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.

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• Parts of the challenge you found unclear
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Answer 1

Finding Distant Primes

Answer 2

Add trailing whitespace code-golf

Sometimes, we accidentally have trailing whitespace in test cases, and some helpful person notices and fixes that. Thank you, helpful people.

But what if we want to take a string without trailing whitespace and add some?

Your challenge is to write a program that takes a string as input and adds between 1 and 10 spaces (randomly) to the end of each line.

Rules

Between 1 and 10 (inclusive) spaces (" ") must be added to each line. There must be a nonzero chance of getting any number of spaces on any line.

This is code-golf, shortest wins.

Apologies if this already exists - It's really hard to search.

Answer 3

2D Pathfinding with Momentum

Posted to main

Answer 4

Posted

Answer 5

Count What You See code-golfnumbersequence

You may have heard of the Look-and-say sequence, which is generated by reading off the digits of previous entries in the sequence. Here, you will be tasked to generate the "Count-and-say sequence".

In general, the sequence can be generated as follows:

1. Start with an arbitrary sequence of numbers (e.g. 1, 1, 1, 3, 2, 1, 2).
2. Count the occurrences of each number as adjective noun pairs -> "four 1, one 3, two 2", in order of 1st appearance. In the example, this means that you must first count 1s, then 3s, then 2s, since that is the order in which the numbers first appear in the sequence.
3. Write out the result from step 2 numerically ("four 1, one 3, two 2" -> 4, 1, 1, 3, 2, 2).
4. Append the result from step 3 to the original sequence to get 1, 1, 1, 3, 2, 1, 2, 4, 1, 1, 3, 2, 2.
5. Repeat the steps above to continue the sequence.

Task

Your task is to output the "Count-and-say sequence", such that the sequence starts with 1. You may choose to:

• Take an input \$ n \$ and output the first \$ n \$ integers.
• Take an input \$ n \$ and output the \$ n \$-th integer.
• Output the sequence indefinitely.

For convenience, here are the first 100 numbers in the sequence (also A217780):

1, 1, 1, 3, 1, 4, 1, 1, 3, 6, 1, 2, 3, 1, 4, 8, 1, 3, 3, 2, 4, 1, 6, 1, 2, 11, 1, 5, 3, 3, 4, 2, 6, 3, 2, 1, 8, 13, 1, 8, 3, 4, 4, 3, 6, 5, 2, 2, 8, 1, 11, 1, 5, 16, 1, 10, 3, 6, 4, 4, 6, 7, 2, 4, 8, 2, 11, 3, 5, 1, 13, 18, 1, 12, 3, 9, 4, 6, 6, 9, 2, 5, 8, 3, 11, 4, 5, 2, 13, 1, 16, 1, 10, 1, 7, 22, 1, 14, 3, 11

Answer 6

Equalizing fractions

Answer 7

Node one-liner to fetch a URL, like curl

I'm interested in the shortest one-liner to output the contents at a given URL, using Node.js from the command line, for practical purposes. In other words, the equivalent of curl, written as a Node one-liner.

Not interested in other languages. Would this respect the site's rules, or does it belong on SO?

Rules:

1. The URL is passed via the command line, so accessed via process.argv[1]
2. Must invoke node with the -e argument, followed by the code, followed by the URL
3. Only the length of the actual script passed to node via -e "..." is counted.

My best solution so far, with http://x.com as a conveniently short example, is:

node -r got -e "require('got')(process.argv[1]).then(r=>console.log(r.body))" http://x.com

Answer 8

Program-Write a program to display repeating terms of a given sentence.

Explanation-the program must output the repeating terms of two or more letters from the given input(input is a sentence seperated be spaces without any punctuation except the full-stop indicating the end.) For example, if input is the sentence "I am an ameture mathemagician" the outupt must be am, ma, an. ( not that em is not a valid output as it is separated by space)

Example-

input->International competitions are better than intercollege ones.

output-> Inter, ti, er, tion, io,on,ion, tio, co, on,.......etc (t, l must not be included as they are 1 letter.) (Upper lower Cases do not matter)

Test cases-

input-> aabcde cdec

output-> cde, cd, de

input-> aab aacab

output-> aa, ab

input-> aaa aabcaaa ababa

output-> aaa, aa, ab, aba, ba

Winning Criterion:- code golf

Answer 9

Getting to the root of the problem

While I was sleeping in my bed, unwilling to wake up, an idea entered my head: why is the syntax for powers, especially roots, so cumbersome? It would save so many bytes if we could just use the square root symbol instead, and easier to understand too. So, your challenge is to encode this in whatever format you choose, in as few bytes possible.

Answers should be able to:

a) convert a string such as 2**(1/2) into √2 or some other format that distinguishes it from 2√2 (note, if you choose to write 2√2 as 2 * √2 and write things like 2**(1/3) as 3√2, that is allowed).

b) Work for arbitrary powers (2**(1/50) should work fine).

c) Simplify roots. (4**(1/4) = √2)

and should be able to perform this on inputted strings.

Deduct 10% from your score if you can handle addition of roots, deduct a further 10% off that if you can handle the ret of the basic operators (-, *, /), another 10% if you can simplify expressions such as (2 - √2)/(2 + √2), another 10% if you can write 16**1/4 (for example) as √(2^2), and, if you're amazing enough to implement exponentiation, you can subtract 50%.

Input will be presented in the form of [0-9]**([0-9]/[0-9]), where the 0-9s can be any number of digits. Output should ideally be in the form of [0-9] * [0-9]√[0-9], again, with the 0-9s being any number of digits, but I will let other forms slide so long as as 3√2 (that's the cube root of 2) is distinguishable from 3 * √2.

Tags: code-golfnumbermath

Lowest score wins. Good luck!

Answer 10

Computer Tree

Consider an infinite amount of same computers building a tree, running same program. Each computer has infinite memory and infinite pins 0 to Infinity, where pin 0 connect to its parent, or the IO we see for the root; and pin 1..Inf connect to its childs.

Each connection is bidirectional, and has buffer in each direction. Writer put the value into buffer, and reader gets from it.

The computers need to support these abilities: (Here dest is a variable in the memory, and src1, src2 are either variable or immediate integers. [x] mean the memory in address x.

dest = src1 op src2, op in +,-,*
[dest] = src1
dest = [src1]
if(src1 op src2) goto inst, op in <,==,<=,!=
if((not)pin src1 writing) goto inst
if((not)pin src1 reading) goto inst
write src2 to pin src1, block if already writing
read dest from pin src1, block if not reading

It's fine if you need several elements to do one job above, but each job defined above should use same amount of time(In this model timing matters). It's also fine if you take input as some other formats, but to avoid taking too ready functions, an same-type input shouldn't lead to an infinite loop. Input for root is given when started and will never need to wait unless all input used up, but it doesn't always halt.

Shortest code win.

Answer 11

Tags: code-golfunicodestringconversion

Interpret a Cangjie Input Method String

The Cangjie input method is a method for inputting Chinese characters using a standard QWERTY-like keyboard. Each Chinese character is encoded as a sequence of Latin letters, each letter representing a radical, or part, of the character's form. Each letter encodes both the radical character it represents, as well as other, related radicals (such as E encoding 水 as well as 氵, and more).

There are 24 radicals encoded in Cangjie, as well as 3 other characters for wild cards and other purposes. For the purposes of this challenge, only the subset of the main 4 groups are used, shown below with meanings:

Philosophical group
A   日 sun
B   月 moon
C   金 gold
D   木 wood
E   水 water
F   火 fire
G   土 land

Stroke group
H   竹 bamboo
I   戈 dagger axe
J   十 ten
K   大 big
L   中 centre
M   一 one
N   弓 bow

Body parts group
O   人 person
P   心 heart
Q   手 hand
R   口 mouth

Character shapes group
S   尸 corpse
T   廿 twenty
U   山 mountain
V   女 woman
W   田 field
Y   卜 fortune telling

Cangjie Basic Rules

Characters are analyzed as such to create a Cangjie code (based on the Wikipedia article above):

• Direction of decomposition: left to right, top to bottom, outside to inside
• Geometrically connected forms: takes 4 Cangjie codes from the 1st code to the last code
• Geometrically unconnected forms:
• • Forms in exactly 2 subforms: Follow the direction of decomposition rules, then take the first and last codes of of the first subform, and the first, second, and last code of the second subform.
• • Forms in more than 2 subforms: take the first and last codes of the first subform according to direction of decomposition, then break the remainder into subforms. Take the first and last codes of the first remainder, and the last code of the last remainder.

The Challenge

Write a full program or function that, when given a valid Cangjie code string as input, outputs its corresponding traditional Chinese character.

Additional Rules

• Use Cangjie version 5.
• Standard loopholes are forbidden.
• An invalid Cangjie code string (not in our subset of codes) is undefined behavior when used as input.
• If multiple characters match a Cangjie code string, you can choose to output both, or choose one. If you choose one, it must only output that character when given that code.
• This is code-golf, so shortest code wins!

Examples

Input - Output (notes)
JWJ - 車 (connected, top to bottom: 十田十)
YRHHI - 謝 (3 parts: first is disconnected, take first and last YR;
           second is is disconnected, take first and last HH; last part take last I)
AN - 門 (special case: fixed decomposition)
OMN - 气 (another fixed decomposition; using version 5)
A - 日
BOB - 肭
JPHI - 蜜
GUMPC - 顤
STKR - 匿 or 𡲢 (if multiple characters exist for that code, pick one deterministically)
HXH - (undefined behavior, since X is not in the set of codes above)

Meta

• Is it clear? Anything that needs adding/removing?
• Any weird test cases I didn't put in?
• Anything else?

Answer 12

Text in aLtErNaTiNg cApS

Sometimes, we want to convey sarcasm in a text message or in a YouTube/Reddit comment. To this end, "alternating caps" is often used. Your task, should you wish to accept it, is to write code that turns the input text into its "alternating caps" version.

(This is a deleted rule. You should ignore this for the challenge) For most sans-serif web fonts, it is hard to distinguish capital I (for India) and lower-case l (for Lima). So we want to avoid either of these letters in our output. To achieve this, we are allowed to sacrifice "exact alternating-ness" of the output. Details below.

Input:

1. A string of words involving [a-zA-Z], with one space in between each word.
2. You may not assume whether or not the string ends with a space/newline/etc.

Output:

1. The input, turned into "alternating caps form", with the first letter of each word being lower-case.

2. (Deleted; you should not implement it. I have included it just to illustrate my thought process) You may not output any capital I (I, for India) or lower-case l (l, for Lima). To avoid these, you may continue outputting the same letter-case as the previous letter, but you must switch the letter-case at the earliest possible instance. (note to self: this requirement means there are sometimes more than two letters of the same case, which I don't really want)

3. Non-suppressible output can be ignored.

Rules:

1. Standard loopholes are forbidden.
2. You must take input from and output to natural places, according to your language.
3. This is code-golf, so the lowest byte-count wins. Ties are broken by earliest submission.
4. Please provide a way for readers to test your code (e.g. TIO).
5. An ungolfed version and an explanation for your code is appreciated, although not required for the challenge.

Examples

Input -> Output
---------------
alternating -> aLtErNaTiNg
lower case letters -> lOwEr cAsE lEtTeRs

Examples that follow the deleted rule (which you should not implement -- these are just for your interest:

I used dcode to find some of these examples. holding -> hOLdiNg radii -> rAdii (has more than 2 lower-cases in a row, if using my rules) fall -> fALL (has more than 2 capitals in a row, if using my rules) volleyball -> [even if you are allowed to change the previous letter-cases to try to stop 'ALL' (3 capitals in a row) from appearing, there is a non-unique way of doing so]

Good luck!

Answer 13

Take two registers, zero-extend one to another one on x64 in a single instruction.

Here, registers are r0-r15(64-bit), r0d-r15d(32-bit), r0w-r15w(16-bit) and r0b-r15b(8-bit), where regs marking same number share same lowest part. In case there's no solution (e.g. writing into r0d, which the opcode would behave writing to r0), output something obviously not an opcode.

Opcodes:

90              do nothing
89 11sssddd     move 16/32/64-bit[1] from sss[2] to ddd[2]
88 11sssddd     move 8-bit from sss[2] to ddd[2]
0F B7 11dddsss  move from 16-bit sss[2] to 32/64-bit[1] ddd[2]
0F B6 11dddsss  move from 8-bit sss[2] to 16/32/64-bit[1] ddd[2]
101101dd 00     move from 8-bit 0dd[2] to 16-bit 0dd[2]             
[WIP]

Shortest code win. -35 Bytes if you support ax cx dx bx sp bi sp di aliasing r0w-r7w, and rax-rdi as r0-r7, eax-edi as r0d-r7d; - another 35 Bytes if you support al cl dl bl aliasing r0b-r3b and ah ch dh bh as theoretically r4b-r7b but without REXs.

Answer 14

Make an image with the pixels from another (WIP)

image-processing code-challenge

---

Given a target image and a source image, output an image that resembles the target image by rearranging the pixels of the source image.

You will be scored based on speed and accuracy.

$$ score = {similarity(Image_{target}, Image_{result}) \times {time_{reference} \over time_{program}}} $$

Higher scores are better

Answer 15

On a 150x150 area, each cell have 15% probable of being a mine. Opening a safe(non-mine) cell tells you amount of mines with <1.5 distance. Opening a mine makes you fail. Find most safe cells in 5 second.

Answer 16

Packing numbers to interval

code-golf, math

Interval notation is a way to write complicated range bounds more conveniently and concisely than writing an inequality.

Like a list 1, 2, 3, 4 can be written like [1,4].

There have been already challenges on interpreting interval notations to number ranges, but now we will do the reverse.

Some examples (test cases):

• Input will be a list of numbers (can be positive, negative, 0, but not fractions)

• Input list can be unsorted

• If there is gap between the numbers (I mean in a list like 1,2,5,6, 3,4 is missing), you have to write multiple intervals seperate by Union sign (U)

• There will be no leading 0s in input numbers

• If there is only one number seperate in an interval (I mean like 2 in the list of 2,5,6,7) then make a seperate interval (for the example [2]U[5,7]

• The intervals should go from smallest to largest (for example 1 2 5 6, [1,2]U[5,6] is valid but [5,6]U[1,2] not.

• Input numbers can be separated by anything, it is up to you.

1 2 3 4 -> [1,4]
5 3 4 1 2 -> [1,5]
2 1 6 5 -> [1,2]U[5,6]
6 7 9 8 -4 -2 -3 0 2 1 -> [-2,-4]U[-0,2]U[6,9]

Standard loopholes apply, shortest code wins.

Answer 17

Two player tic-tac-toe game

Create a Tic-Tac-Toe game that allows two human players to play against each other.

• The drawn board can be either in ASCII or graphical (You can use 1-9 digits as a place holder in tic tac toe board)
• Program should randomly choose whose turn is first and randomly give two players X or O
• let both users know whose turn it is amd prompt for input
• Check for winning, and when one player is won, let them both know about win (same for draw game)
• Enforce all tic-tac-toe rules

Standard loopholes apply, shortest code wins

Answer 18

Hamming Distance Lookup Extravaganza

Note: I was originally just going to post this, but I was having trouble coming up with a good scoring strategy. I'd like to make sure that the instructions are clear and scoring strategy is fair and works. Thanks!

Note: This question is a WIP, and some parts may be incomplete or in the middle of editing!

Story

Bitty Benny runs a clothing factory, where, among other things, he produces bundles of shirts. Each shirt has a tag (don't worry, it's not itchy) describing what type of shirt it is.

Similar shirts have similar tags, and Bitty Benny wants to create an organization system, that, given a tag, will fetch the shirt with the most similar tag. Each tag is the same length, and lists a series of ones and zeros. To compare how similar tags are, Bitty Benny bought a Hamming Shirt Comparator (Mark II). Here's a loose schematic as to how the comparator works:

1. First, the Comparator takes the two tags and lays them side by side, like so:

   +----------+
   | 10010100 |
   +----------+
   | 00101101 |
   +----------+
   

2. Then, the comparator goes through each pair of numbers and counts the number of differences:

   +----------+
   | 10000100 |
   +-|---|--|-+
   | 00001101 |
   +-|---|--|-+
     x   x  x : 3 differences
   

3. The comparator then laser-engraves the difference onto a marble stone tablet. Some argue that the Mark I was better, because it printed out results instead, but Bitty Benny likes the satisfying thunk of the tablet as it falls from the machine.

The lower the number the comparator outputs, the more similar the shirts are. A perfect match has a score of 0, an imperfect one has a score of the length of the tag.

Bitty Benny has a lot of impatient (but well-paying) clients who demand specific types of shirts. How can Bitty Benny organize and search through the shirts to find the closest-matching tag as quickly as possible?

Formal Definition

A tag is a bit-vector of size N, where N is a power of two. For this particular challenge we'll assume N to be 64.

Hint: On modern CPU architectures, a tag can be represented by a word (an unsigned 64-bit integer), and the difference between two tags can be written as an xor then a popcount (count the number of ones in the binary representation of the integer). This distance is generally referred to as the hamming Distance (lowercase 'h', of course) between two words.

Naïvely, using a linear search, finding a tag will take O(n) time. Faster solutions exist - can you find them?

Input

Your program will take two inputs:

1. A list of random tags.
2. a different list of target tags.

These lists may be of different sizes. The input format will be as follows:

<Size of random tags list>
<tag as a decimal number `0 <= n < 2^64`>
...
<Size of random target tags list>
<tag as a decimal number>
...

The competition input has been generated, and can be found here.

Task

For each target tag, determine the closest match in the random tag list, using hamming Distance as described above.

In the case of a tie, i.e. multiple tags have the same minimum distance, any one is valid.

Output

In the order of reading, print out the closest match of each tag as a number, in the appropriate base.

Scoring and Rules

The goals of this competition are to find solutions that are:

1. Fast, in terms of execution time.
2. Clever, in terms of algorithm used, amortized cost, and write-up.

To score your program:

Note: I have to finish writing example baseline program Note: I have to generate and upload the testing list. Ideally it should be big enough that the naive solution takes around 3 seconds on a modern computer.

1. Translate this naïve idiomatic program from Rust to your language of choice.
2. Time the naïve solution in your language of choice.
3. Write an optimized solution in the same language, and time it using the same technique.
4. Your score is the optimized execution time, in seconds + that times the speedup, lower scores are better:

   score = fast_time +  ((fast_time ** 2) / slow_time)
   

Time your programs using time, include the time taken for I/O.

Note: This scoring method is good for two reasons:

1. In the case that there is no speedup compared to the baseline, the score is just 2x the time.
2. Any speedups over the base version will decrease the score, but the score will never be less than the wall-clock time it takes.

To determine the answer with the best writeup, we'll also be running a popularity contest.

Entry Template

I'm no stickler, but here's a loose entry template if you'd like to keep things consistent:

## <Language> <Speed Score> (<Calculation>)
<Link to idiomatic solution>
```
<Optimized entry>
<If over a respectable size, put a link here instead>
```

## How it works
<breakdown of the code>
<and the method used>
<and any other interesting notes>

Good luck, and happy tagging! Bitty Benny awaits your entry!

Answer 19

Participant number

code-golf, math

A math Olympiad will be held, and participants are being registered. The highest number of participants is 100. Each participant is given an ID number. It is given in a sequence like \$100, 97, 94, 91, 88, ...., 1\$, and when the first sequence is over, then \$99, 96, 93, 90, 87, ...., 3\$ sequence and so on.

Let's assume one of the participant's ID number is \$k\$ and he/she is the \$n^{th}\$ participant. Given the value of \$k\$, return the value of \$n\$.

Test Cases

59 -> 81
89 -> 71
16 -> 29
26 -> 92
63 -> 47
26 -> 92
45 -> 53
91 -> 4
18 -> 62
19 -> 28

There will be no leading zero in input. Standard loopholes apply, shortest code wins. In output there can be trailing whitespace.

Answer 20

Given a table(2D array of strings), arrange width of each column to shorten total width, such that containment in each cell can be fully shown with a space after it, being allowed to occupy next several cells if they are empty. In another word, for each column provide a width \$W_j\$, making \$\sum_jW_j\$ smallest, and for each non-empty cell in column \$i\$ , if there're \$k\$ empty cells on adjacent right, then its length is smaller than \$\sum_{j=i}^{i+k}W_j\$.

Samples:

"1234", ""  => [2,3] "1234 
"a"   , "b"           a b  "

"Date"  , ""  , "Sum"            "Date   Sum
"Mar"   , "1" , "220"             Mar 1  220
"Mar"   , "15", "130" => [4,3,4]  Mar 15 130
"Apr"   , "3" , "100"             Apr 3  100
"Sum_Up", ""  , "450"             Sum_Up 450 "

"aaa" ""    ""               "aaa
""    "bbb" ""    => [0,0,4]  bbb
""    ""    "ccc"             ccc"

Answer 21

Fastest unique finder

Answer 22

Given a string s, find a string t, containing only printable ASCII characters (32-126), such that PPCG53675(t)=s. You can assume such string exist.

Examples:

• tmop => test (and 23 other possible outputs)
• TEST => T5oV (and 23 other possible outputs)
• !!!! => !!!! (and 17)
• !! => ! (only one solution)
• ~}}~ => ~|~~ (only one solution)

Answer 23

Non-Hamming numbers

Answer 24

Brainfuck to ESOPUNKS

Brainfuck use 8 instructions

byte(or bigint, your choose) a[inf]; bigint i;
+  ++a[i];
-  --a[i];
,  a[i]=getchar();
.  putchar(a[i]);
[  while(a[i]){
]  }
<  if(--i<0) undefined_behavior();
>  ++i;

ESOPUNKS have two registers X and T, two I/O ports #STDI(stdin, read like how brainfuck does), and #STDO(stdout, undefined behavior if written <0 or >255), use these instructions:

COPY a b     b=a; a,b,c can be X,T,#STDI,#STDO or integer as long as it makes sense(no giving integer a value, etc.)
ADDI a b c   c=b+a;
SUBI a b c   c=b-a;
MULI a b c   c=b*a;
DIVI a b c   c=b/a; Halt if a=0
MODI a b c   c=b%a; Halt if a=0
MARK label   label:
JUMP label   goto label;
TJMP label   if(T) goto label;
FJMP label   if(!T) goto label;
TEST a op b  T = (a op b); op = <, =(==), >
HALT         exit(0)

(Didn't cover all instructions from esolangs as some are not implemented in the interperter)

Now write a program that converts a Brainfuck program into a ESOPUNKS one. Your ESOPUNKS output should have O(1) lines.

Note:

• It's possible to convert. Wiki shows a proof that applies with small removal.
• It's possible for bounded lines to store unbounded info as unbounded integer behave as operator
• Outputting may need a snippet repeating 256 times to allow any possible output; However I don't care length of output(as long as it's bounded), and the repeating can be generated with small code, so this shouldn't matter much.

Code-golf, shortest code in the language wins.

Answer 25

Extract json, with only few bytes.

Extract the "name" of each dictionary in the json list.

You are allowed to use any package which can be installed on Ubuntu 20.04.

Example json:

[
    {
        "id":"d963984c-1075-4d25-8cd0-eae9a7e2d130",
    "extra": {
        "foo": false,
        "bar": null
    },
    "created_at":"2020-05-06T15:31:59Z",
    "name": "NAME1"
    },
    {
    "id":"ee63984c-1075-4d25-8cd0-eae9a7e2d1xx",
    "name": "NAME2"
    }
    ]

This script would work:

import json
import sys

for item in json.loads(sys.stdin.read()):
    print(item['name'])

Desired output:

NAME1
NAME2

But since I am very lazy, I am looking for a solution which needs less characters.

The solution with the minimal number of bytes wins.

Using non-ascii characters is not allowed.

Compressing into base64 or similar is not allowed. The solution should be "type-able" by a human.

---

Since the question does not fit ot code-gold, I published it here: https://stackoverflow.com/questions/67194693/filter-json-on-the-command-line

Answer 26

Largest Compatible Maze

Answer 27

Generate a uncomputable number

An uncomputable number is a number that some digit can't be computed in finite time.

Now you're to generate and output one of them.

You can(and need to) use \b to undo an outputted byte, but every byte should stop changing from some time.

An example solution, assuming stepN(p, n) checks if program p halts in n steps, returning 0 or 1:

s = [];
output('0.');
for (i=1; ; ++i) {
    t = [stepN(j, i) for j in [1,n]]
    while (s is not a prefix of t) {
        output('\b');
        s.remove_last();
    }
    for (j=s.length; j<t.length; ++j) {
        s.insert_to_last(t[j]);
        output(t[j]);
    }
} // 0.s[0]s[1]s[2]s[3]..., s[i] mean if program i halt

Shortest code wins.

Answer 28

Write a fast-growing assembly function

Synopsis

Your goal is to implement the (asymptotically) fastest growing function within bounded code on a fictional CPU utilizing a quite limited, yet (probably) turing-complete instruction set.

Environment

The CPU utilizes unbounded RAM as well as two registers, the accumulator A and the program counter C, with words consisting of arbitrary integers, such that neither overflows nor underflows are possible. RAM is used to store data as well as code, allowing for self-modifying programs. Each instruction takes one parameter and therefore consists of two words; all instructions of your program are stored sequentially in RAM, starting at address 0. The following instructions can be used, P representing the parameter of the instruction:

Mnemonic	Corresponding word	Behavior
LOAD P	0	A := RAM[P]; C += 2
SAVE P	1	RAM[P] := A; C += 2
CNST P	2	A := P; C += 2
ADDT P	3	A += RAM[P]; C += 2
NEGA P	4	A := -RAM[P]; C += 2
JUMP P	5	C := P
JMPN P	6	If A <= 0 then C := P else C += 2.
HALT P	every other number	The program halts.

At each step, the instruction at address C will be executed using the parameter stored at C + 1. Both A and C will be initialized to 0 at the start of a program's execution. The word at -1 is supposed to be your input which can be guaranteed to be non-negative, other words not storing any instructions initially contain 0. The number stored at -2 will be considered your program's output, which must also be positive in all but finitely many cases.

Rules

At the initial state, your program may not occupy more than the first 2048 words, however, during execution, there are no bounds. Of course, you don't have to write your program in bytecode, using some assembly equivalent or ultimately any other language is fine as well, as long as you provide some rules/translator and show the result does not exceed the given bounds.

Every answer should come with some rough argument showing the program always halts, as well as some approximate lower bound on its growth rate. As the given space might very well suffice for some extremely fast-growing functions, it might be helpful to utilize the slow-/fast-growing hierarchy, as it provides a relatively simple way to compare two answers. Answers will be ranked by lower bounds that can be shown to hold.

Questions

I wonder what tags could be used in this case, atomic-code-golf, restricted-source and busy-beaver perhaps? Not entirely sure whether these fit. Also, is there any behavior left undefined? It doesn't seem like that's the case, but there might be some edge cases I forgot about.

Answer 29

May the wind be always at your back

Answer 30

Compute a real root of a cubic polynomial.

You are given a cubic polynomial of the form \$x^3 + a x^2 + b x + c\$ and your task is to compute one real root of this polynomial, or equivalently a solution to the equation \$x^3 + a x^2 + b x + c = 0\$.

Input will be three numbers \$a\$, \$b\$ and \$c\$. These are guaranteed to be real numbers. The inputs may be taken separately or as a list or a vector or whatever else is convenient in your language.

A cubic polynomial always has at least one real root, and can have up to three. It always has three complex roots but the non real ones are of no interest for this challenge. If the polynomial has multiple real roots, outputting any one of them is fine.

Output should be one number. Solutions with three correct decimal places are good enough, more accuracy or exact algebraic expressions are fine too.

This can be solved by using Cardano's formula but this requires handling of complex roots and some messy lengthy algebra. Alternatively one could use some algorithm for a numeric approximation such as Newton's method. If your language has a build-in that works as well as long as you fish out exactly one real root.

Test cases can be easily generated with any online solver for cubic equations such as this one.

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