Columnar Transposition Cipher
While I have plenty of programs I have written for more advanced ciphers, I just realised I don't actually have one for one of the simplest: Columnar Transposition. The cipher, in case you don't know, works as follows:
First, you take the key, and write it as numbers. The numbers are made by replacing the letter which comes first in the alphabet with
1
, the letter that comes next2
and so on, ignoring duplicates (the keyGOAT
would become2314
). These numbers are the headers of the columns.2314 ----
Next, you write your message under the columns.
2314 ---- Hell o Wo rld!
Finally, rearrange the columns into the numerical order in which they would fall, and read the ciphertext across.
1234 ---- lHel Wo o drl!
Which will result in your encoded text:
lHelWo odrl!
Rules
- Each submission should be either a full program or function. If it is a function, it must be runnable by only needing to add the function call to the bottom of the program. Anything else (e.g. headers in C), must be included.
- There must be a free interpreter/compiler available for your language.
- If it is possible, provide a link to a site where your program can be tested.
- Your program must not write anything to STDERR.
- Your program should take input as an argument or from STDIN (or the closest alternative in your language).
- Standard loopholes are forbidden.
Requirements
- Case must be preserved.
- Your cipher should be 'irregular', that is, if there are any spaces left after you have written out your message, it is treated as if it were a normal space character.
- Only encryption is required, decryption may come in a later challenge.
- Input should be taken from
STDIN
with the key on the first line, and the plaintext on the second. If you are taking input as an argument, please specify how this is done for your language. - The key can be in any case.
- Duplicates in the key should be ignored - that is,
ABCDB
would becomeABCD
. Duplicates also apply in any case. - Trailing whitespace is included.
Test Cases
CBABD, Duplicates are ignored. ==> puDlacit sea eriongr.de
bDaEc, Key can be in multicase! ==> yKce aenbn mi tucliea s!
Full example, with 'surplus space' rule.
ADCB
----
"Goo
d Mo
rnin
g!"
he c
alle
d.
ABCD
----
"ooG
dom
rnin
g "!
hc e
aell
d .
Message: "ooGdom rning "!hc eaelld .
Scoring
code-golf is how we score this challenge!
Submissions
To make sure that your answer shows up, please start your answer with a headline, using the following Markdown template:
# Language Name, N bytes
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:
# Ruby, <s>104</s> <s>101</s> 96 bytes
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:
# Perl, 43 + 2 (-p flag) = 45 bytes
You can also make the language name a link which will then show up in the leaderboard snippet:
# [><>](http://esolangs.org/wiki/Fish), 121 bytes
Leaderboard
Here is a Stack Snippet to generate both a regular leaderboard and an overview of winners by language.
/* Configuration */
var QUESTION_ID = 79810; // 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 = 53406; // 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,]*[^\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 = '<h1>' + c.body.replace(OVERRIDE_REG, '') + '</h1>';
});
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 = jQuery(lang).text();
languages[lang] = languages[lang] || {lang: a.language, 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 > b.lang) return 1;
if (a.lang < b.lang) 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);
}
}
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;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b">
<div id="answer-list">
<h2>Leaderboard</h2>
<table class="answer-list">
<thead>
<tr><td></td><td>Author</td><td>Language</td><td>Size</td></tr>
</thead>
<tbody id="answers">
</tbody>
</table>
</div>
<div id="language-list">
<h2>Winners by Language</h2>
<table class="language-list">
<thead>
<tr><td>Language</td><td>User</td><td>Score</td></tr>
</thead>
<tbody id="languages">
</tbody>
</table>
</div>
<table style="display: none">
<tbody id="answer-template">
<tr><td>{{PLACE}}</td><td>{{NAME}}</td><td>{{LANGUAGE}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr>
</tbody>
</table>
<table style="display: none">
<tbody id="language-template">
<tr><td>{{LANGUAGE}}</td><td>{{NAME}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr>
</tbody>
</table>
u
in 16th position can't end up in 14th position, since that's now a different block of 5. \$\endgroup\$i
fromin
) should be in 11th place in the result: it is put into first place of it's chunk because it lines up witha
from the key. \$\endgroup\$yKce aenbn mi tuclieas!
. It may be my mistake, but in any it should be explained how the output is obtained in that case \$\endgroup\$