,5,6,7,8,9,10

Output:

55

Input:

1,1

Output:

2

Answer 12

Prove the Undecideability of the Halting Problem

code-challenge halting-problem

More information on the halting problem.

Either:

Create a program that, when given an input, no single program (which receives your source and your input) can determine if your program terminates, or

Create a function that, when given an input, no single program (which receives your source and your input) can determine if your function returns.

Your score is the byte count of your program plus the byte count of your input (or of the shortest input in the set of input that solves this problem).

Lowest score wins.

//I would love some input on my wording.

Answer 13

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.

Answer 14

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?

Answer 15

Draw an XBox

Here's an X:

\  /
 \/
 /\
/  \

And here's a Box:

+----+
|    |
|    |
|    |
|    |
+----+

So, for an XBox, just draw an X in a Box:

+----+
|\  /|
| \/ |
| /\ |
|/  \|
+----+

Your input will be a number (in any standard way) that will represent the size of the box. To output the above box, this could be the number of -/|\s (4), or the number of lines/columns (6), or even the intercept of the second diagonal (5) would be acceptable. (Don't ask me to accept the base256 encoding of the output though, as that's one of the many banned standard loopholes.)

Your program or function should then output (in any standard way) the XBox of the given size. If the \/s cross in the same character, place an X (as per Draw a big slash X). For example, here's an XBox three sizes larger than the one above:

+-------+
|\     /|
| \   / |
|  \ /  |
|   X   |
|  / \  |
| /   \ |
|/     \|
+-------+

This is ascii-art code-golf, so the shortest program wins!

Answer 16

Print a Variable's Memory Address suggestions-needed

Similar to this puzzle I posted earlier, with a difference that should make this challenge easier.

Create a function (not a full program) that prints or returns the memory address of the parameter passed in. Literal values should return a falsey value.

Examples:

var foo = 4901
var bar = "foobarbaz"
var baz = true

getMemoryAddress(from: foo) // 0x00000000004030f0
getMemoryAddress(from: bar) // 0x00000000004030f8
getMemoryAddress(from: baz) // 0x0000000000403110
getMemoryAddress(from: "Bad Value") // false

Note that you probably won't get the same exact result as show above.

Answer 17

Migrate questions to and from the Sandbox! popularity-contest stack-exchange-api

Challenge

Write user scripts that will migrate challenges to and from the Sandbox.

Criteria

These are my suggestions for criteria that will create the most beautiful user scripts. Feel free to suggest your own!

Migrating to the Sandbox

The script should...

• only act on a question that has been closed for "unclear what you're asking"
• answer the Sandbox as the original author of the question
• make the title and tags the first line of the answer as a H1-sized header
• link the original question to the Sandbox post, and then delete it

Migrating from the Sandbox

The script should...

• use the first line to determine the title and tags for the post, and eliminate it from the post body
  • error handling here would be a good idea
• create the question as the author of the Sandbox answer
• comment on the question with a link to the Sandbox answer
• replace the Sandbox answer with just the title and link to the question, then delete the Sandbox answer

Scoring

This is a popularity-contest, so the answer with the highest net of votes will win.

Sandbox

• Is what I'm asking for even possible? I've never written a user script before. Maybe it should be a stack-exchange-api question?
• Should this be a Community effort rather than a challenge? Does it even belong on main?

Answer 18

Grep for math in a pdf document

This challenge is likely to need the use of libraries. You may use any free library of your choice as well as any library.

The challenge is simply to write a tool that can grep for "2^n" in a pdf document. That is the math that represents 2 to the power n. You may assume that the pdf was produced from LaTeX which contains $2^n$ and that the pdfr was made using the command line tool pdflatex.

What should the code do?

The code should take a pdf file as input either by reading a file or from standard in. It should output if the file contains "2^n" or not.

Scoring

I will provide a number of pdf files as test examples. Your score will just be how many your code gets right.

Requests for help

I could provide sample pdf documents that do or do not contain 2^n in them.

Does it always appear as an image in the pdf as Mego suggests? If so, this image will depend on the font and font size and this is an image processing task.

Answer 19

Is it cat-urday?

Caturday is one of the oldest memes out there. For this challenge you need to write a program that outputs the input, but only on Saturday.

The catch:

You can acquire the date via UNIX timestamp, or as a formatted date string (local or UTC). However, you can not:

• use day of the week information in a date string
• directly acquire the day of the week of a date by some other means
• use Date or Calendar functions, beyond one to simply give you the current date
• use any external resources (files, Internet)

Don't forget leap years!

code-golf

---

Does this question work as is? Should I make anything clearer?

Answer 20

Output the infinite sequence of middle positions of odd square numbers code-golf

As everyone knows, every odd square number has an element at its central position — I represent those central elements as an *:

n=1 => 1
*

n=9 => 5
###
#*#
###

n=25 => 13
#####
#####
##*##
#####
#####

n=49 => 25
#######
#######
#######
###*###
#######
#######
#######

The challenge consists on output the sequence 1, 5, 13, 25, ... uninterruptedly. The separator does not need to be a comma, but use the same separator always.

There will not be any accepted answer, except if I see some very creative answer. There will be a winner for each language (I will steal Leader board code somewhere)

code-golf math sequence

Answer 21

Hello, Quine! code-golfquinehello-worldrestricted-source

Your task is to write a program which, if given an input of "Hello," will output "Hello, world!", if given any other input, it will output its source code.

---

Rules

• Input does not have to be case-sensitive.
• Your program may not contain the string "Hello, world!" or any variation with different cases of letters (i.e "hELLO, WORLD!", "HeLlO, WoRlD!", and "hello, world!").
• No "cheating quines."
• Standard loopholes are strictly forbidden.

---

This is code-golf, so may the shortest code win and the best programmer prosper...

Answer 22

Complicating Simple Maths code-golf

We do know what 1 + 1 is, or 2 - 1. How about we turn those and other really simple operations into complex numbers?

Goal:

As stated in the intro, taking an operation that can be done within the range of the following operators ( +, -, /, *, ^ and () ), print out a complex number operation that is pretty much a transformed version, and when done using the order of operations, results in the same answer as the inputted operation.

Examples:

Input: 5 - 1
Output: 5 + 2i

Input: 4 * (7 ^ 2)
Output: (4 * 4i) * (7 ^ 2) 

Rules:

• It is recommended you print out the sector(s) that holds your complex number(s) as a + bi, e.g. (a + bi) - (ci * (di ^ f)). (NOTE: If you are doing non-communicative operations, such as ^, /, or -, the recommendation doesn't apply to the sub-operation).

• No standard loopholes.

• If you want to, feel free to use operations/functions other than the set mentioned in the Goal, but your input operation must have at least one of them.

• You can format your operators in any way, e.g. x or • instead of *, ÷ instead of /, etc.

• Input and output is allowed in any format as long as it fits within the standard I/O rules.

• Input must also be flexible (as in to return any input from a simple operation to a complex number operation.

• This is code-golf, so shortest answer wins.

Sandbox use only:

Is there any way I can improve this challenge? Are there any other loopholes to be covered in the rules?

Answer 23

The Self-Referential Algorithm

Most people are familiar with Tupper's self-referential formula. When the formula is graphed on a calculator it magically graphs itself. Wouldn't it be interesting if we could do something similar with a programming language?

Your task

Write a small program that will be able to output exactly itself when ran.

This is a code-golf question so answers will be scored in bytes, with the fewest bytes winning.

Answer 24

Pascal's Particulars

Pascal is feeling very particular today. He wants to get an element from his famous triangle without going through the work of generating all the prior elements. He'll provide you with a row number and an entry number and you'll provide him with the element at that location.

Example:
Input row = 1, entry = 1, output 1. (row 1 is 1)
Input row = 3, entry = 2, output 2. (row 3 is 1-2-1)
Input row = 6, entry = 3, output 10. (row 6 is 1-5-10-10-5-1)

Rules

• You will only be provided valid inputs (i.e. x will never be higher than n).
• Your code should either print or return the output value, either works.
• Standard golfing rules apply (lowest byte-count wins, etc.).

Happy golfing!

Answer 25

Break this block

Your challenge is to break this block.

But of course that would be a pretty easy challenge, that's why this is a cops-and-robbers challenge.
The robber's challenge: Break the block. As breaking qualifies everything that has the result that no diamond block is at the coordinates 0 128 0 (even pushing it with a piston) and that follows the rules (see below).
The cop's challenge: Prevent the robbers from breaking the block. As preventing the breaking counts everything that guarantees that there is a diamond block at 0 128 0 in every future game tick despite the robber attempting his solution (and also if he doesn't). You are not in the world while the robber makes his attempt, so you have to prepare the world for him.

Rules

• You may not use modded Minecraft or external tools that change the save file. Reading it with external tools is allowed.
• You have to show a reproducible way to break/secure the block. Just uploading a world save without saying what you changed is invalid. You should offer a detailed explanation and preferably more (video, screenshots, structure file, etc.), if necessary.
• This challenge starts with a normal world (default generation, Creative+cheats, random seed), where one diamond block was placed using the command
  /setblock 0 128 0 diamond_block
  The spawn chunks can include 0 0, but they don't have to. Since both sides have access to commands, that shouldn't matter anyway.

Sandbox questions

• How should I restrict the version? Should it be "latest release", "any stable release", "only 1.12.1", "any snapshot, release or historical version" or something else? People could come up with interesting solutions using past versions (maybe even past snapshots that aren't selectable in the launcher anymore), but I have to somewhat restrict it. If a certain downgrade automatically breaks the block, it's of course boring, especially since they instantly win. And if they load the world in any of the 9 oldest versions in the launcher (called "Classic" and "pre-Classic), there isn't even a diamond block in the game, so it would be deleted.
• Should I discourage people from instantly preventing every single breaking method with their first "cops" post? To have an interesting challenge, it should slowly become more difficult. If I should discourage it, how to "enforce" it?
• What other rules do I need?
• I'm planning to be very active myself on the "cops" side (I already have some nice ideas), possibly creating the majority of posts there. Is there a problem with that? If no, would it be considered unfair or boring to ask the others to wait up to a day with their solutions? Of course they don't have to do it, I just originally planned this to create programming challenges for myself.
• If every answer on one side can have multiple answers on the other side, which itself could have answers on the first side and so on, that could lead to a tree-like structure. But such a structure would lead to many unanswered questions (if it doesn't keep growing exponentially, what I highly doubt). Is there a way to prevent that or should I even try it?
• Apparently this is the first Minecraft-only programming challenge here. Should a minecraft tag be created for it?

Answer 26

The Compressor

code-challenge test-battery

You are given this list of 100 positive integers that are at between 7 and 18 digits long:

[list to come]

You need to generate 100 snippets that will produce these numbers in some language (either as a numeric or string). Your score is the total length of the snippets. Lowest score overall wins, but you should also try to get the lowest score in whichever language your snippets are in. Please include both your snippets and any code you used to generate them in your submission. Note: the generating code isn't actually scored.

Rules

• The snippets must all be in one language, however it does not need to be the same language as the generating program(s).
• You may assume that any pre-existing libraries you use are already imported.
• You don't need to include the line terminator (i.e ';' in Java and others) for snippets that fit on one line. For multi-line snippets, you don't need to put a terminator on the last line.

Examples

• 1357000 => 1357e3 (many languages)
• 1234567 => 1234567 (most languages)
• 307422089600 => S6*99b (CJam, returns value of [32,32,32,32,32,32] in base 99)
• 12582912 => 12<<20 (JS + others)

---

Alternative: code-golf

I generated this 100 digit random number with random.org:

7160708104901559695507628057638725214364226867212714872539720713967912042100814603497742352846014272

Write the shortest possible program that outputs this number.

---

Related: No strings (or numbers) attached

Questions? Clarifications?

Answer 27

Ulam spiral 2

Like Ulam, I had a boring moment and began drawing a spiral like him's. But his version is utterly incorrect, as the \ diagonal distorts the equation n^2.

The following picture illustrates an wrong Ulam spiral at left and a correct at right:

I challenge you to output a numbered Ulam spiral, the right version, where it is mandatory to highlight the primes. The input is n, meaning the point where the spiral ends. For the image example I gave n was 100. It will always begin at 1

I don't care what highlight style you use (different color, font weight, circle around number, etc), given it makes the primes easily distinguishable form the rest.

There will be no accepted answer; just did it for fun.

graphical-output math sequence primes number integer

Answer 28

Looking for some help to make this code golf/question better.

Proposal:

Now that twitter has increased it's character limit from 140 to 280, there's a joke of almost enough to write Hello World! in Java. But what actual programs could you write in 280 characters, fizz buzz? Sure you could write many in 140 or less, but maximum points if you get a good program in the full 280.

Answer 29

Shortest golang code to println the first byte of a function’s code

Rules

• The code must be a function which takes another function as parameter and will print the first cpu instruction byte of parameter such as :

.

func dummy() {
}
print_first_native_instruction_byte(dummy)

would print :

0x90

which is a nop instruction on x86.

• You don’t need to perform disassembling : if the first instruction is longer than one byte, just print it’s first byte anyway without caring about instruction meaning or instruction length. Please note this is harder than just printing the value pointed by &dummy in the case of my example though.
• The function parameter must be a go function, not a cgo or assembly function.
• You can include as many golang packages as you want.
• The code need to be written in Go. A well known language developped at Google and part of the four Google’s app engines supported languages and answers should be able to run on the official go playground.

Winner

The one with the shortest code… Import statements included.

Answer 30

Preposition, not possession

code-golfstring

Enthralling background

Back in 1960s Soviet Russia, communism was the thing, and –– as we all know –– in a completely socialist society, there is ideally no personal property.

Our dear client is an author who is moving to the Soviet Union. However, as is Bolshevik custom, our client is afraid his works will be censored. That is why we are going to help this industrious author by revising his writings so that they will not be censored.

What will be censored? Any overt references to ownership.

How will we do this? Quite simply: we will replace all possession with preposition.

Let's get specific

Example

Text in parenthesis is added; text in curly-brackets is removed.

[Input]   All the author's works will be censored!
[Output]  All (the works of )the author{'s works} will be censored!

Algorithmically

1. For each word with a 's attached to it:
2. Call the word with an 's attached to it _word_
3. Call the following word _object_
4. Remove all 'ss and _object_
5. Insert The _object_ of two words before _word_
6. If there are not two words before _word_, place _object_ right before _word_.

Here are some more examples:

Then the red horse stopped and took the orangutang's oranges. What a fuss ensued!
Then the red horse stopped and took the oranges of the orangutang. What a fuss ensued!

It is the people's right to not own anything!
It is the right of the people to not own anything!

The world's tallest building was once the Empire State Building.
The tallest of the world building was once the Empire State Building.

Bill likes Fred's shoes, and Jill likes Beth's dress.
Bill likes the shoes of Fred, and Jill likes the dress of Beth.

Ryan's fear was a stack overflow.
The fear of Ryan was a stack overflow.