Sandbox for Proposed Challenges

Question

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

Sandbox FAQ

Posting

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

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

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

Discussion

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

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

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

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

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

Other

Search the sandbox / Browse your pending proposals

The sandbox works best if you sort posts by active.

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

Get the Sandbox Viewer to view the sandbox more easily!

Answer 1

How Many Colours?

Take a grid of ASCII art rectangles as input and output the minimum number of colours you would need to colour it in so that no two rectangles of the same colour are touching.

Rules

• Input can be any type of grid format (multine string, array of strings, etc...).
• Rectangles only count as touching if the inside is adjacent to the inside of another rectangle (see the bottom-left rectangle in the example).
• You may use different characters to # and space, but if you do, please specify what you use in your answer.
• The grid itself will always be rectangular.
• Grid width and height will always be between 3 and 99.
• Shortest code in bytes wins.

Example

The output for this input would be 3. An example arrangement of each colour 1 to 3 is labelled in the input below. Note how the bottom-left rectangle does not count as adjacent to the middle one.

#################
# 1  #      # 1 #
######      #   #
# 2  #  3   #####
#    #      #   #
######      # 2 #
# 3  ########   #
#    #  1   #   #
#################

Test Cases

TODO...

Links

Four Colour Theorem

Tags

code-golf ascii-art

Answer 2

Wheels on the Bus Go...

Scenario

There is a bus heading for an intersection. Usually that is when buses would stop and give way to traffic, but there's a bomb on the bus! The bomb blows up if the speed of the bus falls below 50 miles-per-hour. Find out what speed the bus needs to travel at to avoid crashing into the cars going through the intersection.

Input

• Take a list of cars coming from the left and another list of cars coming from the right. The lists contain the distance of each car from the intersection as integers.
• The distances will always be from 1 to 99 units.
• There will always be 1 to 9 cars in either direction (2 to 18 total).

Output

• The speed the bus must travel to make it through the intersection without hitting a car.
• The speed can be an integer from 5 and to 9 which is the speed in miles-per-hour / 10.

Rules

• Each iteration, every vehicle moves speed in mph / 10 units forwards. The "path" of a vehicle for each iteration includes it's position before the iteration, it's position after the iteration and every position in between.
• The cars always travel at 40 mph.
• A crash occurs when the path of the bus intersects the path of a car in the intersection.
• The bus starts 20 units before the intersection.
• Cars cannot crash into other cars.
• The speed of each bus cannot change during the simulation. You can only give each bus one speed.
• Only solvable inputs will be given.
• Shortest code in bytes wins.

Example

TODO: Example doesn't make sense yet. Will complete later...

Here's an example using ASCII art to illustrate what would happen with this input and a bus speed of 6. Note: despite what it may look like, the intersection should behave as if it's size is only one unit.

• B = Bus
• . = Vehcile movement during iteration
• C = Car

Input: [ ... ]

                  |     ^ |
                  |   | | |
------------------ ---     --------------
        <-                |    C . . . C
--  --  --  --  --         --  --  --  --
. C           C . |     .  . C     ->
------------------     --- --------------
                  |   |   |
                  |     B |
                  |   | . |
                  |     . |
                  |   | . |
                  |     . |
                  |   | . |
                  |     B |

Test Cases

TODO...

Tags

code-golf simulation

Answer 3

From Smiles to Molecular formula!

code-golf

---

SMILES is an algorithm to represent chemical molecules in one-line ASCII.

In this challenge, we will only be dealing with purely organic chemicals.

• All the Hydrogens are not represented.
• All single bonds not represented, double bond is =, triple bond is #. For example, ethane is CC, ethene is C=C, ethyne is C#C.
• Branches are represented by (). For example, isobutane is CC(C)C, acetone is CC(=O)C.
• Cycles are represented by numbers. For example, cyclohexane is C1CCCCC1.
• All other things are ignored in this challenge.

Your task is to determine the molecular formula of a molecule, given its SMILES representation.

Specs

Any reasonable input/output format.

These are all accepted, for formaldehyde:

• CH2O
• C1H2O1
• CxHxxOx (unary)
• CHHO
• OCHH
• OHCH

Scoring

This is code-golf. Shortest solution in bytes wins.

Testcases

input       output
C=O         CH2O
O=C=O       CO2
C1C(=O)CC1  C4H6O
C#CCC       C4H6

Answer 4

The incremental Gijswijt's sequence

The Gijswijt's sequence G is a sequence where the next term is the maximal number of repeating blocks of terms going so far backward.

The first numbers of this series are: 1, 1, 2, 1, 1, 2, 2, 2, 3

The incremental Gijswijt's sequence I is a sequence of Gijswijt's indices where any term of this last sequence I(n) has an image in Gijswijt G(I(n)) that is greater or equal all terms that precede it in that sequence G .

In other terms, It is an increasing sequence of indexes i for which G(i) is at least as large as G(j) for any j < i. Thus it contains the index of every 1 up to the first 2, every 2 up to the first 3, etc

Example:

  G= 1, 1, 2, 1, 1, 2, 2, 2, 3, 1, 1, 2, 1, 1, 2, 2, 2, 3, 2, 1, 1, 2, 1, 1, 2, 2, 2, 3, 1, 1, 2, 1, 1, 2, 2, 2, 3,...

  I= 1, 2, 3,       6, 7, 8, 9,                        18,                           28,                        37,...

Your program must output the most you can print from the starting of sequence until the delay between printing two consecutive terms exceeds 10 minutes, the actual number of outputs is your score.

For matter of reliability, the complete accurate "run-lengthed" G sequence must be linked through pastbin or any raw data repository.

the output will be so large to fit an int32 registry, so i suggest to print it modulo 1000007 or dont.

if the scores are not be divergent enough i will apply some salt, scoring is evaluated to N/T where T is executon time in seconds for the last term of sequence, the tie broken by the earlier post .

Only another 45 secs after the delay cap are given as an extra time.

code-challenge

Answer 5

Functional Programming in Your Language

A lot of modern programming languages allow some form of functional programming, but I don't often see them used. I'm curious to see how different languages tackle problems that are naturally solved with some form of functional programming. The winning entry to this contest will have the shortest total code as measured in bytes for these four questions

1. Given a three-part list, return a list containing only those members for which the third element is a string.

   sampleIn1={{1,2,"fred"},{3,2,1.23},{3,2,"this one too",1.23},{},{"apple","banana",{1,2,3}}}

   sampleOut1={{1,2,"fred"},{3,2,"this one too",1.23}}

2. Given a list of lists, each sub-list known to have exactly two elements, both of which are numbers, return a list of the first element in each sublist multiplied by the absolute value of the second.

   sampleIn2={{3,4},{-1,3},{1.0,-3}};

   sampleOut2={12,-3,3.0}

In the sample output above I distinguish between integer and real output; in practice you can treat everything as a real number if you prefer.

3. Given a list known to be composed only of numbers, return a list of the cube of each member, sorted by the square of each member (or its absolute value, which will have the same result).

   sampleIn3={1,-2,0.5,4};

   sampleOut3={.125,1,-8,64}

4. Given a list known to be composed only of numbers, return a list with each member of the list divided by the number before it. Since this is undefined for the first number in the input list, that element should be omitted. Where division by zero would result, the list should include notification of exception ("N/A" or something similar as befits your language of choice).

   sampleIn4={1,-2,0,5,4};

   sampleOut4={-2,0,"N/A",0.8}

Presume that input has been assigned to a variable a in the natural list format for your language, assuming it has one.

To be clear, you don't have to use abstract functions or lambda calculus here, though I suspect that in many languages this will provide a short solution.

Standard rules apply, the examples above are only examples. Your code should work for arbitrary input.

Answer 6

Shortest path to the exit:

• Given a n*n grid of 3 symbolic characters {'.','#',*} , where n is inputted, the dot is a safe spot to move from/to, # is a dragon who blows fire and spits magma, * is the outlet . Define (if it can be) the shortest path to take from the extreme upper/right to the star character that a moving point can take where:

  m is an integer m < n given by user-input or a function dimention with n, that generates obstacles # at the dynamic point m modulus n from the starting point, the last # point so far is replaced by an exit *, if no such path exists print 0 or a negative amount or undifined/null anything witch doesnt throw an error.

Testcases:

input: 7,3
output:9

why? the input generates this grid

...#...
#...#..
.#...#.
..#...#
...#...
#...*..

The shortest path is marked as _

__.#...
#__.#..
.#__.#.
..#__.#
...#_..
#..._..

More TODO ...

Hints/notes

• Solution is cyclic

• No solutions when m+1 divides n or n-1 . (to verify)

Answer 7

Simulate a DNA Computer code-golf

DNA computers are very powerful computational models, theoretically able to solve NP-complete problems such as SAT deterministically in polynomial time. Your task in this challenge is to write a program/function that simulates the behaviour of a very simple DNA computer that accepts only four different kinds of commands.

DNA and Tubes

To make things a bit easier, we model DNA strands as non-empty words over {0,1}. So for our purpose, the following are all valid strands of DNA: 1, 010010, 01, 1100101.

Our DNA computer has access to an infinite number of (test) tubes T₁,T₂,T₃,..., each of which contains a finite number of DNA strands. That is, T_i ⊂ {0,1}^* for all i ∈ ℕ⁺. For example, T₁ = {1,0100101,000} would be a valid tube. At the beginning of a simulation, all tubes are assumed to be empty (T_i = ∅ for all i ∈ ℕ⁺).

---

Commands

Our computer supports four different commands: Initialize (I), Merge (M), Filter (F), and Amplify (A). In the following, let the pairwise different numbers i, j, k ∈ ℕ⁺ denote indices of tubes T_i, T_j and T_k. Furthermore, let n ∈ ℕ⁺ and b ∈ {0,1}.

Initialize

• Description: We take all possible DNA strands of length n and put them into tube i.
• Syntax: i = I n
• Semantics: T_i ← {0,1}ⁿ
• Example: After the execution of 2 = I 3, we have T₂ = {000, 001, 010, 011, 100, 101, 110, 111}.

Merge

• Description: We mix the contents of tubes j and k and put them into tube i.
• Syntax: i = M j k
• Semantics: T_i ← T_j ∪ T_k ; T_j ← ∅ ; T_k ← ∅
• Example: If T₂ = {00, 111} and T₃ = {1, 010, 00}, then after the execution of 1 = M 2 3, we have T₁ = {00, 111, 1, 010} and T₂ = T₃ = ∅.

Filter

• Description: We remove all DNA strands from tube j whose n-th bit is not equal to b. We put the remaining strands into tube i.
• Syntax: i = F j n b
• Semantics: T_i ← T_j ∩ {0,1}^n-1∘{b}∘{0,1}^* ; T_j ← ∅
• Example: If T₂ = {1010000, 111, 1, 0101}, then after the execution of 1 = F 2 3 1, we have T₁ = {1010000, 111} and T₂ = ∅

Amplify

• Description: We put an exact copy of the contents of tube j into tube i.
• Syntax: i = A j
• Semantics: T_i ← T_j
• Example: If T₂ = {1010000, 111, 1, 0101}, then after the execution of 1 = A 2, we have both T₁ = {1010000, 111, 1, 0101} and T₂ = {1010000, 111, 1, 0101}.

---

Input

Input will be a DNA program, i.e. a sequence of these four commands, that can be read from STDIN, taken as a function argument or even be stored in a file. It's up to you whether you take them as a list or a string with some kind of separator. Also, you can choose a different separator for the parameters of the commands or encode each command as a list as long as you do so consistently. For example, instead of the command 1 = F 5 10 0, you may use [1,"F",5,10,0], 1;F/5/10/0, 1=F(5,10,0) or the like. You may assume that the input is always syntactically correct. For example input/output pairs, see below.

---

Output

You have to output a truthy value iff tube 1 is not empty (i.e. T₁ ≠ ∅) after the execution of the DNA program specified in the input. Otherwise output a falsey value. Note that you are not actually required to simulate the DNA program step by step - if you find a more clever way to calculate the output of a given program, feel free to use it.

---

Examples

In the below examples, all commands are ;-separated and encoded as described in the "Commands" section.

Truthy

• 1 = I 20
• 2 = I 4; 1 = A 2
• 3 = I 1; 1 = M 3 9
• 1 = I 4; 2 = A 1; 3 = F 1 1 0; 4 = F 3 2 0; 5 = F 2 1 1; 5 = M 3 4; 1 = M 2 5
• 1 = I 3; 2 = A 1; 3 = A 1; 4 = A 1; 5 = F 2 1 1; 6 = F 3 2 0; 7 = F 4 3 1; 2 = M 6 7; 1 = M 2 5; 2 = A 1; 3 = A 1; 4 = F 2 1 0; 5 = F 3 2 1; 1 = M 4 5 (¹)

Falsey

•  (the empty program)
• 2 = I 5
• 1 = I 2; 2 = A 1; 3 = F 1 2 0; 2 = A 3; 1 = F 2 2 1
• 1 = I 1; 2 = I 1; 3 = M 1 2
• 1 = M 2 3

---

Scoring

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

---

¹ In case you are interested: this example evaluates the formula (x₁ ∨ ¬x₂ ∨ x₃) ∧ (¬x₁ ∨ x₂), that is, the contents of T₁ after execution of the program are exactly the assignments to (x₁,x₂,x₃) that make this formula true. One can create similar such programs for any 3SAT formula. The number of commands needed is linear in the size of the given formula.

Answer 8

Inspired by this, but also different. I need help phrasing things, putting them together coherently, etc.

Also, I can't decide on what the magic numbers (size, toggles per turn, etc.) should be.

Lastly, is this even winnable?

(oh, and if anyone wants to write a nice "backstory", that'd be much appreciated)

(also I have a couple of notes to myself in there so I remember what I was doing when I come back to this later)

---

---

Murderous Life

cops-and-robbers cellular-automata game-of-life king-of-the-hill

Overview

The game is played on a 100-cell-wide, 300-cell-long board. It's cylinder-shaped -- patterns will wrap around the long sides, but not the short ones. Attempts to toggle cells behind the short edges will fail, and all cells along the short edge are considered dead. The center 200x100 area (the "no man's land") is the focus of the game. The farthest left 50x100 area (next to the origin) is the Police Headquarters, and is where the police can send units from. The far right is the Robber Hideout, and is where they operate from.

Your program will communicate with the controller via standard input and output. Each message is terminated with a newline (\n, ASCII code 10). The code your program must exit when it receives Control+C (ASCII code 3). It doesn't have to stop immediately -- for example, if you have to close IO handles -- but it should take less than a second. It also doesn't have to end cleanly -- throwing an error is fine. As long as you've tidied up after yourself.

Immediately, both programs print to STDOUT their name and their author's name, with a hyphen in between, followed by a newline. This signals that they are ready to begin receiving input. After that, the turns will start immediately. The turns work like this:

1. Both players are sent a string containing the current map through their STDIN. The format is detailed below.
2. The desired moves are collected from each program in no particular order.

   • Note: If the moves are invalid for any reason -- they attempt to change a blocked square, too long, fail to precisely match the format, anything like that -- then the program is immediately ejected from the game, and I'll drop a comment on your post letting you know what happened.

3. All of the moves are applied at once to the board
4. One iteration of Conway's Game of Life (standard rules) is run on the map.
5. The number of living cells in the No Man's Land is tallied.

The game runs for 5000 turns, after which the average number of living squares in the No Man's Land is calculated. This is the score of both the cop and the robber. Once three answers of each type have been submitted -- aside from the example ones -- I'll begin playing the answers against each other. The scoreboard will be updated daily until at least a week after the first answers have been submitted, or if it's later, three days after the last one has. The full score of any given program is the average of all of its scores.

Each program will be played against every other exactly once. Any attempts to communicate or disrupt the other AI -- except through the board -- are banned. If your bot doesn't respond to CTRL+D or CTRL+C, it will be banned.

Note that, if you have to do some cleanup before exiting, that's fine -- the "kill switches" don't have to work instantly. They do, however, have to work quickly. They can throw an error or something like that if you like.

You can always assume you'll get valid input.

In Cops version:

The point of the game, for the cops, is to keep the board as dead as possible. You can toggle up to 30 cells in the Police Headquarters per turn, creating or removing whatever patterns you like. At the end of the game, the Cop program with the lowest score wins.

In Robbers version:

The point of the game, for the robbers, is to make as many cells in the No Man's Land alive as possible. You can toggle up to 20 cells in the Robber Hideout per turn, in whatever arrangement you want. At the end of the game, the Robber program with the highest score wins.

[link to the opposite side's version]

---

Message format

Aside from the initial name string, all messages passed between programs will be like this:

1,4 12,0 9,125 299,6

Each pair is a coordinate pair, with the X values first and Y values second. The origin is at the top left of the board -- on the Police side of the board. The indexes are zero-based.

To be explicitly clear, the format is a space-delimited string of pairs. Each pair consists of two base-ten numbers, between 1 and 3 digits long, separated by a comma. The first number must not have a value greater than 299 or less than 0, and the second number must not have a value greater than 99 or less than 0. In addition, the first number must be between 0 and 49 (inclusive) if the player is a Cop, or between 250 and 299 (inclusive) if the player is a Robber.

---

I've written a basic example bot. To change what side it's on, simple change the comments on the lines indicated.

# Uncomment the part marked with the team this one should be on
#Cops
place_at = (0..47).to_a.product (0..97).to_a
glider = [[1, 0], [2, 1], [0, 2], [1, 2], [2, 2]]
toggles = 30
#Robbers
place_at = (0..47).to_a.product (0..97).to_a
glider = [[1, 0], [0, 1], [2, 2], [1, 2], [0, 2]]
toggles = 20

puts 'GliderLover-QPaysTaxes'

while gets
  # We don't care what the board is like in this dumb AI.
  puts toggles.times.map {
    loc = place_at.sample
    glider.map { |offset| loc.zip(offset).map { |(a, b)| a+b }.join ',' }.join ' '
  }.join ' '
end

---

---

Is there anything else I need to specify?

Answer 9

An idea for a king-of-the-hill challenge:

You have a "memory arena" with a fixed size. You have several programs which "reside" in the memory arena (I mean you take the assembly and put it in the arena). The goal of the game is to get another program to access memory outside of this "arena" which then causes it to die because access outside of the memory arena is not defined. The last program standing wins.

You enter in assembly code (I have not determined which architecture yet). At the beginning of a round all of the entries get randomly placed in the memory arena. Each program will execute one instruction per turn.

It would be very similar to red code but in actual assembler.

Please feel free to post comments

Answer 10

Collatz or Hailstone sequence efficiently

fastest-code sequence number-theory

Sorry for everywhere I posted in the wrong place and thank you to all of the mods for helping me find the sandbox.

---

Winner is the shortest run time to check whether all numbers up to N will end in x=1 or goes 70 iterations without returning to the original number or without decreasing under a step over Log(N) steps in a row under iterating f(x)=x/2 if x is even and f(x)=(3x+1)/2 if x is odd.

Hint: all one needs to show is that for all x under iteration it hits another y in the sequence that has already been shown to hit 1.

---

Sandbox questions

• How can I phrase the above challenge. I set it with parameters that halt for all natural numbers n. I care more about the speed of the program then the shortness of the program.

Answer 11

Kill the mosketeers

Taken a NxN square field, where you are supposed to be on the extreme upper right corner, n mosketeers are waiting an execution instruction that begins with the first lefttmost shooter alternatively until the last righttmost one, in a continuous unceasable order, meanwhile, between any shot and another you are allowed to move one step either to 4 allowed perpendicular directions.

T a period permitted to reload the riffle from a shot to another, dependently of steps taken from a move to another, a step is expressed in other words, as the time taken from two consecutive shots that of a mosketeer and his neighbor, so once T steps are elapsed, the mosketeer takes turn to shot again where two shots can occur in real-time.

Your task, is more than saving your head on your shoulders, but it is rather the ability of killing all the mosketeers while they are reloading their riffles by a knife, noted that : a mosketeer can shot in an horizontal dimention if his turn comes out, and no moketeer is between him and you, morover, a mosketeer do never move.

Given two inputs, N T, say in term of integer output how many mosketeers you are able to kill, return -1 or nil the case you end up killed no matter what you tried.

Example:

input:

   4,3

steps:

...*  |... .|.. ..|. |..| .|.. ..|. |..| .|.. ..|. ...| .... ....
....  |..* .|.. ..|. |..| .|.. ..|. |..| .|.. ..|. ...| .... ....
....  |... .|.* ..|* |.*| .|*. .*|. |*.| *|.. ..|. ...| .... ....
$$$$  |$$$ $|$$ $$|$ |$$| $|$$ $$|$ |$$| $|$$ *$$$ .*$| ..*$ ...*

Output:

  4

---

example 2

input:

   4,2

steps:

...*  |... .|.. |.|. .|.| |... .|.| |... .|.| .... .|.| 
....  |..* .|.. |.|. .|.| |... .|.| |... .|.| .... .|.| 
....  |... .|.* |.|* .|*| |... .|*| |*.. *|.| .... *|.| 
$$$$  |$$$ $|$$ |$|$ $|$| |$*$ $$.$ $$.$ $$.$ *$.$ .$.$ 

Output:

  2

---

Answer 12

Scry sort

In Magic the Gathering, your library is a stack of cards, the effect Scry 2 causes you to take the top two cards of your library and arrange them as you choose on the top and/or bottom of your library.

You have six total choices:

• Put both cards on top in either order
• Put one cards on the bottom and one on top
• Put both cards on the bottom in either order

If you are able to Scry 2 at will, you can repeatedly do so to arrange your library in any order. In this challenge, the cards of your library will be numbered from 1 to n, and your goal will be to arrange them in sorted order.

---

What should be the challenge here?

• Code golf to find the minimum number of Scry 2's needed
• Code golf to find any sequence that arranges your library, no matter how long
• Fastest code or code challenge to sort in as few Scry 2's as possible.

Answer 13

International Choice of Urinal Protocol efficiency

code-golf

A long while ago, Randall Munroe of xkcd fame wrote a blog post entitled Urinal protocol vulnerability. The titular "International Choice of Urinal Protocol" is that when men enter a bathroom that has a row of urinals along the wall, they will first take the end urinals, and then take the urinals that are furthest from the other men. All men seek to avoid awkwardness, which happens when two men use adjacent urinals.

For example, if there are five urinals in a row, then by following this protocol, men will take urinals in this order:

UUUUU
1 3 2

In this case, the packing efficiency is optimal. However, when there are seven urinals, then this happens:

UUUUUUU
1  3  2

This is essentially the worst case. Fewer than half of the urinals are used, and Randall continues investigating when the best and worst cases happen. For this challenge, though, your only task is to calculate the packing efficiency of this protocol when given a number n of urinals, which is k/n where k is the number of urinals taken before awkwardness ensues.

Spec

• Standard I/O and code-golf rules apply.
• Input is a single positive integer n, which may be given as either decimal or unary.
• Output must be either a float or a simplified fraction. If your language cannot do either of these easily (e.g. BF or Retina), then you may simply output k (in decimal or unary).

Test cases

Decimal

 1 1.0
 2 0.5
 3 0.6666666666666666
 4 0.5
 5 0.6
 6 0.5
 7 0.42857142857142855
 8 0.5
 9 0.5555555555555556
10 0.5

Fractions

 1 1/1 {or} 1
 2 1/2
 3 2/3
 4 1/2
 5 3/5
 6 1/2
 7 3/7
 8 1/2
 9 5/9
10 1/2

Urinals taken k

 1 1
 2 1
 3 2
 4 2
 5 3
 6 3
 7 3
 8 4
 9 5
10 5

Note: this is A166079.

Related: The Urinal Protocol, which asks for all the possible ways men could take urinals with no restriction on the first and no awkwardness.

Answer 14

Matching a string using a huge number of steps

regular-expression code-challenge

Your task is to write a regex that matches a string you defined in as close to n steps as is humanly possible.

The regex must match the whole string without the global flag on.

Scoring

The score would be regex length + string length + absolute difference between the number of steps and n.

For example, if n = 65536, this example has 6 bytes as regex, 49152 bytes in the string, and 65539 steps, which would account for a total score of 6+49152+3=49161.

Lowest score wins.

Requirements

1. n = 65536 (2**16)
2. n = 59049 (3**10)
3. n = 40320 (8!)

The total score will calculated from the scores of the three programs.

Questions:

• How can I make this challenge better?

Answer 15

Find the smallest number bigger than the input whose digital sum is the input

code-golf arithmetic

"Digital sum" refers to the sum of all the digits in a number.

For example, the digital sum of 1324 is 10, because 1+3+2+4 = 10.

The challenge is to write a program/function to calculate the smallest number bigger than the input whose digital sum is the input.

Example with walkthrough

As an example, take the number 9 as the input:

9 = 1+8 -> 18
9 = 2+7 -> 27
9 = 3+6 -> 36
...
9 = 8+1 -> 81
9 = 9+0 -> 90

The valid output would be the smallest number above, which is 18.

Specs

Note that 9 is not the valid output for this example, because the reversed number must be greater than the original number.

Note that the input will be positive.

Test-Cases:

 2 => 11
 8 => 17
12 => 39
16 => 79
24 => 699
32 => 5999

References:

This is OEIS A161561.

Answer 16

Light the Way!

This is based on the Lights Out game. There is a grid of tiles, and clicking on a tile (performing a "move") toggles the state of the clicked tile as well as the (orthogonally) adjacent tiles. This variation will also toggle the diagonally adjacent tiles.

It is helpful to note that (on a board with only two states) all moves commute, so the order in which they are performed is not important. It follows that performing a collection of moves a second time will undo what was done the first time.

There are a few ways to present this challenge, so I'll describe some possibilities. Let me know what you think. The challenge could be one of the below:

• Given a board size n (optional) and the initial state of the n-by-n board, determine an optimal collection of moves that will toggle every lit ("on") tile into its dark ("off") state.
• Given n and a sequence of moves performed on an initially dark board of size n, provide the resulting matrix of states.
• A variation on the above involving graphical output.

Input format would be flexible. n >= 1.

---

Snippet to show how the game works:

The board size may be adjusted in the first input field. The second field (functionality added by Conor O'Brien) will take a list of coordinates ([[0,0],[1,2],[3,0],...]) and perform the moves for you.

var table;
var color1 = "aqua",
	color2 = "yellow";
var moveList = [];

window.onload = function () {
	table = document.getElementById("lightGame");
	buildTable();

	var updateButton = document.getElementById("updateButton");
	if (updateButton) {
		updateButton.onclick = buildTable;
	}

	// added by Conor O'Brien
	document.getElementById("perform").addEventListener("click", function() {
		var toPerf = JSON.parse(document.getElementById("moves").value);
		//console.log(toPerf);
		function rec(arr) {
			var m = arr.shift();
			var x = m[0],
				y = m[1];
			var cell = table.rows[y].cells[x];
			update(cell);
			if (arr.length) {
				setTimeout(rec, 500, arr);
			}
		}
		rec(toPerf);
	});
};

function buildTable() {
	// get size
	var input = document.getElementById("size");
	var size = new Number(input && input.value || 5);
	
	var rows = size,
		cols = size;
	
	// clear moves
	moveList = [];
	moveHolder.innerHTML = "[]";
	
	// remove existing rows
	while (table.lastChild) {
		table.removeChild(table.lastChild);
	}
	
	// create new rows
	for (var y = 0; y < rows; y++) {
		var row = document.createElement("tr");
		
		for (var x = 0; x < cols; x++) {
			var cell = document.createElement("td");
			cell.style.backgroundColor = color1;
			cell.x = x;
			cell.y = y;
			cell.onclick = function () {
				update(this);
			};
			row.appendChild(cell);
		}
		table.appendChild(row);
	}
}

function update(cell) {
	var x = cell.x;
	var y = cell.y;
	
	var xMax = table.rows[0].cells.length;
	var yMax = table.rows.length;
	
	// update cell
	changeColor(cell);
	
	// update orthogonally adjacent
	if (x > 0) changeColor(table.rows[y].cells[x - 1]);
	if (x + 1 < xMax) changeColor(table.rows[y].cells[x + 1]);
	if (y > 0) changeColor(table.rows[y - 1].cells[x]);
	if (y + 1 < yMax) changeColor(table.rows[y + 1].cells[x]);
	
	// update diagonally adjacent
	if (x > 0 && y > 0) changeColor(table.rows[y - 1].cells[x - 1]);
	if (x > 0 && y + 1 < yMax) changeColor(table.rows[y + 1].cells[x - 1]);
	if (x + 1 < xMax && y > 0) changeColor(table.rows[y - 1].cells[x + 1]);
	if (x + 1 < xMax && y + 1 < yMax) changeColor(table.rows[y + 1].cells[x + 1]);
	
	// update moves
	// added by Conor O'Brien
    moveList.push([x, y]);
    moveHolder.innerHTML = JSON.stringify(moveList);
}

function changeColor(cell) {
	cell.style.backgroundColor = cell.style.backgroundColor === color1 ? color2 : color1;
}

function getStyle(elt, styleProp) {
	if (elt.currentStyle)
		return elt.currentStyle[styleProp];
	return document.defaultView.getComputedStyle(elt, null)[styleProp];
}

body {
	background-color: darkslategray;
	color: white;
}
#gameDiv {
	text-align: center;
}
header {
	margin: 25px;
}
h2, h4 {
	color: red;
	text-shadow: -2px -2px black;
}

#lightGame {
	border: 1px solid white;
	margin: auto;
}
#lightGame td {
	/*background-color: aqua;*/
	padding: 1px;
	height: 25px;
	width: 25px;
}
#updateDiv {
	margin: 25px;
}
button {
	margin-left: 10px;
}

#autoMoveDiv {
	margin-top: 10px;
}

footer {
	position: fixed;
	bottom: 0px;
	width: 100%;
}
footer small {
	color: cyan;
	position: absolute;
	bottom: 0px;
}
img {
	float: right;
}

<div id="gameDiv">
	<header>
		<h2>Light Game</h2>
	</header>
	<div>
		<table id="lightGame">
		</table>
	</div>
	<div id="updateDiv">
		<input id="size" name="size" type="number" min="1" max="20" pattern="\d{1,2}" value="5" required />
		<button id="updateButton" type="button">Update</button>
	</div>
	<div>
		Your moves: <span id="moveHolder">[]</span>
	</div>
	<div id="autoMoveDiv">
		Auto move: 
		<input id="moves" />
		<button id="perform" type="button">Do Moves</button>
	</div>
</div>

---

Related Questions

JsFiddle of the snippet I made.

Answer 17

Version Comparator

Given two version strings, return a positive, negative or zero value depending on which one is earlier. Version strings consist of one or more non-negative integers separated by full stops, optionally suffixed by a lowercase letter and a final non-negative integer. Examples of versions:

1.5a2
1.5b1
1.5
2.19
2.20b
2.20 or 2.20.0 (these should compare equal)
8.1a
8.1
9
10

When comparing versions the integers should of course be compared numerically, not lexically. Missing components should compare as zero against numbers, but they compare after letters. You should then be able to recognise that the above versions are in version order, but you can choose whether this should be a positive or negative result. Reversing the parameters should obviously negate the sign of the result, but you can return a different absolute value if you prefer.

Builtins that compare versions are disallowed, but things like regexes are OK.

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

Answer 18

Find the duration of a worst-case brute-force attack

Given the following information about a 7-bit ASCII-encoded password and the computer that will crack it with a brute-force attack:

• Length of the password in characters
• Charset size (i.e total count of the possible characters one character in the password can be)
• Number of passwords the computer can test in one second millisecond (rounded down)

Write the shortest program that finds out how long the attack will take in the worst-case scenario where the computer tries all possible passwords.

• The output is the duration in this format: years months days hours minutes seconds milliseconds
  • One "month" is 30 days long.
  • Fractions of milliseconds are rounded up.
  • You can assume that the cracking finishes immediately if it takes less than 50 milliseconds, and make the program print out Instant in such cases.
  • Similarly, the cracking can be considered Neverending if it takes more than 292 billion years.
• The program can output using any method, from merely printing to STDOUT to causing a kernel panic/bluescreen with the duration as the error message.
• The input method to get the info about the password/the machine can be anything, as well. Don't use standard loopholes though.
• It's not enforced, but strongly encouraged to write a standalone program.

Here's how to calculate the charset size:

• Start with 0.
• If there's a digit (in the password), add 10.
• If there's a lowercase letter, add 26.
• If there's an uppercase letter, add another 26.
• If there's punctuation, add 32 (7-bit ASCII has this many punctuation characters).
• If there's a whitespace character, add 2. Whitespace characters are horizontal tab (0x09) and space (0x20).
• Any other character counts as non-printable (including backspace (0x08), DEL (0x7F), line feed (0x0A) and carriage return (0x0D)). Add 29 if there's any of them.

Count of all possible passwords is (charset size)^{password length}.

Here are some applicable-in-real-life cases you can test your program with (let's assume the computer that will crack them can test 1 billion passwords per second, which equals to 1,000,000 passwords/millisecond):

• 4 characters, charset size 10 (PIN) - 10,000 passwords, output is 0 0 0 0 0 0 1 or Instant
• 8 characters, charset size 94 (at least one uppercase letter, one lowercase letter, one digit and one punctuation) - 6,095,689,385,410,816 passwords, output is 0 2 10 13 14 49 386
• 10 characters, charset size 2 (weakest valid Discourse password, contains whitespace only) - 1024 passwords, output is 0 0 0 0 0 0 1 or Instant
• 25 characters, charset size 26 (correcthorsebatterystaple) - 236,773,830,007,967,588,876,795,164,938,469,376 passwords, output is 7612327353651221350 2 14 0 26 4 939 or Neverending
• 127 characters, charset size 96 (strongest password on newer Windows releases) - written below
• 1024 characters, charset size 36 (4096-bit PGP key represented as a hexadecimal number) - written below

These are the stats of the maximum-strength Windows password:

Passwords: 560,333,510,486,846,899,384,847,242,571,130,277,659,458,884,466,874,695,582,912,274,460,529,559,443,783,341,570,989,525,270,653,136,186,432,110,439,597,936,820,880,106,519,625,601,191,574,799,863,912,148,304,962,133,852,037,202,160,056,511,510,962,873,278,300,126,526,144,267,006,137,180,032,492,751,016,171,207,701,495,935,943,049,216
Output: 18014837657113133339276210216407223432981574217685014647084370963880194169360318337544673523362047845500003550655797865897637169483847774934889398916928636347805229296463546812516445182705545212838429981490065783731353925307067135133992 5 15 19 58 55 944
Alternate output: Neverending

And these are the stats of the PGP key:

Passwords: 4,505,684,579,918,576,285,346,738,866,335,056,898,110,301,685,668,199,078,230,938,179,212,682,315,156,231,410,185,391,761,603,272,976,014,035,539,665,517,248,679,228,261,440,294,129,198,036,262,705,242,310,399,830,546,082,361,923,420,737,260,766,677,891,361,176,003,624,143,368,380,527,062,643,297,677,246,518,686,688,642,023,537,863,317,793,178,302,508,440,097,154,593,959,832,175,055,427,351,149,410,096,495,695,380,712,810,868,774,475,142,767,054,868,274,802,269,522,299,482,066,464,842,097,715,922,988,138,315,118,067,288,670,934,735,264,524,936,706,249,961,394,413,647,964,221,767,703,673,264,468,419,121,528,644,906,680,808,060,759,817,669,970,046,776,525,266,199,099,671,937,918,801,013,826,958,891,378,841,908,663,991,372,649,027,188,879,525,186,690,599,345,723,173,064,252,017,258,129,131,786,488,462,307,158,861,824,049,980,863,991,149,295,162,169,512,952,373,415,599,734,988,691,348,925,488,351,712,593,858,837,027,205,238,618,188,975,201,320,681,214,515,875,812,195,250,605,867,622,987,451,763,883,339,709,733,502,125,838,221,788,546,339,051,347,360,900,518,381,976,167,289,930,943,228,024,924,785,158,428,496,314,937,921,503,359,298,542,415,845,218,449,360,806,235,379,253,546,728,753,218,950,843,742,471,105,739,555,344,908,900,309,982,913,223,331,321,839,212,821,903,239,320,600,564,890,951,140,667,647,680,682,245,252,370,183,758,578,065,733,075,207,856,432,661,797,090,351,101,165,469,273,829,754,476,555,209,675,613,232,875,323,406,611,257,057,059,099,019,633,298,079,410,970,345,108,939,943,042,100,267,260,413,671,556,828,411,902,575,269,208,445,279,433,655,878,082,023,068,697,154,581,711,817,787,688,949,105,583,339,471,599,190,831,084,304,744,483,799,555,478,063,729,574,297,623,870,804,763,558,027,580,772,927,971,329,879,231,979,556,301,616,929,595,576,646,883,067,201,999,872,899,862,889,211,861,332,535,050,455,387,251,034,043,732,447,006,164,551,883,918,733,705,027,099,846,583,024,013,092,062,384,703,436,459,115,108,358,829,136,251,317,699,709,899,140,949,893,425,335,769,021,022,912,434,045,643,544,474,460,899,799,213,759,568,795,794,758,914,390,056,283,305,470,380,859,003,818,724,678,434,816
Output: 144858686339974803412639495445442930108998896787172038266169565946909796654971431654622934722327449074525319562291578211137739886840732034401886018044055761311424449664413690224320369299057721231224396352345948448015131278860508182828147139982752631922511354755096078964028889980704480936709984283352948061204198196785328857204061945957268141550998891534834171375541476907019128991072373909056348731183618329634024763694746476776233417623704464804027405450152026906721990999895827471385353870130056140660354679074035526421905828555132520211676677361401337091034117370453939870215183392876069255694823382473711006907851853458746913295694931911314073828877816349504523255816791677974298928074750103049081088894521647398444396729546431174466495229648516324713327536964168664025148591452750098101445502202880078966283755495859954505040675103796820824907455740718188735077328268047865426806174561044520100917915500979652319301547868727504821981520811835192875926630119576922600465887060849654310721522802609638109522185755307201898676461606130734024600227278608209698963323356340446015796148617903068964091403666193996894642822309315198786075754477250953946657292049336910661279747924178751224344877465829301109562043071275369906871767991229129085786546569052197642684662087651029574035646976531236521763373563846425925268656816387911380422031991615290633773786744123323731112880994579065426763237282889858685438654794679302568796507941872848896038602862540480809810919146613018187362072374644736799940064590439265446053422181856817801562474722208358918298576208528044087753034364036 10 24 22 32 4 679
Alternate output: Neverending

code-golfcryptographydate

Answer 19

Array of Integers to Array of Digits

code-golf

Given an array of arbitrary length containing only integers, output an array of integers of each digit of each integer in the array.

Notes

• The input array will only consist of integers in base 10

• The integers will be in the range of [0, MAX_INT] where MAX_INT is the greatest value an integer can have in your language

• Assume that all integers will be positive, however you can interpret the integers as signed or unsigned

• String manipulation and the use of any regex is banned by default

• The outputted array must be exactly 1 deep and contain only integers

• The order of the digits in the outputted array must be exactly as they were in the inputted array

• Leading zeros are to be stripped, as they should be when parsed as an integer

Examples

[2, 3, 5, 7, 11, 13] -> [2, 3, 5, 7, 1, 1, 1, 3]
[1, 2, 3, 4, 5] -> [1, 2, 3, 4, 5]
[123, 456, 789, 101112] -> [1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 0, 1, 1, 1, 2]
[0, 000, 000123] -> [0, 0, 1, 2, 3] //'000' is treated as '0' and '000123' is treated as '123'

Answer 20

Ping Pong

The Challenge

This challenge is to make a program that prints a text ping-pong animation. Your program is to display a string of tildes with a PING on it moving to the right. Each tick, the text PING moves one to the right one character, reducing the number of tildes on the right by one and increasing the amount on the left by one. Once the PING reaches the right side of the string, it changes to a PONG and the reverse happens (i.e it moves to the left instead).

Rules

• The number of tildes must always be the same
• The number of tildes must be at least 30
• The number of milliseconds between ticks must be at least 10 ms and at most 1 s
• The PING must start at the left hand of the string

Scoring

Your score is the number of bytes plus/minus the following (all that apply):

• -10 bytes for browser implementation using the ping after the hash
• +10 bytes if your implementation does not clear previously outputted frames
• More suggestions welcome

Lowest score wins.

Example Implementation (JS, Ungolfed)

i=0;b=false;len=50;td=40;function urlPong(){location.hash=new Array(i+1).join("~")+(!b?"PING":"PONG")+new Array(len-4-i+1).join("~");if(!b){if(len-4-i<=0){b=true;}else{i++;}}else{if(i<=0){b=false;}else{i--;};}setTimeout(urlPong,td);}urlPong();

Answer 21

Implement this cipher

(I'm not sure what to call this cipher)

Goal

Use the algorithm (explained in the Algorithm section) to implement a certain cipher.

The program must read input from STDIN or the closest available equivalent, use the algorithm to generate the ciphertext and a key.

The ciphertext and the key will be written to STDOUT or the closest available equivalent, preferably with the format (ciphertext)\n(key).

Algorithm

Convert the characters in the string into the respective ASCII values. For example:

Hello -> 72 101 108 108 111

Next, you will need to generate a key as long as the string with random numbers in the range of 0-9.

Hello -> 62841

Add the integers in the random number sequence to the ASCII values of the string. In the above examples, 72 would become 78, and 101 would become 104.

72 + 6 = 78, 101 + 2 = 104, 108 + 8 = 116, etc

Next, convert the new ASCII values back to characters. In the above examples, the text Hello has become Nhttp.

Examples

(These are simply examples of what the output might look like. The output can and will vary.)

Hello, World!

Hgqqu/$\\p{ni$
0255634519253

---

This will be encoded
    
Zhjs$~koo gj$iuhofgj
60104723305544750226

Rules

• Submissions must be full programs.
• Languages newer than the challenge are allowed.
• Submissions will be scored in bytes.
• Standard loopholes are forbidden.
• This is code-golf, so the shortest code wins.

---

I'm sure this challenge needs a little tidying up and making it look and sound a bit nicer. I'm not very good at writing challenges, so I'd like some advice.

Answer 22

Latin vs Greek vs Cyrillic / Battle of the Alphabets

code-challengeimage-processingclassificationpattern-recognition

---

Meta: This is just a rough draft, the challenge is still under development, feel free to add suggestions as comments or via chat pinging @flawr

Points that are unclear so far:

• Is there one fixed typeface for all three?
• Will the image always be provided in the exact horizontal orientation?
• How long will the provided text be, just single words? A single line? A multiline piece of text?

---

These three alphabets are relatively similar and even have some letters in common, but also a lot of distinct letters. In this challenge, you have to write a classifier that can distinguish these three alphabets, when presented with a raster image of a corresponding text.

This is an image from Wikipedia that shows the differences in the capital letters:

This challenge was inspired by this message.

Answer 23

Don't let those functions get away

code-golf string

Introduction

My imaginary language, PremOpt discourages the use of functions. They are the source of every performance problem. Your task today is to fix beginner PremOpt programmer's code.

Every statement's and loop's (if, switch, while, for) content is enclosed in brackets:

<if/switch/while/for> <statement here> {
    <stuff>
}

Switch cases are one liners:

switch <value> {
    case <val1>: <statement1>;
    case <val2>: <statement2>;
    case <val2>: <statement2>;
}

Functions look like these:

function <name>(arg1, arg2, arg3) {
    // Stuff here
}

// Calling a function:
<name>(arg1, arg2, arg3);

Other lines end with a semi-colon.

Variables don't need to be declared, they're already initialized to null, you can set a variable to a value with

variableName = value;

Outputting a value is done by doing

out-><value>

Input

Your input is a string with a piece of code. Each row is separated with a line-feed. The input may or may not contain functions.

Output

You need to remove the functions from the code, and put their content to the where they were called.

Examples:

function hello() {
    sayHello1();
    sayHello2();
}
hello();

becomes

sayHello1();
sayHello2();

Multiple function calls:

function func() {
    doStuff1();
    doStuff2();
}
func();
func();

becomes

doStuff1();
doStuff2();
doStuff1();
doStuff2();

If the function takes in arguments:

function argFunc(arg1, arg2) {
    doStuffWithArg(arg1);
    doStuffWithArg2(arg2);
}
argFunc(myVar1, myVar2);
argFunc(myVar3, myVar4);

then you need to change the arguments inside the function to match with the calling arguments

doStuffWithArg(myVar1);
doStuffWithArg2(myVar2);
doStuffWithArg(myVar3);
doStuffWithArg2(myVar4);

Test cases

fibonacci sequence:

a = 1;
b = 1;
function getNextNumber(num1, num2) {
    return num1 + num2;
}

while(true) {
    a = getNextNumber(a, b);
    out->a;
    b = getNextNumber(a, b);
    out->b;
}

Should become

a = 1;
b = 1;

while(true) {
    a = a + b;
    out->a;
    b = a + b;
    out->b;
}

FizzBuzz:

for (counter = 0; counter <= 100; counter++) {
    checkNumber(counter);
}

function checkNumber(num) {
    if (num % 3 == 0  num % 5 == 0) {
        out->"Fizz Buzz";
    } else if (num % 3 == 0) {
        out->"Fizz"
    } else if (num % 5 == 0) {
        out->"Buzz"
    } else {
        out->num;
    }
    out->newLine;
}

Becomes:

for (counter = 0; counter <= 100; counter++) {
    if (counter % 3 == 0  counter % 5 == 0) {
        out->"Fizz Buzz";
    } else if (counter % 3 == 0) {
        out->"Fizz"
    } else if (counter % 5 == 0) {
        out->"Buzz"
    } else {
        out->counter;
    }
    out->newLine;
}

Rules

• There'll be no recursive functions in the input
• Standard loopholes are forbidden

Answer 24

fix show

Your task is given n, you must print first n character returned from Haskell expression fix show.

Let me explain how fix show produces the "magic" string.

show is just escaping the string and then add quote. Since the resulting string consists only double quotes and backslash, show then essentially just put backslash before every character then quote the resulting string.

show str = '"' : concat ( zipWith (\x y->[x,y]) (repeat '\\') str ) ++ "\"" -- Well, this is not what prelude give, but

fix is, well, fixpoint combinator. But thanks for laziness, it won't do a infinite loop first.

The string is equivalent to the string defined below:

Assuming there is a series of string. The first string is "" and the next series is just application of show to previous string:

"" "\"\"" "\"\\"\\"\"" "\"\\"\\\\"\\\\"\\"\"" "\"\\"\\\\"\\\\\\\\"\\\\\\\\"\\\\"\\"\""

For all n, there is k so that for all l above k, n-th character of l-th string from series is same. That character is the n-th character of fix show

TODO: I hate the sentence above, please fix it.

The first 100 character in resulting string

"\"\\\"\\\\\\\"\\\\\\\\\\\\\\\"\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

So, another implementation is

fixshow = '"' : zip (repeat '\') fixshow ++ "\""

Rules

1. You are not allowed to use function fix, show, and the equivalent functions.
2. Shortest answer wins.

Sandbox question

Is there another way to prevent answer like flip take$fix show, or without importing f k=k$f k;j n=take n$f show. And how about array programming language like APL, J and Jelly?

Answer 25

Golfing with ultrasound

Within medical physics, the percentage of ultrasound reflected between material boundaries can be calculated using two pieces of data: the density(p) and the speed(c) at which sound travels through the material.

To calculated the percentage reflection the following equation can be used

(Z1-Z2)^2 / (Z1+Z2)^2

Where Z1 and Z2 are the acoustic impedances(Z) of the two materials. Z is calculated such that Z=pc That is density * speed of sound in the material

This is where the issue lies

I have two ways of asking the question

1:

Given the acoustic impedance for two materials, calculate the percentage reflection.

2:

Given the density and speed of sound in two materials, calculate the percentage reflection

Reason

The first method will be much simpler, in the way you are just plugging values into a formula. However I feel that method 2 is heavy on the inputs, and I understand that four inputs is a large number of inputs in golfing challenges

On posting the question I will also add a number of test cases

Answer 26

Write a BF to Hexagony Converter!

---

code-golfbrainfuckcode-generationhexagonal-grid

---

According to community moderator Martin Ender ♦:

Hexagony is Turing-complete as any brainfuck program can be translated to Hexagony with some effort. (Source)

Your program's job is simple: take a valid brainfuck program, and convert it to an equivalent Hexagony program. For completeness, here are all the relavant commands in both BrainFuck and Hexaongy (taken from esolangs.org).

brainfuck

brainfuck operates on an array of memory cells, also referred to as the tape, each initially set to zero. There is a pointer, initially pointing to the first memory cell. The commands are:

• > Move the pointer to the right
• < Move the pointer to the left
• + Increment the memory cell under the pointer
• - Decrement the memory cell under the pointer
• . Output the character signified by the cell at the pointer
• , Input a character and store it in the cell at the pointer (-1 for EOF)
• [ Jump past the matching ] if the cell under the pointer is less than or equal to 0
• ] Jump back to the matching [ if the cell under the pointer is nonzero

All characters other than ><+-.,[] should be considered comments and ignored.

Modifications:

• Infinite tape in both directions
• Arbitrary precision integers (like hexagony)
  • No overflow/underflow
• [ acts the same for negative numbers as it does for 0

Hexagony

Source code

The source code consists of printable ASCII characters and line feeds and is interpreted as a pointy-topped hexagonal grid, where each cell holds a single-character command.

Because of this restriction, the number of commands in the source code will always be a centered hexagonal number. For reference, the first 10 centered hexagonal numbers are:

1, 7, 19, 37, 61, 91, 127, 169, 217, 271

When reading a source file, Hexagony first strips all whitespace characters. Then the remaining source code is padded to the next centered hexagonal number with no-ops and rearranged it into a regular hexagon. This means that the spaces in the examples above were only inserted for cosmetic reasons but don't have to be included in the source code. The following three programs are identical:

   a b c  
  d e f g 
 h . . . .  
  . . . .   
   . . . 

abcdefgh...........

abcdefgh

But note that

abcdefg

would instead be the short form of

   a b 
  c d e  
   f g

Control flow

Hexagony has 6 instruction pointers (IPs). They start out in the corners of the source code, pointing along the edge in the clockwise direction. Only one IP is active at any given time, initially the one in the top left corner (moving to the right). There are commands which let you switch to another IP, in which case the current IP will make another move (but not execute the next command), and then the new IP will start by executing its current command before making its first move. Each IP has an index from 0 to 5:

   0 . 1
  . . . .
 5 . . . 2
  . . . .
   4 . 3

The direction of an IP can be changed via several commands which resemble mirrors and branches.

The edges of the hexagon wrap around to the opposite edge. In all of the following grids, if an IP starts out on the a moving towards the b, the letters will be executed in order before returning to a:

   . . . .          . a . .          . . k .          . g . .   
  a b c d e        . . b . .        . . j . .        . h . . a  
 . . . . . .      g . . c . .      . . i . . e      . i . . b . 
. . . . . . .    . h . . d . .    . . h . . d .    . j . . c . .
 f g h i j k      . i . . e .      . g . . c .      k . . d . . 
  . . . . .        . j . . f        f . . b .        . . e . .  
   . . . .          . k . .          . . a .          . f . .   

If the IP leaves the grid through corner in the direction of the corner there are two possibilities:

-> . . . .   
  . . . . .  
 . . . . . . 
. . . . . . . ->
 . . . . . . 
  . . . . .  
-> . . . .  

If the current memory cell (see below) is positive, the IP will continue on the bottom row. If it's zero or negative, the IP will continue on the top row. For the other 5 corners, just rotate the picture. Note that if the IP leaves the grid in a corner but doesn't point at a corner, the wrapping happens normally. This means that there are two paths that lead to each corner:

      . . . . ->   
     . . . . .  
    . . . . . . 
-> . . . . . . .
    . . . . . . 
     . . . . .  
      . . . . ->

Special characters

. is a no-op: the IP will simply pass through.
@ terminates the program.

Arithmetic

) increments the current memory edge.
( decrements the current memory edge.

I/O

, reads a single byte from STDIN and sets the current memory edge to its value, or -1 if EOF is reached.
; takes the current memory edge modulo 256 (positive) and writes the corresponding byte to STDOUT.

Control flow

$ is a jump. When executed, the IP completely ignores the next command in its current direction. This is like Befunge's #.
_, |, /, \ are mirrors. They reflect the IP in the direction you'd expect. For completeness, the following table shows how they deflect an incoming IP. The top row corresponds to the current direction of the IP, the left column to the mirror, and the table cell shows the outgoing direction of the IP:

  cmd │  E SE SW  W NW NE
──────┼────────────────────
   /  │ NW  W SW SE  E NE
   \  │ SW SE  E NE NW  W
   _  │  E NE NW  W SW SE
   |  │  W SW SE  E NE NW

< and > act as either mirrors or branches, depending on the incoming direction. The cells indicated as ?? are where they act as branches. In these cases, if the current memory edge is positive, the IP takes a 60° right turn (e.g. < turns E into SE). If the current memory edge is zero or negative, the IP takes a 60° left turn (e.g. < turns E into NE).

  cmd │  E SE SW  W NW NE
──────┼────────────────────
   <  │ ?? NW  W  E  W SW 
   >  │  W  E NE ?? SE  E

[ switches to the previous IP (wrapping around from 0 to 5).
] switches to the next IP (wrapping around from 5 to 0).
# takes the current memory edge modulo 6 and switches to the IP with that index.

Memory manipulation

{ moves the MP to the left neighbour.
} moves the MP to the right neighbour.
" moves the MP backwards and to the left. This is equivalent to =}=.
' moves the MP backwards and to the right. This is equivalent to ={=.
= reverses the direction of the MP. (This doesn't affect the current memory edge, but changes which edges are considered the left and right neighbour.)

Some commands/description omitted for conciseness, full list here.

Other rules:

• Input/Output may be done however is most natural for your language
  • Output does not have to be formatted like a hexagon
• Must run in a reasonable amount of time
  • Minimal brute-force
  • No brute-forcing the entire program
• You can only use Hexagony commands specified in this challenge.
• This is code-golf, so shortest code wins
  • {META NOTE: I know this challenge is hard, is there a better way to score?}
• As usual, standard loopholes are prohibited.

Test Cases:

Input: (cat)

,.[,.]

Output: (example)

   \ . .
  < _ . .
 . _ ; . .
  . . > ,
   . @ .

Input: ("123")

+++++++++++++++++++++++++++++++++++++++++++++++++.+.+.

Output: (example)

     ) ) ) ) )
    ) ) ; ) ; /
   ) ) ) ) ) ) /
  ) ) ) ) ) ) ) /
 ) ) ) ) ) ) ) ) /
  ) ) ) ) ) ) ) )
   ) ) ) ) ) ) )
    ) ) ) ) ) )
     . . @ ; <

Input: (@primo's infinite Fibonacci)

+[[<+>->+>+<<]>]

Output: (example)

       ) \ . . . . |
      . | . / { } < .
     . . . . > [ . / >
    . . . . . . . . . .
   . . . . . . @ . . . .
  / . ] < . > < . ] . . .
 _ > " ' / | . > < . . . .
  _ / . . . / . . [ . . .
   . / . . . . . . ) . .
    . . . . . . . . ] .
     . . . [ . . . . |
      . . [ . . . . (
       . \ ) ] ) ] <

Answer 27

Platformer game

code-golf game

Write a platformer game.

Rules:

• Keyboard input, minimum three commands: left, right and jump;
• Real-time. Screen should update (and the game iterate) on timer. Update speed should not depend on CPU speed. FPS should be between 2 and 120;
• It should be possible both to win and to lose (the game can although be very hard and require preparing a special bot to win or to lose);
• Playing field should have at lest 64 positions, minimum width is 6, minimum height is 5.
• Player may move left, right or jump. Player moves down automatically unless on a platform. Jumping means moving up for some limited time (not higher than 67% of playing field's height), then falling down like usual.
• Falling down outside playing field is losing the game. Stepping on 6 distinct platforms is a win.

• Player, platforms and borders of area should be visible on playing field. If output method is ASCII art, it may looks like this:

  .....----...
  ............
  ...@....----
  ..---.......
  .......---..
  ............
  

• Platforms may be horizontal, vertical, diagonal. Platforms should not overlap (except of differently oriented). Platform's projection to horizontal and vertical axes should not overlap for at least 4 platforms. Example of too projection-overlapping playing field:

  ............
  ....@.......
  .--.--..--..
  ............
  .--.--..--..
  ............
  

• Platforms may move. Overlapping rules apply only to initial positions.

• The game should track losing and winning conditions and stop the game, outputting distinct messages in case of lose or win.

Answer 28

Compute h-index of PPCG users

code-golf stack-exchange-api internet number

Thanks to @Suever for his help refining this challenge.

Background

The h-index is a commonly used metric that measures the amount and quality of publications of a given scholar or researcher. It is defined as follows:

A scholar with an h-index of n has published n papers each of which has been cited at least n times.

Adaptation for PPCG

In this challenge I propose to compute the h-index of PPCG users based on the analogy

• paper → answer;
• paper's citations → answer's vote count, defined as upvotes minus downvotes.

The following examples illustrate the computation of h-index. The array to the left is the vote count of answers in descending order for a hypothetical user, and the number to the right is the resulting h-index:

[5 3 2 1 1]    2
[1 1 1]        1
[]             0
[-1 -2]        0
[0]            0
[9 4 3 ...]    3

Referring to the last example, note that we don't need to know the array entries after the 3.

The challenge

Given a user identification, output their h-index.

Rules

User identification can be defined as anything reasonable, such as user number, user name, or user name without spaces.

The result must be based on actual data from the PPCG site. You may want to take a look at the StackExchange API, for example here.

Note that some users have a lot of answers. For one such user the API may not give all the results, or may only give them split across several chunks. However, if you ask the API to provide the results with an appropriate sorting you may not need all of them to compute the h-index (see last example above). Also, you may assume that the h-index of any user will be less than 100.

If the answer can't be tested in an online compiler (for example due to restrictions to read web content), you are encouraged (although not required) to post some evidence that the answer works, such as a screen capture.

This is code golf. Fewest bytes wins.

Table of h-indices

After submitting your answer, you may optionally edit the table below to include your own h-index, in the indicated format. Please keep the table in decreasing order, so that users with higher h-indices appear higher on the table. I will remove the dummy user names when the table has some actual content.

Example user name: 5
Another example: 3
Yet another user: 3

Answer 29

What is closer?

Tags: math,code-golf

---

Inputs: a, b (Both integer and positive) .Output: Integer, in natural numbers sequence.

We have one single atom which has a electrons, we ionize the atom with b positive charges (take b electrons out).

The output is the sum of the orbital quantum numbers (n,l,ml) which is nearest to the atom shell.

EXAMPLE: We take 3 electrons from ₂₆Fe, Now we have ₂₆Fe³⁺. We need to get the sum of the nearest remained orbitals quantum numbers to the shell.

We have this configuration for Fe³⁺: [Ar], 3d³, 4s²

The nearest orbital to shell has these numbers:

n = 4
l = 0
ml = 0

In this case:

a => 26
b => 3
output => 4

---

My 3rd grade chemistry teacher asked me once to create such a program, but I didn't success, I found the paper that my teacher wrote these descriptions on it and I typed it here because I believe that someone might create an interesting code-golf for this.

Answer 30

king-of-the-hill

KotH Chess Warriors.

This game will be based on fairy chess, but really could be imagined to be anything else.

Submissions will include both: A function that determines the moves of the piece (as in, how the piece can move), called at the start, and a function that determines how it moves each turn, called each turn, of course. Bot's move simultaneously; strategy is needed. A piece may make 5 moves in a row before it must rest.

Bot's will be able to do any valid move they choose, and the input they will get when deciding what to do will be: a value that can be 2, 1, 0, or -1, for each possible move. 2 denotes that an ally is in that square, 1 denotes that an enemy is in that space. 0 denotes an empty space which could be moved to, -1 represents an illegal move, which may result from the board ending or another piece in the way. If a piece attempts to move into it's ally, the following things could happen; A) ally stays still; Piece stays where it is. B) ally moves; Piece moves where it wishes. C) ally is captured; Piece recaptures

See below for early stage point spending system

Sandbox

I don't have the experience to host this challenge, so someone who can program these kind of things will need to help.

I have sketched out some movement point system, but I need to figure out how large the board is, and so how valuable riders (pieces that move continously, like a rook), would be, compared to leapers, before i could finalise it

Here is the quick system done, which could clearly be improved (for one thing, the multiple move thing probably needs to be a bit more expensive):

---

Point buying system

Points: each piece receives (to be decided) points base move: points spent on a move are as so. Largest dimension + floor(small dimension/2). There are no riders in this mode; Only repeated movement Repeated movement by x cost:*ceil(x^1.25) make move-only=/2 It is possible to have a leaping attack and sliding attack on the same square; it is also possible to have only one of these able to attack; How this is sorted is that both moves get their own value, and so you can attack if the attack move by itself can reach there.

Examples for base move costs:

• Any king move: 1
• any knight move: 2
• Zebra move:4
• Camel move:3

PLEASE NOTE: These move values on their own are not representative of how powerful a piece with that move actually is; A knight is better than a camel or zebra. However, when paired with other moves, the zebra and camel moves may become effective.

Example of moves that can be purchased:

     1
7   2  3
6    @55555
     4

• move 1=(2+floor(0/2)):2 points
• move 2=(1+floor(1/2)):1 point
• move 3=(2+floor(1/2)):2 points
• move 4=(1+floor(0/2)): 1 point
• move 5=((1+floor(0/2))*ceil(5^1.25))=8 points
• move 6=(5+floor(0/2))=5 points
• move 7=(5+floor(1/2))=5 points

in total, this piece costs: (2+2+1+1+8+5+5) 24 points.

---

Considerations:

• How large the board is. I'm fairly sure of having a cylindrical board; the left wraps to the right and vice versa.

• how exactly turns work. So far, I have thought that the way it works is this: Everyone moves simultaneously. When you move, you deplete your remaining moves, which tops and starts at 5. You can choose to not move, and replenish your moves at any point.

  However, this could induce stale games which don't end properly.