Sandbox for Proposed Challenges

Question

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

Sandbox FAQ

Posting

To post to the sandbox, scroll to the bottom of this page and click "Answer This Question". Click "OK" when it asks if you really want to add another answer.

Write your challenge just as you would when actually posting it, though you can optionally add a title at the top. You may also add some notes about specific things you would like to clarify before posting it. Other users will help you improve your challenge by rating and discussing it.

When you think your challenge is ready for the public, go ahead and post it, and replace the post here with a link to the challenge and delete the sandbox post.

Discussion

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

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

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

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

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

Other

Search the sandbox / Browse your pending proposals

The sandbox works best if you sort posts by active.

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

Answer 1

Play an audio file code-golf audio

---

Challenge

Your challenge is simple: play an audio file at a given path. Your program will take the file path as input and will play it once and quit.

To make this harder, however, you are not allowed to use external libraries, but modules that are part of your language's standard library (such as ctypes below) are allowed.

Rules

• Standard loopholes are forbidden.
• You may assume (a) specific operating system(s) and/or (a) specific file format(s).
• You may assume an absolute path.
• You do not have to hear the sound every time; you are not expected to unmute muted speakers, and you can play through whichever audio device is the most convenient. However, it must be possible to hear it every time you run it with certain settings. A window such as Control Panel -> Sound -> Playback on Windows must always be able to "show" the sound being played under at least one audio device. You are allowed to play the file under a different device each run.
• Your program must be able to play at least one of the audio file formats listed on Wikipedia. Other formats are allowed, as long as one of the formats listed there is supported.
• Outputting any content to any stream, file, etc. is allowed, but the sound must be played.
• Please explain your answer. This is not necessary, but it makes it easier for others to understand.
• Languages newer than the question are allowed. This means you could create your own language where it would be trivial to do this, but don't expect any upvotes.
• This is code-golf, so shortest code in bytes wins!

Reference implementaion (ungolfed, Python 3, Windows only, .wav only)

# -*- coding: utf_8 -*-

from ctypes import windll

winmm = windll.winmm
audio_file = input('Audio file path: ').encode('utf_8')

winmm.PlaySound(audio_file, 0, 131072)

Golfed reference implementation

import ctypes;ctypes.windll.winmm.PlaySoundW(input(),0,131072)

Answer 2

Visualize tag progress

code-golf ascii-art

Task is pretty simple. Given non-negative positive integers 0 ≤ s ≤ 1000 and 0 ≤ a ≤ 200, your code should draw following progress bars.

Examples

When s ≤ 100 or a ≤ 20:

Input:15 12
Output: 
15/100 score
++++++------------------------------------
12/20 answers
+++++++++++++++++++++++++-----------------

Input:3 1
Output: 
3/100 score
+-----------------------------------------
1/20 answers
------------------------------------------
  
Input:85 35
Output: 
85/100 score
+++++++++++++++++++++++++++++++++++-------
35/20 answers
++++++++++++++++++++++++++++++++++++++++++

When (s > 100 and a > 20) and (s ≤ 400 or a ≤ 80):

Input:156 43
Output: 
156/400 score
++++++++++++++++--------------------------
43/80 answers
++++++++++++++++++++++--------------------
  
Input:666 66
Output: 
666/400 score
++++++++++++++++++++++++++++++++++++++++++
66/80 answers
++++++++++++++++++++++++++++++++++--------

When (s > 400 and a > 80) and (s ≤ 1000 and a ≤ 200):

Input:999 85
Output: 
999/1000 score
+++++++++++++++++++++++++++++++++++++++++-
85/200 answers
+++++++++++++++++-------------------------

Input:666 194
Output: 
666/1000 score
+++++++++++++++++++++++++++---------------
194/200 answers
++++++++++++++++++++++++++++++++++++++++--

The number of +'s in each bar is equal to the value of a or s divided by its max value (max values for s are 100, 400, 1000 and for a are 20, 80, 100, the choice of max values ​​depends on the ranges in which the values ​​of a and s fall.), multiplied by 42 and rounded down. This number cannot be more than 42.
The number of -'s is equal to 42 minus the number of +'s.

End etc. Trailing spaces are allowed. Additional newlines are not allowed.

This is a code-golf challenge so the shortest solution wins.

Meta

I realized that I myself got confused in my task :) ... so this task will be in completion until this text is deleted.

Answer 3

Your task is to create an approximation for sin(x) in the fewest characters possible.

• Given the approximation s(x), it must satisfy 0.95 * sin(x) <= s(x) <= 1.05 * sin(x)

The entry with the fewest characters wins.

Answer 4

Longest Possible Pythagorean Triple Triangle

code-golf math arithmetic

A Pythagorean triple is a set of 3 integers \$\{a, b, c\}\$ where \$a^2 + b^2 = c^2\$. Your task is to, given an integer \$n\$ where \$3 ≤ n ≤ 15\$, output a Pythagorean triple using these rules:

• If \$n\$ is odd, output \$\{n, \frac{n^2-1}{2}, \frac{n^2+1}{2}\}\$.
• If \$n\$ is even, output \$\{n, \frac{n^2}{4}-1, \frac{n^2}{4}+1\}\$.

With these rules, the difference between the lengths of the longest leg and the hypotenuse is minimized.

Rules

• Input and output can be in any convenient format.
• The output does not have to be in any particular order.
• Standard loopholes are forbidden.
• This is code-golf, so the shortest code in bytes wins.

Test cases

Input | Output
------+-------
3     | 3 4 5
4     | 4 3 5
5     | 5 12 13
6     | 6 8 10
7     | 7 24 25
8     | 8 15 17
9     | 9 40 41
10    | 10 24 26
11    | 11 60 61
12    | 12 35 37
13    | 13 84 85
14    | 14 48 50
15    | 15 112 113

See A055523 and A055524.

Answer 5

Repeat Hello World according to another string's length

Answer 6

Do you trust this site?

title is a work in progress

This challenge is simple. Your program must take a URL (which will always exist) as input, download the file, and execute its contents as a program in the language your answer is in. The file will always be a valid program in your language.

Example

Language: Python
Input: https://gist.githubusercontent.com/GingerIndustries/d6f25007b45071e901b2b9057388d8f8/raw/25f838879fdc93f07394afc080eeef0993f55cbe/helloworld.py
Result: Program should print "Hello World!"

Answer 7

This is a famous mathematical problem, Named as Bridges of Königsberg

Task

The bridges of Königsberg is a problem in mathematics which states that the path required for crossing each bridge exactly once without using a boat

You have to find out if there is any path which uses each bridges exactly once without using a boat, if the time exceeds 36000 seconds or 10 hours the program should print no path found yet

Rules

Standard rules of fastest-code

Expected Output: Paths possible: [7, 2, 3, 1, 5, 6, 4], [2, 1, 7, 3, 4, 6, 5], etc.

This is fastest-code so the answer with shortest time is accepted, Even if the code will take a many days without a Quantum Computer

Answer 8

Take one of two distinct, consistent values of your choice. For one input, check if the input is prime. For another input, check if the input is a square.

Standard loophole apply except input complete or partial functions, which is replaced with

No input results in an infinite loop.

Answer 9

Munge my Text code-golf string random

Inspired by this example in the Python documentation.

Write a program that takes as input a string of arbitrary length and returns a version of that string with every letter, except the first and last, of every word randomly shuffled. "Word" is defined here as a contiguous set of alphabetical characters separated by one or more spaces or punctuation marks (!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~).

Examples

Input: Professor Abdolmalek, please report your absences promptly.
Possible output: Poefsrosr Aealmlobdk, pslaee reorpt your abnseces plmrptoy.

META TODO: Add more examples

This is code-golf, so shortest answer wins!

Answer 10

Fibonacci before the zero - Dublicate of Negative Fibonacci Numbers

Answer 11

See Those Sorts

popularity-contestsorting

Using shapes or Unicode, show how some array of numbers is sorted with a particular sorting method. You should include selection sort, merge sort, bubble sort, quick sort, bogo sort, and at least one other sort you find interesting (maybe try one of these).

Make sure that the speed of the sort corresponds to the actual performance on your computer. You can try adding a constant multiplier to the speed if you want.

^{Someone watched sort videos :)}

Answer 12

\$n\$ bottles of beer!

You want to recreate the song "99 Bottles of Beer", but you don't have 99 bottles!

---

Given an input non-negative integer \$n\$, output the lyrics to the song "99 Bottles of Beer" but starting from \$n\$ instead. For a few examples:

Input: 10

Output: 

10 bottles of beer on the wall,
10 bottles of beer.
Take one down, pass it around,
9 bottles of beer on the wall.

9 bottles of beer on the wall,
9 bottles of beer.
Take one down, pass it around,
8 bottles of beer on the wall.

8 bottles of beer on the wall,
8 bottles of beer.
Take one down, pass it around,
7 bottles of beer on the wall.

7 bottles of beer on the wall,
7 bottles of beer.
Take one down, pass it around,
6 bottles of beer on the wall.

6 bottles of beer on the wall,
6 bottles of beer.
Take one down, pass it around,
5 bottles of beer on the wall.

5 bottles of beer on the wall,
5 bottles of beer.
Take one down, pass it around,
4 bottles of beer on the wall.

4 bottles of beer on the wall,
4 bottles of beer.
Take one down, pass it around,
3 bottles of beer on the wall.

3 bottles of beer on the wall,
3 bottles of beer.
Take one down, pass it around,
2 bottles of beer on the wall.

2 bottles of beer on the wall,
2 bottles of beer.
Take one down, pass it around,
1 bottle of beer on the wall.

1 bottle of beer on the wall,
1 bottle of beer.
Take one down, pass it around,
0 bottles of beer on the wall.

Input: 1

Output:

1 bottle of beer on the wall,
1 bottle of beer.
Take one down, pass it around,
0 bottles of beer on the wall.

This is code-golf, so shortest answer wins!

---

code-golf

---

Meta:

• Any more tags?
• Is this a duplicate?
• Is the song formatted correctly in the example?
• Any more test cases?

Answer 13

Square decomposition

Inspired by silly ideas for answers to this CMC.

---

Given a perfect square, take the square root of it. NO NO NO NOT THAT CHALLENGE

---

Explanation

Given a square in Unicode art, output the characters that compose the square.

Rows are separated by newlines, so they cannot appear in the square. Therefore, contrary to I/O defaults, you cannot output leading or trailing whitespace unless it is in the square. You may also output in any order. Remember, this is code-golf, so shortest code wins!

Test cases

Input	Unordered Output
aaa aaa aaa	a
1234 4567 7890 0123	1234567890
"	"
🟥🟨🟩 🟩🟥🟨 🟨🟩🟥	🟥🟨🟩

---

code-golfunicode

---

---

Meta

• Is this a duplicate?
• Is this clear enough?
• Should I add more test cases?
• Should I add or remove any tags?
• Anything else?

Answer 14

Output the number of lines of your code

Your task is to write a program that counts the number of its lines of code and outputs them.

Specs:

• The number mustn't be hardcoded into the program, nor in any other external resource;

• Internet access is forbidden;

• Your program's output must be the number of lines only;

• Your program should not use any tool, macro, function, or similar device designed with the specific purpose of counting lines.

popularity-contest

Answer 15

Here is my first attempt at a cops and robbers post (which is why I'm using the sandbox).

---

Cops - Golfed recursion

You must select a language that satisfies the following criteria:

• Functions - It must be possible to create a function with any number of integer input values and a single integer output (or return) value. The function may also be a complete program in itself. (Your language may not call it a function, but that is ok)
• Arithmetic operations - The integer operations +-*/% should all be possible, either in a simple or a complicated manner.
• Data - You should be able to store one-byte or two-byte long integers (either signed or unsigned will do). You may do this also in an indirect manner.
• Iteration - You must be able to create a loop that will keep running until a condition is satisfied. Therefore < > = <= >= ! & | should also be supported, either directly or indirectly.
• Recursion - You should be able to call a function from within the function itself with a set of input values calculated by the main function.
• Declaration - You should be able to declare new integer variables as needed from within the function.

Task

You need to create a recursive function. Code will be scored by the number of characters in it, the shorter the better. A solved code cannot win the challenge. A post with less than 5 up-votes cannot win the challenge. There will be no overall winner, but a separate winner for each language.

Robbers - Golfed recursion

Your objective is to pick up a cop's post, and write a function in the same language but it should not use any recursion (can use iteration). The function may create any number of variables, loops, etc. but should be able to achieve the exact same end result (atleast, in theory) as the cop's one.

Your score will be the same as the cop's post's score at the time it was solved. His/her post is now invalid, and you get his/her score

Answer 16

Your task is to create a program that outputs a random pizza recipe following this one rule:

No random number choosers, you may have random text choosers. All standard code-golf rules apply. A sample output:

A simple PEPPARONI pizza sprinkled with fish and sausages. Your program must have the following items:

• Anchovies
• Fish
• An adjective for the pizza

The program written with the shortest code wins.

Winner

The winner shall be picked on April 3rd, 12AM on the time zone GMT+3.

Answer 17

What about one question on numeric solve?

Write one function that gets as one argument one function f(x), and one interval a..b and return the list of all element v such f(v)=0 in the interval a..b. In the interval a..b the f must be definite and can not be f(r) = +oo for r in a..b.

Win the one write the function with biggest set of right results. If two have the same set, win the one has less characters. You can not use solve() or nsolve() or fsolve() or one already written function that your sys offer that finds numerical x in f(x)=0

Answer 18

Beep. Boop. Maggot? code-golf

1. Read input from STDIN until enter is pressed.
2. If the input is "Beep", continue.
3. Otherwise, print "Wrong!" and exit.
4. Repeat steps one to three with "Boop" instead.
5. Execute step one.
6. If the input is "Maggot", output "Done".
   • Otherwise, output "Wrong.".

Remove punctuation (?.!'"), ignore capitalization (a-zA-Z only), and strip whitespace (\t and )

Notes: You must print the text word-for-word, character-for-character. Step 3 is Wrong!, while Step 6 is Wrong.

Hints

• Notice how boop is just beep with the o's turned into e's.
• There is lots of repetition here, but with many caveats.

Answer 19

Score Your Language

I believe that each language has a score. The way you find the score of a language is shown in the ungolfed Python program below

def scorer(lang):

    num = 0

    for i in str(lang):
        num += ord(i)

    return num

Basically the score is the total of the unicode values of the language name.

Now this seemed like a fairly trivial challange, so I thought I'd make it a bit more difficult. You aren't allowed to use your language name (case-sensitive) in the code. So this code in C++ would be invalid as I've used C++ in the code.

#include <iostream>

int main() {

    int total = 0;
    std::string s("C++");

    for (char & c : s) {
        total = total + (int)c;
        c = '*';
    }

    std::cout << total;

}

Although this does output the required number (153) it is still invalid.

Rules

• You aren't allowed to use the language name but are allowed to use it in a different case. E.g. Java isn't allowed but java is.
• This is a code-golf so shortest answer in bytes wins
• You are allowed to use hex/octal codes in strings e.g \150 can be used instead of h
• Your program must take no input or function arguments
• You cannot simply output the score. Theoretically the program should work for any language name when changed.
• Languages where the only valid syntax is the name, such as Chicken are allowed to use said name.
• Version shouldn't be included so Python is always Python not Python 2 or 3
• The score is the value of the case-sensitive name

Correct Scores

Language              Score

ArnoldC                675
brainfuck              949
C                       67
C++                    153
Java                   386
Lua                    290
Mornington Crescent   1922
Python                 642
TrumpScript           1165
Vim                    300

Sandbox Questions

1) Why has this been downvoted?

2) I am thinking about putting a reputation limitation so that bosses like Dennis and Martin Büttner can't take answers from people who aren't as accomplished. Is this unfair? Should I not?

3) Is this a duplicate? I couldn't believe it wasn't already taken.

Answer 20

Popularly print the input

popularity-contest

Goal

Write a program or function in a language of your choice that takes input and outputs that exact input.

Specifications

• Your program/function should output the exact input in any reasonable way.
• Your program does not have to end after printing the input. It may end up in an infinite loop if you wish, as long as that loop doesn't output any extraneous characters.

Winner

The winning answer will be the one that has the highest score. Voters should look for answers that use an unique way to print the input, have a special source code or use neat language features.

Answer 21

Make a Login Screen

Challenge: make code that asks the user to enter a username and password. The username and password should be hard coded, but they must not be visible: you cannot have the entire username or the entire password in plain text in the code. Both the username and the password must be 8 characters long. Upon the incorrect username or password, some error should be displayed. It would be good if there are multiple "accounts" that would display different text on login. The password field should not be visible (Only asterisks or something).

This is Code-Golf, Shortest answer wins.

Standard loopholes are forbidden.

Answer 22

Of numbers of letters

there is something special the number 4. When spelled in English the word 'four' uses exactly 4 letters. I wonder whether there are further such numbers Your task is to identify whether there exist further such numbers and output them in any human readable format. To make this more of a challenge you can do the task in any regional Language of your choice (Say Russian or Portuguese or Spanish or Mandarin or Hindi etc.).

The Best entry will be selected by the most number of such numbers regardless of language used

Best of Luck

Answer 23

No strings code bowling

I created this challenege idea with @redwolfprograms. In the challenge, you would create the longest program possible (code-bowling) it can do anything, but it cannot:

• Contain any strings, or quotation marks/apostrophes/backticks
• Contain the same alphanumeric byte more than twice
• Conatin the same non alphanumeric byte more than three times

Answer 24

[Posted, but reference kept]

Given a function with boolean inputs a₁, ..., a_n and a boolean output, output an array of numbers 0 to n satisfying:

For each item in the truth value, if (from the array you output, we repeatedly remove two adjacent numbers x and y satisfying that, for each integer n between x+0.5 and y+0.5, a_n=1), we can get an empty result array iff the given function's output is 1. You can assume the result exist.

Sample input:

a[1] a[2] result
0    0    0
0    1    0
1    0    0
1    1    1

Sample output: 0 2

Sample input:

a[1] a[2] result
0    0    0
0    1    1
1    0    1
1    1    1

Sample output: 0 1 2 0 1 2

Sample input:

a[1] a[2] result
0    0    1
0    1    1
1    0    1
1    1    1

Sample output: (empty)

shortest code win, but optimizing running time and result length is encouraged(I won't accept but I may upvote)

You may check your answer here

Answer 25

Write a function that takes compares each pair of adjacent items and swaps them if they are in the wrong order. The pass through the list is repeated until no swaps are needed, which indicates that the list is sorted.

Static visualization of bubble sort and a gif explanation.

^{The steps go from left to right. At each stage, an exchange is made. The darkest color has the most value and finds its final place (bottom) first.}

---

The rules

• The function must take a list of integers that shall be sorted (less than 20 elements)

• The function must print each step of the sort.

• Yes, built-in Bubble sort algorithms are permitted.

• No, you can not assume only positive integers or unique integers.

• It's code-golf so the shortest code wins!

---

Test cases

input list
5 4 3 1 2
1 2 3 5 4
11 4 2 1 5

---

Optional

Add an interpreter so the submission can be tested. It is allowed to write this interpreter yourself for a previously unimplemented language.

---

Note

^{It's my first code-golf idea I'm fully open to improving it with more experienced users if I missed something.}

^{This is not a duplicate of Bubble sorting in progress.}

^{Thanks to @Erik the Outgolfer for encouraging me to post my idea in the sandbox.}

code-golfbubblesorting

Answer 26

Once, I thought of this. Rules:

1: You must make a fractal that looks like the specified thing.

2: One thing per round.

3: Algorithms are rated by two scores: Resemblance and Compactness. The one that gets the highest scores wins!

4: Only I can tell what thing must be made.

5: Only one entry per user. Do not plagiarize.

6: One may code in anything they wish.

7: Have fun!

Round 1: Squidward's head!

Answer 27

This question is a simplified description of the requirement described at Permutations to the nines

---

Given input integer (minimum) where the first digit is always 1 and the adjacent digits are increasing in value, e.g.,

12

123

1234

12345

with the ability to handle up to the integer

123456789

where the maximum integer is always the input integer in reverse order, e.g.,

21

321

4321

54321

987654321

Task

Return a list (array) of each number between the input minimum and maximum integer which satisfies three conditions

1. the resulting integer list item includes only the individual numbers comprising the input number
2. the resulting integer list item does not contain any duplicate individual digits
3. the resulting integer list item is greater than the preceding integer list item and not greater than a following integer in the list

Test cases

Valid list items

12 -> [21] // done

123 -> [132,213,231,213,312,321] // done

Invalid list items

12345 -> 12344 // contains duplicate digits in whole number

123456789 -> 13256789 // not the next integer by increasing numeric value order

123456789 -> 987654322 // greater than maximum integer and duplicate digits

Winning criteria

The algorithm which uses the least amount of operations to compute the complete resulting list of items.

Examples

123 -> 123+5+4=132 // two mathematical computations

123 -> 123+9=132 // one mathematical computation (winning criteria)

(@JoKing suggested fastest-algorithm tag; math and code-challenge tags are also applicable)

Answer 28

All numeric substrings

code-golf

I like numbers. Really, really, like numbers. If you give me a string with numerals in it, I want to get all the numbers out of it that I can.

Input:

A string.

Output:

Every numeric substring, in any order, but only one of each. Numeric here means anything with Unicode General Category Nd (because I'm no xenophobe).

I/O

Any reasonable format. But languages that don't allow for multibyte-character I/O should use some numeric or other representation.

Test cases

(input → one ordering of the correct output)

• 1212 → [1212, 121, 212, 12, 21, 1, 2]
• 123٤٥6 ‪→ [1, 2, 3, ٤,‪ ٥, 6, 12, 23, 3٤,‪ ٤٥,‪ ٥6,‪ 123, 23٤,‪ 3٤٥,‪ ٤٥6,‪ 123٤,‪ 23٤٥,‪ 3٤٥6,‪ 123٤٥,‪ 23٤٥6,‪ 123٤٥6]‪
• 12t45 → [1, 2, 4, 5, 12, 45]
• abc → []

Answer 29

Fastest prime printer up to 500,000,000 with gapes

---

Write a program that takes no input and prints the first 26,355,867 prime numbers, from 2 to 499,999,993 inclusively. Or in other words, print all the prime numbers smaller the 500,000,000.

The fastest code wins!

Since it will take a long time to print all the numbers, print only every 26355 primes starting with 2 separated by a new line. So the output should look like this:

2
304417
648391
1007681
1376449
1752323
2133689
2520983
2910797
3304633
3702269

The output should not be hardcoded, or there is no fun in it.

The results will be tested on my machine, so please also output in the last line how long it took to run the program and give me some instructions about how to run it locally. I will then share the last line output with you that should contain the time it took to run.

Here is my machine system specs, note that it's Windows.

Answer 30

Mystery Numbers Challenge math

Here are some sample inputs and outputs:

IO

Test 1

Input: 102
Output: 10404 1061208 14002414191924244276669361796022272

Test 2

Input: 10
Output: 100 100000

Test 3

Input: 50
Output: 2500 312500000 312500000

BONUS

If there are two inputs, here are the corresponding inputs and outputs:

Test B1

Input:

50
12

Output: 144 248832 248832

Test B1

Input:

2310
9

Output: 81 729 59049 4782969 31381059609

Notes

If you pass all bonuses too, feel free to third your score. Also add a * to the end.