问:
"Hello, World!"
So... uh... this is a bit embarrassing. But we don't have a plain "Hello, World!" challenge yet (despite having 35 variants tagged with hello-world, and counting). While this is not the most interesting code golf in the common languages, finding the shortest solution in certain esolangs can be a serious challenge. For instance, to my knowledge it is not known whether the shortest possible Brainfuck solution has been found yet.

Furthermore, while all of <s>Wikipedia</s> (the Wikipedia entry has been deleted but there is a copy at archive.org
), esolangs and Rosetta Code have lists of "Hello, World!" programs, none of these are interested in having the shortest for each language (there is also this GitHub repository). If we want to be a significant site in the code golf community, I think we should try and create the ultimate catalogue of shortest "Hello, World!" programs (similar to how our basic quine challenge contains some of the shortest known quines in various languages). So let's do this!

The Rules

Each submission must be a full program.

The program must take no input, and print Hello, World! to STDOUT (this exact byte stream, including capitalization and punctuation) plus an optional trailing newline, and nothing else.

The program must not write anything to STDERR.

If anyone wants to abuse this by creating a language where the empty program prints Hello, World!, then congrats, they just paved the way for a very boring answer.

Note that there must be an interpreter so the submission can be tested. It is allowed (and even encouraged) to write this interpreter yourself for a previously unimplemented language.

Submissions are scored in bytes, in an appropriate (pre-existing) encoding, usually (but not necessarily) UTF-8. Some languages, like Folders, are a bit tricky to score - if in doubt, please ask on Meta.

This is not about finding the language with the shortest "Hello, World!" program. This is about finding the shortest "Hello, World!" program in every language. Therefore, I will not mark any answer as "accepted".

If your language of choice is a trivial variant of another (potentially more popular) language which already has an answer (think BASIC or SQL dialects, Unix shells or trivial Brainfuck-derivatives like Alphuck), consider adding a note to the existing answer that the same or a very similar solution is also the shortest in the other language.

As a side note, please don't downvote boring (but valid) answers in languages where there is not much to golf - these are still useful to this question as it tries to compile a catalogue as complete as possible. However, do primarily upvote answers in languages where the authors actually had to put effort into golfing the code.

For inspiration, check the Hello World Collection.

The Catalogue

The Stack Snippet at the bottom of this post generates the catalogue from the answers a) as a list of shortest solution per language and b) as an overall leaderboard.

To make sure that your answer shows up, please start your answer with a headline, using the following Markdown template:

```<code>## Language Name, N bytes
</code>```

where N is the size of your submission. If you improve your score, you can keep old scores in the headline, by striking them through. For instance:

```<code>## Ruby, <s>104</s> <s>101</s> 96 bytes
</code>```

If there you want to include multiple numbers in your header (e.g. because your score is the sum of two files or you want to list interpreter flag penalties separately), make sure that the actual score is the last number in the header:

```<code>## Perl, 43 + 2 (-p flag) = 45 bytes
</code>```

You can also make the language name a link which will then show up in the snippet:

```<code>## [><>](https://esolangs.org/wiki/Fish), 121 bytes
</code>```

/* Configuration */

var QUESTION_ID = 55422; // Obtain this from the url
// It will be like https://XYZ.stackexchange.com/questions/QUESTION_ID/... on any question page
var ANSWER_FILTER = "!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe";
var COMMENT_FILTER = "!)Q2B_A2kjfAiU78X(md6BoYk";
var OVERRIDE_USER = 8478; // This should be the user ID of the challenge author.

/* App */

var answers = [], answers_hash, answer_ids, answer_page = 1, more_answers = true, comment_page;

function answersUrl(index) {
  return "https://api.stackexchange.com/2.2/questions/" +  QUESTION_ID + "/answers?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + ANSWER_FILTER;
}

function commentUrl(index, answers) {
  return "https://api.stackexchange.com/2.2/answers/" + answers.join(';') + "/comments?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + COMMENT_FILTER;
}

function getAnswers() {
  jQuery.ajax({
    url: answersUrl(answer_page++),
    method: "get",
    dataType: "jsonp",
    crossDomain: true,
    success: function (data) {
      answers.push.apply(answers, data.items);
      answers_hash = [];
      answer_ids = [];
      data.items.forEach(function(a) {
        a.comments = [];
        var id = +a.share_link.match(/\d+/);
        answer_ids.push(id);
        answers_hash[id] = a;
      });
      if (!data.has_more) more_answers = false;
      comment_page = 1;
      getComments();
    }
  });
}

function getComments() {
  jQuery.ajax({
    url: commentUrl(comment_page++, answer_ids),
    method: "get",
    dataType: "jsonp",
    crossDomain: true,
    success: function (data) {
      data.items.forEach(function(c) {
        if (c.owner.user_id === OVERRIDE_USER)
          answers_hash[c.post_id].comments.push(c);
      });
      if (data.has_more) getComments();
      else if (more_answers) getAnswers();
      else process();
    }
  });
}

getAnswers();

var SCORE_REG = /<h\d>\s*([^\n,<]*(?:<(?:[^\n>]*>[^\n<]*<\/[^\n>]*>)[^\n,<]*)*),.*?(\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/;

var OVERRIDE_REG = /^Override\s*header:\s*/i;

function getAuthorName(a) {
  return a.owner.display_name;
}

function process() {
  var valid = [];

  answers.forEach(function(a) {
    var body = a.body;
    a.comments.forEach(function(c) {
      if(OVERRIDE_REG.test(c.body))
        body = '
' + c.body.replace(OVERRIDE_REG, '') + '
';
    });

    var match = body.match(SCORE_REG);
    if (match)
      valid.push({
        user: getAuthorName(a),
        size: +match[2],
        language: match[1],
        link: a.share_link,
      });
    else console.log(body);
  });

  valid.sort(function (a, b) {
    var aB = a.size,
        bB = b.size;
    return aB - bB
  });

  var languages = {};
  var place = 1;
  var lastSize = null;
  var lastPlace = 1;
  valid.forEach(function (a) {
    if (a.size != lastSize)
      lastPlace = place;
    lastSize = a.size;
    ++place;

    var answer = jQuery("#answer-template").html();
    answer = answer.replace("{{PLACE}}", lastPlace + ".")
                   .replace("{{NAME}}", a.user)
                   .replace("{{LANGUAGE}}", a.language)
                   .replace("{{SIZE}}", a.size)
                   .replace("{{LINK}}", a.link);
    answer = jQuery(answer);
    jQuery("#answers").append(answer);

    var lang = a.language;
    lang = jQuery(''+lang+'').text();

    languages[lang] = languages[lang] || {lang: a.language, lang_raw: lang, user: a.user, size: a.size, link: a.link};
  });

  var langs = [];
  for (var lang in languages)
    if (languages.hasOwnProperty(lang))
      langs.push(languages[lang]);

  langs.sort(function (a, b) {
    if (a.lang_raw.toLowerCase() > b.lang_raw.toLowerCase()) return 1;
    if (a.lang_raw.toLowerCase() < b.lang_raw.toLowerCase()) return -1;
    return 0;
  });

  for (var i = 0; i < langs.length; ++i)
  {
    var language = jQuery("#language-template").html();
    var lang = langs[i];
    language = language.replace("{{LANGUAGE}}", lang.lang)
                       .replace("{{NAME}}", lang.user)
                       .replace("{{SIZE}}", lang.size)
                       .replace("{{LINK}}", lang.link);
    language = jQuery(language);
    jQuery("#languages").append(language);
  }

}```
<pre class="snippet-code-css lang-css prettyprint-override"><code>body {
  text-align: left !important;
  display: block !important;
}

#answer-list {
  padding: 10px;
  width: 290px;
  float: left;
}

#language-list {
  padding: 10px;
  width: 500px;
  float: left;
}

table thead {
  font-weight: bold;
}

table td {
  padding: 5px;
}</code>```

<link rel="stylesheet" type="text/css" href="https://cdn.sstatic.net/Sites/codegolf/all.css?v=ffb5d0584c5f">

Shortest Solution by Language

Language	User	Score

Leaderboard

	Author	Language	Size

{{PLACE}}	{{NAME}}	{{LANGUAGE}}	{{SIZE}}	Link

{{LANGUAGE}}	{{NAME}}	{{SIZE}}	Link

```

答:
Your Mom, 14 bytes

```<code>'Hello, World!
</code>```

Explanation

```<code>'...
'... - Push the string. The ending ' is not needed at the end of program
     - Implicit output
</code>```

Title: "Hello, World!"

Body:
Your Mom, 14 bytes

'Hello, World!

Explanation

'...
'... - Push the string. The ending ' is not needed at the end of program
     - Implicit output


问:
Add two numbers
Input: Two integers. Preferably decimal integers, but other forms of numbers can be used. These can be given to the code in standard input, as arguments to the program or function, or as a list.

Output: Their sum. Use the same format for output integers as input integers. For example, the input 5 16 would lead to the output 21.

Restrictions: No standard loopholes please. This is code-golf, answer in lowest amount of bytes wins.

Notes: This should be fairly trivial, however I'm interested to see how it can be implemented. The answer can be a complete program or a function, but please identify which one it is.

Test cases:

```<code>1 2 -> 3
14 15 -> 29
7 9 -> 16
-1 8 -> 7
8 -9 -> -1
-8 -9 -> -17
</code>```

Or as CSV:

```<code>a,b,c
1,2,3
14,15,29
7,9,16
-1,8,7
8,-9,-1
-8,-9,-17
</code>```

Leaderboard

var QUESTION_ID=84260,OVERRIDE_USER=8478;function answersUrl(e){return"https://api.stackexchange.com/2.2/questions/"+QUESTION_ID+"/answers?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+ANSWER_FILTER}function commentUrl(e,s){return"https://api.stackexchange.com/2.2/answers/"+s.join(";")+"/comments?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+COMMENT_FILTER}function getAnswers(){jQuery.ajax({url:answersUrl(answer_page++),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){answers.push.apply(answers,e.items),answers_hash=[],answer_ids=[],e.items.forEach(function(e){e.comments=[];var s=+e.share_link.match(/\d+/);answer_ids.push(s),answers_hash[s]=e}),e.has_more||(more_answers=!1),comment_page=1,getComments()}})}function getComments(){jQuery.ajax({url:commentUrl(comment_page++,answer_ids),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){e.items.forEach(function(e){e.owner.user_id===OVERRIDE_USER&&answers_hash[e.post_id].comments.push(e)}),e.has_more?getComments():more_answers?getAnswers():process()}})}function getAuthorName(e){return e.owner.display_name}function process(){var e=[];answers.forEach(function(s){var r=s.body;s.comments.forEach(function(e){OVERRIDE_REG.test(e.body)&&(r="
"+e.body.replace(OVERRIDE_REG,"")+"
")});var a=r.match(SCORE_REG);a&&e.push({user:getAuthorName(s),size:+a[2],language:a[1],link:s.share_link})}),e.sort(function(e,s){var r=e.size,a=s.size;return r-a});var s={},r=1,a=null,n=1;e.forEach(function(e){e.size!=a&&(n=r),a=e.size,++r;var t=jQuery("#answer-template").html();t=t.replace("{{PLACE}}",n+".").replace("{{NAME}}",e.user).replace("{{LANGUAGE}}",e.language).replace("{{SIZE}}",e.size).replace("{{LINK}}",e.link),t=jQuery(t),jQuery("#answers").append(t);var o=e.language;/s.lang?1:e.lang<s.lang?-1:0});for(var c=0;c<t.length;++c){var i=jQuery("#language-template").html(),o=t[c];i=i.replace("{{LANGUAGE}}",o.lang).replace("{{NAME}}",o.user).replace("{{SIZE}}",o.size).replace("{{LINK}}",o.link),i=jQuery(i),jQuery("#languages").append(i)}}var ANSWER_FILTER="!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe",COMMENT_FILTER="!)Q2B_A2kjfAiU78X(md6BoYk",answers=[],answers_hash,answer_ids,answer_page=1,more_answers=!0,comment_page;getAnswers();var SCORE_REG=/<h\d>\s*([^\n,]*[^\s,]),.*?(\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/,OVERRIDE_REG=/^Override\s*header:\s*/i;```
<pre class="snippet-code-css lang-css prettyprint-override"><code>body{text-align:left!important}#answer-list,#language-list{padding:10px;width:290px;float:left}table thead{font-weight:700}table td{padding:5px}</code>```

 <link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b">

Leaderboard

	Author	Language	Size

Winners by Language

Language	User	Score

{{PLACE}}	{{NAME}}	{{LANGUAGE}}	{{SIZE}}	Link

{{LANGUAGE}}	{{NAME}}	{{SIZE}}	Link

```

答:
GO, 29 bytes

```<code>func (a,b int)int{return a+b}
</code>```

Not that much to say

ContentLicense: CC BY-SA 3.0

Title: Add two numbers

Body:
GO, 29 bytes

func (a,b int)int{return a+b}

Not that much to say


问:
Latin square compression
A Latin square is a square that has no repeated symbols in the rows or columns:.

```<code>13420
21304
32041
04213
40132
</code>```

And as many Sudoku players know, you don't need all of the numbers to deduce the remaining numbers.

Your challenge is to compress a Latin square into as few bytes as possible.  You need to provide one or two program(s) that compresses/decompresses.

Various info:

The numbers used will always be 0..N-1, where N is the length of the square's edge, and N<=25

On decompression, the latin square must be identical to the input.

Your program(s) should be able to (de)compress any latin square (within the maximum square size), not just the ones I've provided.  Compression ratios should be similar as well.

You must actually run the compression and decompressor to obtain your score (No end-of-universe runtimes)

The test cases can be found on github.  Your score is total size of compressed test cases.

EDIT: As of 20:07 on July 7th, I updated the test cases (in order to fix a generation issue).  Please rerun your program on the new test cases.  Thanks Anders Kaseorg.

答:
Python 3, 1955 bytes

Yet another one that uses permutation indices...

from math import factorial

test_data_name = 'latin_squares.txt'

def grid_reader(fname):
    ''' Read CSV number grids; grids are separated by empty lines '''
    grid = []
    with open(fname) as f:
        for line in f:
            line = line.strip()
            if line:
                grid.append([int(u) for u in line.split(',') if u])
            elif grid:
                yield grid
                grid = []
    if grid:
        yield grid

def show(grid):
    a = [','.join([str(u) for u in row]) for row in grid]
    print('\n'.join(a), end='\n\n')

def perm(seq, base, k):
    ''' Build kth ordered permutation of seq '''
    seq = seq[:]
    p = []
    for j in range(len(seq) - 1, 0, -1):
        q, k = divmod(k, base)
        p.append(seq.pop(q))
        base //= j
    p.append(seq[0])
    return p

def index(p):
    ''' Calculate index number of sequence p,
        which is a permutation of range(len(p))
    '''
    #Generate factorial base code
    fcode = [sum(u < v for u in p[i+1:]) for i, v in enumerate(p[:-1])]

    #Convert factorial base code to integer
    k, base = 0, 1
    for j, v in enumerate(reversed(fcode), 2):
        k += v * base
        base *= j
    return k

def encode_latin(grid):
    num = len(grid)
    fbase = factorial(num)

    #Encode grid rows by their permutation index,
    #in reverse order, starting from the 2nd-last row
    codenum = 0
    for row in grid[-2::-1]:
        codenum = codenum * fbase + index(row)
    return codenum

def decode_latin(num, codenum):
    seq = list(range(num))
    sbase = factorial(num - 1)
    fbase = sbase * num

    #Extract rows
    grid = []
    for i in range(num - 1):
        codenum, k = divmod(codenum, fbase)
        grid.append(perm(seq, sbase, k))

    #Build the last row from the missing element of each column
    allnums = set(seq)
    grid.append([allnums.difference(t).pop() for t in zip(*grid)])
    return grid

byteorder = 'little'

def compress(grid):
    num = len(grid)
    codenum = encode_latin(grid)
    length = -(-codenum.bit_length() // 8)
    numbytes = num.to_bytes(1, byteorder)
    codebytes = codenum.to_bytes(length, byteorder)
    return numbytes + codebytes

def decompress(codebytes):
    numbytes, codebytes= codebytes[:1], codebytes[1:]
    num = int.from_bytes(numbytes, byteorder)
    if num == 1:
        return [[0]]
    else:
        codenum = int.from_bytes(codebytes, byteorder)
        return decode_latin(num, codenum)

total = 0
for i, grid in enumerate(grid_reader(test_data_name), 1):
    #show(grid)
    codebytes = compress(grid)
    length = len(codebytes)
    total += length
    newgrid = decompress(codebytes)
    ok = newgrid == grid
    print('{:>2}: Length = {:>3}, {}'.format(i, length, ok))
    #print('Code:', codebytes)
    #show(newgrid)

print('Total bytes: {}'.format(total))
```
<p><strong>output</strong></p>
<pre class="lang-none prettyprint-override"><code> 1: Length =   1, True
 2: Length =   1, True
 3: Length =   2, True
 4: Length =   3, True
 5: Length =   5, True
 6: Length =   7, True
 7: Length =  11, True
 8: Length =  14, True
 9: Length =  20, True
10: Length =  26, True
11: Length =  33, True
12: Length =  41, True
13: Length =  50, True
14: Length =  61, True
15: Length =  72, True
16: Length =  84, True
17: Length =  98, True
18: Length = 113, True
19: Length = 129, True
20: Length = 147, True
21: Length = 165, True
22: Length = 185, True
23: Length = 206, True
24: Length = 229, True
25: Length = 252, True
Total bytes: 1955
</code>```

Title: Latin square compression

Body:
Python 3, 1955 bytes

Yet another one that uses permutation indices...

from math import factorial

test_data_name = 'latin_squares.txt'

def grid_reader(fname):
    ''' Read CSV number grids; grids are separated by empty lines '''
    grid = []
    with open(fname) as f:
        for line in f:
            line = line.strip()
            if line:
                grid.append([int(u) for u in line.split(',') if u])
            elif grid:
                yield grid
                grid = []
    if grid:
        yield grid

def show(grid):
    a = [','.join([str(u) for u in row]) for row in grid]
    print('\n'.join(a), end='\n\n')

def perm(seq, base, k):
    ''' Build kth ordered permutation of seq '''
    seq = seq[:]
    p = []
    for j in range(len(seq) - 1, 0, -1):
        q, k = divmod(k, base)
        p.append(seq.pop(q))
        base //= j
    p.append(seq[0])
    return p

def index(p):
    ''' Calculate index number of sequence p,
        which is a permutation of range(len(p))
    '''
    #Generate factorial base code
    fcode = [sum(u < v for u in p[i+1:]) for i, v in enumerate(p[:-1])]

    #Convert factorial base code to integer
    k, base = 0, 1
    for j, v in enumerate(reversed(fcode), 2):
        k += v * base
        base *= j
    return k

def encode_latin(grid):
    num = len(grid)
    fbase = factorial(num)

    #Encode grid rows by their permutation index,
    #in reverse order, starting from the 2nd-last row
    codenum = 0
    for row in grid[-2::-1]:
        codenum = codenum * fbase + index(row)
    return codenum

def decode_latin(num, codenum):
    seq = list(range(num))
    sbase = factorial(num - 1)
    fbase = sbase * num

    #Extract rows
    grid = []
    for i in range(num - 1):
        codenum, k = divmod(codenum, fbase)
        grid.append(perm(seq, sbase, k))

    #Build the last row from the missing element of each column
    allnums = set(seq)
    grid.append([allnums.difference(t).pop() for t in zip(*grid)])
    return grid

byteorder = 'little'

def compress(grid):
    num = len(grid)
    codenum = encode_latin(grid)
    length = -(-codenum.bit_length() // 8)
    numbytes = num.to_bytes(1, byteorder)
    codebytes = codenum.to_bytes(length, byteorder)
    return numbytes + codebytes

def decompress(codebytes):
    numbytes, codebytes= codebytes[:1], codebytes[1:]
    num = int.from_bytes(numbytes, byteorder)
    if num == 1:
        return [[0]]
    else:
        codenum = int.from_bytes(codebytes, byteorder)
        return decode_latin(num, codenum)

total = 0
for i, grid in enumerate(grid_reader(test_data_name), 1):
    #show(grid)
    codebytes = compress(grid)
    length = len(codebytes)
    total += length
    newgrid = decompress(codebytes)
    ok = newgrid == grid
    print('{:>2}: Length = {:>3}, {}'.format(i, length, ok))
    #print('Code:', codebytes)
    #show(newgrid)

print('Total bytes: {}'.format(total))

output

 1: Length =   1, True
 2: Length =   1, True
 3: Length =   2, True
 4: Length =   3, True
 5: Length =   5, True
 6: Length =   7, True
 7: Length =  11, True
 8: Length =  14, True
 9: Length =  20, True
10: Length =  26, True
11: Length =  33, True
12: Length =  41, True
13: Length =  50, True
14: Length =  61, True
15: Length =  72, True
16: Length =  84, True
17: Length =  98, True
18: Length = 113, True
19: Length = 129, True
20: Length = 147, True
21: Length = 165, True
22: Length = 185, True
23: Length = 206, True
24: Length = 229, True
25: Length = 252, True
Total bytes: 1955


问:
m3ph1st0s's programming puzzle 2 (C++): "Call hard!"
I am back with a brand new puzzle for C/C++ addicts. Following the feedback received on the 1st puzzle, this time I will try to make the requirements crystal clear and to provide a perfectly valid code.

Here is the problem.
Given the following code:

```<code>#include <iostream>

char message[6]="hello";

void print_hello_message() {
   std::cout << message;
}

int main() {
   char* q = &message[0];

   // insert your code here
}
</code>```

You are required to insert two more lines where the comment specifies in order to make the program print "hello" and nothing more, with the following restrictions:

the first line will NOT call any function, including cout

the second line will contain AT MOST 5 letters (and as many other symbols as you want)

the first line may contain new variable declarations but may not initialize them

the symbols # and / will not be used at all.

no logical operators will be used

The shortest code wins!

答:
In thinking about it some more, the problem states "insert two more lines where the comment specifies" not "statements". Taking that into consideration, here is another shorter answer (though it depends on how you define "the first line will NOT call any function, including cout"):

```<code>std::
cout<<q;
</code>```

The first line qualifies which cout will be used, and the second line includes the actual operator that results in calling operator<< for the std::ostream & const char* operands.

Body:
In thinking about it some more, the problem states "insert two more lines where the comment specifies" not "statements". Taking that into consideration, here is another shorter answer (though it depends on how you define "the first line will NOT call any function, including cout"):

std::
cout<<q;

The first line qualifies which cout will be used, and the second line includes the actual operator that results in calling operator<< for the std::ostream & const char* operands.


问:
Post-determined Array Sorting
Input:

An array containing three integers: 0, 1 and 2 in any order (i.e. [2, 0, 1])

And a string of length >= 2 only containing alphabetic letters (both lower- and uppercase) and digits (i.e. a1B2c3)

Output:

Based on the array we sort and output the string.

How does this work?

The array indicates the order precedence of a-z, A-Z and 0-9, the first being 0; second being 1; and third being 2.

The individual characters of the string can then be ordered based on that.

Example:

Array: [2, 0, 1]

String: a1B2c3

Based on the array, we know our order precedence is 0-9a-zA-Z.

Based on that, we can convert and output the string: 123acB.

Challenge rules:

For the array you can choose to use 0-indexed or 1-indexed input, so [3, 1, 2] is also a valid input if you prefer to use 1-indexed arrays.

The string (both input and output) only contains valid characters: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.

If your language doesn't support arrays (or if you choose to), you are free to use strings instead of arrays for the first parameter (i.e. 012, [0,1,2], etc.).

General rules:

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

Don't let code-golf languages discourage you from posting answers with non-codegolfing languages. Try to come up with an as short as possible answer for 'any' programming language.

Standard rules apply for your answer, so you are allowed to use STDIN/STDOUT, functions/method with the proper parameters, full programs. Your call.

Default Loopholes are forbidden.

If possible, please add a link with a test for your code.

Also, please add an explanation if necessary.

Test cases:

```<code>[2, 0, 1]  &  a1B2c3             ->   123acB
[2, 1, 0]  &  aAaA909UuHWw9gh2   ->   02999AAHUWaaghuw
[2, 1, 0]  &  6Bx43              ->   346Bx
[1, 0, 2]  &  jfjf33g            ->   ffgjj33
[0, 2, 1]  &  AbC13              ->   b13AC
[1, 2, 0]  &  Qfl0l              ->   Q0fll
[0, 1, 2]  &  9870abcABC         ->   abcABC0789
[0, 2, 1]  &  test123            ->   estt123
[2, 0, 1]  &  WHAT               ->   AHTW
[2, 0, 1]  &  WhAt               ->   htAW
[1, 0, 2]  &  102BACbac          ->   ABCabc012
</code>```

答:
TSQL, <s>199</s> 191 bytes

Golfed:

```<code>DECLARE @i varchar(99)='abA7B34',@s char(3)='213'

,@ varchar(99)=''SELECT @+=n FROM(SELECT top 99n FROM(SELECT top 99substring(@i,row_number()over(order by 1/0),1)n FROM sys.messages)c ORDER BY CHARINDEX(CHAR(ascii(n)/32+48),@s),n)d SELECT @
</code>```

Ungolfed:

```<code>DECLARE @i varchar(99)='abA7B34'
-- 1 numbers, 2 upper case, 3 lower case
DECLARE @s char(3)='213'

,@ varchar(99)=''
SELECT @+=n
FROM
  (
    SELECT top 99 n
    FROM
      (
         SELECT top 99substring(@i, row_number()over(order by 1/0), 1)n
         FROM sys.messages
      )c
    ORDER BY CHARINDEX(CHAR(ascii(n)/32+48),@s),n
  )d

SELECT @
</code>```

Fiddle

Title: Post-determined Array Sorting

Body:
TSQL, <s>199</s> 191 bytes

Golfed:

DECLARE @i varchar(99)='abA7B34',@s char(3)='213'

,@ varchar(99)=''SELECT @+=n FROM(SELECT top 99n FROM(SELECT top 99substring(@i,row_number()over(order by 1/0),1)n FROM sys.messages)c ORDER BY CHARINDEX(CHAR(ascii(n)/32+48),@s),n)d SELECT @

Ungolfed:

DECLARE @i varchar(99)='abA7B34'
-- 1 numbers, 2 upper case, 3 lower case
DECLARE @s char(3)='213'

,@ varchar(99)=''
SELECT @+=n
FROM
  (
    SELECT top 99 n
    FROM
      (
         SELECT top 99substring(@i, row_number()over(order by 1/0), 1)n
         FROM sys.messages
      )c
    ORDER BY CHARINDEX(CHAR(ascii(n)/32+48),@s),n
  )d

SELECT @

Fiddle


Title: Post-determined Array Sorting

Body:
Input:

An array containing three integers: 0, 1 and 2 in any order (i.e. [2, 0, 1])

And a string of length >= 2 only containing alphabetic letters (both lower- and uppercase) and digits (i.e. a1B2c3)

Output:

Based on the array we sort and output the string.

How does this work?

The array indicates the order precedence of a-z, A-Z and 0-9, the first being 0; second being 1; and third being 2.

The individual characters of the string can then be ordered based on that.

Example:

Array: [2, 0, 1]

String: a1B2c3

Based on the array, we know our order precedence is 0-9a-zA-Z.

Based on that, we can convert and output the string: 123acB.

Challenge rules:

For the array you can choose to use 0-indexed or 1-indexed input, so [3, 1, 2] is also a valid input if you prefer to use 1-indexed arrays.

The string (both input and output) only contains valid characters: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.

If your language doesn't support arrays (or if you choose to), you are free to use strings instead of arrays for the first parameter (i.e. 012, [0,1,2], etc.).

General rules:

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

Don't let code-golf languages discourage you from posting answers with non-codegolfing languages. Try to come up with an as short as possible answer for 'any' programming language.

Standard rules apply for your answer, so you are allowed to use STDIN/STDOUT, functions/method with the proper parameters, full programs. Your call.

Default Loopholes are forbidden.

If possible, please add a link with a test for your code.

Also, please add an explanation if necessary.

Test cases:

```<code>[2, 0, 1]  &  a1B2c3             ->   123acB
[2, 1, 0]  &  aAaA909UuHWw9gh2   ->   02999AAHUWaaghuw
[2, 1, 0]  &  6Bx43              ->   346Bx
[1, 0, 2]  &  jfjf33g            ->   ffgjj33
[0, 2, 1]  &  AbC13              ->   b13AC
[1, 2, 0]  &  Qfl0l              ->   Q0fll
[0, 1, 2]  &  9870abcABC         ->   abcABC0789
[0, 2, 1]  &  test123            ->   estt123
[2, 0, 1]  &  WHAT               ->   AHTW
[2, 0, 1]  &  WhAt               ->   htAW
[1, 0, 2]  &  102BACbac          ->   ABCabc012
</code>```

Body:
Javascript es6 77 bytes

(a,s)=>a.map(o=>s.match([/[a-z]?/g,/[A-Z]?/g,/\d?/g][o]).sort().join``).join``

//test
f=(a,s)=>a.map(o=>(s.match([/[a-z]/g,/[A-Z]/g,/\d/g][o])||[]).sort().join``).join``

f([2, 0, 1], "a1B2c3")             == "123acB" &&
f([2, 1, 0], "aAaA909UuHWw9gh2")   == "02999AAHUWaaghuw" &&
f([2, 1, 0], "6Bx43")              == "346Bx" &&
f([1, 0, 2], "jfjf33g")            == "ffgjj33" &&
f([0, 2, 1], "AbC13")              == "b13AC" &&
f([1, 2, 0], "Qfl0l")              == "Q0fll" &&
f([0, 1, 2], "9870abcABC")         == "abcABC0789" &&
f([0, 2, 1], "test123")            == "estt123" &&
f([2, 0, 1], "WHAT")               == "AHTW" &&
f([2, 0, 1], "WhAt")               == "htAW" &&
f([1, 0, 2], "102BACbac")          == "ABCabc012"


问:
bfcat - encode a file as a brainf*** program

Challenge

Write a program or function that given a string, returns a valid Brainfuck program that when compiled and executed as Brainfuck, returns that string..

Assume all inputs are encoded as ASCII.

Assume the outputted BF program will execute in an environment with an infinite tape.

Assume the pointer starts at cell 0 with every cell initialized to a value of zero.

Each example below represent one possible correct output for the given input. In particular, the examples include extra newlines and spaces to help human readability. Solutions are free to format the outputted BF code in any way.

The tape is doubly infinite.

All cells provided by the interpreter are exactly 8-bit cells. Overflow and underflow wrap around in a predictable and sane matter.

Examples

Space string

Given the input  , your program/function could return:

```<code>+++++ +++++
+++++ +++++
+++++ +++++
++ .
</code>```

Exclamation point

Given the input ! , your program/function could return:

```<code>+++++ +++++
+++++ +++++
+++++ +++++
+++
.
</code>```

Two letters

Given the input hi , your program/function could return:

```<code>+++++ +++++
+++++ +++++
+++++ +++++
+++++ +++++
+++++ +++++

+++++ +++++
+++++ +++++
+++++ +++++
+++++ +++++
+++++ +++++

++++
.
+
.
</code>```

This is code-golf, so the code with the smallest number of bytes wins. Good luck.

答:
Haskell 50 Bytes

```<code>f[]=[]
f(x:y)=replicate(fromEnum x)'+'++".>"++f y
</code>```

Body:
Haskell 50 Bytes

f[]=[]
f(x:y)=replicate(fromEnum x)'+'++".>"++f y


答:
Python 2, 121 Bytes

```<code>lambda a,s:"".join(sum([[sorted(filter(eval(u),s))for u in["str.islower","str.isupper","str.isdigit"]][i]for i in a],[]))
</code>```

Title: Post-determined Array Sorting

Body:
Python 2, 121 Bytes

lambda a,s:"".join(sum([[sorted(filter(eval(u),s))for u in["str.islower","str.isupper","str.isdigit"]][i]for i in a],[]))


问:
Draw the national flag of Iceland
This year's UEFA Euro 2016 is over and besides a couple of negative headlines there has been a very positive surprise as well – the Iceland national football team. Let's draw their national flag.

Input

Well, obviously this challenge has no input.

Output

Draw the flag of Iceland in any applicable visual format of at least 100 x 72 pixels or 25 x 18 characters.

Save the output to a file or present it instantly – example formats are: images like png, jpg etc., vector graphics, draw on HTML canvas or even use non-whitespace characters for visualization.

Use these colors: blue: #0048e0, white: #ffffff and red: #d72828.

If your language doesn't support specific color values, use the standard values for red, blue and white from the ANSI color codes.

Draw the flag with the correct proportions, as shown in the figure below:

Boilerplate

You can write a program or a function. If it is an anonymous function, please include an example of how to invoke it.

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

Standard loopholes are disallowed.

Leaderboard

var QUESTION_ID = 85141; // Obtain this from the url
// It will be like https://XYZ.stackexchange.com/questions/QUESTION_ID/... on any question page
var ANSWER_FILTER = "!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe";
var COMMENT_FILTER = "!)Q2B_A2kjfAiU78X(md6BoYk";
var OVERRIDE_USER = 41859; // This should be the user ID of the challenge author.
var answers = [], answers_hash, answer_ids, answer_page = 1, more_answers = true, comment_page;function answersUrl(index) {return "https://api.stackexchange.com/2.2/questions/" +  QUESTION_ID + "/answers?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + ANSWER_FILTER;}function commentUrl(index, answers) {return "https://api.stackexchange.com/2.2/answers/" + answers.join(';') + "/comments?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + COMMENT_FILTER;}function getAnswers() {jQuery.ajax({url: answersUrl(answer_page++),method: "get",dataType: "jsonp",crossDomain: true,success: function (data) {answers.push.apply(answers, data.items);answers_hash = [];answer_ids = [];data.items.forEach(function(a) {a.comments = [];var id = +a.share_link.match(/\d+/);answer_ids.push(id);answers_hash[id] = a;});if (!data.has_more) more_answers = false;comment_page = 1;getComments();}});}function getComments() {jQuery.ajax({url: commentUrl(comment_page++, answer_ids),method: "get",dataType: "jsonp",crossDomain: true,success: function (data) {data.items.forEach(function(c) {if (c.owner.user_id === OVERRIDE_USER)answers_hash[c.post_id].comments.push(c);});if (data.has_more) getComments();else if (more_answers) getAnswers();else process();}});}getAnswers();var SCORE_REG = /<h\d>\s*([^\n,]*[^\s,]),.*?(-?\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/;var OVERRIDE_REG = /^Override\s*header:\s*/i;function getAuthorName(a) {return a.owner.display_name;}function process() {var valid = [];answers.forEach(function(a) {var body = a.body;a.comments.forEach(function(c) {if(OVERRIDE_REG.test(c.body))body = '
' + c.body.replace(OVERRIDE_REG, '') + '
';});var match = body.match(SCORE_REG);if (match)valid.push({user: getAuthorName(a),size: +match[2],language: match[1],link: a.share_link,});});valid.sort(function (a, b) {var aB = a.size,bB = b.size;return aB - bB});var languages = {};var place = 1;var lastSize = null;var lastPlace = 1;valid.forEach(function (a) {if (a.size != lastSize)lastPlace = place;lastSize = a.size;++place;var answer = jQuery("#answer-template").html();answer = answer.replace("{{PLACE}}", lastPlace + ".").replace("{{NAME}}", a.user).replace("{{LANGUAGE}}", a.language).replace("{{SIZE}}", a.size).replace("{{LINK}}", a.link);answer = jQuery(answer);jQuery("#answers").append(answer);var lang = a.language;if (! /<a/.test(lang)) lang = '' + lang + '';lang = jQuery(lang).text().toLowerCase();languages[lang] = languages[lang] || {lang: a.language, user: a.user, size: a.size, link: a.link, uniq: lang};});var langs = [];for (var lang in languages)if (languages.hasOwnProperty(lang))langs.push(languages[lang]);langs.sort(function (a, b) {if (a.uniq > b.uniq) return 1;if (a.uniq < b.uniq) return -1;return 0;});for (var i = 0; i < langs.length; ++i){var language = jQuery("#language-template").html();var lang = langs[i];language = language.replace("{{LANGUAGE}}", lang.lang).replace("{{NAME}}", lang.user).replace("{{SIZE}}", lang.size).replace("{{LINK}}", lang.link);language = jQuery(language);jQuery("#languages").append(language);}}```
<pre class="snippet-code-css lang-css prettyprint-override"><code>body { text-align: left !important}#answer-list {padding: 10px;width: 290px;float: left;}#language-list {padding: 10px;width: 290px;float: left;}table thead {font-weight: bold;}table td {padding: 5px;}</code>```

<link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/Sites/codegolf/all.css?v=617d0685f6f3">

Leaderboard

	Author	Language	Size

Winners by Language

Language	User	Score

{{PLACE}}	{{NAME}}	{{LANGUAGE}}	{{SIZE}}

{{LANGUAGE}}	{{NAME}}	{{SIZE}}

```

If you can't find your answer, format your language and byte count as explained in the Leaderboard's "Info Section".

This challenge is inspired by Draw the national flag of france.

答:
ZX Spectrum Z80 Assembly, 51 bytes

https://github.com/ralphbecket/Z80/blob/master/IcelandFlag/IcelandFlag.asm

```<code>                zeusemulate "48K", "ULA+"
ZeusEmulate_PC  equ Main
ZeusEmulate_SP  equ $FF40

                org $8000

MinWhite        equ 7
MinRed          equ MinWhite + 1
TopRed          equ MinRed + 2
TopWhite        equ TopRed + 1
Height          equ TopWhite + MinWhite - 2
Width           equ TopWhite + 2 * MinWhite - 1

White           equ %01111000
Red             equ %01010000
Blue            equ %01001000

Main            ld hl, $5800 + ((Height - 1) * 32) + (Width - 1)
                ld c, Height

YLoop           ld b, Width

XLoop           ld (hl), Red
                ld de, MinRed * $100 + TopRed
                call Test
                jr c, Next

                ld (hl), White
                ld de, MinWhite * $100 + TopWhite
                call Test
                jr c, Next

                ld (hl), Blue

Next            dec hl
                djnz XLoop
                ld de, -(32 - Width)
                add hl, de
                dec c
                jr nz, YLoop
                ret

Test            equ *
TestX           ld a, b
                cp d
                jr c, TestY
                cp e
                ret c
TestY           ld a, c
                cp d
                ccf
                ret nc
                cp e
                ret
</code>```

Title: Draw the national flag of Iceland

Body:
ZX Spectrum Z80 Assembly, 51 bytes

https://github.com/ralphbecket/Z80/blob/master/IcelandFlag/IcelandFlag.asm

                zeusemulate "48K", "ULA+"
ZeusEmulate_PC  equ Main
ZeusEmulate_SP  equ $FF40

                org $8000

MinWhite        equ 7
MinRed          equ MinWhite + 1
TopRed          equ MinRed + 2
TopWhite        equ TopRed + 1
Height          equ TopWhite + MinWhite - 2
Width           equ TopWhite + 2 * MinWhite - 1

White           equ %01111000
Red             equ %01010000
Blue            equ %01001000

Main            ld hl, $5800 + ((Height - 1) * 32) + (Width - 1)
                ld c, Height

YLoop           ld b, Width

XLoop           ld (hl), Red
                ld de, MinRed * $100 + TopRed
                call Test
                jr c, Next

                ld (hl), White
                ld de, MinWhite * $100 + TopWhite
                call Test
                jr c, Next

                ld (hl), Blue

Next            dec hl
                djnz XLoop
                ld de, -(32 - Width)
                add hl, de
                dec c
                jr nz, YLoop
                ret

Test            equ *
TestX           ld a, b
                cp d
                jr c, TestY
                cp e
                ret c
TestY           ld a, c
                cp d
                ccf
                ret nc
                cp e
                ret


答:
Clojure, 74 bytes

```<code>#(apply str(mapcat sort(for[i %](re-seq([#"[a-z]"#"[A-Z]"#"[0-9]"]i)%2))))
</code>```

For each value in first list, gets appropriate regex and apply it to the input string. The result is a list of lists of symbols which match the regex. Then sort each one and concatenates the result into one list and transform it to string.

You can see it online here: https://ideone.com/dqAkxg

Title: Post-determined Array Sorting

Body:
Clojure, 74 bytes

#(apply str(mapcat sort(for[i %](re-seq([#"[a-z]"#"[A-Z]"#"[0-9]"]i)%2))))

For each value in first list, gets appropriate regex and apply it to the input string. The result is a list of lists of symbols which match the regex. Then sort each one and concatenates the result into one list and transform it to string.

You can see it online here: https://ideone.com/dqAkxg


问:
Unzip some numbers
Your task is to create a program or function that generates a zipper with a length of 10 lines. Each line of the zipper is represented by two dashes --:

```<code>--
--
--
--
--
--
--
--
--
--
</code>```

The program/function will take a percentage (divisible by 10) as input, and the output will be the zipper "unzipped" (dashes separated) from the top by the percentage, revealing the 1-indexed, lowest level repeated 2 times, with all prior levels repeated 4, 6, 8, ...etc. times, while keeping the bottom of the zipper centered.

Examples

```<code>>>10%
-11-
 --
 --
 --
 --
 --
 --
 --
 --
 --

>>50%
-1111111111-
 -22222222-
  -333333-
   -4444-
    -55-
     --
     --
     --
     --
     --

>>100%
-11111111111111111111-
 -222222222222222222-
  -3333333333333333-
   -44444444444444-
    -555555555555-
     -6666666666-
      -77777777-
       -888888-
        -9999-
         -10-
</code>```

The input (percentage) can be formatted however you like (50%, .5, 50, 5 [zero implied], etc), and it will always be in the range of 0 to 100 and divisible by 10. The spacing in the examples must be preserved in your output.

答:
Julia, 73 bytes

```<code>x->join([" "^min(x,a)*"-$("$(a+1)"^(x>a?a>8?1:2(x-a):0))-"for a=0:9],'
')
</code>```

First Julia answer! Tips are appreciated.

Try it online!

Title: Unzip some numbers

Body:
Julia, 73 bytes

x->join([" "^min(x,a)*"-$("$(a+1)"^(x>a?a>8?1:2(x-a):0))-"for a=0:9],'
')

First Julia answer! Tips are appreciated.

Try it online!


答:
Javascript ES6, 200 bytes

Yes, it is huge. I decided to do text outputting instead of table fiddling and stuff.

N='
',B=(_,t=1)=>`<font color=#${['fff','0048e0','d72828'][_|0]}>@`.repeat(t);C=B(1,7)+B()+B(2,2)+B()+B(1,14)+N;document.body.innerHTML=C+C+C+(L=B(0,8)+B(2,2)+B(0,15)+N)+B(2,25)+N+B(2,25)+N+L+C+C+C```

This does not work well on Firefox, but works fully on Google Chrome.

Title: Draw the national flag of Iceland

Body:
This year's UEFA Euro 2016 is over and besides a couple of negative headlines there has been a very positive surprise as well – the Iceland national football team. Let's draw their national flag.

Input

Well, obviously this challenge has no input.

Output

Draw the flag of Iceland in any applicable visual format of at least 100 x 72 pixels or 25 x 18 characters.

Save the output to a file or present it instantly – example formats are: images like png, jpg etc., vector graphics, draw on HTML canvas or even use non-whitespace characters for visualization.

Use these colors: blue: #0048e0, white: #ffffff and red: #d72828.

If your language doesn't support specific color values, use the standard values for red, blue and white from the ANSI color codes.

Draw the flag with the correct proportions, as shown in the figure below:

Boilerplate

You can write a program or a function. If it is an anonymous function, please include an example of how to invoke it.

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

Standard loopholes are disallowed.

Leaderboard

var QUESTION_ID = 85141; // Obtain this from the url
// It will be like https://XYZ.stackexchange.com/questions/QUESTION_ID/... on any question page
var ANSWER_FILTER = "!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe";
var COMMENT_FILTER = "!)Q2B_A2kjfAiU78X(md6BoYk";
var OVERRIDE_USER = 41859; // This should be the user ID of the challenge author.
var answers = [], answers_hash, answer_ids, answer_page = 1, more_answers = true, comment_page;function answersUrl(index) {return "https://api.stackexchange.com/2.2/questions/" +  QUESTION_ID + "/answers?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + ANSWER_FILTER;}function commentUrl(index, answers) {return "https://api.stackexchange.com/2.2/answers/" + answers.join(';') + "/comments?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + COMMENT_FILTER;}function getAnswers() {jQuery.ajax({url: answersUrl(answer_page++),method: "get",dataType: "jsonp",crossDomain: true,success: function (data) {answers.push.apply(answers, data.items);answers_hash = [];answer_ids = [];data.items.forEach(function(a) {a.comments = [];var id = +a.share_link.match(/\d+/);answer_ids.push(id);answers_hash[id] = a;});if (!data.has_more) more_answers = false;comment_page = 1;getComments();}});}function getComments() {jQuery.ajax({url: commentUrl(comment_page++, answer_ids),method: "get",dataType: "jsonp",crossDomain: true,success: function (data) {data.items.forEach(function(c) {if (c.owner.user_id === OVERRIDE_USER)answers_hash[c.post_id].comments.push(c);});if (data.has_more) getComments();else if (more_answers) getAnswers();else process();}});}getAnswers();var SCORE_REG = /<h\d>\s*([^\n,]*[^\s,]),.*?(-?\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/;var OVERRIDE_REG = /^Override\s*header:\s*/i;function getAuthorName(a) {return a.owner.display_name;}function process() {var valid = [];answers.forEach(function(a) {var body = a.body;a.comments.forEach(function(c) {if(OVERRIDE_REG.test(c.body))body = '
' + c.body.replace(OVERRIDE_REG, '') + '
';});var match = body.match(SCORE_REG);if (match)valid.push({user: getAuthorName(a),size: +match[2],language: match[1],link: a.share_link,});});valid.sort(function (a, b) {var aB = a.size,bB = b.size;return aB - bB});var languages = {};var place = 1;var lastSize = null;var lastPlace = 1;valid.forEach(function (a) {if (a.size != lastSize)lastPlace = place;lastSize = a.size;++place;var answer = jQuery("#answer-template").html();answer = answer.replace("{{PLACE}}", lastPlace + ".").replace("{{NAME}}", a.user).replace("{{LANGUAGE}}", a.language).replace("{{SIZE}}", a.size).replace("{{LINK}}", a.link);answer = jQuery(answer);jQuery("#answers").append(answer);var lang = a.language;if (! /<a/.test(lang)) lang = '' + lang + '';lang = jQuery(lang).text().toLowerCase();languages[lang] = languages[lang] || {lang: a.language, user: a.user, size: a.size, link: a.link, uniq: lang};});var langs = [];for (var lang in languages)if (languages.hasOwnProperty(lang))langs.push(languages[lang]);langs.sort(function (a, b) {if (a.uniq > b.uniq) return 1;if (a.uniq < b.uniq) return -1;return 0;});for (var i = 0; i < langs.length; ++i){var language = jQuery("#language-template").html();var lang = langs[i];language = language.replace("{{LANGUAGE}}", lang.lang).replace("{{NAME}}", lang.user).replace("{{SIZE}}", lang.size).replace("{{LINK}}", lang.link);language = jQuery(language);jQuery("#languages").append(language);}}```
<pre class="snippet-code-css lang-css prettyprint-override"><code>body { text-align: left !important}#answer-list {padding: 10px;width: 290px;float: left;}#language-list {padding: 10px;width: 290px;float: left;}table thead {font-weight: bold;}table td {padding: 5px;}</code>```

<link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/Sites/codegolf/all.css?v=617d0685f6f3">

Leaderboard

	Author	Language	Size

Winners by Language

Language	User	Score

{{PLACE}}	{{NAME}}	{{LANGUAGE}}	{{SIZE}}

{{LANGUAGE}}	{{NAME}}	{{SIZE}}

```

If you can't find your answer, format your language and byte count as explained in the Leaderboard's "Info Section".

This challenge is inspired by Draw the national flag of france.

Body:
Javascript ES6, 200 bytes

Yes, it is huge. I decided to do text outputting instead of table fiddling and stuff.

N='<br>',B=(_,t=1)=>`<font color=#${['fff','0048e0','d72828'][_|0]}>@`.repeat(t);C=B(1,7)+B()+B(2,2)+B()+B(1,14)+N;document.body.innerHTML=C+C+C+(L=B(0,8)+B(2,2)+B(0,15)+N)+B(2,25)+N+B(2,25)+N+L+C+C+C

This does not work well on Firefox, but works fully on Google Chrome.


答:
Java 8, <s>221</s> <s>212</s> <s>193</s> 156 bytes

I should of course try to answer my own challenge as well. :) (And as usual in Java.)

a->i->{for(byte c[],j=0;j<3;System.out.print(new String(c)))java.util.Arrays.sort(c=i.replaceAll("[^a-z];[^A-Z];[^0-9]".split(";")[a[j++]],"").getBytes());}
```
<p>-28 bytes saved thanks to <em>@cliffroot</em>.</p>
<p><strong>Explanation:</strong></p>
<p>Try it here.</p>
<pre class="lang-java prettyprint-override"><code>a->i->{          // Method with integer-array and String parameters and no return-type
  for(byte c[],  //  Temp byte-array
      j=0;j<3;   //  Loop from 0 to 3 (exclusive)
      System.out.print(new String(c)))
                 //    After every iteration: print the byte-array as String
    java.util.Arrays.sort(
                 //   Sort the byte-array
      c=         //    After we've replaced the byte-array with
        i.replaceAll("[^a-z];[^A-Z];[^0-9]".split(";")[a[j++]],"").getBytes());}
                 //    all bytes of the uppercase letters, lowercase letters, or digits,
                 //    depending on the next number in the input-array
</code>```

Title: Post-determined Array Sorting

Body:
Java 8, <s>221</s> <s>212</s> <s>193</s> 156 bytes

I should of course try to answer my own challenge as well. :) (And as usual in Java.)

a->i->{for(byte c[],j=0;j<3;System.out.print(new String(c)))java.util.Arrays.sort(c=i.replaceAll("[^a-z];[^A-Z];[^0-9]".split(";")[a[j++]],"").getBytes());}

-28 bytes saved thanks to @cliffroot.

Explanation:

<a href="https://tio.run/##rZLNauMwFIX3eQrhlURjYTtDZ4yTgBwo3XQxtCUwxoVrVU7lUWRjyW3TkGfPKD/QjunKZCWB7vl0zuVU8Ap@3QhdPf/dcwXGoDuQejtCyFiwkqPKTdDOSkXLTnMra01vzpep1DbLx9@NLGpturVop/e2lXo1nyOOZnvw59Kfb8u6xcXGCsSdupoFSTWdJPcbY8Wa1p2ljZNYrMUbOqkxJ4R8fsLaFjaGmrq1mM8kbUWjgAumFPayJ/A/8iR7Yv6fwxH4ce5R0yhpsZd4JIOsurrK87HnEboSNnU2DCYk2e2TEXKpm65QLvU5/Gstn9HaLQSfnGQ5AnJYDkKcQtOozdHmcQ9bFI1RMEYh2hEKnIvGfQlhGvGJR5Kjpp9RaXx@@Z4WOuB/NAYsDuLH7nb5Fq9eoktxr9P3H8NMhsfI0VdYVVblZLIahDuwehtkxSIc7C3qBf1dqkANdRb2gsa/fgZQcJYuLpXVddGG0eC69Mu3vGUPF2O9MHuphoRBlLJFAfwE3I12@38" rel="nofollow noreferrer">Try it here.

a->i->{          // Method with integer-array and String parameters and no return-type
  for(byte c[],  //  Temp byte-array
      j=0;j<3;   //  Loop from 0 to 3 (exclusive)
      System.out.print(new String(c)))
                 //    After every iteration: print the byte-array as String
    java.util.Arrays.sort(
                 //   Sort the byte-array
      c=         //    After we've replaced the byte-array with
        i.replaceAll("[^a-z];[^A-Z];[^0-9]".split(";")[a[j++]],"").getBytes());}
                 //    all bytes of the uppercase letters, lowercase letters, or digits,
                 //    depending on the next number in the input-array


答:
Jelly, 13 bytes

```<code>2_ịØWs26¤Ff@€
</code>```

Try it online! or verify all test cases.

How it works

```<code>2_ịØWs26¤Ff@€  Main link. Arguments: k (permutation of [0, 1, 2]), s (string)

2_             Subtract the integers in k from 2, mapping [0, 1, 2] -> [2, 1, 0].
        ¤      Combine the three links to the left into a niladic chain.
   ØW          Yield the string following string.
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_'
     s26       Split it into chunks of 26 chars, i.e., ['A...Z', 'a...z', '0...9'].
  ị            Retrieve the chunks from the right result at the indices of the
               left result. The indices of the chunks are modular and 1-based;
               1 retrieves 'A...Z', 2 retrieves 'a...z', and 3 retrieves '0...9'.
         F     Flatten the resulting array of strings.
          f@€  Filter (swapped, each); for each character in the constructed
               string, select all occurrences of that character from s.
</code>```

Title: Post-determined Array Sorting

Body:
Jelly, 13 bytes

2_ịØWs26¤Ff@€

Try it online! or verify all test cases.

How it works

2_ịØWs26¤Ff@€  Main link. Arguments: k (permutation of [0, 1, 2]), s (string)

2_             Subtract the integers in k from 2, mapping [0, 1, 2] -> [2, 1, 0].
        ¤      Combine the three links to the left into a niladic chain.
   ØW          Yield the string following string.
               'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_'
     s26       Split it into chunks of 26 chars, i.e., ['A...Z', 'a...z', '0...9'].
  ị            Retrieve the chunks from the right result at the indices of the
               left result. The indices of the chunks are modular and 1-based;
               1 retrieves 'A...Z', 2 retrieves 'a...z', and 3 retrieves '0...9'.
         F     Flatten the resulting array of strings.
          f@€  Filter (swapped, each); for each character in the constructed
               string, select all occurrences of that character from s.


答:
C#, 384 346 317 292 291 289 Bytes

Simple solution with Windows Forms and GDI

```<code>Func<int,int,Point>p=(x,y)=>new Point(x*10,y*10);var b=new Bitmap(250,180);var g=Graphics.FromImage(b);g.Clear(Color.Blue);g.DrawLines(new Pen(Color.White,40),new[]{p(0,9),p(50,9),p(9,-20),p(9,18)});g.DrawLines(new Pen(Color.Red,20),new[]{p(0,9),p(50,9),p(9,-20),p(9,18)});b.Save("b.png");
</code>```

Usage

Start a new console-project and put the code above in the main-method, add System.Drawing-Namespace.

How it works

The code creates a new image and draws some lines on it. It saves the image to disk. Some of the ending points of the lines are outside the visible area.

Title: Draw the national flag of Iceland

Body:
C#, 384 346 317 292 291 289 Bytes

Simple solution with Windows Forms and GDI

Func<int,int,Point>p=(x,y)=>new Point(x*10,y*10);var b=new Bitmap(250,180);var g=Graphics.FromImage(b);g.Clear(Color.Blue);g.DrawLines(new Pen(Color.White,40),new[]{p(0,9),p(50,9),p(9,-20),p(9,18)});g.DrawLines(new Pen(Color.Red,20),new[]{p(0,9),p(50,9),p(9,-20),p(9,18)});b.Save("b.png");

Usage

Start a new console-project and put the code above in the main-method, add System.Drawing-Namespace.

How it works

The code creates a new image and draws some lines on it. It saves the image to disk. Some of the ending points of the lines are outside the visible area.


答:
Retina, <s>43</s> 39 bytes

Byte count assumes ISO 8859-1 encoding. The trailing linefeed is significant.

```<code>2=`.
!$&"
T04`¶d`#^@%
O`\W?.
O`.\w+
\W

</code>```

Input is expected to be the sort order as a zero-based list without delimiters on the first line, and the string to be sorted on the second line, e.g.

```<code>120
fOo42BaR
</code>```

Try it online!

Explanation

I will use the above input example to walk you through the code:

```<code>120
fOo42BaR
</code>```

Stage 1: Substitution

```<code>2=`.
!$&"
</code>```

The regex itself is just . (matches any non-linefeed character), which is surrounded with !...". However, the 2= is a limit telling Retina to apply the substitution only to the second match of the regex. So we get this:

```<code>1!2"0
fOo42BaR
</code>```

Stage 2: Transliteration

```<code>T04`¶d`#^@%
</code>```

A transliteration stage simply does a character-by-character substitution. The ¶ represents a linefeed and d expands to 0123456789 (although we can ignore all digits after 2). That means, this transliteration corresponds to the following mapping:

```<code>¶012
#^@%
</code>```

The 04 at the front are two limits, which together indicate that only the first four characters from this set should be transliterated. That happens to be the digits on the first line, as well as the linefeed separating the two lines, so we get this:

```<code>@!%"^#fOo42BaR
</code>```

At the front of the string we've now got three pairs of these characters:

```<code>@!
%"
^#
</code>```

Note that the second characters of the pairs are simply in their normal ASCII order (and will always be the same). We'll use these later to sort the groups of characters in the main input into the required order.

The first characters are bit more interesting: their significance is that % comes before digits in the ASCII table, @ comes before upper case letters (but after digits), and ^ comes before lower case letters (but after upper case letters). This will help us group the position markers (i.e. the second character in each pair) with the right set of characters.

Stage 3: Sort

```<code>O`\W?.
</code>```

This is a simple sort stage. It matches two characters if the first one isn't a word character (thereby matching all three pairs I just talked about) or a single character otherwise (matching each character of the main input individually), and sorts those strings. This has two purposes: it brings the characters within each group in the correct order (and since sorting is stable, this order won't be messed up in the next stage), and it due to the %@^ markers, it inserts the pairs in the right positions:

```<code>120
fOo42BaR
</code>```0

Stage 4: Sort

```<code>120
fOo42BaR
</code>```1

This stage sorts all matches of the .\w+ regex which, due to greediness, matches one position marker (i.e. one of !"#) together with all the word characters after it. That is, it sorts these three strings, whose order is determined solely by the marker character:

"24
   !BOR
   #afo

While this shuffles around those markers (while leaving the other three markers in place), most importantly it brings the digits and letters in the correct order:

```<code>120
fOo42BaR
</code>```2

Stage 5: Substitution

```<code>\W

</code>```

All that's left is a little clean-up, where we remove all the markers by matching them and replacing them with nothing.

Title: Post-determined Array Sorting

Body:
Retina, <s>43</s> 39 bytes

Byte count assumes ISO 8859-1 encoding. The trailing linefeed is significant.

2=`.
!$&"
T04`¶d`#^@%
O`\W?.
O`.\w+
\W

Input is expected to be the sort order as a zero-based list without delimiters on the first line, and the string to be sorted on the second line, e.g.

120
fOo42BaR

Try it online!

Explanation

I will use the above input example to walk you through the code:

120
fOo42BaR

Stage 1: Substitution

2=`.
!$&"

The regex itself is just . (matches any non-linefeed character), which is surrounded with !...". However, the 2= is a limit telling Retina to apply the substitution only to the second match of the regex. So we get this:

1!2"0
fOo42BaR

Stage 2: Transliteration

T04`¶d`#^@%

A transliteration stage simply does a character-by-character substitution. The ¶ represents a linefeed and d expands to 0123456789 (although we can ignore all digits after 2). That means, this transliteration corresponds to the following mapping:

¶012
#^@%

The 04 at the front are two limits, which together indicate that only the first four characters from this set should be transliterated. That happens to be the digits on the first line, as well as the linefeed separating the two lines, so we get this:

@!%"^#fOo42BaR

At the front of the string we've now got three pairs of these characters:

@!
%"
^#

Note that the second characters of the pairs are simply in their normal ASCII order (and will always be the same). We'll use these later to sort the groups of characters in the main input into the required order.

The first characters are bit more interesting: their significance is that % comes before digits in the ASCII table, @ comes before upper case letters (but after digits), and ^ comes before lower case letters (but after upper case letters). This will help us group the position markers (i.e. the second character in each pair) with the right set of characters.

Stage 3: Sort

O`\W?.

This is a simple sort stage. It matches two characters if the first one isn't a word character (thereby matching all three pairs I just talked about) or a single character otherwise (matching each character of the main input individually), and sorts those strings. This has two purposes: it brings the characters within each group in the correct order (and since sorting is stable, this order won't be messed up in the next stage), and it due to the %@^ markers, it inserts the pairs in the right positions:

%"24@!BOR^#afo

Stage 4: Sort

O`.\w+

This stage sorts all matches of the .\w+ regex which, due to greediness, matches one position marker (i.e. one of !"#) together with all the word characters after it. That is, it sorts these three strings, whose order is determined solely by the marker character:

"24
   !BOR
   #afo

While this shuffles around those markers (while leaving the other three markers in place), most importantly it brings the digits and letters in the correct order:

%!BOR@"24^#afo

Stage 5: Substitution

\W

All that's left is a little clean-up, where we remove all the markers by matching them and replacing them with nothing.


答:
Python 2, <s>67</s> 66 bytes

lambda s,k:`sorted(s,key=lambda c:`k.index(3-ord(c)/32)`+c)`[2::5]
```

Test it on Ideone.

Title: Post-determined Array Sorting

Body:
Python 2, <s>67</s> 66 bytes

lambda s,k:`sorted(s,key=lambda c:`k.index(3-ord(c)/32)`+c)`[2::5]

Test it on Ideone.


答:
Haskell, <s>62</s> 63 bytes

```<code>a#b=[c|i<-b,c<-[' '..],d<-a,d==c,div(fromEnum c)16==[6,4,3]!!i]
</code>```

Usage example: "cD12ab" # [2,0,1] -> "12abcD".

How it works:

```<code>i<-b                                  -- loop i through the input array
   [c|   c<-[' '..]]                  -- loop through all chars c
       d<-a                           -- loop through all chars d in the input string
       d==c                           -- and keep those that are in the input string
       div(fromEnum c)16==[6,4,3]!!i  -- and where the the ascii value divided by
                                      -- 16 equals the number from [6,4,3] indexed
                                      -- by the current i
</code>```

Edit: @Christian Sievers found a bug. Thanks! Fixed for 1 additional byte.

Title: Post-determined Array Sorting

Body:
Haskell, <s>62</s> 63 bytes

a#b=[c|i<-b,c<-[' '..],d<-a,d==c,div(fromEnum c)16==[6,4,3]!!i]

Usage example: "cD12ab" # [2,0,1] -> "12abcD".

How it works:

i<-b                                  -- loop i through the input array
   [c|   c<-[' '..]]                  -- loop through all chars c
       d<-a                           -- loop through all chars d in the input string
       d==c                           -- and keep those that are in the input string
       div(fromEnum c)16==[6,4,3]!!i  -- and where the the ascii value divided by
                                      -- 16 equals the number from [6,4,3] indexed
                                      -- by the current i

Edit: @Christian Sievers found a bug. Thanks! Fixed for 1 additional byte.


问:
Print a bunch of uninteresting numbers!
An uninteresting number (which I totally didn't make up only for this challenge) is created like this:

Take a positive integer N

Create a new number O by adding the digits of N at the end of N

The final uninteresting number is O*N

For example for N=12:

O = 1212

O*N = 1212 * 12

Final number is 14544

Input

A positive integer N (N > 0) or your language's equivalent. You don't have to catch incorrect input.

Output

The corresponding uninteresting number.

Test cases

```<code>  1 -> 11
  2 -> 44
  3 -> 99
 10 -> 10100
174 -> 30306276
</code>```

Scoring

Shortest Code in Bytes wins.

答:
Python, 46 bytes

```<code>i=input("N:")           # Standard input
y=i+(i[-2:])            # Using strip method to take last two chars from input
print(int(y)*int(i))    # Temp convert strings into integers for maths and print the result.
</code>```

Title: Print a bunch of uninteresting numbers!

Body:
Python, 46 bytes

i=input("N:")           # Standard input
y=i+(i[-2:])            # Using strip method to take last two chars from input
print(int(y)*int(i))    # Temp convert strings into integers for maths and print the result.


答:
Python 2, <s>140</s> <s>117</s> <s>101</s> <s>100</s> 99 bytes

Everyone say, "Ewww!". At least it's readable... cough not really cough

lambda l,s:`sorted(s,key=lambda c:[[c<'a',c<'A'or'Z'<c,c>'9'][l[i]]for i in 0,1,2]+[ord(c)])`[2::5]
```

Try it online

Title: Post-determined Array Sorting

Body:
Python 2, <s>140</s> <s>117</s> <s>101</s> <s>100</s> 99 bytes

Everyone say, "Ewww!". At least it's readable... cough not really cough

lambda l,s:`sorted(s,key=lambda c:[[c<'a',c<'A'or'Z'<c,c>'9'][l[i]]for i in 0,1,2]+[ord(c)])`[2::5]

Try it online


答:
PowerShell v2+, 107 bytes

```<code>param($n,[char[]]$s)-join(-join(($s=$s|sort)|?{$_-ge97}),-join($s|?{$_-in65..96}),-join($s|?{$_-lt58}))[$n]
</code>```

I'm exploring algorithms using regex, but thus far they all seem longer.

Takes input as explicit array $n (see examples below) and string $s which is immediately cast to a char-array. We're then constructing three elements of a new dynamic array, each of them encapsulated with a -join:

- (($s=$s|sort)|?{$_-ge97})

- ($s|?{$_-in65..96})

- ($s|?{$_-lt58})

The first we take $s and run it through Sort-Object. Thankfully, since we've already cast it as a char-array, it's case-sensitive sorting. That gets re-saved into $s and then piped to a Where-Object with a clause of greater than 97 (i.e., ASCII lowercase a-z). The second is for A-Z and the third for 0-9.

Thus we now have an array of strings, where each string is composed one of the three character types and is sorted. We slice that with [$n] and then -join the result together to form our final output string. That is left on the pipeline and printing is implicit.

Test Cases

```<code>PS C:\Tools\Scripts\golfing> $test = (@(2,0,1),'a1B2c3'), (@(2,1,0),'aAaA909UuHWw9gh2'), (@(2,1,0),'6Bx43'), (@(1,0,2),'jfjf33g'), (@(0,2,1),'AbC13'), (@(1,2,0),'Qfl0l'), (@(0,1,2),'9870abcABC'), (@(0,2,1),'test123'), (@(2,0,1),'WHAT'), (@(2,0,1),'WhAt'), (@(1,0,2),'102BACbac')

PS C:\Tools\Scripts\golfing> $test |%{"($($_[0]-join',')) & $($_[1])".PadRight(28)+" -> " + (.\post-determined-array-sorting.ps1 $_[0] $_[1])}
(2,0,1) & a1B2c3             -> 123acB
(2,1,0) & aAaA909UuHWw9gh2   -> 02999AAHUWaaghuw
(2,1,0) & 6Bx43              -> 346Bx
(1,0,2) & jfjf33g            -> ffgjj33
(0,2,1) & AbC13              -> b13AC
(1,2,0) & Qfl0l              -> Q0fll
(0,1,2) & 9870abcABC         -> abcABC0789
(0,2,1) & test123            -> estt123
(2,0,1) & WHAT               -> AHTW
(2,0,1) & WhAt               -> htAW
(1,0,2) & 102BACbac          -> ABCabc012
</code>```

Title: Post-determined Array Sorting

Body:
Input:

An array containing three integers: 0, 1 and 2 in any order (i.e. [2, 0, 1])

And a string of length >= 2 only containing alphabetic letters (both lower- and uppercase) and digits (i.e. a1B2c3)

Output:

Based on the array we sort and output the string.

How does this work?

The array indicates the order precedence of a-z, A-Z and 0-9, the first being 0; second being 1; and third being 2.

The individual characters of the string can then be ordered based on that.

Example:

Array: [2, 0, 1]

String: a1B2c3

Based on the array, we know our order precedence is 0-9a-zA-Z.

Based on that, we can convert and output the string: 123acB.

Challenge rules:

For the array you can choose to use 0-indexed or 1-indexed input, so [3, 1, 2] is also a valid input if you prefer to use 1-indexed arrays.

The string (both input and output) only contains valid characters: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.

If your language doesn't support arrays (or if you choose to), you are free to use strings instead of arrays for the first parameter (i.e. 012, [0,1,2], etc.).

General rules:

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

Don't let code-golf languages discourage you from posting answers with non-codegolfing languages. Try to come up with an as short as possible answer for 'any' programming language.

Standard rules apply for your answer, so you are allowed to use STDIN/STDOUT, functions/method with the proper parameters, full programs. Your call.

Default Loopholes are forbidden.

If possible, please add a link with a test for your code.

Also, please add an explanation if necessary.

Test cases:

```<code>[2, 0, 1]  &  a1B2c3             ->   123acB
[2, 1, 0]  &  aAaA909UuHWw9gh2   ->   02999AAHUWaaghuw
[2, 1, 0]  &  6Bx43              ->   346Bx
[1, 0, 2]  &  jfjf33g            ->   ffgjj33
[0, 2, 1]  &  AbC13              ->   b13AC
[1, 2, 0]  &  Qfl0l              ->   Q0fll
[0, 1, 2]  &  9870abcABC         ->   abcABC0789
[0, 2, 1]  &  test123            ->   estt123
[2, 0, 1]  &  WHAT               ->   AHTW
[2, 0, 1]  &  WhAt               ->   htAW
[1, 0, 2]  &  102BACbac          ->   ABCabc012
</code>```

Body:
PowerShell v2+, 107 bytes

param($n,[char[]]$s)-join(-join(($s=$s|sort)|?{$_-ge97}),-join($s|?{$_-in65..96}),-join($s|?{$_-lt58}))[$n]

I'm exploring algorithms using regex, but thus far they all seem longer.

Takes input as explicit array $n (see examples below) and string $s which is immediately cast to a char-array. We're then constructing three elements of a new dynamic array, each of them encapsulated with a -join:

- (($s=$s|sort)|?{$_-ge97})

- ($s|?{$_-in65..96})

- ($s|?{$_-lt58})

The first we take $s and run it through Sort-Object. Thankfully, since we've already cast it as a char-array, it's case-sensitive sorting. That gets re-saved into $s and then piped to a Where-Object with a clause of greater than 97 (i.e., ASCII lowercase a-z). The second is for A-Z and the third for 0-9.

Thus we now have an array of strings, where each string is composed one of the three character types and is sorted. We slice that with [$n] and then -join the result together to form our final output string. That is left on the pipeline and printing is implicit.

Test Cases

PS C:\Tools\Scripts\golfing> $test = (@(2,0,1),'a1B2c3'), (@(2,1,0),'aAaA909UuHWw9gh2'), (@(2,1,0),'6Bx43'), (@(1,0,2),'jfjf33g'), (@(0,2,1),'AbC13'), (@(1,2,0),'Qfl0l'), (@(0,1,2),'9870abcABC'), (@(0,2,1),'test123'), (@(2,0,1),'WHAT'), (@(2,0,1),'WhAt'), (@(1,0,2),'102BACbac')

PS C:\Tools\Scripts\golfing> $test |%{"($($_[0]-join',')) & $($_[1])".PadRight(28)+" -> " + (.\post-determined-array-sorting.ps1 $_[0] $_[1])}
(2,0,1) & a1B2c3             -> 123acB
(2,1,0) & aAaA909UuHWw9gh2   -> 02999AAHUWaaghuw
(2,1,0) & 6Bx43              -> 346Bx
(1,0,2) & jfjf33g            -> ffgjj33
(0,2,1) & AbC13              -> b13AC
(1,2,0) & Qfl0l              -> Q0fll
(0,1,2) & 9870abcABC         -> abcABC0789
(0,2,1) & test123            -> estt123
(2,0,1) & WHAT               -> AHTW
(2,0,1) & WhAt               -> htAW
(1,0,2) & 102BACbac          -> ABCabc012


答:
Kipple, 55 bytes

```<code>33>o<100 108>o<114 111>o<87 32>o<44 111>o<108>o<101o<72
</code>```

Shorter answer here. This, however, is supporter by each and every intepreter of the language. The other one uses ", which does not have full portability between interpreters.

ContentLicense: CC BY-SA 4.0

Title: "Hello, World!"

Body:
So... uh... this is a bit embarrassing. But we don't have a plain "Hello, World!" challenge yet (despite having 35 variants tagged with hello-world, and counting). While this is not the most interesting code golf in the common languages, finding the shortest solution in certain esolangs can be a serious challenge. For instance, to my knowledge it is not known whether the shortest possible Brainfuck solution has been found yet.

Furthermore, while all of <s>Wikipedia</s> (the Wikipedia entry has been deleted but there is a copy at archive.org
), esolangs and Rosetta Code have lists of "Hello, World!" programs, none of these are interested in having the shortest for each language (there is also this GitHub repository). If we want to be a significant site in the code golf community, I think we should try and create the ultimate catalogue of shortest "Hello, World!" programs (similar to how our basic quine challenge contains some of the shortest known quines in various languages). So let's do this!

The Rules

Each submission must be a full program.

The program must take no input, and print Hello, World! to STDOUT (this exact byte stream, including capitalization and punctuation) plus an optional trailing newline, and nothing else.

The program must not write anything to STDERR.

If anyone wants to abuse this by creating a language where the empty program prints Hello, World!, then congrats, they just paved the way for a very boring answer.

Note that there must be an interpreter so the submission can be tested. It is allowed (and even encouraged) to write this interpreter yourself for a previously unimplemented language.

Submissions are scored in bytes, in an appropriate (pre-existing) encoding, usually (but not necessarily) UTF-8. Some languages, like Folders, are a bit tricky to score - if in doubt, please ask on Meta.

This is not about finding the language with the shortest "Hello, World!" program. This is about finding the shortest "Hello, World!" program in every language. Therefore, I will not mark any answer as "accepted".

If your language of choice is a trivial variant of another (potentially more popular) language which already has an answer (think BASIC or SQL dialects, Unix shells or trivial Brainfuck-derivatives like Alphuck), consider adding a note to the existing answer that the same or a very similar solution is also the shortest in the other language.

As a side note, please don't downvote boring (but valid) answers in languages where there is not much to golf - these are still useful to this question as it tries to compile a catalogue as complete as possible. However, do primarily upvote answers in languages where the authors actually had to put effort into golfing the code.

For inspiration, check the Hello World Collection.

The Catalogue

The Stack Snippet at the bottom of this post generates the catalogue from the answers a) as a list of shortest solution per language and b) as an overall leaderboard.

To make sure that your answer shows up, please start your answer with a headline, using the following Markdown template:

```<code>## Language Name, N bytes
</code>```

where N is the size of your submission. If you improve your score, you can keep old scores in the headline, by striking them through. For instance:

```<code>## Ruby, <s>104</s> <s>101</s> 96 bytes
</code>```

If there you want to include multiple numbers in your header (e.g. because your score is the sum of two files or you want to list interpreter flag penalties separately), make sure that the actual score is the last number in the header:

```<code>## Perl, 43 + 2 (-p flag) = 45 bytes
</code>```

You can also make the language name a link which will then show up in the snippet:

```<code>## [><>](https://esolangs.org/wiki/Fish), 121 bytes
</code>```

/* Configuration */

var QUESTION_ID = 55422; // Obtain this from the url
// It will be like https://XYZ.stackexchange.com/questions/QUESTION_ID/... on any question page
var ANSWER_FILTER = "!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe";
var COMMENT_FILTER = "!)Q2B_A2kjfAiU78X(md6BoYk";
var OVERRIDE_USER = 8478; // This should be the user ID of the challenge author.

/* App */

var answers = [], answers_hash, answer_ids, answer_page = 1, more_answers = true, comment_page;

function answersUrl(index) {
  return "https://api.stackexchange.com/2.2/questions/" +  QUESTION_ID + "/answers?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + ANSWER_FILTER;
}

function commentUrl(index, answers) {
  return "https://api.stackexchange.com/2.2/answers/" + answers.join(';') + "/comments?page=" + index + "&pagesize=100&order=desc&sort=creation&site=codegolf&filter=" + COMMENT_FILTER;
}

function getAnswers() {
  jQuery.ajax({
    url: answersUrl(answer_page++),
    method: "get",
    dataType: "jsonp",
    crossDomain: true,
    success: function (data) {
      answers.push.apply(answers, data.items);
      answers_hash = [];
      answer_ids = [];
      data.items.forEach(function(a) {
        a.comments = [];
        var id = +a.share_link.match(/\d+/);
        answer_ids.push(id);
        answers_hash[id] = a;
      });
      if (!data.has_more) more_answers = false;
      comment_page = 1;
      getComments();
    }
  });
}

function getComments() {
  jQuery.ajax({
    url: commentUrl(comment_page++, answer_ids),
    method: "get",
    dataType: "jsonp",
    crossDomain: true,
    success: function (data) {
      data.items.forEach(function(c) {
        if (c.owner.user_id === OVERRIDE_USER)
          answers_hash[c.post_id].comments.push(c);
      });
      if (data.has_more) getComments();
      else if (more_answers) getAnswers();
      else process();
    }
  });
}

getAnswers();

var SCORE_REG = /<h\d>\s*([^\n,<]*(?:<(?:[^\n>]*>[^\n<]*<\/[^\n>]*>)[^\n,<]*)*),.*?(\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/;

var OVERRIDE_REG = /^Override\s*header:\s*/i;

function getAuthorName(a) {
  return a.owner.display_name;
}

function process() {
  var valid = [];

  answers.forEach(function(a) {
    var body = a.body;
    a.comments.forEach(function(c) {
      if(OVERRIDE_REG.test(c.body))
        body = '
' + c.body.replace(OVERRIDE_REG, '') + '
';
    });

    var match = body.match(SCORE_REG);
    if (match)
      valid.push({
        user: getAuthorName(a),
        size: +match[2],
        language: match[1],
        link: a.share_link,
      });
    else console.log(body);
  });

  valid.sort(function (a, b) {
    var aB = a.size,
        bB = b.size;
    return aB - bB
  });

  var languages = {};
  var place = 1;
  var lastSize = null;
  var lastPlace = 1;
  valid.forEach(function (a) {
    if (a.size != lastSize)
      lastPlace = place;
    lastSize = a.size;
    ++place;

    var answer = jQuery("#answer-template").html();
    answer = answer.replace("{{PLACE}}", lastPlace + ".")
                   .replace("{{NAME}}", a.user)
                   .replace("{{LANGUAGE}}", a.language)
                   .replace("{{SIZE}}", a.size)
                   .replace("{{LINK}}", a.link);
    answer = jQuery(answer);
    jQuery("#answers").append(answer);

    var lang = a.language;
    lang = jQuery(''+lang+'').text();

    languages[lang] = languages[lang] || {lang: a.language, lang_raw: lang, user: a.user, size: a.size, link: a.link};
  });

  var langs = [];
  for (var lang in languages)
    if (languages.hasOwnProperty(lang))
      langs.push(languages[lang]);

  langs.sort(function (a, b) {
    if (a.lang_raw.toLowerCase() > b.lang_raw.toLowerCase()) return 1;
    if (a.lang_raw.toLowerCase() < b.lang_raw.toLowerCase()) return -1;
    return 0;
  });

  for (var i = 0; i < langs.length; ++i)
  {
    var language = jQuery("#language-template").html();
    var lang = langs[i];
    language = language.replace("{{LANGUAGE}}", lang.lang)
                       .replace("{{NAME}}", lang.user)
                       .replace("{{SIZE}}", lang.size)
                       .replace("{{LINK}}", lang.link);
    language = jQuery(language);
    jQuery("#languages").append(language);
  }

}```
<pre class="snippet-code-css lang-css prettyprint-override"><code>body {
  text-align: left !important;
  display: block !important;
}

#answer-list {
  padding: 10px;
  width: 290px;
  float: left;
}

#language-list {
  padding: 10px;
  width: 500px;
  float: left;
}

table thead {
  font-weight: bold;
}

table td {
  padding: 5px;
}</code>```

<link rel="stylesheet" type="text/css" href="https://cdn.sstatic.net/Sites/codegolf/all.css?v=ffb5d0584c5f">

Shortest Solution by Language

Language	User	Score

Leaderboard

	Author	Language	Size

{{PLACE}}	{{NAME}}	{{LANGUAGE}}	{{SIZE}}	Link

{{LANGUAGE}}	{{NAME}}	{{SIZE}}	Link

```

Body:
Kipple, 55 bytes

33>o<100 108>o<114 111>o<87 32>o<44 111>o<108>o<101o<72

Shorter answer here. This, however, is supporter by each and every intepreter of the language. The other one uses ", which does not have full portability between interpreters.


问:
Palindrome Hello, World
Your task is to create a program that prints "Greetings, Planet!" exactly to the console. Seems simple enough, right? Well, here's the trick. The code must be a palindrome, meaning it reads from right to left the same as in left to right.
Standard loopholes are NOT allowed.

答:
Brachylog, 41 bytes

```<code>"Greetings, Planet!"w"!tenalP ,sgniteerG"
</code>```

This will call w - write with "Greetings, Planet!" as input and "!tenalP ,sgniteerG" as output. w writes its input to STDOUT and does nothing with its output.

Title: Palindrome Hello, World

Body:
Brachylog, 41 bytes

"Greetings, Planet!"w"!tenalP ,sgniteerG"

This will call w - write with "Greetings, Planet!" as input and "!tenalP ,sgniteerG" as output. w writes its input to STDOUT and does nothing with its output.


答:
Your Mom (non-competing), 331 bytes

Decode the string and decompress it using the Jelly compressor

```<code>'IF8KfCgpL1z/AQAAAQAAAAAAAAAAAAAAAAAAEREREAAAAAAAAAAAAAAAAAAQIwMAAwMAAAAAAAAAAAAAAAAAQREREVAAAAAAAQAAAAAAAAAwMjAxEDAwEREBERABERABAAEAABEREAAREQAREwMQAREQARETAyMAEVMDYBADABBzABBzAwMDADABEVBgEANhEVABVgEAVgERUTIwMAAwQEAwMDAwMDAwMDEwMAMDERFAQDAxEQMDFARgYwMAABAjEwADE3EzEwMxYwMxYHEQAwAxERERUTMUERYHERUREVEwADEyAAAAAAAAADEwADEwAEERFg=='`
</code>```

Title: Display "Happy Easter!"

Body:
Your task is to print the following ASCII Art:

```<code> _     _                            _______                           _
| |   | |                          (_______)          _              | |
| |__ | | ____ ____  ____  _   _    _____   ____  ___| |_  ____  ____| |
|  __)| |/ _  |  _ \|  _ \| | | |  |  ___) / _  |/___)  _)/ _  )/ ___)_|
| |   | ( ( | | | | | | | | |_| |  | |____( ( | |___ | |_( (/ /| |    _
|_|   |_|\_||_| ||_/| ||_/ \__  |  |_______)_||_(___/ \___)____)_|   |_|
              |_|   |_|   (____/
</code>```

Remember, this is code-golf, so the code with the smallest amount of bytes wins.
Good luck.

Body:
Your Mom (non-competing), 331 bytes

Decode the string and decompress it using the Jelly compressor

'IF8KfCgpL1z/AQAAAQAAAAAAAAAAAAAAAAAAEREREAAAAAAAAAAAAAAAAAAQIwMAAwMAAAAAAAAAAAAAAAAAQREREVAAAAAAAQAAAAAAAAAwMjAxEDAwEREBERABERABAAEAABEREAAREQAREwMQAREQARETAyMAEVMDYBADABBzABBzAwMDADABEVBgEANhEVABVgEAVgERUTIwMAAwQEAwMDAwMDAwMDEwMAMDERFAQDAxEQMDFARgYwMAABAjEwADE3EzEwMxYwMxYHEQAwAxERERUTMUERYHERUREVEwADEyAAAAAAAAADEwADEwAEERFg=='`


答:
Pyth, 41 bytes

```<code>"Greetings, Planet!"K"!tenalP ,sgniteerG"
</code>```

Prints "Greetings, Planet!", then assigns "!tenalP ,sgniteerG" to K

Title: Palindrome Hello, World

Body:
Your task is to create a program that prints "Greetings, Planet!" exactly to the console. Seems simple enough, right? Well, here's the trick. The code must be a palindrome, meaning it reads from right to left the same as in left to right.
Standard loopholes are NOT allowed.

Body:
Pyth, 41 bytes

"Greetings, Planet!"K"!tenalP ,sgniteerG"

Prints "Greetings, Planet!", then assigns "!tenalP ,sgniteerG" to K


问:
ASCII art reflection
In this challenge, you will be given a text block, and you need to perform reflection on the text.

Input:

A string to be reflected. The text may not be supplied as an array whose elements are the lines of text. For example, "ab\ncd" and ['a','b','\n','c','d'] are allowed, but ['ab','cd'] or [['a','b'],['c','d']] are not. You can assume that all of the lines have the same number of characters (padded with whitespace where needed).

A boolean where True indicates Y reflection and False indicates X reflection

The two inputs can be passed in any order.

Output:

The reflected string. The characters do not change, only their position. The resulting image block should be aligned to the top left (the first row and column must each contain a non-whitespace character). Trailing whitespace (on any of the lines) is allowed.

Test cases:

```<code>False
  o /
--|/
  |
 / \

/ o
 /|--
  |
 \ /
</code>```

```<code>True
  o /
--|/
  |
 / \

 / \
  |
--|/
  o /
</code>```

```<code>True
text

text
</code>```

```<code>False
text

txet
</code>```

```<code>True
P
P
C
G

G
C
P
P
</code>```

```<code>False
P
P
C
G

P
P
C
G
</code>```

```<code>True
abcde
fghij
kl mn
opqrs
tuvwx

tuvwx
opqrs
kl mn
fghij
abcde
</code>```

This is a code-golf, so answer with the shortest answer in your favorite language!

答:
Brachylog, <s>26</s> <s>24</s> 16 bytes

```<code>t1,?h@nr~@nw|hrw
</code>```

Expects a list containing the string and the boolean 1 or 0, e.g.

```<code>run_from_file('code.bl',["P
|    P
|    C
|    G":1]).
</code>```

Explanation

```<code>t1,              If the tail of the input is 1
   ?h@n              Split the string on \n
       r             Reverse the resulting list
        ~@n          Join the list of strings with \n
           w         Write to STDOUT
|                Or
hr                   Reverse the string
  w                  Write to STDOUT
</code>```

Title: ASCII art reflection

Body:
Brachylog, <s>26</s> <s>24</s> 16 bytes

t1,?h@nr~@nw|hrw

Expects a list containing the string and the boolean 1 or 0, e.g.

run_from_file('code.bl',["P
|    P
|    C
|    G":1]).

Explanation

t1,              If the tail of the input is 1
   ?h@n              Split the string on \n
       r             Reverse the resulting list
        ~@n          Join the list of strings with \n
           w         Write to STDOUT
|                Or
hr                   Reverse the string
  w                  Write to STDOUT


答:
Haskell, <s>51</s> <s>49</s> 45 bytes

```<code>r=reverse
f b=unlines.last(map r:[r|b]).lines
</code>```

Usage example:

```<code>f True "abc\ndef\nghi\njkl"
"jkl\nghi\ndef\nabc\n"

f False "abc\ndef\nghi\njkl"
"cba\nfed\nihg\nlkj\n"
</code>```

Split into lines, either reverse the lines (True) or reverse each line (False) and join into a single string again. In case of a True input, map r:[r|b] is a list of two functions [<reverse each line>, <reverse lines>] and for a False input a list with one function [<reverse each line>]. last picks the last element of this list.

Title: ASCII art reflection

Body:
In this challenge, you will be given a text block, and you need to perform reflection on the text.

Input:

A string to be reflected. The text may not be supplied as an array whose elements are the lines of text. For example, "ab\ncd" and ['a','b','\n','c','d'] are allowed, but ['ab','cd'] or [['a','b'],['c','d']] are not. You can assume that all of the lines have the same number of characters (padded with whitespace where needed).

A boolean where True indicates Y reflection and False indicates X reflection

The two inputs can be passed in any order.

Output:

The reflected string. The characters do not change, only their position. The resulting image block should be aligned to the top left (the first row and column must each contain a non-whitespace character). Trailing whitespace (on any of the lines) is allowed.

Test cases:

```<code>False
  o /
--|/
  |
 / \

/ o
 /|--
  |
 \ /
</code>```

```<code>True
  o /
--|/
  |
 / \

 / \
  |
--|/
  o /
</code>```

```<code>True
text

text
</code>```

```<code>False
text

txet
</code>```

```<code>True
P
P
C
G

G
C
P
P
</code>```

```<code>False
P
P
C
G

P
P
C
G
</code>```

```<code>True
abcde
fghij
kl mn
opqrs
tuvwx

tuvwx
opqrs
kl mn
fghij
abcde
</code>```

This is a code-golf, so answer with the shortest answer in your favorite language!

Body:
Haskell, <s>51</s> <s>49</s> 45 bytes

r=reverse
f b=unlines.last(map r:[r|b]).lines

Usage example:

f True "abc\ndef\nghi\njkl"
"jkl\nghi\ndef\nabc\n"

f False "abc\ndef\nghi\njkl"
"cba\nfed\nihg\nlkj\n"

Split into lines, either reverse the lines (True) or reverse each line (False) and join into a single string again. In case of a True input, map r:[r|b] is a list of two functions [<reverse each line>, <reverse lines>] and for a False input a list with one function [<reverse each line>]. last picks the last element of this list.


答:
OPL-32, 33 bytes

...see Open Programming Language.

```<code>proc m:
print"Hello, World!"
endp
</code>```

(no trailing newline)

Tested on Nokia Communicator 9300 with opl-1.56.

Title: "Hello, World!"

Body:
OPL-32, 33 bytes

...see Open Programming Language.

proc m:
print"Hello, World!"
endp

(no trailing newline)

Tested on Nokia Communicator 9300 with opl-1.56.


问:
Is it a sum-free set?
A set is sum-free if no two (not necessarily distinct) elements when added together are part of the set itself.

For example, {1, 5, 7} is sum-free, because all members are odd, and two odd numbers when added together are always even. On the other hand, {2, 4, 9, 13} is not sum-free, as either 2 + 2 = 4 or 4 + 9 = 13 add together to a member of the set.

Write a program or function that takes a set as input, and outputs a Truthy value if the set is sum-free, and Falsy otherwise.

Examples:

```<code>Sum-free:
{}
{4}
{1, 5, 7}
{16, 1, 4, 9}

Not sum-free:
{0}
{1, 4, 5, 7}
{3, 0}
{16, 1, 4, 8}
</code>```

答:
PowerShell 50 bytes

```<code>param($a)$a|%{$b=$_;$a|%{if($b+$_-in$a){1;break}}}
</code>```

Where 1 is true and no output is false.

Though, if outputting multiple truthy values is allowed, then I could save 6 bytes:

```<code>param($a)$a|%{$b=$_;$a|%{if($b+$_-in$a){1}}}
</code>```

But I will wordsmith myself and agree that the OP asked for 'a Truthy value'

Explanation:

```<code>param($a)$a|%{$b=$_;$a|%{if($b+$_-in$a){1;break}}}
param($a)                                          # assigns first passed parameter to variable $a
         $a|${                                   } # foreach $_ in $a
              $b=$_;                               # assign $_ to $b for access from further down the pipe
                    $a|%{                       }  # foreach $_ in $a
                         if($b+$_-in$a){       }   # if $a contains the value $b+$_
                                        1;         # implicit output of 1 (true)
                                          break    # exit the loops
</code>```

Title: Is it a sum-free set?

Body:
PowerShell 50 bytes

param($a)$a|%{$b=$_;$a|%{if($b+$_-in$a){1;break}}}

Where 1 is true and no output is false.

Though, if outputting multiple truthy values is allowed, then I could save 6 bytes:

param($a)$a|%{$b=$_;$a|%{if($b+$_-in$a){1}}}

But I will wordsmith myself and agree that the OP asked for 'a Truthy value'

Explanation:

param($a)$a|%{$b=$_;$a|%{if($b+$_-in$a){1;break}}}
param($a)                                          # assigns first passed parameter to variable $a
         $a|${                                   } # foreach $_ in $a
              $b=$_;                               # assign $_ to $b for access from further down the pipe
                    $a|%{                       }  # foreach $_ in $a
                         if($b+$_-in$a){       }   # if $a contains the value $b+$_
                                        1;         # implicit output of 1 (true)
                                          break    # exit the loops


答:
Pyke, 7 bytes

```<code>!I_)ncX
</code>```

Try it here!

```<code>!I )    - if not boolean:
  _     -  input = reversed(input)
    nc  - input.split("\n")
      X - splat(input)
        -  (print lines backwards)
</code>```

Title: ASCII art reflection

Body:
Pyke, 7 bytes

!I_)ncX

Try it here!

!I )    - if not boolean:
  _     -  input = reversed(input)
    nc  - input.split("\n")
      X - splat(input)
        -  (print lines backwards)


Title: Unzip some numbers

Body:
Your task is to create a program or function that generates a zipper with a length of 10 lines. Each line of the zipper is represented by two dashes --:

```<code>--
--
--
--
--
--
--
--
--
--
</code>```

The program/function will take a percentage (divisible by 10) as input, and the output will be the zipper "unzipped" (dashes separated) from the top by the percentage, revealing the 1-indexed, lowest level repeated 2 times, with all prior levels repeated 4, 6, 8, ...etc. times, while keeping the bottom of the zipper centered.

Examples

```<code>>>10%
-11-
 --
 --
 --
 --
 --
 --
 --
 --
 --

>>50%
-1111111111-
 -22222222-
  -333333-
   -4444-
    -55-
     --
     --
     --
     --
     --

>>100%
-11111111111111111111-
 -222222222222222222-
  -3333333333333333-
   -44444444444444-
    -555555555555-
     -6666666666-
      -77777777-
       -888888-
        -9999-
         -10-
</code>```

The input (percentage) can be formatted however you like (50%, .5, 50, 5 [zero implied], etc), and it will always be in the range of 0 to 100 and divisible by 10. The spacing in the examples must be preserved in your output.

Body:
Perl, 122 bytes

$k=<>;for(my $i=0;$i++<10;){$s="-"."$i"x($k/10-$i+1);$p=length $s;$l=$l>$p?$l:$p;printf "%${l}s%s\n",$s,scalar reverse $s}


答:
PowerShell, 41 bytes

```<code>"Greetings, Planet!"#"!tenalP ,sgniteerG"
</code>```

Output is implied is PowerShell and anything after # is a comment.

Title: Palindrome Hello, World

Body:
PowerShell, 41 bytes

"Greetings, Planet!"#"!tenalP ,sgniteerG"

Output is implied is PowerShell and anything after # is a comment.


答:
MATL, 11 bytes

```<code>10&Ybc2i-&P
</code>```

Try it online!

The first input is the multiline string. Since MATL doesn't recognize \n as linefeed, the multiline string should be defined as a concatenation of substrings, or individual characters, and 10 (ASCII for line feed, which is interpreted as a character). Concatenation in MATL is [... ...] or [..., ...] (commas are optional). So for example, input can be as follows (concatenation of a string, linefeed, and another string):

```<code>['first line' 10 'second']
</code>```

or equivalently (concatenation of individual characters)

```<code>['f' 'i' 'r' 's' 't' ' ' 'l' 'i' 'n' 'e' 10 's' 'e' 'c' 'o' 'n' 'd']
</code>```

or (same with commas)

```<code>['f', 'i', 'r', 's', 't', ' ', 'l', 'i', 'n', 'e', 10, 's', 'e', 'c', 'o', 'n', 'd']
</code>```

The second input can be entered as 1/0 or equivalently as T/F for true/false respectively.

Explanation

```<code>10     % Push 10 (ASCII for linefeed)
&Yb    % Take input string implicitly. Split at linefeeds. Gives a cell array
c      % Convert to a 2D char array, right-padding with spaces
i~Q    % Input Boolean value. Negate and add 1. Gives 1/2 for true/false resp.
&P     % Flip along that dimension (1: vertically; 2: horizontally). Display implicitly
</code>```

Title: ASCII art reflection

Body:
MATL, 11 bytes

10&Ybc2i-&P

Try it online!

The first input is the multiline string. Since MATL doesn't recognize \n as linefeed, the multiline string should be defined as a concatenation of substrings, or individual characters, and 10 (ASCII for line feed, which is interpreted as a character). Concatenation in MATL is [... ...] or [..., ...] (commas are optional). So for example, input can be as follows (concatenation of a string, linefeed, and another string):

['first line' 10 'second']

or equivalently (concatenation of individual characters)

['f' 'i' 'r' 's' 't' ' ' 'l' 'i' 'n' 'e' 10 's' 'e' 'c' 'o' 'n' 'd']

or (same with commas)

['f', 'i', 'r', 's', 't', ' ', 'l', 'i', 'n', 'e', 10, 's', 'e', 'c', 'o', 'n', 'd']

The second input can be entered as 1/0 or equivalently as T/F for true/false respectively.

Explanation

10     % Push 10 (ASCII for linefeed)
&Yb    % Take input string implicitly. Split at linefeeds. Gives a cell array
c      % Convert to a 2D char array, right-padding with spaces
i~Q    % Input Boolean value. Negate and add 1. Gives 1/2 for true/false resp.
&P     % Flip along that dimension (1: vertically; 2: horizontally). Display implicitly


答:
C#, <s>168</s> <s>144</s> <s>141</s> 120 Bytes

```<code>using System.Linq;i=>y=>string.Join("\n",y?i.Split('\n').Reverse():i.Split('\n').Select(x=>string.Concat(x.Reverse())));
</code>```

New version utilizes the obvious string.Join overload that takes an IEnumerable, the first solution was using it inadvertently I was just able to use it for the else side of the ternary as well.

Update:

New version is an anonymous lambda and uses currying to save 21 bytes total. This changes usage to be f("text")(false) where f is the anonymous function.

Ungolfed:

```<code>using System.Linq;

//Using currying to save one byte
input => IsYReflect =>
         //Lambda makes return implicit
         string.Join("\n", IsYReflect
            //Y Reflect, just need to reverse the array
            ? input.Split('\n').Reverse()
            //X Reflect, reverse each line into an IEnumerable
            : input.Split('\n').Select(x => string.Concat(x.Reverse())));
</code>```

Title: ASCII art reflection

Body:
C#, <s>168</s> <s>144</s> <s>141</s> 120 Bytes

using System.Linq;i=>y=>string.Join("\n",y?i.Split('\n').Reverse():i.Split('\n').Select(x=>string.Concat(x.Reverse())));

New version utilizes the obvious string.Join overload that takes an IEnumerable, the first solution was using it inadvertently I was just able to use it for the else side of the ternary as well.

Update:

New version is an anonymous lambda and uses currying to save 21 bytes total. This changes usage to be f("text")(false) where f is the anonymous function.

Ungolfed:

using System.Linq;

//Using currying to save one byte
input => IsYReflect =>
         //Lambda makes return implicit
         string.Join("\n", IsYReflect
            //Y Reflect, just need to reverse the array
            ? input.Split('\n').Reverse()
            //X Reflect, reverse each line into an IEnumerable
            : input.Split('\n').Select(x => string.Concat(x.Reverse())));


答:
Python, 56 bytes

```<code>lambda s,r:'\n'.join(s[::2*bool(r)-1].split('\n')[::-1])
</code>```

Call with a string s and any truthy/falsey value r.

Title: ASCII art reflection

Body:
Python, 56 bytes

lambda s,r:'\n'.join(s[::2*bool(r)-1].split('\n')[::-1])

Call with a string s and any truthy/falsey value r.