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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.

The Sandbox works best if you sort posts by "active".

Add Proposal

Search the Sandbox

Browse your pending proposals

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]

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  • \$\begingroup\$ How are tags added to questions? \$\endgroup\$ – guest271314 Jan 9 at 7:51
  • \$\begingroup\$ @guest271314 You can use this markup to create a tag in a draft: [tag:code-golf] \$\endgroup\$ – DJMcMayhem Aug 29 at 15:19
  • \$\begingroup\$ Why no featured anymore? Can't we have it auto-added or something? \$\endgroup\$ – JL2210 Sep 26 at 15:57
  • 1
    \$\begingroup\$ @JL2210 We now have a permanent info box that links to the Sandbox, so the featured tag isn't necessary \$\endgroup\$ – caird coinheringaahing Sep 29 at 13:43

2579 Answers 2579

0
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Kaprekar Transformation

Kaprekar Transformation is an transformation a number by following that instruction:

  1. Take n-digit integer.
  2. Sort it anscending and descending.
  3. Subtract the largest number and smallest number.

Your program have to do this:

  1. Take 1 number, x.
  2. Output all possible cycle and fixnums for doing repeated x-digit Kaprekar Transformation on all possible input. Rotation is considered same. So it is invalid to print:

    [00],[09,81,63,27,45],[81,63,27,45,09]

The output is a list consisting of list representing the cycle. You may using any style of list and even intermix it with restriction that it should not be ambigous. For example, comma separated item with item using comma separated item with enclosing bracket is OK, but not comma separated item with item using comma separated item without enclosing bracket.

Example:

8
>[00000000],[43208766,85317642,75308643,84308652,86308632,86326632,64326654],[63317664],[64308654,83208762,86526432],[97508421]

Or

>[00000000],[[43208766,85317642,75308643,84308652,86308632,86326632,64326654],[63317664],[64308654,83208762,86526432],[97508421]]
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  • \$\begingroup\$ I'm afraid this is a duplicate: codegolf.stackexchange.com/q/2762/8478 ... also, for future reference, requiring one specific list format is bound to put an arbitrary set of languages at a massive advantage (those which can just use their native string format), while all others may have to do some non-trivial string processing which distracts from the (interesting) core of the challenge. \$\endgroup\$ – Martin Ender Nov 2 '15 at 12:56
  • \$\begingroup\$ @MartinBüttner No, it is the generalization. You have to handle arbitrary digit this time. And you have to detect cycle and find all cycle given a digit. Btw, there is typo. 2 39 is different example. \$\endgroup\$ – Akangka Nov 2 '15 at 13:04
  • \$\begingroup\$ Task one seems to be identical. The fact that the other challenge only has to work with 4-digit numbers doesn't seem substantial. I'm pretty sure almost any answer there can be adapted to a variable number of digits in a couple of bytes. As for Task 2, I did overlook that. You could simply reduce the challenge to just task 2 (I'm not even sure why you'd combine two independent tasks into a single challenge?). Even task 2 can be solved by simply looping the solution to task 1 over all possible X-digit numbers, but there might be other ways to golf this one. \$\endgroup\$ – Martin Ender Nov 2 '15 at 13:07
  • \$\begingroup\$ @MartinBüttner Then, why it isn't duplicate of codegolf.stackexchange.com/questions/1255/hitting-495-kaprekar ? \$\endgroup\$ – Akangka Nov 2 '15 at 13:14
  • \$\begingroup\$ Because it has been overlooked, I suppose. Fixed. \$\endgroup\$ – Martin Ender Nov 2 '15 at 13:15
  • \$\begingroup\$ @MartinBüttner Maybe add time limit make this different enough. \$\endgroup\$ – Akangka Nov 2 '15 at 13:15
  • \$\begingroup\$ I don't know. Since you have to output the entire list anyway, there is not much you can optimise beyond actually applying the transform until you hit a cycle. If you limited the challenge to the second task, a time limit might make more sense, but then again the second task might be different enough not to be a duplicate in the first place. \$\endgroup\$ – Martin Ender Nov 2 '15 at 13:17
  • \$\begingroup\$ @MartinBüttner Then remove task 1 and it won't be duplicate? And add speed limit. \$\endgroup\$ – Akangka Nov 2 '15 at 13:29
  • \$\begingroup\$ I don't even think a time limit is necessary for part 2. \$\endgroup\$ – Martin Ender Nov 2 '15 at 13:30
  • \$\begingroup\$ @MartinBüttner Is Task 1 still have to deleted. And please, don't discuss in the Chat, because I can't access that. Better use my email: christianirwanhw@gmail.com \$\endgroup\$ – Akangka Nov 2 '15 at 13:57
  • \$\begingroup\$ As I said above, I don't see why you would want to squeeze both tasks into a single challenge in the first place. (How would you score answers? Sum of the two solutions?) And if you split them up, then the first answer is certainly a duplicate, but the second is fine (and if you didn't split them up, I don't see why you'd redo the same challenge as part of another challenge either). \$\endgroup\$ – Martin Ender Nov 2 '15 at 13:59
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    \$\begingroup\$ The cycle identification is borderline duplicate of codegolf.stackexchange.com/q/26578/194 \$\endgroup\$ – Peter Taylor Nov 2 '15 at 14:32
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Show How a Regex Is Matched

What your program or function should do:

  1. Accept input of two strings; let's call them r and s.
  2. Determine whether r is a valid regular expression (you can use any common definition of regex for this purpose, or any common definition of regexes but with lookahead and lookbehind removed; indicate which you're using). Otherwise, don't output.
  3. If so, determine whether s matches r as a regex. Otherwise, don't output.
  4. If so, output/print, in order, the part of r matched by each character of s, and also the part of s that matches it.

Note: You may use your language's regex-matching library for this.

Example:

Using PCRE; my inputs and outputs are r first and then s.

^.el*(o.*)*d\b and Hello, world!
^.ello......d\b and Hello, world

.\1\W and 800-555-1212
..\W and 00-

\b and a
\b and empty string

\d and a
no output (it doesn't match)


First floated in chat.
Not a dupe of Compile Regexes (which asks you to match regexes whereas this allows you to use the resources of your language to do so).

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  • \$\begingroup\$ 1. It sure looks like a dupe to me: what's your argument for it not being a trivial transformation of the previous question? 2. In your examples, you seem to try to draw a distinction between outputting the empty string and not outputting anything. How does that work? 3. What exactly is the output format? E.g. the first example and the second example don't seem to be consistent in their treatment of metacharacters. \$\endgroup\$ – Peter Taylor Nov 5 '15 at 22:49
  • \$\begingroup\$ @PeterTaylor 1. It's not a dupe at all: the older question asks you to match regexes whereas this allows you to use the resources of your language to do so; also, the older question outputs a means of determining matching, without regard to how it's matched, whereas this requires an output of the latter. 2. This question is OBE because of the edit I'm doing to fix #3. 3. Yeah, I messed up an example: I'll fix that immediately. \$\endgroup\$ – msh210 Nov 5 '15 at 23:05
  • \$\begingroup\$ 1. With respect to the second half, see "simple transformation". But the first half is relevant, and worth editing in to the "Not a dupe" sentence. 3. I still can't figure out the output format from the examples. Obviously you want to ensure that it's not as trivial as asking the regex engine for group 0, but I think you need to first write a clear spec for the output and then write the examples (or, better, write a reference implementation to generate the examples). \$\endgroup\$ – Peter Taylor Nov 6 '15 at 7:27
  • \$\begingroup\$ @PeterTaylor, yeah, I'll have to work on it some more. If anyone else has ideas, please chime in! \$\endgroup\$ – msh210 Nov 6 '15 at 9:24
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Python assembler

Python is a hybrid interpreted language. It first gets compiled into byte-code and then gets interpreted.

What does this byte-code look like you may ask? The dis module disassembles python code. Source code for dis module here

print "Hello, World!"

Gets disassembled into the following assembly.

  1           0 LOAD_CONST               0 ('Hello, World!')
              3 PRINT_ITEM
              4 PRINT_NEWLINE
              5 LOAD_CONST               1 (None)
              8 RETURN_VALUE

The output is divided in the following columns:

  1. the line number, for the first instruction of each line

  2. a labelled instruction, indicated with >>,

  3. the address of the instruction,

  4. the operation code name,

  5. operation parameters, and

  6. interpretation of the parameters in parentheses.

The disassembly of a basic for loop

for i in range(10):
    print i

gives

  1           0 SETUP_LOOP              25 (to 28)
              3 LOAD_NAME                0 (range)
              6 LOAD_CONST               0 (10)
              9 CALL_FUNCTION            1
             12 GET_ITER
        >>   13 FOR_ITER                11 (to 27)
             16 STORE_NAME               1 (i)

  2          19 LOAD_NAME                1 (i)
             22 PRINT_ITEM
             23 PRINT_NEWLINE
             24 JUMP_ABSOLUTE           13
        >>   27 POP_BLOCK
        >>   28 LOAD_CONST               1 (None)
             31 RETURN_VALUE

Your task:

Given some python code that has been disassembled, recreate the original code object as close as you can. You can take the disassembled code through any method you chose.

Your program will output all the arguments to recreate a python code object

That is to say your program will output the following

0,             
0,      
nlocals,              
stacksize,            
0,                
codestring,           
consts,               
names,                
varnames,             
"a string here",            
"another string here",
0,        
lnotab,               
(),             
()

You can work out the variables listed above but you have to output it all, even the constants.

  • nlocals - The number of local variables
  • stacksize - The maximum number of values held on the stack at once
  • codestring - A binary containing all the opcodes and their arguments
  • consts - A tuple of constants
  • names - A tuple of global variables
  • varnames - A tuple of local names (length of nlocals)
  • lnotab - A tuple containing a map of bytecode positions to line numbers

You may use the following code to disassemble a .pyc file:

import sys, dis, marshal

with open(sys.argv[1], "rb") as code_f:
    code_f.read(8) # Magic number and modification time
    code = marshal.load(code_f)
    dis.dis(code)

This is code-golf, the shortest code in bytes wins

Sandbox notes

Wow that was a long one. Perhaps too long?

Is the spec completely tight?

Should I explain anything further?

Am I making it too hard for non-python entries to take part?

Should I only make it a requirement to reassemble code without any functions/classes? I'm pretty sure dis doesn't show all that.

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  • 1
    \$\begingroup\$ For one thing, yes this looks very hard for non-Python entries to me. For another, I think there's too much going on at once (there's a lot to output), and you don't explain much about how to output each specific component (ideally the post should be self-contained enough to work out what to do without knowing too much about Python/dis) \$\endgroup\$ – Sp3000 Nov 9 '15 at 15:41
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Vigenère Cipher

Write a program that is capable of breaking a text encyripted using Vigenère cipher encyription.

Goals:

  • Take encripted text from STDIN and write plaintext to STDOUT.

Limits

  • Keyword will always be 3 letters in length.
  • Plaintext will always be in between 5-10 letters in length (inclusive).
  • All Plaintexts, Keywords and Encyripted Texts will be in English.

Scoring:

This is a . Shortest code in bytes wins.


I'm not sure if this is a valid and solvable question, so any suggestions are welcomed.

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  • \$\begingroup\$ Dupe \$\endgroup\$ – Mego Nov 10 '15 at 18:19
  • \$\begingroup\$ I'm not sure this can actually be done without having a big dictionary for such a short piece of text. (Also, what does "encrypted texts will be English" mean?) \$\endgroup\$ – Paŭlo Ebermann Nov 15 '15 at 15:01
  • \$\begingroup\$ @PaŭloEbermann It means they will only contain english characters, no special letters from other languages. \$\endgroup\$ – goodguy Nov 15 '15 at 15:12
  • \$\begingroup\$ Then write "consist of the letters A-Z" instead (or similar if you allow spaces and punctuation – though that needs more specification). \$\endgroup\$ – Paŭlo Ebermann Nov 15 '15 at 15:14
  • \$\begingroup\$ For Vigenere, in general you can either try a "plaintext dictionary attack" (which means you'll have a list of valid plaintext words, like in the question linked by Mego – that would be a plain duplicate), or you try analysis of character frequencies or repetitions, which need a lot longer ciphertext in order to analyze anything useful. (Or you just output all possible plaintexts, and let the task of recognizing the correct one to some human.) \$\endgroup\$ – Paŭlo Ebermann Nov 15 '15 at 15:19
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List Style Converter

[code:golf]

Task

Given a list, format it into list of the choice of the input. The list will be list of item defined below, but it can be multidimensional.

List Styles

There is 2 list separators:

  1. Space
  2. Comma

    For one dimensional list, only one separator is accepted. Space and only space between item is considered as separator. It is impossible to have more than 2 dimension without enclosing list of second dimension or third dimension. when parsing list, comma takes lower precedence and it is parsed with least dimension as possible. Space is optional between ] with [; } with {; and ) with (

    There is 3 list enclosure:

  3. [...]

  4. (...)
  5. {...}

    Closing bracket must be present.

Item

There is 2 types of item, another list or those following regex [0-9a-zA-Z]* or everything enclosed with single quote or double quote. If enclosed with single quote, it can contains double quote and vice versa. There is no zero-length item

Here is valid non-list item

98Az
Helloworld
"Hello, world!"
"It's house."

Here is the list

Hello, World!
Space then it is list
()

Here is invalid item.

!$%#%^$*%%^&%^&$%#:;,./<>?
Helloworld!

Input

The input consist of string of number then space then list as defined above. The number indicates the output format.

There are n digit of number where n is dimension of the input array. each number correspond with this one. (Table formatting needed). The dimension is counted from outer into inner. You may assume that there is no two 0 or 1 without being separated by 2 - 7.

  1. 0 = unenclosed comma list
  2. 1 = unenclosed space list
  3. 2 = parantheses enclosed comma list
  4. 3 = parantheses enclosed space list
  5. 4 = square bracket enclosed comma list
  6. 5 = square bracket enclosed space list
  7. 6 = curly bracket enclosed space list
  8. 7 = curly bracket enclosed space list

Output

A identical list but with formatting changed according to input (i.e. each item it list is identical). Space not between list is allowed

Test cases

> denotes output # denotes comment

6 Hello, world
> {Hello world}
5 (1, 1, 2, 3, 5, 8, 13, 21)
> [1, 1, 2, 3, 5, 8, 13, 21]
#Alternatively
> [1,1,2,3,5,8,13,21]
#Or
> [ 1,1, 2,3, 5,8, 13,21 ]
#But it is invalid
> [1,1, 2,3, 5,8, 1 3,2 1]
#Also
> [1,1,2,3,5,8,13,21,]
10 Hello, I am doctor
#Parsing rules that space separator bound tighter
> Hello I,am,doctor
01 Hello, I am doctor
> Hello, I am doctor
0 "Not to be confused be space or comma in a quoted item"
> "Not to be confused be space or comma in a quoted item"
51 [1,2] [3,4]
> [1 2,3 4]
51 [1,2][3,4]
> [1 2,3 4]

Sandbox Question.

The format needs helps. Needs pointing when there is ambiguity.

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  • \$\begingroup\$ I'm not sure that I fully understand this. To take a couple of your examples, Hello, World! appears to have two separators (a comma and a space): is it a one-dimensional three-element list, or a two-dimensional list? Is () a one-dimensional list or a two-dimensional list? And in the input, which order are the dimensions listed in, and what constraints are there on which formats can be used at which levels? (E.g. 00 is clearly not going to work, but I'm not sure whether 010 is permitted). \$\endgroup\$ – Peter Taylor Nov 16 '15 at 23:20
  • \$\begingroup\$ @PeterTaylor That's why I post the challenge here, because this challenge is nontrivial to writing. It is one dimensional comma separated list. Only space between item is list separator. Comma (except inside quote) isn't valid part of item. The input order is from outer into inner. You can assume that 00 and 010 isn't never entered. \$\endgroup\$ – Akangka Nov 17 '15 at 8:35
  • \$\begingroup\$ () is one-dimensional list since you have to it is parsed with least dimension as possible \$\endgroup\$ – Akangka Nov 17 '15 at 8:43
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    \$\begingroup\$ I'm afraid that I'm even more confused than before about spaces and commas. You seem to be saying that in the example 6 Hello, world a (comma plus space) makes a single separator in a one-dimensional list, whereas in 10 Hello, I am doctor a (comma plus space) is two distinct separators in a two-dimensional list. Do you have a reference implementation which we might be able to use to reverse-engineer the spec while the question is still in the sandbox? \$\endgroup\$ – Peter Taylor Nov 17 '15 at 16:55
  • \$\begingroup\$ In "Hello, world", "Hello" and "World" can be 1-item space separated list, however, lowest dimension takes precedence. In "Hello, I am a doctor" It is list containing 2 item. One is 1-item list, other is 4-item list. \$\endgroup\$ – Akangka Nov 18 '15 at 9:56
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Triangularity

The diagram of the triangle the program needs to solve.

This is a challenge where you have to work out the length of a given w and h.

To qualify as a correct solution:

  1. The program uses STDIN to get the values of w and h.
  2. The program uses STDOUT to output the value of a in the above diagram.

The shortest code in bytes wins.

Tags: code-golf, maths

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  • \$\begingroup\$ What's the formula? Unless it's very complicated, I expect it will be totally straightforward to golf. \$\endgroup\$ – xnor Nov 18 '15 at 11:45
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    \$\begingroup\$ @xnor, a = w/2 * sin(atan(h/w)). The diagram throws in some irrelevancies and omits a relevant line, but it's not an interesting problem. \$\endgroup\$ – Peter Taylor Nov 18 '15 at 13:02
  • \$\begingroup\$ @Peter Should I post this or do you think it's too easy? \$\endgroup\$ – Tobsta Nov 18 '15 at 21:31
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    \$\begingroup\$ @Tobsta I think it's too straightforward. Languages with trig will use the formula Peter gave, and the rest will do something like h*w/sqrt(h*h+w*w)/2. \$\endgroup\$ – xnor Nov 18 '15 at 21:58
  • \$\begingroup\$ @xnor Ok, got it \$\endgroup\$ – Tobsta Nov 18 '15 at 22:54
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Wildcard Golf

Introduction

I've read this problem long time ago somewhere but I still don't know what's the best solution, so I'm posting it here. I don't remember the original author or wording so here is all in my own words.

This is different from regex golf because only two wildcards, * (equivalent to the regex .*) and ? (equivalent to the regex .), are allowed.

Challenge

You are given two lists of strings. You need to generate the shortest wildcard that matches all strings in the first list (the wanted-list) and none in the second list (the unwanted-list). In the wildcard, you can use * to match 0 or more chars and use ? to match any one char.

For simplicity we can assume that inputs only have lowercase English characters and each string won't be longer than 100 characters. But the list can be very long (like several thousand), so speed of your program is important.

The correct answer that has the lowest average-case theoretic time complexity wins. In a tie, an easier-to-read answer wins.

Example Input and Output

Input:

  • Wanted list: abacum, academ, alarm, adam
  • Unwanted list: alien, african, atom

One possible output: a?a*

I'd also like to hear about how to approach this problem, and how to prove the theoretic lower bound of time/space complexity.


I'm new to this so comments are welcome. I'm not sure if my winning criteria is clear and practical. Also I don't know what tags I should put there. This is not a code-golf question.

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  • 1
    \$\begingroup\$ It's already been done \$\endgroup\$ – Peter Taylor Nov 17 '15 at 21:46
  • \$\begingroup\$ Thanks for pointing it out @peter-taylor. This challenge is different in terms of using wildcards, not regex. So you think it is not worthy to post? \$\endgroup\$ – Yan Li Nov 17 '15 at 22:06
  • \$\begingroup\$ Ah, I thought you were using wildcard as a synonym of regex. I take the point that removing alternation does make quite a different problem. Although it has the downside that there are insoluble cases (e.g. I don't think your wildcards can separate a wanted list of a and abba from an unwanted list of aba), so you'd need to specify how those cases should be handled. \$\endgroup\$ – Peter Taylor Nov 17 '15 at 22:16
  • \$\begingroup\$ Thanks! I'll edit and clarify these concerns. \$\endgroup\$ – Yan Li Nov 17 '15 at 22:18
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C++ Expression Matching

So, I like C++. And I like regex matching puzzles (heck, "regex golf" is what first got me lurking on this site). Might as well try to sort of combine the two!

Rules

Write a full program that takes as input two lists of zero to five integers in the range [1, 127], and outputs a string representation of a C expression that evaluates to nonzero / true for all integers in the first list, and zero / false for all integers in the second list. Input can be taken in any convenient form.

As a special case, if the second list is empty, then the expression returned must evaluate to true for only the integers in the first list, and false for all other integers in the range [1, 127]. Likewise, if the first list is empty, it should evaluate to false for the integers in the second list, and true for all others in that range.

The program will not receive two empty lists as input. If both lists are non-empty, there are no requirements on the result of the output when evaluated with an integer not in the input. (any return value is fine, as is undefined behavior, division by 0, etc).

The following tokens may be used in the expression:

  • Integer literals in decimal, hex, or octal, with optional U and/or LL suffix to denote unsigned / long long ints.
  • A single int variable, which will contain each of the integers from the input in turn. The variable can have any legal variable name.
  • Any of the unary operators + - ! ~
  • Any of the binary operators + - * / % << >> < > <= >= == != & | ^ && || ,
  • The ternary operator ?:
  • Parentheses.
  • Operators that mutate their arguments (++ --, = += -= etc.) are not allowed.
  • Character literals ('a', '_', '\0', etc.) are not allowed.

Some examples of possible outputs:

true            false           sample expression
[1, 3, 5, 7],   [2, 4, 6, 8]    c%2
[5, 6, 10],     [2, 8, 16]      t&~-t
[7, 14, 21],    []              22>x&!(x%7)

(TODO: Specify undefined / implementation-defined behavior details? My test program assumes 32-bit ints / longs, 64-bit long longs, and "nice" two's-complement signed overflow / conversion.)

This challenge is ; your score is determined by the total number of characters in the outputs for these ten randomly-generated inputs: (TODO).

Bonus: Subtract 15 from your score if the output expression evaluates to 1, not just nonzero, for all 'true' inputs.

Sandbox Questions

Welp, turns out my "Round Fractions" question from earlier is pretty much a subset of "Closest fraction". So here's another idea I've been tossing around since the one challenge I answered in C a while back (Area of an ASCII Polygon).

This is still very much a work-in-progress spec, though; some questions I have:

  • I believe this could be tagged as C rather than C++; the only difference I'm aware of is the ternary conditional's precedence, and given that no assignment operators are allowed, it might not make a difference.
  • I'm not sure what tags would go best on this (is it if the output isn't fixed?)
  • I imagine there should probably be some additional constraint to prevent theoretically optimal but impossibly slow brute-force searches.
  • The range [1, 127] is kind of arbitrary; my thought is that it should be able to handle anything in ASCII range + whitespace characters, but not much more than that, so as to make the special cases less restrictive.
  • Would there be a way to spin this off as , if establishing run-time conditions is too arbitrary?

I'm mostly done writing a program to test the output expressions; just need to do a bit more testing.

That's pretty much it; hopefully this is enough to work with for feedback. Thoughts / comments?

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  • \$\begingroup\$ Interesting challenge. I think a time-limited code-challenge is a better fit than code-golf, because there's a lot of complexity with that many operators and golfed code would be hideous. I think the random test cases should be supplemented with some which are designed to favour different operators, so that deciding to leave some out for speed becomes a real trade-off. There's only one integer literal which anyone would want to use in octal, so you could make a special case for 0. If you're going to allow LL in tokens then you really should be explicit about type widths. \$\endgroup\$ – Peter Taylor Nov 26 '15 at 21:01
0
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Typographic Chemistry

Inspired by this: https://xkcd.com/1442/

Task

You must make a program or function that take input a string from STDIN and output the possible allowed reactions (1 point per unique reaction, see also "Score" below)

Rules

A chemical reaction is allowed if all the "legs" of the elements are used, i.e., there are no unpaired "legs". A "leg" is just the end of a curve in the typographic print of the chemical symbol (see the comic and it should be clear). So for example:

Carbon - C - 2 legs

Oxygen - O - 0 legs

Hydrogen - H - 4 legs

Nitrogen - N - 2 legs

Potassium - K - 4 legs

Phosphorus _ P 1 leg

An element can be rotated, reflected but not stretched in any way, so that the only possible bonds are (here I don't know how to rotate the chars, if somebody can help it would be welcome):

$$CH \;\mathrm{(with\;the\;C\;on\;top\;or\;bottom\;rotated\;by\;90\;degrees)}\\CK \;\mathrm{(with\;the\;C\;on\;top\;or\;bottom\;rotated\;by\;90\;degrees\;or\;to\;the\;right\;rotated\;by\;180)}\\ HK\;\mathrm{(on\;top\;of\;each\;other\;or\;on\;the\;side\;rotating\;one\;by\;180)}\\ NN\;\mathrm{(with\;one\;reflected\;has\;two\;legs\;on\;top\;and\;two\;diconnected\;legs\;on\;bottom)}\\ P\;\mathrm{(with\;anything)}\\ O\;\mathrm{doesn't\;bond}$$

These are the only possible elements passed from STDIN. Notice that the difference between H and K is that K can bond also laterally with a C.

Extra Rule

If no reaction is possible, the output should be equal to the input

Score

1 point per reaction. Bonus: X3 the score if you can print the reaction diagramatically, i.e. print the shape of the molecule (like in the comic)

Example

$$Input \rightarrow Output\\ C\,C \rightarrow (C_2)\\ N \, N \rightarrow N \, N\\ C\,N \, N\,P\,P \rightarrow (C N_2 P_2)\\ C\,C\,K \, H\,H\rightarrow (KC_2H_2)\\ C\,H\,O\rightarrow C\,H\,O $$

\$\endgroup\$
  • \$\begingroup\$ Your rules seem to be imposing extra grid-alignment constraints on the letters (e.g. you don't seem to permit the hydrogen crystal from the xkcd). Does that mean that although P can bond with anything except O, the positions in which it can do so are restricted? \$\endgroup\$ – Peter Taylor Nov 24 '15 at 19:05
  • \$\begingroup\$ Hi, I don't want to impose necessarily the extra grid alignment, thanks for noticing it. Yes, P can bond with anything, I added it so that it is easier to have "allowed" reactions. \$\endgroup\$ – Costantino Nov 25 '15 at 15:01
  • \$\begingroup\$ So does that mean e.g. that CP_2 is possible? \$\endgroup\$ – Peter Taylor Nov 25 '15 at 15:12
  • \$\begingroup\$ yes it is, although I have no idea how you could print it. Do you have any good way to state the rules simply and effectively? \$\endgroup\$ – Costantino Nov 25 '15 at 15:39
  • \$\begingroup\$ This is so far from the truth of chemistry that you really need some decent drawings to show what's acceptable. The number of bonds an atom can make is in reality determined by its column in the periodic table: K=1 (except the bond is usually ionic not covalent), H=1, C=4, N=3, P=3 (sometimes 5), O=2. \$\endgroup\$ – Level River St Nov 25 '15 at 23:25
  • \$\begingroup\$ Hi, I have prepared an image, but I can't upload it because I don't have enough reputation. Can you help me? \$\endgroup\$ – Costantino Nov 26 '15 at 16:06
  • \$\begingroup\$ The easiest solution I can see is to remove entirely the list of possible bonds and the bonus and to effectively convert it into a question of whether there exists a graph with the desired degree sequence. IMO that's still an interesting question, and one which hasn't been asked here before. \$\endgroup\$ – Peter Taylor Nov 26 '15 at 21:08
0
\$\begingroup\$

Note: I think the question is fine. I just need some more testcases for it.



You are given the priority order of alleles for a particular trait. For example,

A B
O

means that A and B are equally dominant and O is recessive to both of them. An organism has exactly two alleles, but only the dominant trait(s) is/are expressed. So an organism with gene AO will express only A but an organism with gene AB will express both A and B. An organism with two same alleles will express that allele only.

Each offspring will receive two alleles - one from the mother and the other from the father. So if the initial parents are AB and AO, the offspring formed will be:

AA - 25%
AO - 25%
AB - 25%
BO - 25%

Expressed traits will be

A - 50%
AB - 25%
B - 25%

Offspring of one generation may breed only with a single member of the opposite sex in the same generation during its lifetime. Assume for the sake of this challenge that every male finds a random female in the same generation and has exactly two children - one male and one female. Siblings may interbreed. Note that, except for the first generation, we can ignore the sex of the individuals as their sex chromosomes assort independently of their other characteristics.

Input

  • Priority order of all alleles (may include unnecesary alleles)
  • Genotype of every organism in initial generation
  • Number of generations created
  • Any one allele
  • (Optional) Number of lines of input for priority order (for languages like C++)

Output

  • Probability of the specified allele existing in a randomly selected individual in the specified generation (accurate to three decimal places)

Challenge

  • Once two/three answers are posted, I'll use the same testcases in all of them to see which of them are faulty.
  • After a week (or I could prolong the deadline) I will upload a lengthy test case in a few days. The code that solves it in the fastest time wins.

Sample data (Some simple testcases)

#1

A
B
C
Male(s) - AA
Female(s) - AB
5
C

Output 0

#2

A
B
C
Male(s) - AA
Female(s) - AB
2
A

Output 0.75

#3

A B
C D
Male(s) - AC,BD
Female(s) - AC,BC
1
C

Output 0.125

\$\endgroup\$
  • 1
    \$\begingroup\$ "Once two/three answers are posted, I'll use the same testcases in all of them to see which of them are faulty" You should have a way to verify answers without using other answers. \$\endgroup\$ – FryAmTheEggman Dec 1 '15 at 17:35
  • \$\begingroup\$ @FryAmTheEggman I am abandoning this Q, anyone else is free to post it themselves. \$\endgroup\$ – ghosts_in_the_code Dec 2 '15 at 9:47
0
\$\begingroup\$

Cops and Robbers - Find the Formula

Cops will write a function that takes numerical inputs and produces numerical outputs (note - outputs can be any base and may contain letters). They will post the language, the number of bytes it takes to write the code (up to 128), rounded up to the nearest power of 2, as well as a minimum of 2 test cases. The robbers will try to write a program that takes the same numerical inputs as the test cases and produces identical outputs.

Note - PRNG's, hashing, and other forms of encryption are not allowed.

Scoring

Cops (if safe)

The floor of the product of:

  • 128 divided by the power of two rounded up for the bytes
  • The natural logarithm of the number of test cases

If cracked, -10 points.

Robbers

The floor of the quotient of

  • Half the number rounded up to by the cops
  • The natural logarithm of the number of test cases
\$\endgroup\$
  • \$\begingroup\$ Say I have a function f(x) that returns x when x<2 and 3*x ᴏtherwise. Would the robber's function only have to match the given test cases, or have to match all test cases? \$\endgroup\$ – Conor O'Brien Nov 27 '15 at 3:06
  • \$\begingroup\$ @CᴏɴᴏʀO'Bʀɪᴇɴ The given test cases only. \$\endgroup\$ – Arcturus Nov 27 '15 at 3:16
  • \$\begingroup\$ Is there a maximum of test cases? \$\endgroup\$ – Conor O'Brien Nov 27 '15 at 3:24
  • \$\begingroup\$ @CᴏɴᴏʀO'Bʀɪᴇɴ I'm not sure if there should be. If there were, I'd say maybe 10 or 12. \$\endgroup\$ – Arcturus Nov 27 '15 at 3:25
  • \$\begingroup\$ I think the scoring algorithm might be a bit complex. \$\endgroup\$ – Conor O'Brien Nov 27 '15 at 3:41
  • \$\begingroup\$ @CᴏɴᴏʀO'Bʀɪᴇɴ I want to do something that awards points depending on the number of test cases because that makes it more likely that the robber found the intended solution and is "more" right. \$\endgroup\$ – Arcturus Nov 27 '15 at 5:03
  • 2
    \$\begingroup\$ The cops-and-robbers lesson which everyone should have learnt by now is that built-in crypto functions should be banned because otherwise the cops have an easy time. \$\endgroup\$ – Peter Taylor Nov 27 '15 at 13:49
  • 1
    \$\begingroup\$ ^ That should include hashing and PRNGs. Although it's really hard to rule them out conclusively. My personal goal is still to come up with more CnRs that aren't susceptible to stuff like that in the first place (like my Programming Language Quiz). \$\endgroup\$ – Martin Ender Nov 27 '15 at 14:00
  • \$\begingroup\$ @MartinBüttner Given that I've explicitly disallowed hashing, PRNGs, and encryption, what do you think of this challenge? \$\endgroup\$ – Arcturus Nov 27 '15 at 22:15
  • \$\begingroup\$ @Eridan It's still susceptible to arbitrary base conversions or expmod (just check out any CnR-submission by Dennis to see some examples). People can just throw together a quasi-random program in a golfing-language without having to understand it and just run some numbers through it to generate test cases. \$\endgroup\$ – Martin Ender Nov 27 '15 at 22:36
  • \$\begingroup\$ @MartinBüttner I didn't realize those were bad for CnR challenges (I even mentioned base conversion above). Is there a specific way I could describe methods like those to disallow them? \$\endgroup\$ – Arcturus Nov 27 '15 at 22:50
  • \$\begingroup\$ @Eridan none I can think of. That's why I meant that this is an inherent problem of any CnR that lets participant choose what their program does. In CnRs where the programs need to solve a specific task, this is not such a big issue, because the cops actually need to find a convoluted but working implementation themselves. \$\endgroup\$ – Martin Ender Nov 27 '15 at 23:07
  • \$\begingroup\$ Even with crypto banned, numerical functions make for boring CnR challenges since it's much more likely to be about finding parameters rather than guessing the structure of the code. \$\endgroup\$ – xnor Nov 28 '15 at 9:57
  • 1
    \$\begingroup\$ A problem: Anyone can just write an interpolating polynomial. \$\endgroup\$ – LegionMammal978 Nov 28 '15 at 13:49
0
\$\begingroup\$

Quiddler

Quiddler is a card game where you try to create words from letter cards drawn from a deck. A word is defined as being more than 2 cards in length. Sometimes letters are combined on cards in this game, however that will not be the case in this challenge.

Your mission is to write a program which creates words from the letters read in on standard input. Your dictionary of words is the words file on any standard unix system. You may assume that all strings this file is all lowercase.

Input

The string of letters you can use to create words is read in on standard input. This string will be all lowercase, and will not have any spaces in it.

Valid examples are:

actlj
jactl
ljdkj
jjabc

Invalid are:

jklKLJKKJLKUIU
klj kljklj djkas;

Output

The list of all possible results from said string each string. Remember you can produce multiple words in the same answer.

Examples of valid output include. Please remember that I came up with these off the top of my head, and may not be complete. Input is left aligned and the output is presented as the indented lines. The -> is for your benefit.

tacb  -> 
         cat
         act
         bat
         tab

fivquedrr ->
         five qud
         quid five
         river
         quiver

The order of the solutions output does not need to be in any specific order.

The environment

This program must run in a standard UNIX-like environment. This means that you may use any standard shell (bash, ksh, csh, zsh, fish), and you have access to all the standard tools. This challenge is restricted to the shell scripting languages.

The path to the dictionary file in the environment variable, DICT, the path to the file should not be in any valid solution. Use $DICT as the path to the dictionary. This is included so that you can provide testing instructions for your program.

Winner

The winner is the one with the fewest bytes of code that produces the correct output.

\$\endgroup\$
  • \$\begingroup\$ In the example output, I'm not sure why for the first input the output is newline-separated, but for the second it's space-separated. I also don't understand the second paragraph in the section "The environment". \$\endgroup\$ – Peter Taylor Nov 27 '15 at 21:30
  • \$\begingroup\$ @PeterTaylor In quiddler you can have multiple words per possible solution. I'll add a second example to demo. \$\endgroup\$ – HSchmale Nov 27 '15 at 21:53
  • \$\begingroup\$ So is this basically a variant on Countdown where the dictionary is amplified by including its Cartesian power? \$\endgroup\$ – Peter Taylor Nov 28 '15 at 8:08
  • \$\begingroup\$ @PeterTaylor: Pretty much, except I did not know that existed. Also, for each answer you can only use each answer once. \$\endgroup\$ – HSchmale Nov 28 '15 at 16:43
0
\$\begingroup\$

Ancient Language Translator

<insert a silly story here>

Task:

Write a program that takes an English sentence and translates it into the Ancient Language. You have to implement at least 42 words. For the purpose of this challenge, you do not have to care about special rules such as "(may be shortened to al when used as a prefix, as in albitr)".

Input:

An English sentence.

Output:

A translated version of the input, simply replace the English words with the Ancient ones.

Examples:

To be added.

Scoring:

Suggestions?

\$\endgroup\$
  • 2
    \$\begingroup\$ This might be considered as too broad as there is no specific words to implement. For scoring a code-challenge might work with the score being something like the sum of the length of all words implemented. code-golf might also work. Kind of related challenge. The title is also possibly misleading, so I'd suggest putting "Ancient Language" in quotes \$\endgroup\$ – Downgoat Nov 29 '15 at 16:55
  • \$\begingroup\$ I think this would be uninteresting just because it's just replacement, not actual translation. \$\endgroup\$ – cat Nov 30 '15 at 3:07
  • \$\begingroup\$ @sysreq Translating English into the "Ancient Language" is just replacement as far as I know... \$\endgroup\$ – Stefnotch Nov 30 '15 at 17:24
  • \$\begingroup\$ @Downgoat Oh, ok! So, what words should have to be included? A selection of) the most common words: en.wikipedia.org/wiki/Most_common_words_in_English \$\endgroup\$ – Stefnotch Nov 30 '15 at 17:26
0
\$\begingroup\$

Nested Header List

The goal of this challenge is to complete a list of consecutive nested header numbers when given a start and an end. When given 1.1.1 and 1.1.5 you should generate 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5

Specific Rules

  1. Your entry must take in a start, end, and multiple optional range parameters. Parameters can be taken form STDIN (or nearest equivalent) or a file.
  2. Your entry may assume valid input
  3. Input will be of the following format:
    1. start and end will be strings of . delimited integers of the same length
    2. start and end will have three segments; (1) set values, (2) iterator, (3) trailing values.
      • The iterator is the first value which differs between start and end.
      • The set values are the values before the iterator. These values never change
      • The trailing values are the values after the iterator. These values iterate up as determined by the range parameter(s). All trailing values will be 1.
    3. range will be a list of integers with a length corresponding to the number of trailing values. When there are no trailing values, range is not specified. The value of range corresponding to each trailing value determines the inclusive upper bound which that entry iterates to.
  4. Output will be to STDOUT (or closest alternative) and will show each value separated by at least one delimiter. Delimiter can by any character or string of characters, but it must be consistent. Output must be sorted correctly

Examples

start = '1.1.5.1', end = '1.1.6.1', range = [5]
Output: 1.1.5.1, 1.1.5.2, 1.1.5.3, 1.1.5.4, 1.1.5.5, 1.1.6.1
                                                  ^
                                                  previous value is iterated
                                                  only when iterating value
                                                  limit set by range


start = '1.1.5.1', end = '1.1.7.1', range = [5]
Output: 1.1.5.1, 1.1.5.2, 1.1.5.3, 1.1.5.4, 1.1.5.5, 1.1.6.1,
        1.1.6.1, 1.1.6.2, 1.1.6.3, 1.1.6.4, 1.1.6.5, 1.1.7.1

start = '1.5.1.1', end = '1.6.1.1', range = [5,2]
Output: 1.5.1.1, 1.5.1.2, 1.5.2.1, 1.5.2.2, 1.5.3.1, 1.5.3.2, 
        1.5.4.1, 1.5.4.2, 1.5.5.1, 1.5.5.2, 1.6.1.1

This is code golf so shortest code by bytes wins.

Bonuses

  1. Allow trailing values to be values other than 1 in end parameter - 12.5% off
  2. Handle incorrect number of values in range parameter - 12.5% off
  3. Handle end less than start by producing list in reverse - 50% off
\$\endgroup\$
0
\$\begingroup\$

Count the Connect Four Positions

Connect Four is a two-player game on a rectangular board. The board is m spaces wide and n spaces tall, and players alternate placing pieces in columns. A placed piece always fills the lowest empty space in a column, and a player may not move in a full column. In the standard game, m=7 and n=6.

The game ends when one player completes a row of four pieces vertically, horizontally, or diagonally, or all m columns are full. The edges of the board do not wrap.

Challenge

Write a program or function to determine the number of distinct, legal m by n Connect Four boards after p plies. (A ply is one move by one player.) A legal position is one reachable from the empty board through a sequence of moves in which no player had already won. (A position in which one player has just won is legal.)

Rules

You may assume that 0<=p<=m*n, m<=8 and n<=8.

As usual, hardcoding is not allowed.

Your code should be at most 1024 bytes in length, and use at most 16 GB of memory.

Related: Determine winner of Connect 4

Test cases

[need to add; include OEIS]

Relevant links:

\$\endgroup\$
0
\$\begingroup\$

Compile from Brainfuck

The professors at Brainfuck University realized their jobs are horrible, because all they do is discuss quantum mechanics using Brainfuck, so they decided to take their programs and compile them to a better language. Because of the randomness of quantum particles, their program needs to be small so it has a smaller chance of being disrupted in the Higgs Field.

Your task is to get a Brainfuck program from any input and output that program transcompiled into another language. Here is an example:

++-->><<

Compiles to the C program:

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {
    unsigned char *cell = calloc(30000, 1);
    unsigned char *cells = cell;
    if (!cell) {
        fprintf(stderr, "Error allocating memory.\n");
        return 1;
    }
        //actual program
        ++*cell;
        ++*cell;
        --*cell;
        --*cell;
        --cell;
        --cell;
        ++cell;
        ++cell;

        free(cells);
        return 0;
}

Score

Your score is the size of your program added to the size of the output.

Bonuses

\$\endgroup\$
  • 3
    \$\begingroup\$ Dupe \$\endgroup\$ – Mego Dec 5 '15 at 9:55
0
\$\begingroup\$

Logic Puzzle Solver/Inference Engine

Your goal is to take the clues and other facts given in a grade-school logic grid puzzle such as these and solve the puzzle. To keep things simple, your program will only solve specific logic problems about which it can make the assumptions you wish to hard-code in, but the program need not perform any checks to see if those assumptions can be made.

You may not use:

  • A declarative language
  • Any function provided - by an external dependency - for the solving of a logic puzzle.

Input

Your program will take input from the command line. After gathering assumptions, the program will ask for facts written as such:

subject.verb object

for all true facts. For false facts:

!subject.verb object

Examples: If Chad bought donuts,

Chad.bought donuts

If he didn't:

!Chad.bought donuts.

If Nancy's last name isn't Wesley,

!Nancy.is Wesley.

Output

Your program will output its conclusions as such:

subject verb object.

So, if your program determines that Chad bought donuts and Nancy's last name is Wesley, then it will output:

Chad bought donuts.

Nancy's last name is Wesley.
\$\endgroup\$
  • 3
    \$\begingroup\$ The "these" link goes to a login page. I'm not going to create an account on some random site just to find out what the spec is. \$\endgroup\$ – Peter Taylor Dec 15 '15 at 22:24
  • \$\begingroup\$ "You may not use a declarative language" :-( \$\endgroup\$ – Fatalize Dec 16 '15 at 12:59
  • \$\begingroup\$ Does "is" always refer to someone's last name? If not, how can our code know the difference between Nancy.is Wesley and Nancy.is chef? \$\endgroup\$ – Luke Dec 16 '15 at 14:49
0
\$\begingroup\$

New user to Programming Puzzles!

Spades CHALLENGE!!!

I would like a king of the hill challenge for bots playing the game of spades. Spades is a card game. The rules are shown on wikipedia.

Scoring rules:

  • Nils allowed, with 50 points for completion (not 100). -50 for losing.
  • 10 points a hand, with sandbagging allowed.
  • Partnership Playing
  • Sum of all four players hands cannot equal 13!

Winner is first to 500 points. The bot will be paired with all other bots entered into the competition. The pair of winners will be crowned with +10 meta-points (Mpoints), losers will get -1 Mpoints. Whoever has the most Mpoints wins - ties based upon sum of points earned in the games.

Gameplay:

  • The bot with the lowest Mpoints bids first. Bidding proceeds from down until reaching 4th slot, then goes back to first slot and continues. Play starts with this player.
  • The bot will be given a string of cards - AS for Ace of Spades, JC for Jack of Clubs, 2D for 2 of Diamonds, 8H for 8 of hearts, randomly dealt from a single 52-card deck. Each will be comma separated: AS,JC,2D,8H,4C,5S,8D,3D,3S,JS,10S
  • The bot will get the bids from the other bots before making the bid.
  • Upon winning a hand, the bot gets to continue making plays until someone else wins the hand.
  • Hands are scored at the end using the scoring rules. If a team's score is less than 500, gameplay continues with a new hand.

Unfortunately, I do not know how to setup the servers or any of that stuff. I just think the challenge will be interesting. If anyone can help with that, run with it. I like to watch these challenges unfold - but I'm too much of an engineer and not enough of a programmer to make these kinds of programming happen.

\$\endgroup\$
  • \$\begingroup\$ You should fully list out the rules in the body of the question - it's considered poor form for challenges to require exterior resources to be fully understood. \$\endgroup\$ – Mego Dec 22 '15 at 22:56
0
\$\begingroup\$

I was thinking about a challenge on wrapping time.

I am a member here for 34 days now. I would have expected for the date to wrap to 1 month.

Rules:

  • starting with hours from the joining date to now.

  • first wrapping happens when you go over 24 hours, the count will be in days now.

  • second wrapping happens after reaching 30 or 31 days, you can decide, to months.

  • third wrapping really wraps when a year is reached, it shall be displayed as i.e. 2 years 3 month.

  • round to neares full unit, i.e. 43 days = 1 month, 50 days = 2 month

  • take either a build in function to get the current time or hardcode it to ´2015-12-19-11´ <- time when challenge will be posted. If hardcoding it is shorter you may take the bytecount from the hardcoded version.

  • Dates after the current or hardcoded date can do whatever.

Input

The joining date and hour like ´YYYY-MM-DD-HH´ the delimeter does not have to be a - choose whatever you like.

Output

The time according to the rules above.

Example:

In: 2015-12-10
Out: 9 Days

In: 2015-10-28
Out: 2 Month
\$\endgroup\$
  • \$\begingroup\$ I believe I saw a challenge about wrapping 24-hour time that may be related, but not a duplicate. Also, what date are we calculating the difference from? \$\endgroup\$ – ASCIIThenANSI Dec 18 '15 at 17:05
  • \$\begingroup\$ that would be the date right now or a set date if no build in is available \$\endgroup\$ – Eumel Dec 19 '15 at 8:19
  • \$\begingroup\$ I think it should be either a built-in date or another date given from input for all languages, to make things fair. \$\endgroup\$ – ASCIIThenANSI Dec 19 '15 at 16:02
  • \$\begingroup\$ I wanted it to be non input, how would you suggest doing that? \$\endgroup\$ – Eumel Dec 19 '15 at 20:01
  • \$\begingroup\$ Use a built-in date such as 01-01-2015 (or 01-01-2000, depending on what the date range should be). The program should not be required to accept dates before that. \$\endgroup\$ – ASCIIThenANSI Dec 20 '15 at 21:14
0
\$\begingroup\$

Browser identifier

There are three major browsers at the moment, Internet Explorer, Google Chrome and Firefox. Sometimes, the JavaScript engines inside of these browsers work a bit differently, and that can break some applications. Therefore, we need a way to identify what browser the user is currently using!

Your answer should be a JavaScript program or function, that when run on the latest version of a browser, should output a string representing that browser. The string outputed could be anything, as long as it stays the same every time you run it. Output should go to a HTML paragraph with id O, console.log, or as return value.

Please put your answer in a snippet, along with <p id="o"></p> in the HTML section if your answer uses it.

(scoreboard snippet goes here)

\$\endgroup\$
  • 1
    \$\begingroup\$ I believe Javascript has a builtin for this. It may be best to forbid using it. \$\endgroup\$ – SuperJedi224 Dec 22 '15 at 17:34
  • \$\begingroup\$ @SuperJedi224 Well, I did some searching before, and I found this thread on SO, and the highest voted answer was a big mess, and no answer was very short and reliable. There is this other thread, and it has some that could be golfed a bit, but there isn't really one function / builtin that checks the browser. \$\endgroup\$ – Loovjo Dec 23 '15 at 2:56
  • \$\begingroup\$ You might need to freeze the version numbers of the 3 browsers, or else require that answers specify version numbers. \$\endgroup\$ – trichoplax Dec 29 '15 at 15:54
0
\$\begingroup\$

Parse a tree for pruning

Windows supplies users with tree: a neat little tool that converts a directory tree to ASCII-CP437 art. It's a very human-readable format. However, it's a bit useless if you want the directory tree of an entire drive, or even just the Windows folder, as it's very hard to prune the parts you don't want. Hence this challenge.

Task

Your task is to produce a function or program that will convert the tree from one or both of the input formats into one or more of the output formats. The smaller your code, the more of a head start you have.

Input

There are two types of input that you might be given:

CP437

This is the default.

Folder PATH listing for volume Main Drive
Volume serial number is 00F3-F586
C:\WINDOWS
│   explorer.exe
│   notepad.exe
│   virus.dll
│   WLXPGSS.SCR
│   write.exe
│   
├───Boot
│   │   BootDebuggerFiles.ini
│   │   
│   ├───DVD
│   │       your.txt
│   │       
│   ├───EFI
│   │       pc.txt
│   │       
│   ├───Fonts
│   │       has.txt
│   │       
│   ├───PCAT
│   │       been.txt
│   │       
│   └───Resources
│           wrecked.txt
│           
├───System
└───System32
        cmd.exe
        conhost.exe
        winlogon.cmd
        winlogon.exe

ASCII

This will be easier to parse for many languages.

Folder PATH listing for volume Main Drive
Volume serial number is 00F3-F586
C:\WINDOWS
|   explorer.exe
|   notepad.exe
|   virus.dll
|   WLXPGSS.SCR
|   write.exe
|   
+---Boot
|   |   BootDebuggerFiles.ini
|   |   
|   +---DVD
|   |       your.txt
|   |       
|   +---EFI
|   |       pc.txt
|   |       
|   +---Fonts
|   |       has.txt
|   |       
|   +---PCAT
|   |       been.txt
|   |       
|   \---Resources
|           wrecked.txt
|           
+---System
\---System32
        cmd.exe
        conhost.exe
        winlogon.cmd
        winlogon.exe

Output

There are several possible types of output you can return, each suited to a different type of language.

Array / List hierarchy of strings

The first element of each array / list is the name, the rest are the contents. Files should be represented by strings, empty folders should be represented by a single-length array containing one string. Note: This should be returned from a function as an array / list, not printed as a string.

["C:\WINDOWS", "explorer.exe", "notepad.exe", "virus.dll", "WLXPGSS.SCR", "write.exe", ["Boot", "BootDebuggerFiles.ini", ["DVD", "your.txt"], ["EFI", "pc.txt"], ["Fonts", "has.txt"], ["PCAT", "been.txt"], ["Resources", "wrecked.txt"]], ["System"], ["System32", "cmd.exe", "conhost.exe", "winlogon.cmd", "winlogon.exe"]]

Object / Dictionary

Similar to array / list, but a little more intuitive. Folders should have the value of their contents as another object / dictionary. Files should have the value "FILE".

{"C:\WINDOWS":{"explorer.exe":"FILE","notepad.exe":"FILE","virus.dll":"FILE","WLXPGSS.SCR":"FILE","write.exe":"FILE","Boot":{"BootDebuggerFiles.ini":"FILE","DVD":{"your.txt":"FILE"},"EFI":{"pc.txt":"FILE"},"Fonts":{"has.txt":"FILE"} [...] } [...] } [...] }

Lisp-style string

Similar to array / list, where the head of the list is the directory name and the tail is the contents. An empty directory is a list with no tail, and a file is a string.

No WAY am I putting an example. No way. I've spent half the time on this question creating the examples. No way. Ok, maybe later.

Bonus

If you satisfy none of these bonuses, your submission is still valid. But its score shall infinite, so it is non-competitive.
These bonuses are to multiply your score by. Bonuses stack by multiplication. These bonuses must all be achieved consistently to be awarded.

  • 100% Allow at least one input mode and output mode
  • 50% Allow both input modes
  • 90% Output in exactly two ways
  • 50% Output in one of two ways depending on parameters
  • 80% Output in exactly three ways
  • 25% Output in one of three ways depending on parameters
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0
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Identifying spies in "Resistance"

This is still very rough, but I think it has the makings of an interesting challenge. Please help me improve it. What do I need to add? What do I need clarify?

Resistance is a party game that pits "resistance members" against "imperial spies" on a series of missions. A very important aspect of the game is that the resistance members do not know who the spies are, whereas the spies do know who is who.

How the game works

The relevant details of the game will be added here. For now, just check the Wikipedia page linked in the title.

Challenge

your challenge is to write a program that takes as input the details of every round and outputs who it thinks is a spy after each round. There are 5 rounds (missions) in a game of resistance, so the program/function will take in all the data for the first round, which includes

  1. Each proposed team to go on the mission
  2. Each public vote following each proposal
  3. The final team to go on the mission
  4. The outcome of the mission (i.e. how many passes and how many fails)

It will then output who it thinks is a spy. It will then do the same for each subsequent round.

Important Details

We will be playing resistance for (6?) people, A, B, C, D, E, and F.

Input format is flexible. It may be done round by round or all at once. However, since ach submission is outputting something for each of the five rounds, the submission may not use information from future rounds (if all information is given at once) in judging the current round.

Here is an example of possible input format:

Since the first mission requires two people, and person A is the first mission planner, the only thing input would be two letters in {A,B,C,D,E,F} indicating his selection. Then the votes of each person, in order, would be input. This continues until a mission team is accepted. Then the votes given on the mission would be input, in no/any particular order. The program would then output the letters of the two people it thinks are spies (there are 2 spies in a 6 person game). Here is an example

A B              # A selects A and B for first mission
P P P F F F      # Everyone votes, mission team is not accepted (lacks majority pass)
B F              # B selects B and F for first mission
P P P P P F      # Mission team is accepted (majority pass)
P F              # Mission fails (there is at least one fail vote). Note that the order does not matter here. 

The bot would then output two people, the people it thinks are most likely to be the spies based on all the information it has up to this point.

B F              # Any two person subset is acceptable

Input then continues for the next 4 rounds, until the game is over.

Scoring

I will write several hundred test cases (from actual games played online). Then each output will be scored in the following way:

  • 1 point for each correctly guessed spy.
  • 1 point for guessing both spies correctly.

The submission's total score will be the sum of all scores on all rounds in all games. The program will never be told who is a spy (unless it is used to self-score and does not factor into the actual guessing) but this information will be available with the test cases for scoring purposes.

Tie break is code golf.


Meta: I think I'm going to remove output after the first round, because very rarely do people ever fail the first mission. So it will likely just be pure chance.

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0
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Nth Regex

This challenge('s explanation) is simple: given a number n and a regex r, output the nth string that matches r!

The regex r uses the syntax used in Python, described here. The regex will be for the whole string, meaning the regex will be implicitly wrapped in ^$.

The only valid strings are printable ASCII characters, and they count up like base 95 (ASCII codes 32-126).

To prevent people from brute-forcing it, I was thinking of making it .

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  • 1
    \$\begingroup\$ I still think you mean "bijective base 95". otherwise, there are no strings with leading spaces (because if count up in base 10, there are no numbers with leading zeroes). \$\endgroup\$ – Martin Ender Dec 29 '15 at 14:09
  • 4
    \$\begingroup\$ I'm not a fan of using a specific real-world flavour, because that gives an advantage to Python over all other languages. I also think it contains way too many features to be fun to tackle (which don't really add anything interesting to the challenge). I think the challenge would be interesting and hard enough for a simplified regex flavour containing only simple quantifiers, alternation and character classes. \$\endgroup\$ – Martin Ender Dec 29 '15 at 14:11
  • \$\begingroup\$ I'm quite sure that some regexes are hard to solve. codegolf.stackexchange.com/questions/39829/… \$\endgroup\$ – Element118 Dec 29 '15 at 15:54
  • \$\begingroup\$ I absolutely don't get the challenge, any example input/output ? \$\endgroup\$ – Tensibai Dec 30 '15 at 14:31
  • \$\begingroup\$ Do you mean nth string lexicographically? \$\endgroup\$ – xnor Dec 30 '15 at 18:45
0
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Robots on ice

Part 1 - The basic

You are helping a robot R on an iced island. R can go up/down/left/right. But since the island is made of ice, it cannot move only 1 square at a time, but instead moves in straight line. Your task is to help R reach G.

Input

The input (file, stdin, input, whatever suits you) is an n×m matrice with the following characters:

  • R The robot
  • G The goal
  • # An obstacle that stops the robot
  • Ice

The island is surrounded by a wall: the edges of the matrice always consist of #.

Output

A list of instructions consisting of U/D/L/R, corresponding to up/down/left/right.

The list should be the shortest possible. The distance traveled by the robot doesn't count.

The output should be the map with the instructions on it, with each instruction at the right coordinates. Each of RG# should be displayed if not overriden by an instruction (that will always be the case for R)

Example

Input:

##########
# #      #
#        #
#  G #   #
#        #
#    R#  #
#        #
##########

Output: Since D,R,U,L,D is one possible solution, the output should be:

##########
# #D    L#
#        #
#  G #   #
#        #
#    D#  #
#    R  U#
##########

Another solution, U,R,U,L,D, should be output as:

##########
# #D    L#
#        #
#  G #   #
#    R  U#
#    U#  #
#        #
##########

Input:

####################
###R             ###
#  ######          #
#      #####       #
##                G#
###              ###
####################

Output:

####################
###R            D###
#RD######          #
#U L   #####       #
##R               G#
###U            L###
####################

You can assume that the puzzle always has at least 1 solution

Part 2 - New options

The pitch is the same, but new characters can be displayed:

Input

The input (file, stdin, input, whatever suits you) is an n×m matrice with the following characters:

  • R The robot
  • G The goal
  • # An obstacle that stops the robot
  • Ice
  • W Some water. Robot doesn’t like water
  • B a Box. Robot can push the box 1 square at a time, in front of him (not on the side), if the next square is . It cannot be pushed into the water, through the goal… Robot cannot push 2 boxes at once. When pushing, the robot stays in place.
  • 1 a numbered teleportation door. Always in pair. When entering a teleportation door, Robot will continue sliding in the same direction through the other door. Can be used more than 1 time.

The island will this time be surrounded by water.

Output

A list of instructions consisting of U/D/L/R, corresponding to up/down/left/right.

The list should be the shortest possible. The distance traveled by the robot doesn't count.

This time the output won't be displayed on the map, but on stdout. The format doesn't matter:

UDRL

or

U
D
R
L

are accepted

Example

Input:

WWWWWWWWWW
W W      W
W        W
W  G 1   W
W        W
W    1R  W
W        W
WWWWWWWWWW

Output:

L

Input:

WWWWWWWWWW
W W      W
W    #   W
W  G     W
W        W
W    BR  W
W        W
WWWWWWWWWW

Output:

LLUL

The first L moves the box (but not the Robot) 1 square:

WWWWWWWWWW
W W      W
W    #   W
W  G     W
W        W
W   B R  W
W        W
WWWWWWWWWW

Input:

WWWWWWWWWWWWW
W         # W
W G 2       W
W           W
W   B 1     W
W#2         W
W   # 1R   #W
W          #W
W    #     #W
WWWWWWWWWWWWW

Output:

L #entering teleportation 1
L #pushing the box to the left
L #going to the box
U #entering teleportation 2

The solution RULU is also valid

Input:

WWWWWWWWWWWWW
W #         W
W     #     W
W#   1      W
W           W
W           W
W    1 R    W
W           W
W    G      W
WWWWWWWWWWWWW

Output:

L #entering teleportation 1
U #going to the wall
R #going to the wall
D #entering teleportation 1

In this situations, Robot cannot moves to the left:

W  GBR   W

W  #BR   W

W  BBR   W

W  WBR   W

W    R   W

You can assume that the puzzle always has at least 1 solution

Part 3 - With help

Same as part 2 but with others robots:

Input

The input (file, stdin, input, whatever suits you) is an n×m matrice with the following characters:

  • R The robot
  • G The goal
  • # An obstacle that stops the robot
  • Ice
  • W Some water. Robot doesn’t like water
  • B a Box. Robot can push the box 1 square at a time, in front of him (not on the side), if the next square is . It cannot be pushed into the water, through the goal… Robot cannot push 2 boxes at once. When pushing, the robot stays in place.
  • 1 a numbered teleportation door. Always in pair. When entering a teleportation door, Robot will continue sliding in the same direction through the other door. Can be used more than 1 time.
  • abcde up to 5 robots that can move the same as Robot. They cannot go through other robots, including R, and can pass through the Goal. They can be sacrified by going into the water. They can be used more than 1 time.

The island is surrounded by water.

Output

A list of instructions consisting of U/D/L/R, corresponding to up/down/left/right, prefixed by the name of the robot moving.

The list should be the shortest possible. The distance traveled by the robot doesn't count.

As usual, theformat doesn't matter:

a:UDR
R:LU

or

aU
aD
aR
RL
RU

are accepted

Example

Input:

WWWWWWWWWWWWWWWWWW
W        a     # W
W   G            W
W                W
W                W
W                W
W             R  W
W                W
W       #        W
W             #  W
W                W
WWWWWWWWWWWWWWWWWW

Output:

a:R
R:UL

The answer DLUL is valid but not the shortest

Input:

WWWWWWWWWWWWWWWWWW
W                W
W                W
W                W
W                W
W  G    a    R   W
W                W
W                W
W                W
W                W
W                W
WWWWWWWWWWWWWWWWWW

Output:

a:U
R:L

Input:

WWWWWWWWWWWWWWWWWW
W           #    W
W                W
W  #             W
W           G    W
W                W
W                W
W           b    W
W   R       a    W
W                W
W                W
WWWWWWWWWWWWWWWWWW

Output:

b:U
a:UL
R:UR

Input:

WWWWWWWWWWWWWWWWWW
W                W
W           #    W
W          B     W
W  #             W
W     G          W
W                W
W  #             W
W   e       R#   W
W                W
W           a    W
WWWWWWWWWWWWWWWWWW

Output:

e:R
R:U
a:UL
R:LLDLUR

Input:

WWWWWWWWWWWWWWWWWW
W                W
W         G #    W
W   b            W
W                W
W           a    W
W   c            W
W           #    W
W   R            W
W                W
W          #     W
WWWWWWWWWWWWWWWWWW

Output:

a:U
b:RD
a:D
C:RD
R:RU

Input:

WWWWWWWWWW
W    G   W
W aBbBR  W
WWWWWWWWWW

Output:

a:L
b:LL
R:LLU

In this situations, Robot and b cannot move to the left:

W  GaRb  W

W  #b#R  W

W aBbBR  W

You can assume that the puzzle always has at least 1 solution

Sandbox Questions

Has it been done before?

What do you think? Is it understandable? Should I do 3 separated challenges (and in the sandbox)? More, less? Which part needs more examples? What part is unclear?

I would like to go with shortest-code win. Should I use kolmogorov instead?

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Everything about PI

Pi is the most popular transcedental number. As a result, pi has been thoroughly studied. This challenge is in spirit of 9-Hole challenge.

1. Digits of PI

Given n and k, output n'th digit after the decimal point in the base-k representation. For example, the 5th digit of PI base 10 is 9.

5 10
9
10 2
0
6 16
10

If the base is more than 10, output like in the last test case

More information : http://www.virtuescience.com/pi-in-other-bases.html

2. Continued fraction of PI

Given n, output n'th number in continued fraction of Pi.

5
292
7
1

3. Closest to PI

Given a positive integer d, output the integer n such that n/d is closest to pi. For example, 17/5 is closer to pi than any other n/5.

 5
 17
 7
 22
 21
 66

4. Closest to PI 2

Given a positive integer n, output the integer d such that n/d is closest to pi.

5
2
7
2
20
6

Restriction.

  1. You should not have any floating-number buildin, only integer, including PI constants.
  2. Standard loophole is disallowed.
  3. The program may be 4 program or a program that reads challenge number.

Sandbox Question

Originally, I have 5 challenge, 4 more required. Now, one of them is dupe. 5 more required.

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  • \$\begingroup\$ This does look suspiciously like lot of questions rolled into one. +1 and you could split it up into loads of challenges. \$\endgroup\$ – wizzwizz4 Dec 30 '15 at 12:10
  • \$\begingroup\$ Also, you could add more clarification on what a "9-Hole challenge" is. \$\endgroup\$ – LegionMammal978 Dec 30 '15 at 12:12
  • \$\begingroup\$ @LegionMammal978 codegolf.stackexchange.com/q/16707/46245 \$\endgroup\$ – Akangka Dec 30 '15 at 12:38
  • \$\begingroup\$ The spirit is more than one challenge in one question. \$\endgroup\$ – Akangka Dec 30 '15 at 12:48
  • \$\begingroup\$ Are you looking for 4 more sub-challenges, or a catchy name for a 5 component question? \$\endgroup\$ – trichoplax Dec 30 '15 at 16:17
  • \$\begingroup\$ Quintessential pi question? \$\endgroup\$ – trichoplax Dec 30 '15 at 16:18
  • 2
    \$\begingroup\$ A. I believe that the "many small holes in one question" model is considered a failed experiment. B. I don't understand the spec for part 1 at all. Part 2 is inadequately specified. Part 3 is a dupe. Parts 4 and 5 look almost completely trivial (or completely trivial for languages with a pi built-in). \$\endgroup\$ – Peter Taylor Dec 30 '15 at 18:39
  • \$\begingroup\$ Added that pi build-in is not allowed \$\endgroup\$ – Akangka Dec 31 '15 at 4:08
  • \$\begingroup\$ What about getting pi via inverse trig? Complex logs? Evaluating integrals? Banning the built in value still lets languages express it via math, and it's tricky to draw the line. \$\endgroup\$ – xnor Dec 31 '15 at 5:16
  • 1
    \$\begingroup\$ Also, why does every question need to use pi? If you want a challenge about, say, rational approximations, you can use arbitrary inputs or square roots or anything all langs have access to roughly equally. \$\endgroup\$ – xnor Dec 31 '15 at 5:18
  • \$\begingroup\$ @xnor 1. trigonometry, log, etc. is useless without floating point number. And any uses of floating point number isn't allowed (Even if it just uses addition only). However, I am afraid of integrals, too. 2. Just because. \$\endgroup\$ – Akangka Dec 31 '15 at 5:52
  • \$\begingroup\$ In the revised version, I think that if these were posted separately then part 1 would be closed as a dupe of part 3. Also, part 2 is still inadequately specified. You need to at minimum explain the indexing convention, and ideally specify what a continued fraction is (since some answers may use generalised continued fractions and confuse people who aren't familiar with them). \$\endgroup\$ – Peter Taylor Dec 31 '15 at 11:12
  • \$\begingroup\$ @PeterTaylor I don't understand how part 1 is dupe of part 3. For part 2 I uses simple continued fraction and what is indexing convention? \$\endgroup\$ – Akangka Dec 31 '15 at 11:17
  • \$\begingroup\$ A. Part 3 says "Given d, find n such that (n-0.5)/d < pi < (n+0.5)/d". Part 1 is essentially (since there isn't a general Plouffe formula for all bases) "Given k and n, find b such that b / k^n < pi < (b+1) / k^n and then return b % k". The core problem is almost identical. B. It's not enough for you to know that you're using simple continued fractions: the question has to make it clear. The indexing convention is whether you count the initial 3 + ... as index 0 or 1. \$\endgroup\$ – Peter Taylor Dec 31 '15 at 11:34
  • \$\begingroup\$ @PeterTaylor A. The insight clears my mind. Thanks. I don't think as far as that. B. 1. But I don't know how to explain that. Please add yourself. \$\endgroup\$ – Akangka Dec 31 '15 at 11:43
0
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How to print 2016 using only the number 2?

Print 2016 using only the digit 2 operators and native language built-in functions.

The objective is to

  • Output the integer 2016 without using any digits except 2.
  • no characters / strings literals are allowed, i.e. no tricks like ord('b')
  • The code that uses the least number of 2s in the code wins.

For example, in python, the following code uses 8 twos.:

>>> int(str(2**2*2) + str(2**2)) * int(str(2) + str(2**2))
2016

Or like this code, uses 13 twos:

>>> 2 ** 2 ** 2 * 2 ** 2 ** 2 * 2 * 2 * 2 - 2 ** 2 ** 2 * 2
2016
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  • 3
    \$\begingroup\$ Can you use constants initialized to a certain value (like CJam's Z variable which defaults to 3)? \$\endgroup\$ – GamrCorps Dec 31 '15 at 19:42
  • 1
    \$\begingroup\$ What's the tiebreaker if multiple answers have the same number of 2s? \$\endgroup\$ – Doorknob Dec 31 '15 at 19:46
  • 6
    \$\begingroup\$ 1. Every language that has variables will have a score of at most 1, since you can just save the initial 2 in a variable. 2. There are many ways to produce numbers without using characters, strings or other numbers, like taking the length of a list, for example. That means a score of 0 is just as easy. \$\endgroup\$ – Dennis Dec 31 '15 at 19:47
  • \$\begingroup\$ I would suggest making the scoring system a normal code-golf challenge and disallowing date functions. \$\endgroup\$ – GamrCorps Dec 31 '15 at 19:55
  • \$\begingroup\$ I will make my original suggestion again: require that every function and operator take as input either a number consisting entirely of 2's in some base, or the output of some function or operator that obeys this rule. If you insist on your "least number of 2's metric" count 2's passed inside variables or in the outputs of functions as contributing to this count. \$\endgroup\$ – quintopia Dec 31 '15 at 21:15
  • \$\begingroup\$ What about such version: In repl environment produce value 2016 using only number 2, operators and math functions. No any other functions allowed. Code golf or code challenge. \$\endgroup\$ – Qwertiy Dec 31 '15 at 21:17
0
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Growing Quine 2

Your task is to give program P1..P5 so that.

  1. For all k<5, length of Pk < length of Pk+1
  2. For all k<5, Pk outputs Pk+1
  3. For all k<=5, Pk is semi-pristine program. (Program that if any run on the source-code is deleted, will output different output)
  4. P5 return P1 sufficient times that the output will be longer than P5

Shortest P1 wins

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  • \$\begingroup\$ By rule 4, do you mean if P1 is abc, then the output should be abcabcabc... for the minimum amount of repetitions that is longer than P5? can we output it more often that necessary? Also, I think rule 3 makes this incredibly hard. \$\endgroup\$ – Martin Ender Jan 1 '16 at 16:40
  • \$\begingroup\$ First, Yes. The rule 3 is to prevent the padding of source code with nop. Maybe I will change into different output to make this easier. \$\endgroup\$ – Akangka Jan 2 '16 at 0:50
  • \$\begingroup\$ I mean rule 4 can repeat more often than necessary \$\endgroup\$ – Akangka Jan 17 '16 at 1:22
0
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Zipping double quine.

You must provide 2 program, A and B. Both are a quine and have same length.

If A and B is zipped each other(Both when A is zipped first, or B is zipped first), the result is also an quine.

Standard Loopholes is not allowed and standard quine rules apply.

Examples

If program A is ABCDEF and program B is GHIJKL then

slangi "ABCDEF"
ABCDEF
slangi "GHIJKL"
GHIJKL
slangi "AGBHCIDJEKFL"
AGBHCIDJEKFL
slangi "GAHBICJDKELF"
GAHBICJDKELF
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  • \$\begingroup\$ Do all three quines have to use the same language? Are function quines allowed? \$\endgroup\$ – Dennis Jan 6 '16 at 17:03
  • \$\begingroup\$ @Dennis All three quine have to use same language. Function quines is allowed. \$\endgroup\$ – Akangka Jan 7 '16 at 7:57
0
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War of Flatland

If you haven't read Flatland, please do so here. It is a must-read, for mathematical and non-mathematical alike.

Oh no. No no no! War has broken out in Flatland. Society has crumbled, and all the women and children are either hiding or dead1. It is total anarchy, kill or be killed. It is such conflict that the 4th dimensional people have erected indestructible borders to prevent the conflict spreading.

On the plus side, if you came out on top, you could rule (some of) the entire world!

Specifications

  • You can be a shape with three or more sides. (No women1, remember?)
  • All shapes are regular.
  • You can only see by sight. (No feeling; you'll be killed if you get close enough to do that!)
  • Everybody starts with 1 health.
  • You can hurt other people by stabbing one of their edges with a vertex.
  • The vertex of an n sided shape deals 1/n damage.
  • An n sided shape has 4n angles of vision (sensors evenly spaced around the shape which see the nearest point and return the distance to it).
  • An n sided shape can see 2n different distances (range [0,16))
  • People don't see themselves. (What good is sight if your body gets in the way?)
  • People are all the same size (radius).
  • People can see everything within 16 units of their centre point.
  • If your health is 0 or below, you are killed.
  • The world has borders.
  • You can rotate by a maximum of 15 degrees either direction, then move exactly 1 unit towards either of your vertices every turn.
  • Each shape's "radius" is 8 units.
  • Degrees are anticlockwise from 3 O'clock. The 0th sensor is at 3 O'clock relative to the shape's orientation.

1 This is not me being sexist. Read Flatland.

Sandbox Meta:

I am using the Sandbox as a public incubator. I will build up and work on the challenge until it is ready, then post it as a question. But it made more sense to let others see, comment on and help with this challenge's development.

The Specifications are probably not going to remain in this format once the Stack Snippet and actual code is up and running.
I am working on, and have got quite far with, a JavaScript class to let people write code. If anyone can write a code to do the boring rendering thing onto a HTML5 canvas, I would be grateful.

Stuff I plan to add:

  • A stack-snippet battlefield
  • A JavaScript class to let people write code
  • A web-socket system to let people make submissions in other languages
  • A system to pull submissions from answers (I'm no good at this sort of thing)
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  • \$\begingroup\$ 1. What counts as stabbing an edge? (I can see the numerical issues involved in working out whether a contact is vertex-vertex or edge-vertex being quite hairy). 2. What does it mean that "an n sided shape has 4n angles of vision"? 3. How does movement work? \$\endgroup\$ – Peter Taylor Jan 3 '16 at 17:07
  • \$\begingroup\$ @PeterTaylor 1. I calculate line intersections on shapes with close enough centres, then I count the intersections and work out where the intersections are. 2. First, read up on how Flatlanders see distance. Distance is represented by a number. You have 4n numbers, evenly spaced around the shape. So a triangle will have 12 angles of vision. 3. You can rotate by a maximum of undecided degrees and move 1 unit towards either of your vertices every turn. \$\endgroup\$ – wizzwizz4 Jan 3 '16 at 17:21
  • \$\begingroup\$ The word distance occurs only 9 times in the text, and none of them seem to address how distance is perceived per se. \$\endgroup\$ – Peter Taylor Jan 3 '16 at 18:01
  • \$\begingroup\$ @PeterTaylor Part 1 Chapter 5 \$\endgroup\$ – wizzwizz4 Jan 3 '16 at 18:24
  • \$\begingroup\$ Why not just say that vision extends out to 16 units and that each movement is 1 unit? Other considerations: what prevents a player from repeatedly stabbing another one? If everyone moves the same distance in a turn, I don't see how escape is possible. Do people/bots choose how many sides they have? It seems to me like a triangle would be the best choice. The only downside is fewer sensors, but I don't think that's a particularly bad one. \$\endgroup\$ – El'endia Starman Jan 5 '16 at 7:42
  • \$\begingroup\$ @El'endiaStarman I've been trying to make higher shapes more balanced. And hopefully there will be a defined bouncing mechanism after stabbing. (Spinning like a saw however...) And yes, they choose. \$\endgroup\$ – wizzwizz4 Jan 5 '16 at 8:00
  • \$\begingroup\$ @El'endiaStarman what if you always start as a triangle, a vertex forms on a side whenever one gets stabbed there (like a bruise swelling up). Or, in other words, an n-gon becomes an n+1-gon when stabbed. Stabs don't do ANY damage other than this. You die when n exceeds some threshold. This seems self-balancing: The more vertices you have the more people you can poke at once and the sooner you can poke them (because you already have a vertex aimed at them). \$\endgroup\$ – quintopia Jan 7 '16 at 17:05
  • \$\begingroup\$ Another balancing possibility is making higher-sided shapes move faster. \$\endgroup\$ – quintopia Jan 7 '16 at 17:07
  • \$\begingroup\$ @quintopia But that is simply a balancing system, and is in no way derived from the book. (But will probably be used if nobody can think of another way to balance the higher shapes that is derived from the book). \$\endgroup\$ – wizzwizz4 Jan 7 '16 at 17:42
  • \$\begingroup\$ I was purposefully avoiding letting the content of the book influence my recommendations. It's more important that the game is fun than that it's thematic. \$\endgroup\$ – quintopia Jan 8 '16 at 16:19
  • \$\begingroup\$ @quintopia I suppose... But your speed idea would introduce the issue of how fast? Would it be logarithmic? Would there be a point where it is unrealistic to be able to kill a higher-sided shape because they can practically teleport? \$\endgroup\$ – wizzwizz4 Jan 8 '16 at 16:51
  • \$\begingroup\$ @quintopia And the n=>n+1 idea is a completely different challenge! \$\endgroup\$ – wizzwizz4 Jan 8 '16 at 16:52
0
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Print Euler's number on its own graph

Print the first n characters of Euler's number (e, 2.718281828459...) on a 'graph' of e^n. For example, input 3 (the x and y-axis scales here are provided for reference, and need not be implemented in your program):

20 |         1
19 |
18 |
17 |
16 |
15 |
14 |
13 |
12 |
11 |
10 |
 9 |
 8 |
 7 |     7
 6 |
 5 |
 4 |
 3 | 2
 2 |
 1 |
 0 | - - - - - - -
     1   2   3
      digit #

In the example above, note that:

  • Three digits of Euler's number are presented
  • Each digit is shown at a height equal to e^n, where n is the digit number. 2, for example, is shown at height 3 because e^1 = 2.72, which we round up to 3. You may round up or down, see below.

Various other informational bits:

  • Rounding need not be implemented; 271 is acceptable output for input 3, as is 272.
  • You will always be provided with input >= 1 , and your input will never contain decimal places nor any characters other than 0-9.
  • You may round the y value up or down, I.e. e^3 = 20.0855 may be shown as y=20 or y=21.
  • Your graph must have higher y-values at the top and higher x-values to the right; it must have a positive slope
  • You may use any amount of horizontal spacing >= 1 between successive digits. In the example above, there are 3 spaces between successive digits. You just can't have digits stacked on top of eachother.
  • You are not required to print scales on the x or y axis.
  • Your input will always be <= 10.
  • You may hardcode the required digits if you so desire.
\$\endgroup\$
  • \$\begingroup\$ You should specify about trailing and leading whitespace, on each line and before and after the graph. \$\endgroup\$ – FryAmTheEggman Jan 14 '16 at 15:50

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