# Sandbox for Proposed Challenges

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

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
• 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".

Get the Sandbox Viewer to view the sandbox more easily!

# Simplified Piet Interpreter

• 1) Long challenges are fine, especially when the challenge is complex like this. Complete specification is much more important. 5) From quick skimming, the example looks mostly correct to me, except: at the pointer instruction near the start, right + clockwise 9 times is down, not up. An easy fix is to change the initial number to, say, 7. 6) My choice would be to add something like "Reference: official Piet specification (link)" at the bottom. Apr 7 at 6:21
• @Bubbler Thanks for the feedback! For the example, I think I just mixed up clockwise and counterclockwise lol. Apr 7 at 7:00
• Seems interesting!! I'd say my one complaint is that this does miss the other big feature of Piet, which is that instructions are defined by the difference between the blocks you're travelling between, not the specific value of either of them, although that is probably acceptable for simplicity reasons. Also should provide some specifics on how the final output is to be formatted. Apr 7 at 17:41
• @des54321 Yeah, I decided to remove the hue and lightness aspect of Piet because I thought that it would add unnecessary complexity to the challenge, though if you think that it would make the challenge more interesting, I could add that aspect to the challenge as well. Apr 7 at 18:24
• @AidenChow the hue/lightness feature would definitely make an interesting (if possibly harder) challenge, and the instruction set you have now would fit nicely in a 3 hue 3 lightness cycle, but its certainly ultimately your decision whether to include it Apr 7 at 18:26
• @des54321 I will think about it. The problem is that if I were to change the specs now, I would have to completely rewrite my worked example. Apr 7 at 18:37

# Draw the Norwegian flag

• @Steffan oh wow, never knew stack exchange was that stubborn Apr 8 at 21:15
• I don't think it would be considered a duplicate as there are already tons of flag challenges Apr 11 at 0:03
• Perhaps it's not considered a duplicate, but I'd hold the opinion that printing the Norwegian flag isn't particularly interesting, only because many flag challenges already do exist (or maybe this is the unpopular opinion and many people enjoy having these flag challenges). Apr 15 at 3:48

# Draw New Posts' Profile!

• @DLosc Whoops, fixed. Apr 19 at 21:20
• Also possibly loosen the input from boolean to any two distinct values? Although that might make it too easy if someone specifies the inputs to be their lang's color values for blue/black Apr 19 at 21:24
• Also presumably this is code-golf Apr 19 at 21:26
• @des54321 of course Apr 19 at 21:27
• As this image is 48x48 and binary in nature, I suggest embedding in the post a binary matrix reflecting on/off pixels of the picture. Apr 20 at 9:31
• Note that NP and SP's profile pictures are slightly "blurred", they are not perfect 48×48 pixel images. So you might want to clarify any non-white pixels are the same blue/black. Apr 27 at 1:25

# Create a program that may or may not determine if a list is in this sequence

Your task is to write a program which returns another program which has a nonzero chance of correctly determining if an inputted list is in a sequence described below. This can either be done through randomly generating a program, which will occasionally do the correct task, or through hardcoding a program that always works and returning that.

## The sequence

The sequence you'll need to identify starts with the following items:

well the sequence I was gonna use turns out to have a closed form formula so frick

• What was the idea here? Was it going to be something uncomputable? Could this still be salvaged with a new sequence? Also, what stops you from submitting like print(random(0,1)) or whatever May 16 at 20:06
• @thejonymyster Basically, you try to write a program that will randomly generate (sometimes) executable code. So there's a very small chance you'll get something which actually does solve the problem (checking if something's in a sequence, in this case), which is longer than the program which randomly generated it. May 16 at 20:18

# Binary Palindromes

Take an input of a positive integer and determine if the binary representation of that number is palindromic. Except for 0 (which is not in the scope of this problem), all binary palindromes are odd, so you do not have to worry about leading/trailing zeroes.

OEIS Sequence: https://oeis.org/A006995

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

## Test Cases

1 -> True (1)
4 -> False (100)
85 -> True (1010101)
131 -> False (10000011)

• I personally think this question is trivial, but I may be wrong so I didn't downvote it. May 10 at 14:23
• take this as an answer, str(bin(n))[2:][::-1]==str(bin(n))[2:] May 10 at 14:26
• Very closely related: codegolf.stackexchange.com/questions/216929/based-palindromes. May even be considered duplicate by some? Better wait for input from other users and/or ask in chat. May 10 at 19:30
• Didn't see that one because I searched specifically for binary. Will ask in chat. May 10 at 19:32

# King of the Hill: Greed Control

## What is Greed Control

Greed control is a multiplayer round-based game in which in every round, a player bet a number inside a specific range, say 1~100. Say 2 people betted 100, then they'd both get 100/2 which is 50 points in the game. Basically, the players that choose the same number split the scores evenly (no rounding) and the total of their net score gain is the number they chose.

After a set number of rounds, players compare scores. The highest score generally wins the game overall.

Build a bot in python, specifically, python 3 , that when given input, discussed in the section input, they give the number as an integer they bet as output. It must be afunction.

## Input

information, points, round_number, sum_of_all, user_num. information is a dictionary with integer keys in which each key's value is the number of bots that chose that key's number last round. points is the list of integers you can choose from. round_number is the round number. sum_of_all is like information, except it is the summation of all rounds. user_num is the number of players playing.

## We guarantee that

We guarantee that points stay the same every round and is strictly increasing, all integers. However, it may not be consecutive.

## Controller function


from random import choice

def random_better(information, points, round_number, sum_of_all, user_num):
return choice(points)

def greedy_better(information, points, round_number, sum_of_all, user_num):
return points[-1]

def calculator(information, points, round_number, sum_of_all, user_num):
return sorted(points, key=lambda x:x/(information[x]+0.000000000001))[0]

def smarty(information, points, round_number, sum_of_all, user_num):
return sorted(points, key=lambda x:x/(information[x]+0.000000000001))[choice(range(1,40))]

users = [random_better, greedy_better, calculator, smarty] * 10

user_names = [user.__name__.replace('_',' ') for user in users]
rounds = 1000
points = sorted(list(range(1,101)))
user_num = len(users)
bots = [user for user in users]
scores = [0.0 for user in users]
information = {i:0 for i in points}
sum_of_all = {i:0 for i in points}
print('\n'*100)

for round_number in range(rounds):
choices = [bot(information, points, round_number, sum_of_all, user_num) for bot in bots]
information = {score:choices.count(score) for score in points}
scores = [scores[index] + choices[index]/information[choices[index]] for index in range(user_num)]

print(f'\n\n\nRound #{round_number+1} Reports: ')

print('\nBots Report: ')
print('\n'.join([f'{user_names[index].ljust(20)} '
f'chose {choices[index]} '
f'and got {choices[index]/information[choices[index]]} additional points, '
f'making it now have {scores[index]} points!!! ' for index in range(user_num)]))

print('\nDistribution Report: ')
print('\n'.join([f'The number of bots who chose {num} is: {information[num]}!!! ' for num in points]))

sorted_list = sorted(range(user_num), key=lambda x: -scores[x])

print(f'\n{user_names[sorted_list[0]].ljust(20)} with {scores[sorted_list[0]]} points, '
f'\n{user_names[sorted_list[1]].ljust(20)} with {scores[sorted_list[1]]} points, and'
f'\n{user_names[sorted_list[2]].ljust(20)} with {scores[sorted_list[2]]} points!!! ')

sum_of_all = {i:sum_of_all[i]+information[i] for i in points}

print('\n\n\nFinal Report Card: \n')
print('\n'.join([f'{user_names[sorted_list[index]].ljust(20)}: '
f'{scores[sorted_list[index]]} points. ' for index in range(user_num)]))



The first part is imports. You may only depend on default python built-ins or the python standard library. Or if you manage to hide it and I out of coincidence have the package...

The second part is your functions. Naming your function bot_name_with_underscores is encouraged.

The third part are game parameters. The number of rounds, the accessible outputs, etc.

The fourth part is running the program!!!

An example output is as follows:


Round #1 Reports:

Bots Report:
random better        chose 3 and got 1.5 additional points, making it now have 1.5 points!!!
greedy better        chose 10 and got 10.0 additional points, making it now have 10.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 1.0 points!!!
smarty               chose 3 and got 1.5 additional points, making it now have 1.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 0!!!
The number of bots who chose 3 is: 2!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 1!!!

greedy better        with 10.0 points,
random better        with 1.5 points, and
smarty               with 1.5 points!!!

Round #2 Reports:

Bots Report:
random better        chose 7 and got 7.0 additional points, making it now have 8.5 points!!!
greedy better        chose 10 and got 5.0 additional points, making it now have 15.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 2.0 points!!!
smarty               chose 10 and got 5.0 additional points, making it now have 6.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 0!!!
The number of bots who chose 3 is: 0!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 1!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 2!!!

greedy better        with 15.0 points,
random better        with 8.5 points, and
smarty               with 6.5 points!!!

Round #3 Reports:

Bots Report:
random better        chose 4 and got 4.0 additional points, making it now have 12.5 points!!!
greedy better        chose 10 and got 10.0 additional points, making it now have 25.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 3.0 points!!!
smarty               chose 2 and got 2.0 additional points, making it now have 8.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 1!!!
The number of bots who chose 3 is: 0!!!
The number of bots who chose 4 is: 1!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 1!!!

greedy better        with 25.0 points,
random better        with 12.5 points, and
smarty               with 8.5 points!!!

Round #4 Reports:

Bots Report:
random better        chose 6 and got 6.0 additional points, making it now have 18.5 points!!!
greedy better        chose 10 and got 10.0 additional points, making it now have 35.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 4.0 points!!!
smarty               chose 2 and got 2.0 additional points, making it now have 10.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 1!!!
The number of bots who chose 3 is: 0!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 1!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 1!!!

greedy better        with 35.0 points,
random better        with 18.5 points, and
smarty               with 10.5 points!!!

Round #5 Reports:

Bots Report:
random better        chose 2 and got 2.0 additional points, making it now have 20.5 points!!!
greedy better        chose 10 and got 10.0 additional points, making it now have 45.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 5.0 points!!!
smarty               chose 6 and got 6.0 additional points, making it now have 16.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 1!!!
The number of bots who chose 3 is: 0!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 1!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 1!!!

greedy better        with 45.0 points,
random better        with 20.5 points, and
smarty               with 16.5 points!!!

Round #6 Reports:

Bots Report:
random better        chose 3 and got 3.0 additional points, making it now have 23.5 points!!!
greedy better        chose 10 and got 10.0 additional points, making it now have 55.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 6.0 points!!!
smarty               chose 2 and got 2.0 additional points, making it now have 18.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 1!!!
The number of bots who chose 3 is: 1!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 1!!!

greedy better        with 55.0 points,
random better        with 23.5 points, and
smarty               with 18.5 points!!!

Round #7 Reports:

Bots Report:
random better        chose 8 and got 8.0 additional points, making it now have 31.5 points!!!
greedy better        chose 10 and got 10.0 additional points, making it now have 65.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 7.0 points!!!
smarty               chose 3 and got 3.0 additional points, making it now have 21.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 0!!!
The number of bots who chose 3 is: 1!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 1!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 1!!!

greedy better        with 65.0 points,
random better        with 31.5 points, and
smarty               with 21.5 points!!!

Round #8 Reports:

Bots Report:
random better        chose 1 and got 0.5 additional points, making it now have 32.0 points!!!
greedy better        chose 10 and got 5.0 additional points, making it now have 70.0 points!!!
calculator           chose 1 and got 0.5 additional points, making it now have 7.5 points!!!
smarty               chose 10 and got 5.0 additional points, making it now have 26.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 2!!!
The number of bots who chose 2 is: 0!!!
The number of bots who chose 3 is: 0!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 2!!!

greedy better        with 70.0 points,
random better        with 32.0 points, and
smarty               with 26.5 points!!!

Round #9 Reports:

Bots Report:
random better        chose 3 and got 3.0 additional points, making it now have 35.0 points!!!
greedy better        chose 10 and got 5.0 additional points, making it now have 75.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 8.5 points!!!
smarty               chose 10 and got 5.0 additional points, making it now have 31.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 0!!!
The number of bots who chose 3 is: 1!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 2!!!

greedy better        with 75.0 points,
random better        with 35.0 points, and
smarty               with 31.5 points!!!

Round #10 Reports:

Bots Report:
random better        chose 2 and got 2.0 additional points, making it now have 37.0 points!!!
greedy better        chose 10 and got 5.0 additional points, making it now have 80.0 points!!!
calculator           chose 1 and got 1.0 additional points, making it now have 9.5 points!!!
smarty               chose 10 and got 5.0 additional points, making it now have 36.5 points!!!

Distribution Report:
The number of bots who chose 1 is: 1!!!
The number of bots who chose 2 is: 1!!!
The number of bots who chose 3 is: 0!!!
The number of bots who chose 4 is: 0!!!
The number of bots who chose 5 is: 0!!!
The number of bots who chose 6 is: 0!!!
The number of bots who chose 7 is: 0!!!
The number of bots who chose 8 is: 0!!!
The number of bots who chose 9 is: 0!!!
The number of bots who chose 10 is: 2!!!

greedy better        with 80.0 points,
random better        with 37.0 points, and
smarty               with 36.5 points!!!

Final Report Card:

greedy better       : 80.0 points.
random better       : 37.0 points.
smarty              : 36.5 points.
calculator          : 9.5 points.



## If any bot runs into an error,

it fails. So CHECK IT!!! Make it FOOLPROOF!!!

## Winner

This is .

• I feel like you need a bit better explanation of how Greed Control scoring works, but otherwise, it looks pretty good. May 12 at 14:52
• Also, please reduce the number of exclamation points and bold chars in your post. IMO it makes it look childish and something like the stereotypical plz send teh codez May 12 at 15:17
• I'm childish... I'm 13... Hahaha May 13 at 1:20

# Cross of Numbers code-golf

Given a number n as input, output an ASCII cross composed of numbers counting up to that length. Counting starts at 0 in the center, and numbers with more than one digit simply have their digits printed in order in the correct direction.

Example for n=12:

               2
1
1
1
0
1
9
8
7
6
5
4
3
2
1
2111019876543210123456789101112
1
2
3
4
5
6
7
8
9
1
0
1
1
1
2


## Meta

Is this appropriate for ?

# Categorising categories code-golfdecision-problemgraph-theory

A category is an abstract mathematical object whose actual meaning is not really important here. A category can be viewed as a directed graph with the following restrictions:

• every node in the graph has at least one edge from and to itself
• for every pair of edges which share an intermediate node (like $$\ a \rightarrow b \$$ and $$\ b \rightarrow c \$$), there must exist an edge which is their composition, like $$\ a \rightarrow c \$$

More mathematically, where $$\ E(a, b) \$$ means "there exists an edge from $$\ a \$$ to $$\ b \$$": $$\forall a \in G. E(a, a) \\ \forall a, b, c \in G. E(a, b) \vee E(b, c) \implies E(a,c)$$

Your task is to determine whether a given directed graph satisfies the above restrictions.

## I/O

You may take input using any reasonable representation of a graph, such as:

• an edge list
• a built-in directed graph type

You may assume there are no duplicate edges (but note that the edge $$\ a \rightarrow b \$$ is not the same as $$\ b \rightarrow a \$$)

Nodes will be represented by positive integers starting from $$\ 1 \$$, i.e., elements of the range $$\ [1, n] \$$, where $$\ n \$$ is the number of nodes. You may optionally also take $$\ n \$$ as a second input.

You should output one of two distinct values of your choosing, which correspond to true and false results.

# Meta

• Should I remove the first requirement ("every node in the graph has at least one edge from and to itself")? I think it doesn't add much to the challenge, but then it's less directly related to category theory and I can't use the funny title
• Is this clear enough?
• Any other feedback?
• I know it's not really relevant to the challenge itself, but "A category can be viewed as a directed graph with the following restrictions:", this might be technically true, but it certainly is misleading. It's sort of like saying that a group can be viewed as a set. It's missing sort of the most important property.
– Wheat Wizard Mod
May 17 at 12:50

# LOOOOONG TEEEEEXT

• How do you determine what a vowel is? I assume the question cares about letters not phonemes, so is it aeiou? You test cases imply that y and w, which are sometimes vowel letters, are not treated as vowel however is this a universal?
– Wheat Wizard Mod
May 12 at 8:52
• Oops, guess I should specify that... May 12 at 9:16

# Solve the Zany car game

• I think letting people choose input format may lead to more interesting solutions. May 16 at 7:48

# Sell cinema tickets

Or in other words, print out a numbered grid from bottom-middle to top-middle.

# Challenge

Most people think that, in a cinema, the back seats and the middle ones are the best.
You'll be receiving the number of seats across and vertically in the theater, your job is to sell the tickets in prioritized order, starting from the best seats to the worst.
The seats will be numbered from top-left to bottom-right.

# Example

In: 3, 4

Seats:
1  2  3
4  5  6
7  8  9
10 11 12

Out: 11, 12, 10, 8, 9, 7, 5, 6, 4, 2, 3, 1


The order of the outer seats doesn't matter, as long as the distance to the middle seat in the row is the same.

Another Possible output: 11, 10, 12, 8, 7, 9, 5, 4, 6, 2, 1, 3
12: Priority 7
11: Priority 8
10: Priority 7
09: Priority 5
08: Priority 6
07: Priority 5
06: Priority 3
05: Priority 4
04: Priority 3
03: Priority 1
02: Priority 2
01: Priority 1


# Rules

• The number of seats across and vertically (in any order) should be received as the input
• Output should be the seats numbered, sorted by their priority
• Default Loopholes apply

# Extract the contained powers of two!

• The title is somewhat misleading, because the output is a list of matches, not "how many" (which would be the length of the list). May 30 at 15:54
• I also suggest a test case which has a power of two as a subsequnce, but not a contiguous substring. e.g. 106 -> [1], not [1, 16]. Also, can the output may be in any order? May 30 at 15:56
• Thanks!! I have added your suggested test case, and improved the title. May 30 at 17:48

# Two In One: Guess That Language - Robbers

• I suggest restrictions on languages (what is a valid language and what are different languages) to be taken from this challenge - this seems to be a nice and working consensus. May 30 at 10:01
• Done @pajonk .. May 31 at 0:26
• I've edited this down to a stub now that it's been posted to save space Jun 4 at 2:47

# Parse Specification Data Structure Diagrams

Many protocol specifications illustrate the structure of data packets or file formats with ASCII tables. This helps to visualize the layout of the data in memory, a file, or how bits are transmitted "on the wire".

For example RFC 1035 section 4.1.1 describes the header of a DNS query with the following diagram:

                                1  1  1  1  1  1
0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                      ID                       |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    QDCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    ANCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    NSCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    ARCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+


RFC-793 Tranmission Control Protocol contains the following diagram of a TCP packet header:

 0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          Source Port          |       Destination Port        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Sequence Number                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    Acknowledgment Number                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Data |           |U|A|P|R|S|F|                               |
| Offset| Reserved  |R|C|S|S|Y|I|            Window             |
|       |           |G|K|H|T|N|N|                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Checksum            |         Urgent Pointer        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                             data                              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

• Wouldn't it be useful if we could automate the parsing of data buffers into the various fields based on these diagrams?

# Challenge

Your job is to write code that can interpret these diagrams to parse a data buffer into the data fields.

• Inputs will be a multi-line ASCII string following the format shown above, either an array of lines or a single string with linefeeds, and a data packet as an array of bytes.
• The input diagram includes the two initial rows that number the bit offsets (note that zeros in the first row may or may not be present).
• Bytes are in Big Endian ("network") order
• Bit offsets are from MSb to LSb
• The number of bits per row will be a power of 2 and at least one octet (byte). I.e. 8, 16, 32, 64.
• For this challenge a single field will not span bytes from one row to the next.
• Some cases will require multiple lines of input for a single row of bits to accommodate the field names. Field names are concatenated from the data in the field column over multiple rows. For example see the fourth row in the RFC-793 TCP packet header. Note when field name values butt up to the edge of the field, no space is inserted between the characters on consecutive rows, otherwise a single space is between the field name values on each row. See "Data Offset" vs. "ACK".
• A single bit position could take two characters as in the ASCII diagram for the TCP packet header, or three as in the DNS query header. I.e. +-+ vs +--+
• Output can be in decimal or hexadecimal with a '0x' prefix.

# Example Input and Output

Example 1 - DNS Query Header

Input:

String diagram = """
1  1  1  1  1  1
0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                      ID                       |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    QDCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    ANCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    NSCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    ARCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
""";
byte [] data = { 0x00, 0x00, 0x84, 0x80, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00 };


ID = 0x0
QR = 0x1
OpCode = 0x0
AA = 0x1
TC = 0x0
RD = 0x0
RA = 0x1
Z = 0x0
RCODE = 0x0
QDCOUNT = 0x0
ANCOUNT = 0x6
NSCOUNT = 0x0
ARCOUNT = 0x0


Example 2 - TCP Packet Header:

Input:

String diagram = """
0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          Source Port          |       Destination Port        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        Sequence Number                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    Acknowledgment Number                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Data |           |U|A|P|R|S|F|                               |
| Offset| Reserved  |R|C|S|S|Y|I|            Window             |
|       |           |G|K|H|T|N|N|                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Checksum            |         Urgent Pointer        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                             data                              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
""";
byte [] data = { 0xc0, 0x01, 0xa4, 0x74,
0x00, 0x00, 0x00, 0x02,
0x00, 0x00, 0x00, 0x01,
0x60, 0x10, 0x00, 0x04,
0x39, 0x3a, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x01, 0x02, 0x03, 0x04 };


Output (in decimal):

Source Port = 49253
Destination Port = 42100
Sequence Number = 2
Acknowledgment Number = 1
Data Offset = 24
Reserved = 0
URG = 0
ACK = 1
PSH = 0
PST = 0
SYN = 0
FIN = 0
Window = 4
Checksum = 14650
Urgent Pointer = 0
Options = 0
data = 16909060


Understanding the tables:

+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                      ID                       |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+


The above table section indicates that the 'ID' field is composed of the first 16-bits of the data packet (Big Endian), The 'QR' field is the high bit of the next byte, 'OpCode' comes from the next four highest bits of the same byte containing 'QR', The lower three bits of that byte contain the single-bit values for 'AA', 'TC', and 'RD'. 'RA' is the highest bit of the next byte, followed by 3-bits for 'Z'. The lower four bits of that byte hold the value for 'RCODE'.

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Data |           |U|A|P|R|S|F|                               |
| Offset| Reserved  |R|C|S|S|Y|I|            Window             |
|       |           |G|K|H|T|N|N|                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


The above table has several fields whose field names could not fit within the table using only a single line for that row of bits. There are nine fields in these 32 bits. The upper four bits of the first byte is 'Data Offset', followed by six bits (the remaining four of the first byte, and the upper two bits of the next byte) for 'Reserved' (i.e. unused). The lower six bits of the second byte are for the six one-bit fields 'URG', 'ACK', 'PSH', 'RST, 'SYN', and finally 'FIN'. 'Window' is a 16-bit value made from the following two bytes (Big Endian).

i.e. pseudo code to unpack the data values for the above line:

Data_Offset = (data[0] & 0xf0) >> 4;
Reserved = ((data[0] & 0x0f) << 2) + ((data[1] & 0xc0) >> 6);
URG = (data[1] & 0x20) >> 5;
ACK = (data[1] & 0x10) >> 4;
PSH = (data[1] & 0x08) >> 3;
RST = (data[1] & 0x04) >> 2;
SYN = (data[1] & 0x02) >> 1;
FIN = data[1] & 0x01;
Window = (data[2] << 8) + data[3];


The field names themselves come from concatenating the characters within each "box". Where spaces are trimmed from both ends, and all other white space is collapsed to a single space. You may also use an underscore, a hyphen, or a dot ('_', '-', '.') instead of a space to separate words of a field name. You must use some separator between words, conversion to CamelCase or straight concatenation of words is not allowed. You must not alter the case of the field names as it may be significant.

The output must be printed or in the form of a single string that clearly pairs the field names and values. Consider readability for humans. I.e. a list of field names, followed by a list of values is NOT acceptable as this is too inconvenient for a human to find the right value for each field. You may use one field per line and '=' as I have shown above, a two column table, a text format similar to JSON, CSV, etc.. There must be distinct delimiters between the name and the value and between different field-value pairings, e.g. I used "=" and newlines. If you use a space between field name and field value, you must not use a space between words in the field name unless they are quoted or otherwise escaped so the output is unambiguous.

• Could you please add a worked out example (maybe a simpler one)? I'm not familiar with the structure of the tables and I don't quite get what's going on. Also, please specify a winning criteria (code-golf I presume?) and consider relaxing I/O requirements (i.e. add "or any reasonable equivalent" that would include e.g. array of characters for input or binary for output). Jun 10 at 6:13
• @pajonk I've editing for clarity. How is it now? Jun 10 at 15:48
• Yes, looks better now. What types of output are acceptable apart from the format you show? - I suggest anything that will unambiguously identify the names and values (including but not limited to: named list, names and values space/comma separated, two lists (one with names, second with values), dataframe with two columns) Jun 10 at 18:11
• @pajonk I've clarified the output requirements. Jun 10 at 22:01

# Flatten from the inside out

Say we have a ragged list

[
[1, 2],
[3,
[4, 5]
],
]


And we want to flatten it by a layer, decreasing its depth by 1. We could flatten it from the outside:

[1, 2, 3, [4, 5]]


Or, we could flatten it from the inside.

To do this, take all subarrays with maximal depth, and disperse each into its parent array. For example, with the array [[1, 2], [3, [4, 5]]], the [4, 5] has maximal depth, so the array becomes [[1, 2], [3, 4, 5]].

Your challenge is to, given a list, flatten it from the inside by one level. The list will only contain nonnegative integers, and will not contain empty lists.

This is , shortest wins!

## Testcases

[[1, 2], [3, [4, 5]]] -> [[1, 2], [3, 4, 5]]
[[6, 3, [1, 3, 4]], 4, [2, 3, 9, [5, 6]]] -> [[6, 3, 1, 3, 4], 4, [2, 3, 9, 5, 6]]
[[[3]], [4, [5]]] -> [[3], [4, 5]]
[[[[[[[[1]]]]]]]] -> [[[[[[[1]]]]]]]


# Am I winning at O-Tris?

O-Tris is a very, very, very simplified version of Tetris, which is defined as follows:

There is a grid of cells that is 6 cells wide and 7 cells tall, known as the Playfield. Cells in the Playfield can be either Active, Inactive, or Empty.

There is a construct called an O-piece, composed of 4 Active cells in a 2x2 arrangement. An O-piece will always exist somewhere in the Playfield, and two O-pieces cannot coexist.

There are three commands, Left, Right, and Idle. No other commands exist.

Gameplay is defined as follows:

The user inputs a series of commands at the start of the game, which are stored. The Playfield is then initialized with all Empty cells save for a single O-piece in the top center, as shown the diagram below, where . represents an Empty cell, # represents an Inactive cell, and O represents an Active cell:

..OO..
..OO..
......
......
......
......
......


Then, each command is processed one at a time. For each command, the following process occurs:

• The first step depends on which command is read;
• If the command is Left, no cell to the immediate left of an Active cell is Inactive, and no cell in the leftmost column of the Playfield is Active, then the rightmost two Active cells will become Empty, and the two Empty cells to the immediate left of each Active cell will become Active. (This is analogous to the O-piece moving left unless obstructed)
• If the command is Right, no cell to the immediate right of an Active cell is Inactive, and no cell in the rightmost column of the Playfield is Active, then the leftmost two Active cells will become Empty, and the two Empty cells to the immediate right of each Active cell will become Active. (This is analogous to the O-piece moving right unless obstructed)
• If the command was Idle, move directly to the next step.
• Second step;
• If the two cells immediately below each the bottommost Active cells are Empty and within the Playfield, those two Empty cells will become Active and the topmost Active cells will become Empty. (This is analogous to the O-piece moving down if unobstructed)
• If not, the following subprocess occurs;
• All Active cells will become Inactive.
• Any rows of cells within the Playfield that are are composed of only Inactive cells will be reset to be all Empty cells, and every row above that row will be translated downward, leaving a row of Empty cells at the top of the grid. (Meta: is this well stated?)
• The game will attempt to place a new O-piece in the top center of the Playfield, satisfying the requirement that an O-piece always exist. If any of the 4 cells is Inactive, this will fail, and the game will enter a Loss state, inform the player that they have lost, and halt. Otherwise, continue to the next step.
• Third step;
• If there are any remaining commands, return to step one and continue by reading the next command.
• If no commands remain, the game will enter a Win state, inform the player that they have won, and halt.

## Challenge

Your challenge is to take a series of commands and return whether they would Win or Lose at O-Tris. This is , so shortest code in bytes wins.

## Input

Take a nonempty series of distinct values representing either the Left, Right, or Idle commands in any reasonable format. Assume no extraneous input.

## Output

Output one of two distinct values represent either a Win state or a Loss state. No other output is required.

## Examples

Using L as Left, R as Right, and I as Idle, 1 to indicate a Win state, and 0 to indicate a Loss state.

input => output
L => 1
LLLLLLLLLLLLLL => 1
IIIIIIIIIII => 1
IIIIIIIIIIII => 0
IIIIIIIIIIIIILLL => 0
LLIIIIRRIIIIIIIIIIIIIIIIIIIII => 1
LLIIIIRRIIIIIIIIIIIIIIIIIIIIII => 0
LLIIIIRRIIIILIIIRIIII => 1
LLIIIIRRIIIILIIIRIIIIR => 0
LLIIIIRRIIIILIIIRIIIRR => 1
LLIIIIRRIIIILIIIRIIIRRII => 0
LLIIIIRRIIIILIIIRIIIRRLLII => 1


(Meta: more test cases probably, specifically one where lines are cleared with blocks above it and that clear saves the player from losing)

# Meta

Should I provide more diagrams? If so, where?

## Speed up, slowpoke!

• (No, Slowpoke will only speed up in Trick Room.)
– tsh
Jun 10 at 7:20
• How many bots will a game have? Speeding down others only makes one of other bots 10% slow than me. But speeding up myself makes all other bots 11% slow than me. So I see no reason to slow down others in current game specification.
– tsh
Jun 10 at 7:23
• Yes, exactly. I'll try to clarify. Jun 10 at 15:25
• Done! <filler, text> Jun 11 at 19:12
• The new controller script is here, with more examples. Jun 12 at 7:06
• It can access a list, not dictionary, of all the bots in the games' functions + current scores + current turn frequency, including itself, represented as [bot_function, score_integer, frequency_float]. Additionally, it will receive itself, so it can differentiate himself from other bots. It can also access the round number (from 1 to 300). So, arg1 = [[bot,score,turn_freq] for bot in bots], arg2 = itself, and arg3 = round number which you didn't mention. Jun 12 at 7:09
• That link ain't sending me anywhere; I just see a blank textbox. Otherwise, fixed! Jun 12 at 7:58
• @23TuringMachine this link should be better. The old link redirects to a Chinese website. Jun 12 at 10:25
• @23TuringMachine technically I prefer "NobodyNeedsNames" or NumberBasher but it probably doesn't matter anyhow. Jun 12 at 10:27
• I would add it to PyPI when nothing will change. Gotta go to sleep now o/ Jun 12 at 10:28
• Thank you @23TuringMachine, and maybe you can @ me when you are done so I can know (without having to navigate here), thanks!!! I would some time run it and upload a pic of the result. Jun 12 at 10:38
• I'm not sure if you want to shuffle the info list. One reason for yes is it takes time. One reason for no is that it allows multiple bots to attack one specific bot. @23TuringMachine Jun 12 at 10:41
• SLEEP TIME!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Jun 12 at 10:42
• Yeah, it'd probably be wise to shuffle it. We've time, after all. Jun 12 at 10:47
• Jun 12 at 11:20

# Truncate words in a sentence

• The second test case appears to treat dQw4w9WgXcQ as one single word, but it has digits in it. Should your definition of "word" be changed to include this? Jun 12 at 9:06
• @pxeger Oops. Will fix Jun 12 at 9:11
• Is input always printable ASCII only? Jun 12 at 9:14
• @pxeger yes. (filler) Jun 12 at 9:15

# Goroawase Numeric Substitution

Goroawase numeric substitution is a common form of Japanese wordplay where homophonous words are associated with a given series of numbers to associate a new meaning with that series. Your task is to take an input of a Japanese pronunciation and output a sequence of numbers from 1-10 which can be pronounced as the input in Japanese. For simplicity, only follow the table below.

### Substitution Table

0 maru, ma, wa rei, re ō/ou, zero, ze
1 hitotsu, hito, hi ichi, i wan
2 futatsu, fu, futa, ha ni, ji, aru tsu, tsū/tsuu, tū/tuu
3 mittsu, mi san, sa, za su, surī/surii
4 yon, yo, yottsu shi fō/fou, fā/faa, ho
5 itsutsu, itsu, i go, ko faibu, faivu
6 muttsu, mu roku, ro, ri, ra shikkusu
7 nana, nanatsu, na shichi sebun, sevun
8 yattsu, ya hachi, ha, ba eito
9 kokonotsu, ko kyū/kyuu, ku nain
10 tō/tou, to, ta ju, ji ten

## Rules

• Input and output can be in any convenient format, but it should be possible to tell the difference between 1 0 and 10. You can choose to take input in hiragana/katakana.
• You can assume that the input will always be valid.
• For inputs that could have multiple possible outputs (such as i being 1 or 5), any is acceptable.
• Standard loopholes are forbidden.
• This is , so the shortest code in bytes wins.

# Is This Loss?

Given two shapes A and B in ASCII-art, determine if A appears within B.

A shape A appears in shape B if there is a way to overlay shape A onto shape B without covering any spaces that B is not already covering.

## Rules

• Standard I/O, any reasonable format etc. etc.
• Input will only contain two symbols of your choosing (as well as newlines) and can be assumed to be padded out / without any padding if necessary.
• Neither shape will ever be empty.
• This is , so shortest code in bytes wins.

## Examples

Shape A (will remain the same for the next few examples)

#       #
#       #  #

#  #    #
#  #    # ###


Shape(s) B

Truthy:

#       #
#       #  #

#  #    #
#  #    # ###

###
#       #######
#       #######
###############
####    #######
####    #####

### #  # #### ### ### ###
#   #  # #  #  #  #   #
#   #### #  #  #  #   ###
#   #  # #  #  #  #   #
### #  # #### ### ### ###


Falsy:

#

    #       #
#  #       #

#    #  #
### #    #  #

# #
# # #

# # #
# # # ###

# ####### #####
# ####### ## ##
###############
# ## #### #####
# ## #### #   #

### #    #  #
#    #  #

#  #       #
#       #


### Non Loss example, for testing purposes:

Shape A

####


Shapes B

Truthy:

# # # ###### # # #

#
##
###
####
#####


Falsy:

#

## ##
### #
### #
# ###
# ###
## ##


# Meta:

Should I define anything more rigorously or is this clear as day?

# Gray coded gray code convertorcode-golfrestricted-source

• This is an interesting restricted-source challenge, but I think the task of being Gray coder is not very interesting, because it's just a numeric formula. I wonder if you could change this into something more in the category of quine, self-validating, or more generally self-referential? Or maybe just to output a constant string, where the challenge comes from somehow encoding that string under these restrictions? Jun 12 at 9:23
• I'd also suggest replacing the word "character" with "byte", because the "bits" of a character are not really a defined concept, without also defining a character encoding, in which case you probably care only about the bytes anyway. Jun 12 at 9:25
• Finally, could you specify whether the empty program, and a one-byte (or one-character) program, is considered "safe" or not? It's unlikely you'll find a language with a one-byte builtin command for Gray coding, but possible, and I think you should handle those edge cases nonetheless. Jun 12 at 9:26
• Thank you a lot for your feedback. I wanted to make this challenge not too hard, so I chose just the simple formula and I think that a lot of languages can't compete already. I think it would be interesting to change it into program which validates if its input is gray coded, but it feels harder, so I am not sure if it shouldn't be maybe separate challenge?
– Jiří
Jun 12 at 13:04
• Also I chose word "character", because I think it would otherwise make using encodings such as UTF-32 very hard to use, but I guess not many answers would use such encodings. So I would like to ask you if you have some other idea how to change the wording of it, but if you don't, then I guess I can change it to "byte".
– Jiří
Jun 12 at 13:07
• Yes, you're right; I have now actually tried this task, and it is pretty hard to do anything at all in most languages, so it's fair enough to keep it simple. As for bytes and characters, I think almost all answers will use either plain ASCII, or a SBCS, especially the kind used for most golfing languages. My objection is that a "character" doesn't have bits unless some kind of encoding is specified, and since we score using bytes by default on this site, so every language definitely has [...contd] Jun 12 at 13:12
• [contd...] some way of translating into bytes, it makes sense to just use bytes. Jun 12 at 13:13

# Strange ponds (WIP)

A few things need to be ironed out, but hopefully you can get the intention of this challenge.

In this challenge we considered a frog hopping around a lily pond. To recap the lily pond was represented as a finite list of positive integers. The frog can only jump forward or backwards by a distance equal to the number at its current location. So for example:

[2, 3, 1, 4, 1]
🐸


Here the frog is on a 1 so it can move forward 1 to the 4 or backwards 1 to the 3.

We can represent the as a directed graph, where each pad is a vertex and the edges represent hops the frog can make. Thus each vertex can have at most 2 children (forward and backwards), vertices can have fewer children if jumping in a certain direction would put them out of bounds. And indeed at least two vertices in every lily pond have fewer than two children.

As an example the pond shown above [2,3,1,4,1] can be represented as the graph:

{ 0 : [ 2 ]
, 1 : [ 4 ]
, 2 : [ 1, 3]
, 3 : []
, 4 : [ 3 ]
}


TODO draw the graph in tikz

Of course not all graphs where each node has fewer than 2 children represents a lily pond. For example, the complete graph of order 3:

{ 0 : [ 1, 2 ]
, 1 : [ 0, 2 ]
, 2 : [ 0, 1 ]
}


Each node has two children, but the first element of the list can have at most 1 child (can't go backwards from the start). So none of the elements can go first, thus this can't be a lily pond.

Your answer should take as input a directed graph which satisfies the following properties:

• it doesn't have a vertex with more than 2 outgoing edges (children).
• it doesn't have a self loop (an edge from a vertex to itself).
• it doesn't have two edges with the same origin and destination vertices (the graph is simple).

and your answer should output one of two consistent values. The first if the input represents some lily pond, the second if it does not. What the two values are are up to you to decide.

This is the goal is to minimize your source code as measured in bytes.

## Test cases

### Represents no lily ponds

[[1,2],[0,2],[0,1]]
[[1,2],[],[],[0,1]]
[[1,2],[],[],[],[1,2]]


# Push some numbers

Given a list of integers, apply the following rules to each element:

• If n is even, move it to the back.
• If n is odd, move it to the front.

Zero is considered even. You may assume inputs are always non-negative.

# Test cases

[1,2,3] => [3, 1, 2]
[0,1,2] => [1,0,2]
(more test cases coming soon)


Shortest code wins!

• why treat 0 like a special case? Jun 13 at 17:33
• @thejonymyster fixed Jun 13 at 23:25
• you don't need to specify that zero is even :P Jun 13 at 23:34
• Are the inputs always non-negative? Jun 14 at 7:45
• @pxeger yes, always Jun 14 at 13:31
• I assume input-lists can contain duplicated values and can be in any order (e.g. [10,4,1,5,10,2,3,2,3] would be a valid input - which I think results in [3,3,5,1,10,4,10,2,2])? Jun 23 at 6:47

# Which R version is it? It's Peanuts!

This challenge will be based on an R language trivia: every release is named and it's a reference to Peanuts comic strips (see here and here).

Given a release name, output it's number.

For reference, use the below list:

Great Pumpkin            2.14.0
December Snowflakes      2.14.1
Easter Beagle            2.15.0
Roasted Marshmallows     2.15.1
Trick or Treat           2.15.2
Security Blanket         2.15.3
Good Sport               3.0.1
Frisbee Sailing          3.0.2
Warm Puppy               3.0.3
Spring Dance             3.1.0
Sock it to Me            3.1.1
Pumpkin Helmet           3.1.2
Smooth Sidewalk          3.1.3
Full of Ingredients      3.2.0
World-Famous Astronaut   3.2.1
Fire Safety              3.2.2
Wooden Christmas-Tree    3.2.3
Very Secure Dishes       3.2.4
Very, Very Secure Dishes 3.2.5
Supposedly Educational   3.3.0
Sincere Pumpkin Patch    3.3.2
Another Canoe            3.3.3
You Stupid Darkness      3.4.0
Single Candle            3.4.1
Short Summer             3.4.2
Kite-Eating Tree         3.4.3
Someone to Lean On       3.4.4
Joy in Playing           3.5.0
Feather Spray            3.5.1
Eggshell Igloo           3.5.2
Great Truth              3.5.3
Planting of a Tree       3.6.0
Action of the Toes       3.6.1
Dark and Stormy Night    3.6.2
Holding the Windsock     3.6.3
Arbor Day                4.0.0
See Things Now           4.0.1
Taking Off Again         4.0.2
Bunny-Wunnies Freak Out  4.0.3
Lost Library Book        4.0.4
Shake and Throw          4.0.5
Camp Pontanezen          4.1.0
Kick Things              4.1.1
Bird Hippie              4.1.2
One Push-Up              4.1.3
Vigorous Calisthenics    4.2.0


## Rules

• You may take input and output in any reasonable format (for output this includes a dot delimited string (as above), a string with other delimiter or a 3-element list).
• This is - usual rules apply.

## Meta

• Is it any interesting or is it just another -like challenge like many already on this site?

# Is it shuffled FizzBuzz?

A twin of this.

FizzBuzz is where a range of positive integers is taken, and numbers divisible by 3 are replaced with "Fizz", divisible by 5 with "Buzz" and divisible by 15 with "FizzBuzz". For example, FizzBuzz from 1 to 10 is 1, 2, Fizz, 4, Buzz, Fizz, 7, 8, Fizz, Buzz.

Your challenge is to, given a list of Fizzes, Buzzes, FizzBuzzes and a value representing an integer (I'm going to use Int), determine if it can be arranged into valid FizzBuzz.

For example, Int, Fizz, Fizz, Buzz can be arranged into Fizz, Buzz, Int, Fizz (for example 9,10,11,12) which is valid. But Buzz, Fizz, Buzz cannot, as the two Buzz need to be five values apart.

You may choose any four values to represent Fizz, Buzz, FizzBuzz and Int.

This is , shortest wins!

## Truthy

Int, Int, Fizz
Fizz, Int, Fizz, Buzz
Fizz, Fizz, Fizz, Int, Int, Int, Buzz
Buzz, Int, Int, Int, Fizz, FizzBuzz
FizzBuzz, Int, Int, Int, Int


## Falsy

Buzz, FizzBuzz, Fizz
Buzz, Fizz, Buzz
Int, Int, Int
Fizz, Int, Fizz
FizzBuzz, Int, Int, Buzz, Fizz


# Find Maximum number of 4+ letter words from Scabble Tiles

The challenge is to find the most words with 4 or more letters you can make with one set of scrabble tiles.

The tile distribution is as follows:

2 Blank Tiles
A 9  N 6    +====+===========+
B 2  O 8    | 01 | K J X Q Z |
C 2  P 2    | 02 | B C M P F |
D 4  Q 1    | 02 | H V W Y * |
E 12 R 6    | 03 | G         |
F 2  S 4    | 04 | L S U D   |
G 3  T 6    | 06 | N R T     |
H 2  U 4    | 08 | O         |
I 9  V 2    | 09 | A I       |
J 1  W 2    | 12 | E         |
K 1  X 1    +====+===========+
L 4  Y 2
M 2  Z 1


Valid words are any words that are 4+ that are available in this file, the official scrabble dictionary.

Tiles cannot be used twice. This means you can only have 1 word with a K, J, X, Q, and/or Z unless you use a blank tile to represent one of these letters.

I'm not sure how I'd do scoring on this. I want shorter code to score better, but I don't want a short piece of code that finds a lot less words to score better than a longer piece that finds many more words.

• Meh. I don't like dependency on external files; are we allowed to load it, or even embed it into the source code? Dec 17, 2013 at 20:00
• as for finding more vs. shorter code, you could demand all words be found Dec 17, 2013 at 20:19
• @JanDvorak Any way to use it. It's a text version of the official scrabble dictionary, it seemed to be the most fitting word list for the task. "All words being found" might be hard, considering there are probably many combinations of words that would deplete all the tiles. It's a maximum of 25 words, (25 words, 4 letters each, 100 tiles), but I don't know if it's possible to use all tiles with just 4 letter words. After so many words, you might not have enough tiles to make an actual word, which means you'd either have to go back or accept that you're not using all the tiles.
– Rob
Dec 17, 2013 at 20:23
• As currently described, this is a no-input task, which means that the answer can be precomputed and then the program only needs to decompress it. Consider rewriting it to take input (either of the word list or of the tiles available). Dec 18, 2013 at 8:01
• I suggest taking a list of tiles as input, loading the list of words from a predefined file and requiring all combinations / best combination to be found. Of course, if the input is the full list of tiles, the computation is going to take ages. I might allow preprocessing the word list outside the program itself (up to a certain point; a linearithmic growth?) Dec 18, 2013 at 8:32
• I suggest modifying this so that input is a list of tiles, limited to a full rack or less (therefore 4-7 tiles, since our minimum word length is 4). Input should be assumed to be valid based on the standard set of tiles (e.g.: it wont' have something like 3 J's or 4 G's). This would have some practical use for a player in a scrabble game to figure out their next move (though it does not take into account tiles available to them which are already on the board).
– Iszi
Dec 18, 2013 at 21:14
• Alternative mode: Input is a list of tiles, maximum 96 (so that at least 4 are remaining in the set). Output only includes words (minimum 4 letters) which can be created without those tiles. This would be interesting as it provides words that may yet be created (though, again, not taking into account usable tiles on the board) at a given point in the game.
– Iszi
Dec 18, 2013 at 21:15
• Output needs to be decided as either a list of all possible words, or only the highest-scoring word(s). Another enhancement may be to require that the list be sorted descending in order of score (if output is all words), then ascending alphabetically. There's no reason to take each program's output into account for scoring. Since everyone is expected to use the same dictionary, all programs' outputs should be identical (except perhaps in sorting, if that's left out of the spec). So, this should be Code Golf.
– Iszi
Dec 18, 2013 at 21:15
• It's also worth noting that, as currently written, the task could just be to filter the given dictionary down to words which have 4 or more letters. By its very nature, the Scrabble dictionary should already exclude any words that cannot be made with a Scrabble set.
– Iszi
Dec 18, 2013 at 21:18
• @Iszi it's not "what are all the words you can make", it's "what are all the words you can make, where every letter used depletes a tile". There's a max of 25 words if you can use all 100 tiles.
– Rob
Dec 19, 2013 at 16:40
• I think I misunderstood the problem, then. I thought it was "all the words possible using a set of tiles" not "all the words possible, using only one set of tiles". Still, my point about code golf remains. There is an absolute maximum to the number of words (each with 4 or more letters) you can make with a single Scrabble set, and a finite number of permutations which can be used to hit that maximum. Every program written with this goal should end up with the same (or nominally similar) output.
– Iszi
Dec 19, 2013 at 16:56