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.

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Other

Search the sandbox / Browse your pending proposals

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Answer 1

Formatting a Lisp-like Syntax

POSTED

Answer 2

From A to Zilch

Zilch, Farkle, Greed, Dice 10000: The game goes by many names, and many rules. Your goal is to make a program that can play them all optimally. The base rules goes as follows:

1. At the beginning of your turn, you have 6 available dice
2. At the beginning of each roll, you either choose to bank or continue.
3. If you choose to bank, then you receive the total number of points you have accumulated and your turn is over.
4. Roll all available dice
5. If you didn't roll any combinations, you get 0 points for your entire turn, and your turn is over
6. You must take one or more distinct combinations from your available dice and score them.
7. If you have no available dice left over, you are able to use all 6 dice again.
8. Go back to step #2

Your goal is to write a function or program that accepts 3 parameters:

1. The number of points you currently have
2. The number of dice you have left
3. A list of (Combination, Point) pairs that define what combinations give points

and then returns a Truthy value if you should continue, otherwise a Falsy value.

Combinations are passed as a list of integers that represent the required digits for that combination.

For example, if I named my function foo, then a call to my function might look like:

foo(100, 5, [([1],100), ([5],50), ([1,1,2],1000)])

This would mean that I have 100 points so far, 5 dice left, and there are 3 possible combinations:

1. Rolling a 1 would give me 100 points
2. Rolling a 5 would give me 50 points
3. Rolling 2 1s and a 2 would give me 1000 points.

Considering I have 5 dice, and it is quite likely for me to roll a 1 or a 5, I should definitely return a Truthy value. Also, note that in the above example, rolling 11235 would give me a maximum of '112'=>1000 + '5'=>50 = 1050 points. Each die can only be included in one combination.

Answer 3

Pirates!

king-of-the-hill

Introduction

Arrr mateys!

All hands on deck! Tharr be a ship o' other pirates comin' starboard up t' us on t' starboard! Man t' six pounders! We'll show these guys what we're made of!

...

What? They have t' exact same ship, and t' exact same six pounders as us? That don't matter, we've got better cannon strategy! As long as we reinforce points o' our ship that they fire upon, and fire upon unreinforced parts o' their ship, we're aye t' win! Now, where's that techno thingamabob that said what t' do...?"

Game Description

In this King of the Hill challenge, you write a program to command a pirate crew in a naval war. The other pirate crews are controlled by other players' programs. By carefully choosing where and when to fire, you can defeat the other pirate crews and claim the golden treasure -- the green checkmark of legend.

A battle occurs between two ships. Each ship is mounted with 7 cannons in a row, labelled 1 to 7. Each cannon is directly opposite to the cannon on the other side. Ships all start with 0 damage. If a ship reaches 10 damage, it sinks, and the crew of the other ship win the battle. If both ships sink at the same time, the battle is a draw.

Each battle consists of several turns. On each turn your crew can do any of the following actions:

L:n

Load a cannonball into cannon n. All the cannons start with cannonballs in them, and naturally firing a cannon without a cannonball doesn't do anything.

You can only load one cannonball into a cannon at a time.

R:n

Reinforce a cannon n. Reinforcements will nullify a single attack on that cannon. However, reinforcements are but a transient defence -- they will wear off two turns after they have been applied.

[Todo: Clarification on "two turns"]

F:n

Fire a cannon n, which will hit cannon n on the opposing side. If the cannon is not reinforced, the opposing ship's damage will increase by 1. If the cannon is reinforced, the ship will not take damage, but the reinforcement will be destroyed.

Input Description

The controller will call your program from the command line like this:

<command> <history> <enemy_history> <damage> <your_damage>

where:

• command is the command needed to run your program. For instance, if your program's source code was in the file arrr.rb, the command is ruby arrr.rb.
• history is a comma separated list of moves that you have made. For instance, L:1,F:1,L:2,F:2 would mean that you loaded and fired cannon 1, and loaded and fired cannon 2.
• enemy_history is a comma separated list of moves the enemy has made.
• damage is your ship's damage (from 0 to 9, since 10 means you've sunk)
• enemy_damage is the enemy ship's damage

Output Description

Output to STDOUT in the form:

A:N

where A is either L, R, or F, and N is an integer from 1 to 7. This indicates the move that you want the pirates to do.

[Todo: The rest of the spec. I'm tired and I'm posting it here to save it. Will come back some time to finish it. Maybe. Honestly I'm not too fond of the idea but it might have some potential.]

Answer 4

Chinese Checkers

I'm considering writing a challenge that will have people write Chinese Checkers players.

Image courtesy of Wikipedia

The game is quite simple: In clockwise turns, players try to move their 'pegs' across the board. They may only move one peg each turn. Valid moves are either moving to an adjacent empty space, or hopping over any number of pegs (friend or foe). These moves cannot be combined. The game is won when somebody has all their pegs in the triangle opposite of where they started.

I will write a controller, that will match up all players against each other in a sufficiently large number of matches. Each match, there will be points for the first, second and third place. Winner is the one with the most points.

Players must have a time limit on each move. This limit will be checked by the controller, and penalties will be applied accordingly. There will also be a limit on total number of moves, to prevent my poor laptop from calculating Chinese Checkers until the heat death of the universe because some idiot decided that random walks would be the way to go.

Since I've never written a controller before, I'd first like to see whether you guys are interested at all in this challenge. Furthermore, which language is generally preferred for these kind of challenges: Java or C++?

Answer 5

Captcha cops-and-robbers

Cops develop a captcha algorithm in minimum bytes. Robbers tries to implement a recognizer that recognizes 90 of 100 generated captchas.

Answer 6

Merging Words

code-golfstringssubstrings

Input

Two strings, and two numbers: "hlwl", "elo_ord!", 1 2

These may be function parameters, STDIN or language equivalents.

Output

The second string merged into the first string. The numbers specify how many characters to add when merging.

This is what happens:

h  l  w  l        //notice there is only 1 char per group (first number)
 el o_ or d!      //2 chars per group here (second number)
-------------
hello_world!

More formal-ish procedure:

• start with the first string
• Remove the first n chars from the first string and append it to r, where n is the first numerical input and r is the output string
• Remove the first k chars from the second string and append it to r, where k is the second numerical input
• Repeat the last 2 steps until both the first and the second string are empty. You may assume that first_string.length / second_string.length == n / k

Test Cases

input: aaaa bbbb 1 1
output: abababab

input: abcd iiiiiiii 1 2
output: aiibiiciidii

input: chmeeo aln 2 1
output: chameleon

input: emblem ezzent 3 3
output: embezzlement

This is code-golf, so shortest code wins!

Answer 7

Can you lose from this chess position?

code-challenge chess

Introduction

You are an arbiter who supervises a very large number of chess tournaments. Thus, you frequently rule on whether a player who runs out of time may claim a draw based on Article 6.9 of the FIDE Laws of Chess:

[...] If a player does not complete the prescribed number of moves in the allotted time, the game is lost by the player. However, the game is drawn, if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.

In order to be able to perform your job more efficiently, you decide to create a computer program that determines whether it is possible for a player to be checkmated from a given position.

Regulations

The input will be a position with White to move, with at least one legal move available. You may assume that in the initial position, neither player will retain castling rights and no en passant capture will be available. Additionally, you may assume that the existence of en passant is irrelevant to the correct output. Your program must determine whether, starting from the input position, there exists any sequence of legal moves that ends in Black checkmating White's king.

Either a program utilizing standard input and output, or a function accepting a string and returning a number is acceptable.

Input will be given in FEN notation, but excluding the last 4 tokens – only the locations of the pieces on the board are described.

The program shall output 1 if it is possible for white to be checkmated, or 0 if it is not.

Restrictions

• Your source code must fit inside a post on this site.
• If the program exceeds 1 minute of thinking about a position, it is equivalent to an incorrect output.

The winner is the first competitor to submit a correct program. A program shall be considered correct if no one provides an input that causes the program to fail to produce correct output in time for three days after the program is posted.

Examples

Input

kb6/8/8/8/8/8/8/KB6

Output

1

Input

1kb5/8/8/8/8/8/8/KB6

Output

0

Input

3k4/8/1p1p1p1p/pPpPpPpP/P1P1P1P1/8/8/3K4

Output

0

---------------------------

Feedback

Suggestions for improvement are welcome. I would most like to have some input on the victory condition. Is it too difficult to achieve? Should I score it on a fixed set of positions instead?

Answer 8

Am I offering a bite that's more than people are willing to chew?

---

Truth Table Solver

Goal

This code golf challenge is to display a rule that is valid for a given truth table.

Input

The input into the program is a boolean array, though you may choose how this is formatted (array, string, etc.) Each value in the array is true or false (or 1 or 0 or any other boolean pair). The index of the value represents the truth table inputs and the value itself is the result of applying the unknown rule to these inputs.

For the truth table inputs, A is the least significant bit of the index. B is the second-least significant bit, and so on. The number of indices in the table determines the number of inputs: log₂(n).

For example:

index c b a value
  0   0 0 0   0
  1   0 0 1   0
  2   0 1 0   0
  3   0 1 1   1
  4   1 0 0   1
  5   1 0 1   1
  6   1 1 0   1
  7   1 1 1   1

Output

Given this truth table, your program must determine the rule is, in this case, (a&b)|c and output it. The variables may be in any order and printing redundant brackets is fine.

Requirements

Rules may include any of the following operations NOT (~), AND (&), OR (|), XOR (^) and identify priority with brackets.

Test Cases

Here are some test cases, expressed as a string of boolean results:

0100              (~a)&b
00011111          (a&b)|c
01101000          a^b^c
0000011101110111  (a|b)&(c|d)
0100010100010000  a&(((~b)|c)^d)

Scoring

The shortest code after two weeks wins the contest.

Answer 9

Translate Treehugger to BrainF**k

code-challenge (?)

Overview

This problem deals with two esoteric programming languages that I will briefly describe for completeness.

Brainfuck is a language that has only 8 commands. Imagine a tape of values (generally 0-255) stretching infinitely to the right, initialized to zero, and an instruction pointer P pointing to the first element:

|-----|-----|-----|-----|-----...
|  0  |  0  |  0  |  0  |  ...
|-----|-----|-----|-----|-----...
   ^
   P

The eight commands effect the pointer and tape in the following way:

+ ===== increment the value that `P` currently points to
- ===== decrement the value that `P` currently points to
, ===== read a byte from stdin into the location that `P` points to
. ===== output the value that `P` points to as an ASCII character
> ===== move `P` one cell to the right
< ===== move `P` one cell to the left
[ ===== if the value pointed to by `P` is zero, jump past the matching ] ( while(*P){ )
] ===== if the value pointed to by `P` is non-zero, jump to the preceding [ ( } )

Some finer points, for the purposes of this question:

• Adding one to 255 yields 0, and decrementing 0 yields 255.
• Moving left off of the tape causes the program to abruptly halt.
• All [ must be matched with a single ]. They may be nested.

Treehugger is a language derived from Brainfuck, but differs greatly in how memory is stored. Instead of viewing memory as a tape, view memory as a binary tree that expands infinitely downward:

       P
       v
       0
  0---/ \---0
 / \       / \
0   0     0   0
.   .     .   .
.   .     .   .
.   .     .   .

P begins at the top of the tree, and again all values are initialized as 0. Most of the commands are exactly the same as corresponding Brainfuck commands, but there are two differences:

< ===== move P down the left branch of the tree once
> ===== move P down the right branch of the tree once

There is also one new command:

^ ===== move P one node up the tree

It is simple to translate Brainfuck to Treehugger by replacing every < with a ^. Translating Treehugger to Brainfuck, however, is far more difficult.

Input

Your program or function will take in a list of characters from +-<>^,.[], representing a complete Treehugger program.

• You may assume that the input ends in some terminating character, like a newline or EOF.
• You may assume that, other than the optional terminating character, every character is one of the 9 commands.
• The Treehugger program will have balanced [ and ].
• The Treehugger program will not attempt to move up one node from the top of the tree at any point.
• The Treehugger program will never contain a , character inside of a [] loop. The program will always take a finite, known number of input bytes.
• The Treehugger program will terminate for all inputs.

Input must be taken as a string of characters through stdin or a function argument.

Output

Your output should be a functioning Brainfuck program that takes the same number of inputs and provides the same output as the corresponding Treehugger program. Brackets must be balanced, and the code must never move left off of the tape. Your Brainfuck program must terminate.

Rules and Scoring

Your score for this challenge is:

Length of your code + 0.1 * the length of each test case's output

Lowest score wins!

Standard Loopholes are disallowed.

Test cases

Coming soon to a challenge near you...

---

Is this interesting?

Too easy/hard?

Is the scoring system appropriate?

Answer 10

Proposed King-of-the-Hill: Synchronous Bughouse Chess960

king-of-the-hill ai-player chess board-game

I have an idea for what I think could be a fun and somewhat different KOTH contest. However, before I put in the work writing explicitly detailed instructions and writing/deploying a test server, I want to make sure that (a) there will be sufficient interest to go through this effort and (b) the best way to design the contest and restrictions if people would like to play.

Chess960 is a chess variant in which the starting positions of the back-rank pieces are randomized with constraints such that there are 960 possible starting positions. Bughouse chess is a team-based chess variant played asynchronously on two boards in which teammates hand the pieces they capture to their teammates to potentially drop on the board.

Synchronous Bughouse Chess960 (SBC960) is a chess variant I developed to combine these two variants and to impose some synchronization rules to make it suitable for a tournament. Each of the two boards is set up independently using the rules of chess960 of the other (thus making for 921,600 overall starting positions). Game play is organized into orderly rounds during which each player takes his turn in the following order: team 1 white, team 2 white, team 1 black, team 2 black. On a player's turn, he may move a piece according to chess960's rules, drop a captured piece according to bughouse chess's rules, or delay.

Each player starts the game with five delays. When a player uses a delay, his opponent's next turn is skipped (at no cost to the opponent other than perhaps momentum). Delays are legal moves. Play continues until a player has no legal actions when his turn in the round comes up (no legal moves, no legal drops, and no remaining delays). When that condition comes, the outcome of the game is determined by whether that player is in check. If so, the team who has checked the player wins. If not, the game ends in a draw. For convenience, a position is only considered "checkmate" if a player is in check and has no legal moves left.

My KOTH tournament idea is to have players design AIs to play SBC960. I think this game has some interesting possibilities because of the team-based play. For example, rushing for the win on one's board might be a losing strategy for a player if the other team can checkmate his teammate faster. It might also be viable for a player to allow himself to be checked toward checkmate if one's teammate can achieve checkmate before that player runs out of delays. Also, the many starting positions makes it impractical for anyone to write an entry that uses opening libraries.

So, the first question is:

1) Would anyone be interested in participating in an SBC960 tournament? If at least four people would compete, I am willing to put in the work to get this together

If people are willing to play, then I need to know the best way to structure the rules for the entries. This entails the server-client interface (STDIN/STDOUT? sockets with TCP/IP?), whether to permit people from designing AIs that think when it is not their turn, and whether I should have an official "pre-play" round so that AIs can learn how the other entries play. I see the opportunity to make a KOTH that is different than most of the KOTHs on the site, but I want to know:

2) What are people's recommendations for the best way to design the entry rules?

I would appreciate any feedback.

Answer 11

Vowel-Consonant Imbalance

Sandbox question: Is it too easy/too close to an existing question? Related ones I found: Find words containing every vowel and Finding the most 'unique' word

You should write a program or function which receives a list of space-separated words as input and outputs or returns one of the words with the greatest difference between its vowel and consonant counts.

E.g.

"cars" has 1 vowel and 3 consonant so the difference is 2
"queue" has 4 vowels and 1 consonant so the difference is 3

If multiple words have the same maximal difference, exactly one (any of them) should be returned.

Input

todo

Output

todo

Examples

todo

This is code golf so the shortest entry wins.

Answer 12

CJam Expander

Input: a program written in CJam. You can accept input however you'd like.

Output: the same program ready to be put into a PPCG answer. You must:

• Not change the horizontal position of any token in the program.
• Put each token one line below the previous one except } which must appear on the same line as the corresponding {. The token immediately following a } will be one line below the }.
  • For this challenge, every letter is considered a token except literal strings and numbers which count as one token regardless of character length.
• Add e# to the end of every line. The e#s must line up vertically two spaces to the right of the last character in the program.
• Either prefix each line with four spaces or surround your output with <pre> and </pre>.

Example:

Adapted from Martin Büttner♦'s answer.

Input: 4,{"Happy Birthday "\2="Dear CJam""to You"?N}%

Output:

    4                                               e#
     ,                                              e#
      {                                         }   e#
       "Happy Birthday "                         %  e#
                        \                           e#
                         2                          e#
                          =                         e#
                           "Dear CJam"              e#
                                      "to You"      e#
                                              ?     e#
                                               N    e#

Bonus:

If you output a header and footer like the one below, multiply your score by 0.8. Using the same input, here is an output that qualifies for the bonus:

#CJam, 46 bytes


    4,{"Happy Birthday "\2="Dear CJam""to You"?N}%

Explanation:

    4                                               e#
     ,                                              e#
      {                                         }   e#
       "Happy Birthday "                         %  e#
                        \                           e#
                         2                          e#
                          =                         e#
                           "Dear CJam"              e#
                                      "to You"      e#
                                              ?     e#
                                               N    e#

[Try it online.][1]

[1]: link

Of course, you have to adjust the byte count to match the input. You are not required to make a working link for the online demo (although that would be cool).

Answer 13

Sort a CSV list by key...imperfectly.

Tags: underhanded popularity-contest sorting

Anything I missed and/or overlooked here? I'm pretty sure I closed up most of the holes here. Also, what is there that could use some improvement?

Another question: would this be better tagged as popularity-contest?

---

Introduction

You are working for some company you can't stand, two-week notice already turned in, and you've just been tasked with sorting all the CSVs the company has gathered over the years. This doesn't sound like much, except your boss, whom you also don't like, has demanded you implement your own sort. He doesn't care about Big-O whatever (he has never even heard of the term), but he just wants it done. You want to get back at him for making you do this, so you want to make that sort imperfect. At least you know he won't have time to check it until you're gone.

Objective

Your task is to write a program that sorts a CSV table (incorrectly), by key.

A correct program for purposes of this challenge:

• doesn't use one of the tried-and-false, unfunny techniques.
• takes two arguments (in order): the key to sort by, and optionally a separator, defaulting to a comma (,).
• takes the CSV via standard input, in the following format:
  • Each row is separated by a Unix-style line feed.
  • Each entry within each row is delimited by the separator.
  • Each entry is unquoted/etc. It is solely delimited by the separator.
  • Each entry may be assumed to not contain an instance of the separator or a newline.
  • The first row indicates the key names. The successive rows are the data that needs sorted, by key
• emits the sorted CSV via standard output.
  • The emitted data must also adhere to the above format, including the separator. It must be syntactically correct.
• looks completely innocent, despite being completely and totally wrong. That's the underhanded spirit.
  • Please don't use Unicode lookalikes. It's not funny nor original, especially after seeing it multiple times on a single question.

In this case, the values for the key key are 1, 2, and 3.

foo,key,value
spammer,1,32nefr2u34
ball,2,304u23rne2
blarger,3,32o4u3jnk4

Invariants

• The input CSV is assumed to be correct, including each row having the same number of entries. At least they weren't made by such air-headed people.
• The entries may have varying lengths.
• The associated values for the key is assumed to be a float (decimal not required) in textual form, base 10.
• The list may vary in length.

Requirements

• At least 1% of the list must vary from the "correct" output every single time. This may mean entries that are out of order, lost, or corrupted. This may also include entire columns going missing (in which 100% is "incorrect").
  • This is only required when there are at least 4 entries in the input.
  • The keys themselves are not counted as part of the list, but they don't necessarily have to remain intact.
• It must print at least 50% of the data it took in, but more than 100% of the original is permitted.
  • As a special case, empty stdin allows empty stdout, and input just consisting of the headers may simply print just headers coming out.
• The program must have no other external side effects other than what is required to do the above.

Other information

• The sorting algorithm is up to the implementation. It doesn't matter, as long as it sorts, the sort is stable, and the algorithm's complexity is bounded (i.e. no Bogosort, infinite loops, etc.).
• No other features may be added, including a help message.

Example

Input:

foo,key,value
ball,5.2,304u23rne2
spammer,1,32nefr2u34
blarger,3.1,32o4u3jnk4

Output (correct):

foo,key,value
spammer,1,32nefr2u34
blarger,3.1,32o4u3jnk4
ball,5.2,304u23rne2

Output (passes this challenge):

foo,key,value
spammer,1,32nefr2u34
ball,5.2,304u23rne2
blarger,3.1,32o4u3jnk4

The person with the highest number of votes wins!

Answer 14

Save the bunny!

This King of the Hill competition is about a 2D flawn populated with bouncing balls and bunnies. The balls will collide with each other and the boundaries. If a bunny gets hit by a ball, it´s dead teleported away (for cuteness sake).
Your task is to write a AI for the bunnies, such that they live as long as possible.

The AI:

The AI shall be a C++ Class with a constructor that takes a pointer to the array of balls and a function that returns the direction the bunny should go as a angle. Of course AIs that modify the game will not be accepted. @ Meta: Will be more specific once the framework is finished.

Scoring:

Competitions will be run on several dates based on the valid submissions, after that the video will be posted on Youtube.
The time your bunny survives is your score.
To minimize randomness, there will be several runs and a 3 second spawn protection.

Meta

I will do the framework in the next few weeks and enhance this post with pictures, source code and more specific stuff. Is the basic idea clear?

Answer 15

Weight Configuration

Introduction

Gyms have machines that contain a stack of weights and a pin. You insert the pin into the hole that matches the amount of resistance you want, and then you work out. However, the machines often have an additional set of smaller weights at the top that are pinned onto a fixed piece of the machine; you can unpin these weight and slide them down to sit on top of the big stack to add a few more options for your workout. In ASCII form, these weight stacks look something like this (this one is annotated):

-----------   }- top of stack, always required
___|___|___   \
|____5____|   |
___|___|___   |
|____5____|   |
   |   |      }- "neck" section
   |   |      |
   |   |      |
 __|___|__    /
_|_____o_|_   \
|_20___o__|   |
|_30___o__|   |
|_40___o__|   }- weight stack
|_50___o__|   |
|_60___o__|   /

...and so on. Notice that there is a smaller block on top of the big stack that has no number; putting the pin in this block means there is no extra resistance beyond the base amount the machine provides. If you wanted to exercise with only 5 or 10 resistance on this machine, you would put the pin in this block and then unpin one of the extra weights.

Challenge

Given the number of small weights on the machine, the configuration of the large weights, and the level of resistance someone wants to work out at, you must output a picture of the correct configuration of weights so that the given resistance is met. The small weights always have a value of 5 (pounds, kilos, stones, whatever). For example:

Input:

3 [20,30,40,50,65,80,100] 45

Output:

-----------
___|___|___   
|____5____|
___|___|___   
|____5____|
   |   |
   |   |
   |   |
   |   |
___|___|___   
|____5____|
_|_____o_|_
|_20___o__|
|_30___o__|
|_40___O__|
|_50___o__|
|_60___o__|
|_70___o__|
|_80___o__|
|_90___o__|
|_100__o__|

One of the 5 weights has been unpinned and now sits on the stack; the 40 weight has the pin in it (as denoted by the capital O). Another valid solution would be to put the pin in the 30 weight and slide all of the extra weights down onto the stack, as both would achieve 45. That would look like this:

-----------
   |   |
   |   |
   |   |
   |   |
   |   |
   |   |    
___|___|___   
|____5____|  
|____5____|   
|____5____|
_|_____o_|_
|_20___o__|
|_30___O__|
|_40___o__|
|_50___o__|
|_60___o__|
|_70___o__|
|_80___o__|
|_90___o__|
|_100__o__|

Notice the length of the "neck" in both cases of the machine; the number of rows in the neck section must be exactly 2*(number of extra weights)+4. In this case, since there are 3 extra weights, that number is 10. No matter how the extra weights are positioned, there must be 10 rows (because when you slide a weight down the neck, part of the neck doesn't disappear!), and extra weights that are pinned at the top must have a row of neck between them (as in the examples). Since the weights slide down, the lowest weight must be used first, then the next, and so on. All the 5s are centered, and all of the numbers on the large weights are left-aligned to the third column.

Input specifications:

The three pieces may be inputted in any format you like (newline separated, space separated, list in any format of your choosing, etc), subject to the following restrictions: The number of extra weights is always the first piece of input and will be between 0 and 4. The list of weights is the next input; each element will be between 15 and 200 and a multiple of 5; the whole list may be assumed to be sorted. The target resistance is last and will be between 0 and 220; it will also be a multiple of 5.

Output specifications:

Output a weight stack as specified above, with the pin in the appropriate place and the appropriate extra weights slid down onto the stack such that the target resistance is met. If the target resistance can't be met with the given configuration, you may either output an unmodified stack (with all extra weights pinned at the top, and no pin inserted), an error message, or nothing. Some resistances have multiple configurations that achieve it; you are only required to output one of them, and your program need not output the same one every time.

Whitespace:

• Trailing whitespace on lines is okay and need not be uniform.
• Leading whitespace on lines is acceptable as long as the leading whitespace on each line is the same (this doesn't include the whitespace required to draw the neck section or zero-weight pin block).
• Leading and trailing newlines are acceptable.

Scoring

This is code-golf, so lowest byte count wins. Multiply your byte-count by 0.9 if instead of only outputting one configuration when there are multiple solutions, you output all of them (either side-by-side with at least one empty column between them, or one after the other with at least one blank line between them).

Tags: code-golf ascii-art

Suggestions? I think the neck bit is a little confusing and there may be too much going on.

Answer 16

Theoretical Analysis of Pulley System

(I think it is gonna be a code golf challenge?)

Introduction

In rope access and rescue, as well as sometimes in climbing, caving and rock climbing you need to build pulley systems for hauling equipment or rescuing injured people. Here we will look at them from a more abstract perspective. As those systems can get arbitrarily complex we will limit ourselves to a certain class of pulley systems: They are one dimensional (only two opposing directions) and there is only one fixed anchor. Further we assume that there is one piece of load on one end of the rope and unit of force pulling at the other end of the rope.

Challenge

Write a program that accepts a pulley system encoded as a string (see below) that returns the actual mechanical advantage (AMA) - polynomial.

Introduction of symbols

• Rope There is one continuous piece of rope, beginning at the load and ending where the force is applied. The rope is not cut, always just one piece.

• Attachment points:

  • Anchor: In each example we consider here, there is exactly one anchor (you can imagine it as the ceiling). Other than that, the anchor behaves the same way as a knot (see below):

  • Knot: You can attach an unlimited number of pulleys to each knot. Those connections will also be shown as black lines in the following graphics, but do not count as rope.

  • Pulley: A pulley can be attached to a knot (or the anchor), (indicated by the black lines from center of the pulleys to the knots). When the rope is passing a pulley (the lines that are tangent to the circle), it acts as a redirection (rope coming in in the opposite direction of the rope going out).

• Load: In each example we consider here there is exactly one piece of load. It is connected to one end of the rope.

• Pulling force: In each example we consider here there is exactly one point where external force is applied, this is the other end of the rope.

Theory: The T-Method

(You can skip this if you are already familiar with how to calculate the mechanical advantage of pulley systems assuming a friction coefficient.)

Theoretical mechanical advantage (only an intermediate step, we do not use this for the challenge)

With the so called T-Method we can calculate the theoretical mechanical advantage (TMA) of a pulley system. Here we use the assumption that a rope going through a pulley has the same tension on both sides of the pulley. We define the applied force (tension) to be one unit and follow along the rope in order to successively figure out the force/tension on each piece of rope, pulley or knot and eventually the load. The force on the load is the TMA of the whole pulley system. (The TMA is only considered for teaching how to calculate the AMA and usually has no practical application.)

Actual mechanical advantage (AMA)

Each redirection of the rope (=pulley) creates some friction so the assumption of having the same amount of tension on both sides of the pulley can lead to way too optimistic results. We can improve this model by assuming that each pulley has an efficiency 0<=X<=1. This means that if we apply and amount of force F to the rope on one side of the pulley, the rope on the other side of the pulley will only experience a force of X*F. Here an example with X=0.9 (90% efficiency):

(The AMA with known efficiencies is a great tool for estimating the real mechanical advantage of a pulley system especially if you have to rely on low efficiency pulleys/redirections, as most have an efficiency of <<95%. But there are only a few pulley systems that are actually used in the mentioned applications.)

Assuming that every pulley has the same efficiency X we can now use the same procedure as with the TMA in order to find the AMA. If we do not know the efficiency X we have to use X as a variable. When calculating the AMA of a certain pulley system with an unknown efficiency we get a polynomial in X for the AMA. This is what your program has to do for a given pulley system.

---

Input format

The input consists of a string of lower- and uppercase letters (a-z and A-Z). For a given pulley system, we start at the load and follow along the rope. Each time we encounter an attachment point (a pulley, a knot or the anchor) we write down the corresponding letter. We use uppercase letters if the rope is attached via knot to that attachment point or a lower case letter when the rope goes through a pulley. The attachment points are labeled alphabetically in the order of first occurrence during the rope traversal. Each time you find a knot, you can assume that the rope will go on in the same direction. Each time you find a pulley, you can assume that the rope gets redirected by 180°. The anchor point always gets the letter Z.

Output format

The output should comprise a list that encodes the polynomial coefficients. E.g. the polynomial a_0 + a_1 * x + a_2 * x^2 + a_3 * x^3 + …+ a_n * x^n will be encoded like so: [a_0, a_1, a_2, a_3, …, a_n]

Other Examples:

11:1

META: Is this ok/clear enough so far? Are there any mistakes? Can you understand it? I would of course add more examples.

Answer 17

Write a Foo-immune program

In The Programming Language Quiz, Foo has quickly become one of the most annoying languages. Ever. Various people have started to "immunize" their code to avoid it being valid Foo.

Now, here's the challenge. You need to write a polyglot. A polyglot that appears to work in Foo but does something totally different versus the intended language. For instance:

a=(1)
print "Hello, World!"

would appear to work in Foo, but it actually loops indefinitely (the (1)). In Python (the intended language), it prints Hello, World! (if that wasn't already obvious :).

Rules:

• You may not just rely on just Foo's printing of string literals, which means snippets like print "HHello, World!"[1:] are invalid. You have to put something else, too.
• Your program may not print any error messages when run in Foo.
• Try not to be boring. This is a popularity contest, after all!

Answer 18

Invert the Fundamental Transformation on permutations code-golf

A permutation like

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

can be decomposed into cycles

(3, 1) (5, 4, 2) (6)

There's many ways to write these cycles, but we can fix a canonical form by requiring that:

• In each cycle, the greatest element is written first.
• The cycles are sorted in increasing order of greatest element.

In this form, we don't even need parentheses to demarcate the cycles. Just from the list of numbers

3, 1, 5, 4, 2, 6

we can infer that the cycles starts at the numbers that are greater than any to their left.

 3, 1, 5, 4, 2, 6
 *     *        *
(3, 1)(5, 4, 2)(6)

From here, the original permutation [3, 5, 1, 2, 4, 6] can be uniquely recovered, and your task is to write code that performs this recovery.

Input: A list of n distinct numbers 1 through n. Optionally, the value n itself.

Output: The permutation f that produces that canonical form cycle list, listed or printed as [f(1), f(2), ..., f(n)]. Format is up to you.

You may optionally work with 0-indexed values 0 ... n-1 instead of 1 ... n.

Answer 19

3-Hole Golf Course: Text Formatter

code-golf string

This is a series of three code golf challenges. The over-arching idea is that in each of them, you write a program that processes text in some way, and if you pipe an input text through all three solutions (with a small amount of glue code), it spits out a nicely formatted paragraph.

Hole 1: Hyphenation

Hole 2: Line Wrap

You are given as input a hyphenated piece of text, and the maximum width n ≥ 2 of a line. The output shall be a newline-delimited string, obtained by greedily splitting the input into lines of length at most n characters. Lines can be broken between words (replacing a space with a newline), after a tilde (replacing it with a hyphen), or after a hyphen (inserting a newline after it; this is needed with words like well-known). All tildes which are not replaced by hyphens should be removed, and this should be taken into account when computing the lengths of the lines. The correct output for Hy~phen~ate this sen~tence! and 20 would be

Hyphenate this sen-
tence!

A syllable that's at least n characters long and not the last syllable of a word shall be cut after the n-1st character, and a hyphen shall be inserted there before the line break. The same applies to the last syllable of a word that's over n characters long.

Hole 3: Justification

You are given as input one line of text, and the desired width n of a line, which is at least the length of the input. Your output is that line, but with extra spaces added between the words to make its length exactly n. The extra space should be added in an aesthetically pleasing way, so we require the following.

• The lengths of any two runs of spaces differ by at most 1. This means that for some number k, every run of spaces between two words shall be of length k or k+1. For example, we could have runs of only 5 or 6 spaces between the words.
• The list of lengths of these runs shall be balanced, in the following sense. For any two contiguous sublists of the same length, the number of ks in them differs by at most 1. For example, the list of lengths 5, 6, 5, 5, 6, 6, 5 is not balanced, since the length-2 sublist 5, 5 and 6, 6 contain 2 and 0 occurrences of 5, respectively. The list 5, 6, 5, 5, 6, 5, 6, on the other hand, is balanced.

These constraints do not uniquely specify the output. For example, for the inputs Hyphenate this sen- and 20, the two acceptable outputs are

Hyphenate  this sen-

and

Hyphenate this  sen-

If the input contains only one word, it should be left unchanged.

---

Sandbox notes

In all of the above holes, we can add some constraints to the input, if the challenge would otherwise be too complex (all hyphens and spaces occur between letters, all punctuation occurs at the end of words etc). However, I'm a little concerned that the holes may still be too complex. In the first hole, I can relax the case-insensitivity of the hyphenation list, and in the last hole, the second requirement can be dropped, but I feel that the second hole is already about as simple as I can make it.

Answer 20

Enough jQuery?

As a general rule of thumb, jQuery is a vital part of any program. It is really great and does all things. Your job, as a quality-control expert, is to ensure that a given program meets industry standards. Only programs that use jQuery are eligible for your seal of approval.

The Task

Write a program which takes an HTML file as input, and returns a High-Quality (TM) HTML file as output. An existing HTML file is deemed as high-quality if it contains a script tag with the word jquery in it. Examples include the following:

<script src="jquery.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

This condition is satisfied whenever there is the string <script src=", followed by "></script>, with the string jquery located somewhere in the middle.

(I'm not sure if I should make this condition more precise. It's probably good enough.)

If the given file meets quality standards, simply output it as-is. If there is no enough jQuery, however, output the file with the string <script src="jquery.js"></script> at the very top, so that everyone can see that it's a fixed, bug-free program.

Answer 21

The Algebra of Reflecting Points

This is a challenge based on manipulating points with a specific set of operations, each dealing with the reflection of some points over others.

Warning: There's not actually a challenge here yet, just the basis for a challenge that could be to "simplify the given expression" or something.

(I'll add more diagrams later)

Lists of Points

The fundamental object is an ordered list of points, like (A,B,C) or ([2,3],[5,8],[6,8]).

Reflection

A r B represents the reflection of point A across point B, resulting in a new point C so that B is the midpoint of AC.

A r (B,C,D) represents the reflection over a series of points, and is equivalent to A r B r C r D.

(A,B,C) r (D,E) represents (Ar(D,E),Br(D,E),Cr(D,E)), with either list being of any positive length.

The result of the reflection operator is a list of points that is the same length as the first operand. (If the first operand is a single point, then the output is a single point.)

A list with a single point is that same as that single point. (B) == B

Lists can be arbitrary grouped inside of other lists. (A,B,C,D) == (A,(B,C),D) == ((A,B,C),D)

Simplification

A point reflected over itself is an identity, CrC is the same as C. Any point reflected over the same point twice is an identity, rCrC can be removed.

(A,B,C) equals (C,B,A)

For any three points ABC there exists a unique fourth point D=C-B+A such that anything r (A,B,C) = anything r D. This means that any long chain of ArBrCrDrErF... can be reduced to have fewer than three rs.

((A,...,B)r(C,...,D)) == ((D,...,C),(A,...,B),(C,...,D)) and (ArB) == (B,A,B)

Examples

Show that `Cr(CrA)rB == Cr(BrArC)`

Cr(CrA)rB         #original
Cr(A,C,A)rB       #expanding 4th simplification rule
CrArCrArB         #the list is equivalent to a series of `r`s
CrAr(C,A,B)       #grouping to form a list
CrAr(B,A,C)       #swapping, the 2nd simplification rule
CrArBrArC         #expanding list
CrCrArBrArC       #Identity operation of C=CrC
Cr(C,A,B,A,C)     #listifying
Cr((C,A),B,(A,C)) #further grouping
Cr(Br(A,C))       #using the 4th simplification rule
Cr(BrArC)         #expanding parenthesis

Here is this proof visualized geometrically.

Answer 22

Whose Llama is it anyways?

graphical-outputimage-processingpopularity-contest

BetaDecay posted a legit looking movie poster in chat, which got me into thinking that this could be a very nice challenge!

Your task is to overlay a nifty llama poster on top of a movie poster in a way that it still looks a legitimate movie poster. The image posted by Beta Decay is:

a http://pictures.boxxspring.com/pictures/960x0/100588

Your program will be provided with an input of fixed size (TBD) movie poster of any popular movie and a fixed llama cutout to overlay that poster as arguments. You may scale (proportionally), rotate or translate the llama cutout anywhere on the movie poster to make it look like a llama is photobombing the poster. At the same time, the output image should still look like a legitimate movie poster in a way the above poster feels real. You cannot perform any operations on the movie poster and no other operations on the cutout other than scaling, rotation and translation.

This is a popularity contest, so the answer with the most net votes wins. Voters are encouraged to judge answers by:

• The correct placement of the cutout such that it does not outright look like a cutout
• The scaling of the cutout to match with people/objects in the movie poster
• The placement of the cutout with respect to the movie text. i.e. The cutout should not hide the movie title in a way that its no longer understandable.

Input

Two images in any common image format. The input can come as paths to the images or the images themselves (if your language support image input) either as function arguments, ARGV, STDIN or equivalent.

The first image (movie poster) will be of fixed resolution and the second image (the llama cutout) will be of enough resolution in order to have good quality even after scaling or rotation.

Output

A single image of the same resolution as the movie poster image in any favorable image format.

Llama Cutout

Please use this cutout as the second argument in your program:

[TBD]

Test Images

Here are a few images to test your algorithm on. Click on the images to get the actual resolution.

TBD

Please include some examples for these test images (along with other examples if needed) in your submission. Its also a good practice to briefly explain your algorithm as well.

Answer 23

Help Agent Zigzag with his secret messages

The WW2 double agent Eddie Chapman — aka "Agent Zigzag" — used an unusual cipher to communicate with his German controllers. It is described in the appendix of Ben Macintyre's book about Chapman and can also be viewed at the National Archives, apparently.

Read the following description and write a program to encrypt and decrypt messages using this system.

Your program should accept three inputs via stdin and/or command line switches:

1. A keyword
2. A flag to select either encryption or decryption
3. A message to be encrypted or decrypted

The output should be the corresponding ciphertext/plaintext, arranged into groups of 5 letters separated by single spaces. You may assume that the keyword consists entirely of uppercase letters, but should accept plaintexts and ciphertexts containing mixed case characters, punctuation and spaces. Non-alphabet characters should be stripped from the input and should not appear in the output (which may only contain groups of 5 uppercase characters separated by spaces, with an optional line break at the end). The date value used for keyword processing should be obtained from the system clock using the local time zone.

This is a code-golf challenge. The shortest code (measured in bytes) will win.

---

1. Keyword processing

Write out the keyword, and below each letter write the position in which this letter would appear if the letters were all sorted alphabetically. If the same letter appears more than once, number them from left to right. For example, the 14-letter keyword CONSTANTINOPLE would be processed as follows:

C   O   N   S   T   A   N   T   I   N   O   P   L   E
2   9   6   12  13  1   7   14  4   8   10  11  5   3

(Notice how the three Ns are numbered 6, 7 and 8.) Combine this sequence of digits into a single number, and multiply by the current date (from 1 to 31). For example, if the transmission is being made on the 8th of the month:

2961213171448101153 x 8 = 23689705371584809224

2. Encryption

Pad the secret message to a multiple of five characters in length by appending the null character X as many times as necessary, then encrypt Vigenere-style by cycling each letter through the alphabet by offsets corresponding to successive digits of the number calculated at step 1. For example, the message

Have arrived safely and in good health. Awaiting further instructions.

is encrypted as follows:

havearrivedsafelyandingoodhealthawaitingfurtherinstructionsx << Plaintext
236897053715848092242368970537158480922423689705371584809224 << Key (repeated)
JDBMJYRNYLEXIJMLHCPHKQMWXKHJDSUMIAIICKPKHXXBQLRNQZUWCGBIXPUB << Ciphertext

because 'H'+2='J', 'A'+3='D', 'V'+6='B', etc.

Finally, read off the encrypted message in groups of five characters:

JDBMJ YRNYL EXIJM LHCPH KQMWX KHJDS UMIAI ICKPK HXXBQ LRNQZ UWCGB IXPUB

---

code-golf cryptography

Answer 24

Well hello there, fellow golfers. The time has come for us to take part in the game. Time for the official Illuminati Confirmation!

Illuminati Confirmed?

Nah, just joking. We actually want to hide even better - by making conspiracy theorists look ridiculous.

For that, you need to create code in whatever language you want to. Your task is to print the Eye of Providence, as an ascii art. The program may take input, but it shouldn't rely on it.

However, there's a catch. You need to hide as many non-obvious references to Illuminati in source code as you can. One particular requirement is that your code must have an "Illuminati confirmed" sentence hidden somewhere(although it doesn't have to be plain string - in fact, it shouldn't; you can have it hidden by placing it as a first letter to every line, etc. - be creative!)

And because it's popularity-contest, the most upvoted and creative code wins!

---

---

Now I want feedback before posting it - what else should I have in here? What is not clear? And if you come up with better "lore chit-chat"(I actually had no afflatus) - feel free to help me.

Answer 25

1,2,3,4,...n-2,n,n-1

---

Your goal is, with an input "n", to print the numbers 1-n BUT the last two values are flipped. The numbers must be CSV (Comma separated values)

n must be >= 3 (And an integer)

For example, with an input n="10", your output should be as follows: 1,2,3,4,5,6,7,8,10,9.

An input with n="3", your output should be as follows: 1,3,2.

Answer 26

The /\/\aze of Mirrors

code-golf ascii-art

sniffs...something smells...fishy.

The reason being that there's actually a fish! But it's at the end of a maze of mirrors that you have control over. Your task is to rotate the mirrors until you can see that delicious-smelling ><>. Luckily, there are only nine mirrors, so it doesn't take you long to find a solution.

However, if you encounter this again in the future, you don't want to have to actually do the work yourself. Computers are so much better at it. So you decide to write some code to solve it for you. The shorter, the better, because you don't want that fish to rot!

The situation

Your program must accept a single positive integer n as input. It then has to find a solution for an n by n mirror maze with the following conditions:

• You, the observer (>), is seated next to one corner.
• The fish (F) is placed next to the opposite corner, on the adjacent wall if n is even and on the opposite wall if n is odd.
• The maze is toroidal because its designers installed cameras and screens.
• However, there is a wall behind the fish, so you can only see it from inside the maze.
• You must use all of the mirrors. No shortcuts!
• Bonus: take an additional non-negative integer x as input and solve the maze for when the fish is x spaces away from the corner (where x=0 is its usual place), flipping to the other wall if x is odd.

Example solutions

1
+-+
>/F
+-+

2
+--+
>/\|
|//|
+-F+

2 1
+--+
>/\F
|\/|
+--+

3
+---+
>\/\|
|//\|
|\/\F
+---+

4
+----+
>/\/\|
|//\\|
|\\//|
|//\\|
+---F+

Rules

• No standard loopholes, as usual.
• Your program must output the solution in ASCII like what I've shown above.
• Scoring is in bytes, unless you have the bonus: multiply by 0.8.

I look forward to seeing all the amazeing solutions! Ha! _{^{Sorry, that was bad.}}

Answer 27

Categorical logic [on hold]

Inspired by this question:

Task

The point of this challenge is to create a function or program that takes 3 short phrases and returns the logical assessment of the phrases.

Input

Each of the three phrases will be in the form: [All|Some] [A|B|C] are [A|B|C]., where the two A|B|C elements are different. The string Therefore,{space}, where {space} is a single space character, precedes the third phrase and reduces the initial capital of the third phrase to a lower case letter.

You may choose the input source and the separation of the strings. For example, STDIN with three concatenated phrases, text file, phrases separated by newlines, and taking the phrases as command-line arguments in quotes are all acceptable.

Sample input

With three concatenated phrases as example format.

• Some tees are moos. All moos are yees. Therefore, all tees are yees. (output: falsy)
• All A are B. All A are C. Therefore, some B are C. (output: ????)
• All submissions are answers. Some submissions are winners. Therefore, some answers are winners. (output: truthy)

Output

• Output for a logically correct combination of phrases must be a truthy value.
• Output for a logically incorrect combination must be a falsy value. This is also the case if the input is logically unsound e.g. All A are B. No A are B. ...
• Output for a logically uncertain combination must be the following string: ????

The output may be followed by a single newline.

Clarifications for finicky logic

• Some is a subset of All. The following statement is badly written, but truthy: All A are B. All A are B. Therefore, Some A are B.
• The following statement is also truthy: All A are B. All B are C. Therefore, some C are A.

Scoring

This is codegolf, so shortest code in bytes wins.

You may reduce your score by 10% if your values for A|B|C can contain spaces. You may assume that the value for A|B|C will not contain the word {space}are{space}).

You may reduce your score by a further 20% if your function or program also correctly handles No as input as well as All|Some.

Leaderboard

Standard leaderboard code goes here. Tag suggestions are welcome!

Answer 28

Two mountain hikers want to meet, but must stay at the same altitude

This question is totally inspired by this question on Puzzling SE. For ease, I have reproduced the original question here:

Two hikers are separated by a two-dimensional mountain range, like the one shown below. The mountain range alternates between peaks and valleys, connected by straight lines.

Both hikers are at sea level, and the mountain range never dips below sea level.

The two hikers want to meet up with each other. Prove that they can do this while staying at the same altitude as each other for their entire journey. They are allowed to backtrack.

Source: http://www.cs.cmu.edu/puzzle/puzzle12.html

Input/Output

Meta: what input/output format would be better?

Continuous:

• Input: a list of ordered pairs (x,y) that represent the peaks and valleys.
• Output: a sequence of positions where one hiker or both changes direction, formatted like so:

(x1 y1) (u1 v1)
(x2 y2) (u2 v2)
(x3 y3) (u3 v3)
...

Discrete:

• Input: a sequence of heights that represent the height of the terrain (with no flat portions). (I.e., 0 1 2 3 4 5 4 3 4 5 6 7 6 5 6 5 4 3 2 3 2 1 0, maybe with steps larger than 1?)
• Output: the left/right moves each hiker has to make, outputted like

L R
L L
L L
R L
...

Scoring

• Scoring is in bytes.
• Bonus: -5% if your program produces optimal solutions.

Meta:

• I'm pretty sure this is not a duplicate, but still, is it?
• I'd like a better title. Would "Mountain Hikers" be good enough?
• Any other feedback?

Answer 29

Bridge Flowers code-golf

---

One of the example inputs for this challenge is a really minor puzzle in Undertale, and the example output is the solution. You have been warned.

In the Underground, there is a mysterious plant known as the Bridge Flower. They always come in groups of four Bridge Seeds, and have some interesting properties:

• When dropped in water, a Bridge Seed floats away from you in the direction you were facing when you dropped it. It floats until it hits a wall or another Bridge Seed, at which point it stops moving.
• If four Bridge Seeds are touching, forming a straight line, and none of them are moving, they will bloom into Bridge Flowers. Bridge Flowers can support a monster's weight (or a human, but when will that ever happen?), hence the name.
• Another mysterious plant, the Bell Blossom, has a special interaction with Bridge Flowers. The Bell Blossom can be rung to turn all Bridge Flowers back into Bridge Seeds and return them to their original spot.

Consider this map, where . is ground, is water, and X is a Bridge Seed. You'll always be on the part of the map where the Bridge Seeds are. The gap is only four tiles wide, so it's quite easy to make a bridge of Bridge Flowers.

........    ........  |  ........    ........
..X.....    ........  |  ........    ........
.X.X....    ........  |  ........XXXX........
..X.....    ........  |  ........    ........
........    ........  |  ........    ........

Here's a slightly more difficult gap to cross. Even though the straight-line distance is longer than four tiles, you can make it across with a little bit of thought.

........       ........  |  ........       ........
..X.....       ........  |  ........       ........
.X.X....       ........  |  ........       ........
..X.....       ........  |  ........       ........
........       ........  |  ........       ........
..         ............  |  ..     XXXX............
..         ............  |  ..         ............

Here's one that's even trickier than the last two. Most of this river is three tiles wide or fewer, so you can't simply make a straight-line bridge across! Thinking outside the box, though, you'll arrive at the solution.

....   ............  |  .... X ............
...   .............  |  ...  X.............
....   ............  |  .... X ............
.....  ............  |  .....X ............
....   ...X.X......  |  ....   ............
....   ...X.X......  |  ....   ............
     ..............  |       ..............
       ............  |         ............

For this challenge, write a program or function that takes a map like the ones here and outputs the same map, but with the puzzle solved (the Bridge Seeds moved to the final position of the Bridge Flowers). If there's more than one possible answer, any of them will do. You may assume there will be exactly two areas of land separated by water, with the one that you start on denoted by the presence of exactly four Bridge Seeds.

If the program can't find an answer... well, just because it's impossible doesn't mean you should give up! Don't lose your Determination! Output Ding to sound the Bell Blossom, reset the Bridge Seeds and try again!

Answer 30

Based on this question in the Puzzling SE. Not 100% sure on the scoring, and this is my first time posting a PPCG challenge, so I'd appreciate any suggestions on improving it.

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Unicode Box Drawing

Write a program which outputs a diagram using all of the standard Unicode box drawing characters:

─ │ ┌ ┐ └ ┘ ├ ┤ ┬ ┴ ┼
═ ║ ╔ ╗ ╚ ╝ ╠ ╣ ╦ ╩ ╬
    ╒ ╕ ╘ ╛ ╞ ╡ ╤ ╧ ╪
    ╓ ╖ ╙ ╜ ╟ ╢ ╥ ╨ ╫

The diagram should have no loose ends, so:

┌┐ <-Allowed  ┌┐ <-Not allowed  ┌┐┌┐ <-Allowed
└┘            └┴                └┴┴┘

Also, single lines should line up with other single lines, and double with double:

├─, ╟─, ╠═, ╞═ <-Allowed  ├═, ╟═, ╠─, ╞─ <-Not allowed

The diagram must use each of the 40 characters at least once, and must form one contiguous, connected shape. Because the characters might look different depending on your browser font, do not consider the space between double lines to be an actual separation. Separations can only be between two characters. In other words:

┌╖ <-Allowed  ┌┐┌┐ <-Not allowed
└╜            └┘└┘

Your code must compute the diagram from scratch. You may not create an already existing diagram and just print it out. A bonus of 20% will be awarded if your program outputs a different valid diagram based on a random seed. (This seed may be provided as input, or you may use system time, read the seed from a file, or any other means you choose.) Note that a random seed may be provided externally, but the diagram itself may not. If you implement this bonus, please provide multiple examples showing different output.

This is code-golf, so scoring will be based on the number of bytes in the source code. In addition, the length of the output will also be counted. You get 40 characters free to account for the required characters. Any additional characters will come at a 10% penalty. This includes spaces/tabs, and any duplicate graph pieces. Newlines are free (to be fair to the differences between OSs).

If your program produces multiple outputs of different lengths (due to randomness), you may use the shortest output produced, but you must provide a seed that results in that output so it can be verified. Since this might be difficult if you used system time as a seed, entries using system time must somehow prove that they are capable of producing the smallest claimed output. (For instance, if they produce the same length output every time, or produce the minimum claimed output at least 50% of the time.)

So in summary:

• Take length of source code in bytes.
• Add 10% for each whitespace character (not counting newlines) or duplicated character in the output.
• Subtract 20% if you implement the random seed input.

Standard loopholes apply.