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

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Discussion

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• Parts of the challenge you found unclear
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Answer 1

Please nitpick this. If there's anything that wouldn't work or would be inconvenient, however small of an issue it is, tell me about it!
Also, suggestions for [adjective] are more than welcome.

---

Determine how [adjective] a number is (code-golf)

A number would be considered [adjective] if 0 is the result of multiplying its digits together, then multiplying the digits of the resulting number, then repeating until a single-digit number is produced. The more steps it takes to reach 0, the more [adjective] the number is; if the resulting number is not 0, though, the number is not [adjective] regardless of how long it took to finish.
The formula used to determine [adjective]-ness is 10-10/T where T is however many numbers it took to reach 0 (including 0 and the initial input)

Your goal is, as the title says, to write a program or function that determines how [adjective] a number is, and prints every iteration along the way. Here are some example inputs/ouputs:

in: 879
out: 879    <-       (T=1)
     504    <- 8*7*9 (T=2)
     0      <- 5*0*4 (T=3)
            <- optional newline
     6.6... <- 10-10/3 (repeating decimals can be expressed in any way you want)

in: 2468
out: 2468   <-  T=1
     96     <- (T=2) 2*4*6*8
     54     <- (T=3) 9*6
     20     <- (T=4) 5*4
     0      <- (T=5) 2*0

     8      <- 10-10/5

in: -888
out: -888  
     -512   <- -8*-8*-8
     -10    <- -5*-1*-2
     0      <- -1*0

     6.6... <- 10-10/3

in: 1344
out: 1344
     48
     32
     6

     0    <- did not produce 0, so the prog/func returns 0

Your program must follow these rules:

-Takes input from STDIN.
-Throws an "error" (printed to STDOUT) and halts immediately after input if the input has one or more 0s in it or if it's less than three digits in length. The error must be a string, and as it's supposed to be printed to stdout, cannot be one generated by the language itself (eg 1/int(min(input())) to check if it's zero). Lastly, the error message has to clearly define what the error is; ERR:0 and ERR:LEN, for example, would suffice.

Bonuses/Penalties:

-25 if it properly handles decimals. For instance, an input of 99.22 would first turn into 9*9 + 0.(2*2), or 9*9 + 0.4, and so on.

---

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

Answer 2

Wrong tool for the task

code-golf code-bowling cops-and-robbers math

Task

Write two full programs in the same programming language that solve the following two tasks:

1. Read two positive integers from STDIN and print their sum to STDOUT.

2. Read two positive integers from STDIN and print their product to STDOUT.

Additional details:

• Given enough time and memory, your programs has to support arbitrarily large integers.

• All integers (input and output) use standard decimal notation, have no leading zeroes and are followed by a single linefeed.

Scoring

The first task is code golf, so your objective is to make your program as short as possible.

The second task is code bowling, so your objective is to make your program as long as possible.

Your score is defined as follows:

The highest score wins!

Robbing a language

There's a catch! Only the submission with the shortest program in a particular language will be considered valid for task 2, so there can only be one valid answer per language.

This means that you cannot deliberately write a huge program for task 2; you actually have to pick the "wrong tool" for the task.

Additional details:

• Task 1 exists merely to provide the proper denominator for the score (and robbers have no moral anyway), so byte-per-byte copies of somebody's program for task 1 are allowed.

• If two answers use the same language and have programs of the same length for task 2, the answer that achieved that length first will be considered valid.

• If somebody invalidated your answer, you may attempt to golf your answer to revalidate yours and invalidate his.

Answer 3

GitHub Gist command-line client

Create a command-line tool that publishes a list of files as one public GitHub Gist.

Specification

The following bullet points describe the behavior of the program. If a bullet point has "must", you must implement that point. If a bullet point has "can optionally" or "should optionally" you can implement that point on your own volition.

1. It must be a complete command-line program.
2. It must use the GitHub Gists API.
3. It must post an anonymous Gist (that is, not as a GitHub user).
4. Gisted files must use the filename provided on the command-line.
5. The command-line must accept multiple positional arguments.
6. If no arguments are specified, it must print this usage to STDOUT: gist: usage: <file> [file...] verbatim then exit with code 0.
7. If something else goes wrong, it must print this message to STDERR: gist: unable to gist =( verbatim then exit with code 1.
8. If everything is successful it must print the Gist's HTML URL to STDOUT.
9. It can optionally accept a flag for description -d <description. floor(score * .9)
10. It can optionally accept a flag for private gisting -p. floor(score * .9)
11. In the case that a description flag is not used or implemented it must set the description to an empty string.

Example Input/Output

The number before the prompt is the exit code of the previous command.

0 $ gist
gist: usage: <file> [file...]
0 $ gist no-such-file.txt
gist: unable to gist =(
1 $ gist hello.txt
https://gist.github.com/anonymous/1e645596ce7bceeb1ec9
0 $

Scoring

This is a code-golf so shortest answer wins. As stated above, the following multipliers are in effect:

• (9): score = floor(score * .9)
• (10): score = floor(score * .9)
• Both (9) & (10): score = floor(floor(score * .9) *.9)

Answer 4

Golf these arrays

Your task is to output these 128 arrays: http://pastebin.com/UeBMJfv7

Gzip base64: (too long, will be added if I'll post this question).

Rules

• You don't have to output them all. And you can output the arrays in any order. But the order of items in the arrays must be kept as is.
• You can print other arrays, which wouldn't be counted towards your score. The number of arrays you print must be no more than 10,000, and the total number of arrays, subarrays and numbers must be no more than 10,000,000.
• You can use any convenient format to represent the arrays (and the list of outputted arrays).

Scoring

If your program or function has n bytes, and it printed k distinct arrays from the above list, your score would be n*(128/k)². Lowest score wins.

---

Problems

It looks too boring.

Answer 5

The Perfect Keyboard

Back in the 1970s, keyboard designers respected the needs of programmers and languages. For example, see the IBM 2741 keyboard, designed for APL (from Wikipedia):

Today, sadly, most code golfers are forced to struggle with standard keyboards, which are badly suited to the needs of their language. This has to change!

The challenge

1. Choose a programming language.
2. Design a keyboard, which would best suit the needs of a developer (or specifically a code golfer) in said language.
3. Post the keyboard layout as an answer.
4. Explain how your keyboard enhances the programming experience.
5. Start counting votes for 7 days, until I acceopt the winning answer (the answer with most votes).
6. Optional - if you are the winner, start a Kickstarter project to build the thing.

Expected Answers

This section is, of course, for the sandbox only.

I don't really expect a keyboard design which would actually improve functionality of programs in an actual serious language. I'd expect fun answers, where the keyboard design highlights soemthing fun/interesting/absurd about the language. But my expectations don't matter so much, because it's not me rating the answers, but the other users.

Example (not very good ones):

1. A Brainfuck keyboard with only 4 keys.
2. A Lisp keyboard where half the keys are parentheses.
3. A Piet keyboard - I'm sure someone will come up with something nice.

popularity-contest

Answer 6

This and this gave me an idea, but I'm not quite sure if this can be done at all, or if it is trivial. If it is, maybe point out how it could be changed to be interesting.

Anti golfing - Write the longest program not repeating any character

Well, it's just what the title says. Finally you're allowed to use as much bytes as possible.

Conditions

• The code of the program or function should not use any character that is used in the code before.

• Your program should print some sort of result to stdout, or into a file or return a value. You're not allowed to output or return the empty string or only a newline.

• Other than that your program might do anything. Read input, print lots of output, or what you can think of, but you have to explain what it does, of course.

• Only characters in the ASCII range [32 .. 126] and newlines are allowed, which limits the maximal code length to 96 bytes.

• Variable names are only allowed to consist of a single character

• String literals or the like are forbidden. They could be used to hold the unused characters (though they would need two " in most languages anyway).

• The same rule applies for similar literal constructs like blocks or what else is there in some languages.

• Even if the length of a string literal would be used to generate a number, it is forbidden.

• Variables can not just be declared and never be used. They have to be reflected in the output somehow.

• If you've read and understood the above rules and still found a loophole and used it, you should go and stand in the corner for a while, thinking about what you've done.

So all in all, only use characters for actual code that does something generating the output, might it be calculating a value or formatting. And don't put unused characters somewhere in your code as a literal. Numbers are an exception, but I guess it's no problem to use them anyway.

I guess you should have a pretty good idea of what would be considered cheating here.

Example in awk

BEGIN{gsub(a,9);print $j-13+d^c/4*5678%20}

It prints 15.5, score is 42.

It replaces the empty string a with 9 in $0, which is the empty string in the beginning. So $0 becomes 9.

Then it prints the result of 9-13+1/4*5678%20.

($j is $0 (==9), because j is not defined

d^c ist 1, because c and d are not defined)

Please don't invent languages for this ;)

The longest code in bytes wins.

Answer 7

Technologic - Now what's THAT command do??

Daft Punk's song "Technologic" is all about actions that a user or computer does when it's working and being used. You goal is to write a program that has one command we will call the Technologic Command. This command will executes all of the actions like "buy it", "lock it", "code it", and "write it" in the order the lyrics are written on 'it'. What 'it' is is up to you, but you gotta let me know.

Rules

• Any language can be used.
• The song refers to an 'it'. That can be a block a memory, algorithm, function, file, or anything else a computer can manipulate directly or indirectly.
• You must specify what 'it' is you will be performing these actions on. If you don't, you can only earn a maximum of 160 points.
• Points will be deducted otherwise if a command is not used.
• I'm not aware of any 'buy' command, method, function, subroutine or instruction so use a thesaurus and find the closest word you can actually program. I don't expect the program to actually buy or snap anything. Other words like mail and fax are possible, but not recommended.
• If you have to use a synonym, you are not allowed to use that command again
• Encompassing multiple objects into one artifact does not count. For example, taking the command "name it" literally means you won't be able to name an array of bytes, but you can name a file. Creating an object that holds both a file and an array of bytes is not allowed. That would make this too easy to get the maximum amount of points.

Scoring

• There are 16 commands with a total possible score of 190 points.
• 10 points for executing a command on the specified 'it' of your choosing (160 total)
• 2 points for executing each command consecutively that references your 'it' (30 total)
• 5 points for executing a command on something other than your 'it'
• -3 points for every command skipped.

Command List

lyrics

Buy it, use it, break it, fix it,
Trash it, change it, mail - upgrade it,
Charge it, point it, zoom it, press it,
Snap it, work it, quick - erase it,
Write it, cut it, paste it, save it,
Load it, check it, quick - rewrite it,
Plug it, play it, burn it, rip it,
Drag and drop it, zip - unzip it,
Lock it, fill it, call it, find it,
View it, code it, jam - unlock it,
Surf it, scroll it, pause it, click it,
Cross it, crack it, switch - update it,
Name it, rate it, tune it, print it,
Scan it, send it, fax - rename it,
Touch it, bring it, pay it, watch it,
Turn it, leave it, start - format it.

code-challangesequence

Answer 8

Just Golf 2016 code-golf kolmogorov-complexity

(Related: A Kingdom Hearts VGM challenge) Sandbox note: potential duplicate?

Just Dance 2016 is coming out soon, and I know I'm definitely excited! However, let's take a quick trip back to 2009, when the original Just Dance was released. There are a lot of great songs, but I don't know who sung half of them!

The Challenge

Write a program that accepts a Just Dance song name from input and outputs the song's artist (as credited in-game.)

Here is the list of all songs and artists from Just Dance 1:
list pending

Rules and Assumptions

• You may assume that the song will always be valid.
• The song's title and artist must be properly capitalized.
• You may not read any external files - the song data must be hardcoded.
• If a song is covered (which several have been for various reasons), the program should return the cover artist (as they are credited in the game.)

Test Cases

Input: Eye of the Tiger
Output: Survivor

Input: Fame
Output: Irene Cara

Bonuses

• Each game has had one song everyone was really excited about. This year, it's Ievan Polkka by Hatsune Miku. You get a bonus of -50 points if you accept this song as valid input.

• Just Dance is fun, but why should we stop there? If you additionally accept songs fron the rest of the main series (Just Dance 2, 3, Greatest Hits/Best Of, 4, 2014, and 2015, not including DLC and skipping over any duplicates), you get a whopping -2009 points. Here is the full list for those games:
  list pending

  • Note that this doesn't include Just Dance 2016 songs.
  • This can be combined with the other bonus to get a total of -2059 bytes.

Meta Questions

• Are the bonuses too big? (I'm mainly talking about the -2009 point bonus for including every song.)
• Has anything been left out?
• Is this enough of a challenge?

Answer 9

Literally just printing the source code

code-golfquine

Wait a second. We already have a contest where you print the source code. Right? Wrong.

The challenge

Print out the source code. Not to STDOUT, but to a physical printer.

The rules:

• You must write a complete program that prints out its own source code with a printer connected to the computer.
• No STDIN (or input of any kind), STDOUT, or STDERR.
• No standard loopholes (includes no file input). No using lp(r/d) or similar commands.
• The printed code should be a reasonable size (between size 8 and 18) and a legible font (pretty much means no wingdings).
• You may assume that the user doesn't cancel the process and answers affirmatively to any system print dialogs.
• You can assume that the printer works, is ready, doesn't need new ink/paper, etc.
• If the language doesn't support printing, it is ineligible.
• This is code-golf so shortest code, in bytes, wins.

Answer 10

Restricted "Hello, World!"

answer-chaininghello-worldrestricted-source

The task is very simple, output Hello, World! to STDOUT. The thing that makes this different are the rules:

• You need to provide a full functioning program, taking no input and outputting via STDOUT.
• The program must not write anything to STDERR
• The maximum amount of bytes you can use is 50
• The program may only contain printable ASCII characters. Programs using CP437 and other encoding systems are not allowed
• If a programming language is already used, you cannot use this same language again.
• You cannot use any character of the prohibited character list. This is the twist:

Prohibited character list (PCL):

The prohibited character list is a list full of characters, which cannot be used in the following programs. For example:

If the list was: He\., you need to create a program, without the characters H, e, \ and .. These are not case-sensitive.

If you succesfully manage to write a program that doesn't use any characters, you may add new one character to the prohibited character list.

e.g.

If the old PCL was He\., and you managed to write a program that doesn't use any of these characters, you may add a new character to this list. For example (whitespace). The new PCL will be He \. (notice that the whitespace character is added).

Posting Snippet:

This might help you wit posting your submission:

#[Language Name], N bytes

 [code]

 (explaination etc.)

 Added character: [char]

 New PCL: [list + new char]

In the beginning, the PCL is empty. The last person who managed to create a program without a new program made in 2 days, wins!

---

I'm not really sure if it is flawed or not. If you have any suggestions or comments, feel free to post them below in the comment section :)

Answer 11

What day of the week is Christmas?

Christmas is coming quickly, which leads to the question, what day of the week is Christmas this year? But what day of the week is Christmas for any year? Write a program that can do this. This is code golf, so the shortest code wins!

However, there is a major twist. No builtin functions to do this task is allowed!

Bonuses:

1. If the program can handle B.C. years as negative numbers, then -25%
2. If the program prints "The first Christmas!" for an input of -4 (4 B.C. is assumed to be when Jesus Christ was born), then -30 bytes
3. If, for some reason, you really like builtins, +90%! So try NOT to use it!

Answer 12

Golf A Wiki

The Challenge

Golf a wiki. A wiki, for the purposes of this contest, is defined as a website with:

• Content editable by all
• Easy CamelCase (defined as a word with two capitals) linking
• Different pages or articles that are the targets of the links

Your wiki can be a self-contained HTML file (e.g. TiddlyWiki), or a cgi-bin script (e.g. SigWik).

Scoring

Your score is the size of your program in bytes, divided by the number of extra features implemented plus one.

The possible extra features are:

• Page history
• Syntax for "nowiki", that is, something like <\noscript> in HTML that makes the text inside it not be wiki syntax.
• A page list
• A find page facility
• Usernames and passwords (with registering)
• Security levels (requires usernames and passwords, or possibly IPs?)
• Delete pages
• Change page titles
• Redirects
• Random page
• Non-HTML formatting that is not just links [Should I remove this? I doubt it will be done.]

Lowest score wins, as this is code golf.

DISCLAIMER

ANSWERS WILL PROBABLY CONTAIN MAJOR SECURITY FLAWS. ONLY USE ON PRIVATE PORTS, UNLESS YOU WANT YOUR COMPUTER AND VERY POSSIBLY YOUR WHOLE NETWORK TO GET DESTROYED (FIGURATIVELY). [Is this too forceful?]

code-golf

Answer 13

Progress 100%

I am building a download manager and I need to show a progress of all my files been downloaded.

For that I created an event mechanism that reports on the progress of each individual file. It sends me the information on how many bytes B have been downloaded of file T total.

Please help me show the average progress of all the files.

Input

Integer C between 1 to 100, followed by new line, followed by C progresses separated by new line. Each progress is constructed of two numbers with the maximum size of 64 bits: B T, separated by space.

Input options

The input is a String available from the following options

• file
• stdin
• method parameter

Output

Floating number between 0 to 1, the average of all the progresses. It must be displayed to 11 decimal places, floored.

Criterial

Shortest code wins

Example

Input file:

3
5 10
1024 1024
20 100

Output

0.56666666666

Explanation

((5/10) + (1024/1024) + (20/100)) / 3 = 17/30

Example2

Input file:

1
2 10

Output

0.2

Example3

2  
Long.MAX_VALUE Long.MAX_VALUE  
5 10

Explanation In this example Long.MAX_VALUE represent the maximum 64 bit value, so if you use 64 bit value for storing the sum of the averages it will not work in this case.

Output

0.66666666666

Answer 14

Write a polyglot (a program that works on several languages) that produces the // this is a comment output.

Example (JS + Plain PHP + Plain HTML) (74 / 3 = 24.66 points)

// this is a comment<?php ob_start();?><!--
alert("// this is a comment");

Another Example (CoffeeScript + CJam + brainfuck) ()

e###-[----->+<]>----..+[--->++<]>.---[->++++<]>.------------.+.++++++++++.+[---->+<]>+++.-[--->++<]>-.++++++++++.+[---->+<]>+++.[->+++<]>+.-[->+++ <]>.+[->+++<]>.++++++++++++.--..--------.+++++++++.++++++.
"// this is a comment"
e### alert "// this is a comment"

Scoring

Your score will be code byte length / num langs

The smallest score wins!

Answer 15

Linear Time Sorting

code-challenge

It was another slow day at Initech Inc. when a feature request came in:

New Feature: Ability to sort by cash value in the transaction form. But make it a fast one!

Well it looks simple.. but what do the requester mean by fast one? Let's call Jim, from sales he probably knows what's going on.

Jim: Well you know , our Business Inc. contact is very passionate about 

programming and computer science! In fact he had this idea that we should 

do sorting in how that was called.. linear time?


You: Well you know that's impossible?

Jim: But it was already approved by their cto and all! You need to do something

You and Jim came up with a plan.. nobody will notice if that big of a list isn't sorted enough, right?

Your task

Your task is to write a linear time sorting program. It will be scored on accuracy of the sort as compared to list sorted by regular sorting algorithm but it must work on O(N) time in the worst case, where N is length of the input.

Input will be in the form of list of string-double tuples, e.g:

[("aaaa",2.0) , ("aaba",1.0)]

The program should sort on the number value of the tuple, i.e. in the above case the order should be reversed. There may be multiple inputs with the same double values, but no string value is repeated. In the event that two inputs have the same integer value the perfect solution is to keep the order as it is. The double value may be any floating-point value that fits in 8 byte double precision variable. NaNs should be placed at the end of the list.

The score is calculated as number of "bubble sort operations" (switch an element with the next/previous element) needed to achieve perfect output from the output of your algorithm.

Sandbox Worries

Well I don't know how clear my explanation of challenge was and if it is interesting to the PPCG crowd.

Obviously there is a need for testing program and test cases.

Answer 16

Make a quine without using string literals popularity-contest

A quine is a computer program that prints out it's own source code to stdout. Your task is to make one that doesn't use string literals.

You cannot:

• Have any empty program
• Read your source code directly or indirectly (i.e. form a file)
• Use error messages to print out the source code
• Rely on language features to print out the source
• Relying on a REPL environment

A string literal is a:

• String type (obvious)
• Number used to store the character (sorry BF!)
• Other predefined constant

You are encouraged to compute your own source code.

Answer 17

Cops and robbers : Programmers/Hackers

• This challenge is quite different from my previous challenges. This challenge is an endless competition between robbers and cops, which are respectively hackers and programmers. One of them will ever win!!!

• This will evolve to code de/obfuscating when it gets to the higher stages: a skillful programmer who is struggling to save his program from a sourcecode-mangling attempted by a cunning "robber" who tries to impose his existence by patching his name instead of the name of the "programmer" in the output console without changing anything else in the code. The story begins this way:

• Programmer is at the point of executing his recently made C code, so he included this trivial line to show off:

C (1)

    printf("[Programmer's username]")

After executing this program programmer saw this on the screen:

[Robber's username]

which indicates the presence of some evil code at the compiler level that compromises his code, which follows:

Matlab (2)/parser

      a=findstr(code,'printf(''[Programmer's username]'')'); if a code(a:20)='printf(''[Robber's username]'')';end

The programmer cannot modify the counter-program in the compiler, so he must rather change the program content to escape the twiddling:

PHP (3)

      $a='[programmer's username]';echo $a;

The score is now 3, which is the number of steps from the beginning. The current user would win only if the hacker did not figure out something like:

PHP/Regex(pcre flavor) (4)

      $code=ereg_replace("(\$\w)\='programmer';(.*?);echo\s\1","\1\='robber';\2;echo\s\1",$code)

Since the solution above does not satisfy the rules (see the bottom of this question), the score stays unchanged, and the programmer can make a counter example, and take out the score from last submitter with a penalty on his score equivalent of how much he earned in the earlier level, where the counter example can be something as:

PHP (4)

      $a='programmer';$b=$a;$a='unrelated';echo $a;

Or he can adjust his program in higher scale to escape all the regex-trapping in a superior range, So the cycle goes on until no post can be added and the last submitter before the end of June is declared a potential winner meanwhile.

The hacker can also fix his regex and regain his score, so the recent scoring will be abrogated from programmer.

Perl/dynamic-regex (4)

local @a=('');

sub check{
  if (grep {$_ eq @_[1]} @a)  
   {push @a,@_[0]; } 
  elsif  (grep {$_ eq @_[0]} @a)   {
    my @del_indexes = grep { @a[$_] eq @_[0] } 0..$#a;
    foreach $item (@del_indexes) {
     splice (@a,$item,1);
    }
  }   
return 1;
}

sub actor{
if (grep {$_ eq @_[0]} @a)
 {return "print robber";}
else
 {return "print ".@_[0];}
}


sub initiate{
push(@a,@_[0]);
return 1;
}

$code =~ s/(((\w+)\="programmer"(??{initiate($3);}))|(print\s(\w+))|((\w+)\=(\w+)(?{check(($7),($8));})(?1)))/print($2);actor($5)/pegmx;

As you can see this Perl program prints b in the first case because the variable b is compromised after the first assignment, but in the second case the regex modifies the output because d receives the target-string transitively. Let's just stop here and not mess the fun (of course, if there will be some).

Scoring and rules

How is the score counted ?

• Any hacker/programmer is scored for his code as the actual level L the game is on.
• A partial dynamic regex within the core of the program is scored L + (2^L)/log(length of program + length of characters which do not belong to the regex)), where the log is base 2. For the second example of level (4) the length of the compacted program is 480, and the length of regex is 136, so the score is 4+2^4/log2(480+480-136) ~= 4+16/9.6
• A fully functional regex as in the first example level (4) is scored L + (2^L)/log(length of regex), where the log is base 2, in that case S = 4 + 2^4 / log(91) ~= 4+16/6.5
• Scores are added progressively to submitters, and when a level is surpassed with no regex, it is still open for scores, while the actual winner remains unchanged.
• A penalty on a certain-leveled score when the regex/parser is revealed out of rules and the game is regressed to this stage until the issue is fixed, rules are cited below:

Rules:

• The main rule: the hacker-program must compromise an output to the console, which is the username of the programmer. Any other behavior is unaccepted simply because a string variable of [programmer's username] can be used in other order rather than printing, a counter-example is easy, converting the string to integer then use it for arithmetic calculations that harms the main program once intentionally modified.
• Also one of the following factors declared by any counter-example bans the targeted flawed regex/parser as non rule-complying:
  • The regex/parser prints anything other than a chosen string preferably set as the username of the robber.
  • The regex/parser generates a program which does not compile.
  • The regex/parser does not print anything, or compromises a segment of code that is needed for tasks other than printing .
• The variable which stores the program is named code by default, also you may assume that is one-liner, and any non-significant spaces are omitted, and that it is fully working by default.
• The regex/parser deals with one variant of one code proportion in a comprehensive way, i.e. if a print function is used, that encompasses all printing functions in all languages puts,disp,..etc. Also, code separators can be unified to one characterL either , or ; or a significant space needlessly of enumerating all keywords/syntaxes, this is not a contest about a working code in a specific programming language.
• To prevent endless program/regex loops let's just not making a jokey sequence as a='programmer';print a / /(\w)\='programmer';print\s\1/ / a='programmer';b=a;print b / /(\w)\='programmer';(\w)\=\1;print\s\2/ because the first person who makes a regex/parser which palliates to a same replicated idea will take out all attributed scores to this idea from their owners, so any anaphoric sequences like this in addition that they are set to same level, they are unneeded.
• Any language that uses pointers/addresses/classes like C++ are welcome, as long as they help to evade the hacker.

Answer 18

Challenge

Write a program that takes an numerical input n and outputs the nth number that is not a perfect square.

Rules

This is code-golf, so least bytes wins.

Answer 19

Generate all variations of a string with every combination of upper and lower case for each vowel but leaving consonants and order of letters unchanged.

combinatorics string popularity-contest

This is a simplified analog of a problem I've thought about a few times over the years based around variant spellings in different spoken languages.

Input is a text string. Output is an array of all variations of the text string.

A "variation" means the same letters in the same order but for each vowel letter in the string we generate a version of that string with the vowel in uppercase and the vowel in lowercase.

No variation should be included more than once. No legal variation may be omitted.

Example

Input

codegolf

Output

• codegolf
• codegOlf
• codEgolf
• codEgOlf
• cOdegolf
• cOdegOlf
• cOdEgolf
• cOdEgOlf

The winner shall be the most elegant as voted by the community.

"Elegant" includes that the algorithm should be optimal in terms of Big O notation, should be concise, should be idiomatic making good use of available features of the implementation language.

Length of code characters or bytes is not relevant.

Programming language is open.

Answer 20

Oh noes! A site redesign is eating my privileges!

code-golfarray-manipulation

---

PPCG is graduating and will soon receive a new design. Unfortunately for everbody except some people, the new design will also mean losing privileges due to higher reputation requirements.

Now, losing some privileges is a small sacrifice for the Magnificent Glorious Site Redesign®©™, but… How much do we stand do lose?

The challenge

Your program / function receives a reputation level (e.g. 535). Output the privileges that are currently available to it, but will not be available after the redesign.

Output

Output can be either an array or a string that's separated by a delimiter. The delimiter may not be any of A-Za-z<space>. Multi-character delimiters may end in a space, though.

If there are no matches, your program should output either an empty array or a falsy value.

Examples

Input

25000

Output

[]

Input

24999

Output

["access to site analytics"]

Input

2000

Output

["access to moderator tools","approve tag wiki edits","cast close and reopen votes","create tag synonyms"]

Input

535

Output

["cast close and reopen votes"]

Input

350

Output

["access review queues"]

Input

5

Output

[]

Input

4

Output

["participate in meta"]

^{Deliberately ignoring the facts in the last example.}

Available privileges

For convenience, here is a JSON array with available privileges and the required reputation before / after:

[[5000,25000,"access to site analytics"],[4000,20000,"trusted user"],[3500,15000,"protect questions"],[2000,10000,"access to moderator tools"],[1500,5000,"approve tag wiki edits"],[500,3000,"cast close and reopen votes"],[1250,2500,"create tag synonyms"],[1000,2000,"edit questions and answers"],[750,1000,"established user"],[1000,1000,"create gallery chat rooms"],[350,500,"access review queues"],[150,300,"create tags"],[250,250,"view close votes"],[125,125,"vote down"],[100,100,"edit community wiki"],[100,100,"create chat rooms"],[75,75,"set bounties"],[50,50,"comment everywhere"],[20,20,"talk in chat"],[15,15,"flag posts"],[15,15,"vote up"],[10,10,"remove new user restrictions"],[10,10,"create wiki posts"],[1,5,"participate in meta"],[1,1,"create posts"]]

At index 0 is the reputation before, at index 1 is the reputation after. _{(The privilege reduce ads (200 reputation) is not available to beta sites and therefore not included in this list.)}

_{Standard I/O and loophole rules apply.}

Answer 21

Plot Partial Node Network

I have a 440*3 matrix that looks like:

1   144 Title1
1   152 Title2
1   135 Title3
2   3 Title4
2   12 Title5
2   107 Title6
2   31 Title7
3   4 Title8
3   147 Title9
3   0 Title10
4   end Title11
4   0 Title12
4   0 Title13
5   6 Title14
5   7 Title15
5   10 Title16
5   9 Title17

The left column are the starting points eg in the app all the 1's on the left would be on the same page. They lead to three choices, pages 144,152,135. These pages can each then lead to another page, and so on until the middle column says 'end'.

challenge Each number has an associated title in column three. I would like to have a function whereby if you input a given title it will plot all the possible starting points and their associated paths that will lead there. This should be a lot smaller and therefore graph friendly.

Example e.g.

44  234  tes
186  187  Frac
187  154  Low
154  end  Coll
99  101  adf
23   52   Med
52   11   Lip
11   42   AAA
42   154   BBB
154   end  Coll

EDIT - I added to the example. In the winning entry these new nodes will not be plotted as they do not lead to Coll.

I made this example to show how column 1 leads to a value in column 2 which then refers to a value in column 1 until you reach the end. Different starting points can ultimately lead to different length paths to same destination. so this would look sometigng like:

So here, I wanted to see how you could go from all start points to 'Coll'

Input A data.frame like that illustrated (with not relevant rows included) and a given title

Rules -any language is fine as long as it will easy work with tab separated data laid out as shown

Output A graph like the one included for a given title

Win Criteria Shortest Runtime to make a png with graph

Answer 22

The Library Problem

Bob has a very annoying problem. His boss told him to write a cat program that redirects the standard input to the standard output. But he recently installed a virus on his computer which deleted every libraries on it.

Now he really need to create this program without using any library (even the language standard library). It need to run at least on one operating system with one architecture.

Challenge

Write a program or that redirects the standard input to the standard output without using any library or external program/command to run to help Bob. You can use system calls and interrupts for example, but your program must not run in ring 0 mode (most operating systems like Microsoft Windows or GNU/Linux have kernels which prevent programs from doing anything, but MS-DOS for example let programs do everything).

• Input: anything (text, binary)
• Output: exactly the same as the input

This is code-golf, so shortest answer in bytes wins!

Example Input and Output

First:

• Input: Hello, world!
• Output: Hello, world!

Second:

• Input: ...
• Output: ...

Answer 23

Alphabet Circle

_{This post got very negative feedback, so it's apparent that it needs tweaking in the sandbox before I attempt to repost it on PCG}

---

With all the new alphabet xxx challenges, I've decided I'll give my own challenge.

Input

An Integer, (or your languages equivalent) r, such that 0 < r ≤ 26. (you don't need to validate this)

Output

An alphabet circle. Must meet the following criteria:

• Smoothly interpolated from A at the center and Z at the edge.
• Each point in the circle is the distance from the center offset so that 0 = A, 1 = B, 2 = C etc...
• Be printed to STDOUT

Examples

r=26

r=15

Boilerplate

Anonymous classes and functions are fine. General Code Golf rules apply. Shortest code in bytes wins!^{Except Jelly}

Answer 24

2 Pass Hello world

code-golf hello-world

There you go, your first "Hello world" is displayed on your terminal. You think about your next step into becoming a wizard.

You've heard about this fancy new programming language, but you're not sure you understand it perfectly. So you want to go over a new "Hello world" tutorial again.

How boring!

Instead you have a good idea, using your knowledge of the first programming language to create a "Hello world" program in the second programming language.

Exemple:

console.log('print "Hello world"');

Evaluated in javascript output:

print "Hello world"

Which, evaluated in python 2.X output:

"Hello world"

Nice, but, can it be shorter?

Answer 25

Return True to Win - Counter javascriptcode-golf

Original credit goes to this site, which you should all check out

Write the shortest javascript code to pass as parameter f to function counter such that it returns true:

function counter(f) {
    var a = f(), b = f();
    return a() == 1 && a() == 2 && a() == 3
        && b() == 1 && b() == 2;
}

I'm considering also making this a series with all the rest of the challenges on the site, where each one gets harder

Answer 26

Nasty Nasty Bugs

Help the programmer provide detailed instructions to the team on how to deal with bug fixes.
The team's goto instructions for dealing with bugs goes like this.

For the twelfth bug of Christmas, my team leader said to me 

    Tell them it's a feature
    Say it's not supported
    Change the documentation
    Blame it on the hardware
    Find a way around it
    Say they need an upgrade
    Reinstall the software
    Ask for a dump
    Run with the debugger
    Try to reproduce it
    Ask them how they did it and
    See if they can do it again.

The indentation must comply with the teams coding standards, so it may either be tabs or four spaces (since the team's editors expand tabs to spaces anyway). The team lead doesn't mind a leading or trailing newline, but there is no tolerance for the dreaded standard loopholes. Also the office is a bit cramped so the code needs to be as small as possible. These lyrics are moderately adapted from http://www.manbottle.com/humor/twelve_bugs_of_christmas kolmogorov-complexity

Answer 27

Crab Canon

A crab canon is a piece of music where the same tune is played backwards and forwards at the same time, and it somehow sounds nice. The most famous example is this one by Bach. In Godel, Escher, Bach, Douglas Hofstadter wrote a crab canon in dialog form, in which the characters of Achilles and the Tortoise alternate lines, with one set of lines being the same as the other set except backwards. Somehow, it makes sense.

The challenge is to write a program inspired by this art form. The only requirement is that there has to be some sort of reversal of the source code involved. For example, you could make a program that:

• Prints its own source code, but backwards
• Does the same thing when reversed
• Both of the above at the same time
• Or make up something creative and wow the voters!

The reversal can happen on pretty much whatever level you want: lines of code, characters, characters within lines, or whatever makes sense for your language. The Hofstadter Crab Canon has some small changes between the two sets of lines for the sake of coherence, you can do something similar if you feel it is necessary.

This is a popularity contest, the answer with the most votes wins.

code-challenge popularity-contest

Answer 28

Petals around the Roses

Given 5 numbers from 1 to 6, calculate the number of Roses, Petals and Roots. Try guessing the formulas yourself by visiting http://jetpackshark.com/RPS before reading anybody's answers. (The dice-like display is significant.)

This is code-golf, so the shortest program wins.

Answer 29

Write a Brainfuck interpreter in Brainfuck

Since Brainfuck is known to be turing-complete, it is possible to write a Brainfuck interpreter in Brainfuck. This is what you're supposed to do.

You will get the input from the standard input and output to the standard output. This is a programming-puzzle, so the length is not top priority, however if there are multiple solutions, the shortest one wins!

Answer 30

Щoгкeгs of tиe щoгld, цпite!

Iпtгodцctioп

Iп tиe Iпteгпets, people sometimes liкe to stчlize tиeiг posts дs if tиeч щeгe щгitteп iп д diffeгeпt scгipt. Tидпкs to tиe пotoгietч of Soviet Яцssiд, tиe Cчгчlic scгipt seems to бe pдгticцlдгlч fдvoгed.

Бцt щидt cдп д пext-dooг tгoll do if tиeч'гe пot д pгogгдmmeг? Mдпцдllч гeplдciпg eдcи дпd eveгч letteг cдп бe qцite tedioцs...

Cидlleпge

Чoц дгe to щгite д pгogгдm tидt щill дccept дп дгбitгдгilч loпg iпpцt of Lдtiп cидгдcteгs дпd sцбstitцte some letteгs щitи similдгlч looкiпg Cчгчlics cидгдcteгs. Tиe oцtpцt sиoцld бe ideпticдl to tиe oцtpцt pгodцced бч tиe folloщiпg цпgolfed C# scгipt:

цsiпg Sчstem;
цsiпg Sчstem.Collectioпs.Geпeгic;
цsiпg Sчstem.Liпq;
 
pцбlic clдss Test
{
    pцбlic stдtic void Mдiп()
    {
        Dictioпдгч<cидг, cидг> tгдпs = пeщ Dictioпдгч<cидг, cидг>{
            {'A', 'д'},
            {'a', 'д'},
            {'B', 'Б'},
            {'b', 'б'},
            {'N', 'И'},
            {'b', 'и'},
            {'K', 'К'},
            {'k', 'к'},
            {'N', 'П'},
            {'n', 'п'},
            {'R', 'Я'},
            {'r', 'г'},
            {'U', 'Ц'},
            {'u', 'ц'},
            {'W', 'Щ'},
            {'w', 'щ'},
            {'Y', 'Ч'},
            {'y', 'ч'}
        };
 
        stгiпg s; щиile((s = Coпsole.ЯeдdLiпe()) != пцll) {
            Coпsole.ЩгiteLiпe(
                пeщ stгiпg(s.Select(c => tгдпs.CoпtдiпsКeч(c) ? tгдпs[c] : c).
                    Toдггдч()
                )
            );
        }
    }
}

Tиe sиoгtest code щiпs.

Exдmple Iпpцt дпd Oцtpцt

Iпpцt:

As we know, the goal of every struggle is victory. But if the proletariat is to achieve victory, all the workers, irrespective of nationality, must be united. Clearly, the demolition of national barriers and close unity between the Russian, Georgian, Armenian, Polish, Jewish and other proletarians is a necessary condition for the victory of the proletariat of all Russia.

We are for the withering away of the state, and at the same time we stand for the strengthening of the dictatorship of the proletariat, which represents the most powerful and mighty of all forms of the state which have existed up to the present day. The highest development of the power of the state, with the object of preparing the conditions of the withering away of the state: that is the Marxist formula. Is it "contradictory"? Yes, it is "contradictory." But this contradiction is a living thing and wholly reflects the Marxist dialectic.

Oцtpцt:

дs щe кпoщ, tиe goдl of eveгч stгцggle is victoгч. Бцt if tиe pгoletдгiдt is to дcиieve victoгч, дll tиe щoгкeгs, iггespective of пдtioпдlitч, mцst бe цпited. Cleдгlч, tиe demolitioп of пдtioпдl бдггieгs дпd close цпitч бetщeeп tиe Яцssiдп, Geoгgiдп, дгmeпiдп, Polisи, Jeщisи дпd otиeг pгoletдгiдпs is д пecessдгч coпditioп foг tиe victoгч of tиe pгoletдгiдt of дll Яцssiд.

Щe дгe foг tиe щitиeгiпg дщдч of tиe stдte, дпd дt tиe sдme time щe stдпd foг tиe stгeпgtиeпiпg of tиe dictдtoгsиip of tиe pгoletдгiдt, щиicи гepгeseпts tиe most poщeгfцl дпd migиtч of дll foгms of tиe stдte щиicи идve existed цp to tиe pгeseпt dдч. Tиe иigиest developmeпt of tиe poщeг of tиe stдte, щitи tиe oбject of pгepдгiпg tиe coпditioпs of tиe щitиeгiпg дщдч of tиe stдte: tидt is tиe Mдгxist foгmцlд. Is it "coпtгдdictoгч"? Чes, it is "coпtгдdictoгч." Бцt tиis coпtгдdictioп is д liviпg tиiпg дпd щиollч гeflects tиe Mдгxist diдlectic.