Quantise a list code-golf array

In music production, quantisation is the process of "aligning" recorded notes to the beat, to remove the variability caused by imprecise human playing.

In this challenge, we will implement an abstract and approximate version of quantisation, representing notes as runs of positive integers, and using zeroes to represent gaps. The "beat" will be defined as every second note, starting with the first (even indices, 0-based).

Given a list of non-negative integers, insert or remove zeroes such that every run of non-zeroes begins on an even index (using 0-based indexing).

Runs of non-zeroes may not be split or joined together if they weren't already in the input. In other words, a zero cannot be inserted or removed if it only has non-zeroes next to it.

The minimal number of insertion/removal operations must be performed. If a removal is possible, it should be preferred over an insertion.

Test cases

todo

blah blah code golf rules

Zip two arrays

code-golf

Given a list of arrays of the same dimension, zip them at the lowest level. That is, you should output an array of the same dimension, for which the value at each index is a list of the corresponding elements in the input arrays.

For example, for two 3x3 arrays

[[123]  [[abc]    [[[1a][2b][3c]]
 [456] , [def]  →  [[4d][5e][6f]]
 [789]]  [ghi]]    [[7g][8h][9i]]]

and for the three 4x4 arrays

[[19  47  4   69 ]  [[103 67  17  28 ]  [[7   9   48  204]
 [156 120 54  104]   [167 80  99  62 ]   [26  125 230 212]
 [30  70  212 96 ] , [102 165 246 192] , [61  118 137 101]
 [62  80  152 205]]  [118 193 222 65 ]]  [125 247 209 31 ]]
 ↓
[[[19  103 7  ] [47  67  9  ] [4   17  48 ] [69  28  204]]
 [[156 167 26 ] [120 80  125] [54  99  230] [104 62  212]]
 [[30  102 61 ] [70  165 118] [212 246 137] [96  192 101]]
 [[62  118 125] [80  193 247] [152 222 209] [205 65  31 ]]]

Test cases

todo

Sandbox notes

• This feels like something that should've already been posted.
• Name/wording suggestions?

Solve a jigsaw puzzle

Compute the Fabius function

• \$f(x)\$ always takes on rational values at dyadic rationals (i.e. \$\frac m{2^n}\$ with \$m,n\in\mathbb Z\$). It could also be interesting to restrict input to such values, and ask for a rational output.

Convert integer to IEEE 754 float

The task is simple, given a 32 bit integer, convert it to its floating point value as defined by the IEEE 754 (32-bit) standard.

IEEE 754

Here is a converter for your reference.

Here is how the format looks:

The standard is similar to scientific notation.

The sign bit determines whether the output is negative or positive. If the bit is set, the number is negative otherwise it is positive.

The exponent bit determines the exponent (base 2), it's value is offset by 127. Therefore the exponent is \$2^{n-127}\$ where n is the integer representation of the exponent bits.

The mantissa defines a floating point number in the range \$[1,2)\$. The way it represents the number is like binary, the most significant bit is \$\frac 1 2\$, the one to the right is \$\frac 1 4\$, the next one is \$\frac 1 8\$ and so on... A one by default is added to the value.

Now the final number is: $$\text{sign}\cdot 2^{\text{exponent}-127}\cdot \text{mantissa}$$

Test cases

1078523331 ->   3.1400001049041748046875
1076719780 ->   2.71000003814697265625
1036831949 ->   0.100000001490116119384765625
3264511895 -> -74.24919891357421875
1056964608 ->   0.5
3205496832 ->  -0.5625

For this challenge assume that cases like NaN and inf are not going to be the inputs, and subnormals need not be handled, and you may output 0 for the case where the number represented is -0.

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

code-golf

Hexadecimal -> Binary Art

Find a word in the dictionary of all possible words

Generate QR code from string

code-golf binary-matrix

I'm surprised to have not seen anyone doing this particular challenge yet.

The challenge is simple: Take input as a string, your task is to turn it into a QR code.

This challenege originally requires outputting to an image (or any graphical output), but to relax the restrictions down, you only need to output the result as a matrix (or a 2D array). A binary string (with splits between) is also acceptable.

And for sake of simplicity, you will only need to output a 25x25 QR code image (which is the most popular QR code size, I believe). For the input Version 2, the image should look like this:

You may not need to handle empty strings.

Standard loopholes are forbidden.

More resources

• QR Code on Wikipedia
• Reed–Solomon error correction

Integer Bluffing (Still a draft)

king-of-the-hillpython

It's an exciting night at the IGS casino, as a brand new table game is being revealed - Integer Bluffing. Bots from all over the network have come to have a chance at playing the inaugral game, and luckily for you, you just happen to have a seat at the table.

The Rules of Integer Bluffing

At the beginning of a game of Integer Bluffing, each player starts with 20 tokens. A round of Integer Bluffing consists of 4 phases: (i) the deal, (ii) declaring, (iii) reacting, (iv) the showdown

The Deal

Each round, 1 player is chosen to pay an ante, which increases during the game, into the pot. A random integer in the range [1, 8] is then "dealt" to each player. Players only know the true value of their own integer, and once an integer is given to a player, it can't be dealt to anyone else.

Declaring

Starting with the player after the player who paid the ante, each player has the choice to either: a) decline to play the round (fold) or b) put 1 token into the pot and declare what their integer is (play).

Here's the twist - if choosing to play, the player doesn't have to tell the truth about the value of their integer - they can lie and declare they have an integer they don't have. The player also sets a flag whether they say they are bluffing or not - this can also be lied about.

Consider the following game with players A, B, C and D:

Assuming Player A paid the ante for the round, player B goes first in the declaring round. Player B sees that they have a 2, which is highly unlikely to win against other integers, so they fold.

Player C sees that they have a 7, so they choose to play the round. Wanting to trick Players D and A into putting a token into the pot, C declares that they have 2, and states they are not bluffing.

Player D sees that Player C allegedly has 2 and that they aren't bluffing. Player D knows that 3 is higher than 2, but knows that Player A might have a higher integer. Therefore, Player D decides to declare 6, not bluffing, in the hopes that Player A folds.

TODO: Continue writing

Triangular polkadot numbers

Tic, Tac, stub your Toe

Is this series of quotes valid python? code-golfdecision-problem

Python string parsing has quite a few edge cases. This is a string:

"a"

Putting 2 strings immediately after each other implicitly concatenates them, so this is also a string:

"a""a"

However, if you put 3 quotes in a row, it will create a "triple quoted string" which can only be ended by another triple quoted string. A triple quoted string can contain other quotes. These quotes will not end the string unless there are 3 of them. Thus this is valid:

"""a"a"""

Of course, you can combine these together, so this is a valid string:

"""a""""a"

And this:

"""""aaa"""""""""

A string is not valid if:

1. Any a appears outside of a string literal (would get SyntaxError: invalid syntax in python) OR
2. The end of the sequence is inside a string literal (would get SyntaxError: unterminated string literal (detected at line 1) in python)

Your task

Given a string containing 2 distinct characters, one representing a double quote and another representing any alphanumeric character, determine if it would be a valid python string, or invalid syntax.

You do not need to consider single quotes or how double and single quotes normally interact.

A array of booleans or a array of bytes would also be a valid input method.

This is code-golf, shortest answer wins.

Test Cases

eval or exec or ast.literal_eval would be valid answers, though I hope to see more creative python answers as well.

Does the sequence shut the box?

50 digits of π in HQ0-9+-INCOMPUTABLE?

Totally random Catan number distributions

Base Neutral Numbering System code-golfprimes

Turn two dice into one die

KotH: Build an Organism

A while back, I made a thing that simulates a world, with a bunch of organisms with randomly chosen genes:

These would code for things like how the organism would manage resources (such as sugar, water, and starch), whether it could photosynthesize, hunt, run away from enemies, or defend itself using tough materials like wood or stone spikes.

In this challenge, you'll design an organism which can effectively survive. This could be through strategies including:

• Being an effective hunter, chasing down and killing prey
• Being difficult to attack, such as by having tough armor and fleeing from stronger organisms
• Growing and dividing too quickly for it to be possible that all organisms of your species are killed at the same time

I will update this post with a spec listing all available resources, materials, genetic traits, and actions later.

Change the subject code-golfstringarraysorting

Posted here

Simplify a Cycle

Change the Temperature of Swatchlings

Warning: Contains Deltarune Chapter 2 Spoilers

Summary

Your challenge today is to determine the minimum number of turns needed to change the temperatures of an arbitrary amount of Swatchlings to all be the same.

Context

In the second chapter of Deltarune, there are enemies you encounter that are called Swatchlings (suit-wearing butler-like characters that serve the main antagonist of the chapter). These enemies always appear in battle in groups with at least one outlier in terms of suit color^source. Swatchlings are defeated by making all Swatchlings in the group have the same suit colour.

Each Swatchling's color can be changed in stages, either becoming warmer (redder) or colder (bluer). While there are only five colours in the actual game, for this challenge, there will be an infinite amount, represented by positive integers.

During each turn of a battle, there are 3 ways to change the temperature of a Swatchling: increasing/decreasing the temperature by 2 stages, increasing the temperature by 1 stage or decreasing the temperature by 1 stage. You may perform up to 3 of these actions per turn, and no action twice in a turn.

Task and Worked Example

Given a list of Swatchling temperatures, determine the minimal number of turns needed to change the temperatures of all Swatchlings to be the same. Note that

For example, given the following temperatures:

[1, 5, 5]

The optimal solution would be:

Turn 1:
Increase Swatchling #1 by 2 stages: [3, 5, 5]

Turn 2:
Increase Swatchling #1 by 2 stages: [5, 5, 5]

Meaning a minimum of 2 turns are needed to change the temperatures of all Swatchlings to be the same.

Another example is:

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

One optimal solution might be:

Turn 1:
Increase Swatchling #1 by 2 stages: [3, 5, 3, 4, 4, 2, 1]
Decrease Swatchling #4 by 1 stage: [3, 5, 3, 3, 4, 2, 1]
Increase Swatchling #6 by 1 stage: [3, 5, 3, 3, 4, 3, 1]

Turn 2:
Decrease Swatchling #2 by 2 stages: [3, 3, 3, 3, 4, 3, 1]
Decrease Swatchling #5 by 1 stage: [3, 3, 3, 3, 3, 3, 1]

Turn 3:
Increase Swatchling #7 by 2 stages: [3, 3, 3, 3, 3, 3, 3]

Meaning a minimum of 2 turns are needed to change the temperatures of all Swatchlings to be the same.

Rules

• Input will be a list of positive integers representing the temperatures of each Swatchling. The list will contain at least one Swatchling.
• Output will be an integer representing the minimum number of turns needed to change the temperatures of all Swatchlings to be the same.

Test Cases

[1, 5, 5] => 2
[1, 2, 5] => 1
[1, 5, 3, 4, 4, 2, 1] => 3
[1, 7] => 2
[1, 10, 3] => 4

As this is code-golf, the aim of the game is to get y'all's byte count as low as possible, just like the turn count to make all the Swatchlings the same temperature.

Sandbox Meta

• Is the explanation clear enough?

Definitions

A \$ \xi \$-word is defined as a string of letters such that every letter in the string appears an even number of times. For example, aeaeccaa is a \$ \xi \$-word.

The function \$ T \$, which operates on \$ \xi \$-words, is defined as follows:

1. Replace the odd-positioned (first, third, etc.) occurrences of each letter with (. For the example above, this produces ((ae(c(a
2. Replace all the remaining letters (i.e., those that were the even occurrences) with ). For our example, this produces (())()()

This will always produce a string with balanced brackets.

Task

Take, as input, a string \$ i \$, where every letter appears exactly twice (e.g. xffcxc). Note that this is a stricter condition than merely being a \$ \xi \$-word.

Return the lexicographically earliest \$ \xi \$-word, such that the input and output give the same value when \$ T \$ is applied to them.

Hint: a linear-time algorithm is possible.

Rules

• You do not need to handle an empty input
• Letters are ASCII lowercase (a to z)
• You may choose to operate on integers instead of strings of letters. You can use any set of integers, as long as there are at least 26 of them.
• You may use any standard I/O method
• Standard loopholes are forbidden
• This is code-golf, so the shortest code in bytes wins

Test cases

todo

Sandbox notes

At the moment, this challenge is very abstract, which I think means it will look seem quite boring (until you start to actually solve it, which I think is fun, although fairly simple). (What kind of a title is Lexicographically earliest \$ T \$-invariant \$ \xi \$-word?)

If you can think of a good domain to make it concrete, I think it would be much better. (Unfortunately I can't reveal the original context in which I encountered it). At the least I will probably replace the symbolic names with cute names before posting.

Yakko's New World Order

Sum of Consecutive Squares

Infinite Apple Dilemma

Posted here

Base64 fixed point

It can be proven that there's exactly one string of infinite length that remain same after base64 encoding Vm0wd2QyUXlVWGxWV0d4V1YwZ...

Given \$n\$, output one of

• the \$n\$-th character
• the first \$n\$ characters
• The whole string

code-golf sequence

Rotate an Image

Reverse the polyglot, change the language.

Approximate a root of an odd degree polynomial

Whole Number Groups