Clock (transliterate) Cipher

Question

Introduction:

I have loads of different ciphers stored in a document I once compiled as a kid, I picked a few of the ones I thought were best suitable for challenges (not too trivial, and not too hard) and transformed them into challenges. Most of them are still in the sandbox, and I'm not sure yet whether I'll post all of them, or only a few. Here is the third and easiest one (after the Computer Cipher and Trifid Cipher I posted earlier).

---

With a Clock Cipher we use the following image to encipher text:

So a sentence like this is a clock cipher would become:

t  h i s     i s     a     c l  o  c k     c i p  h e r    (without additional spaces of course, but added as clarification)
19:7:8:18:00:8:18:00:AM:00:2:11:14:2:10:00:2:8:15:7:4:17

Challenge:

Given a string sentence_to_encipher, encipher it as described above.

Challenge rules:

• You can assume the sentence_to_encipher will only contain letters and spaces.
• You can use either full lowercase or full uppercase (please state which one you've used in your answer).
• You are not allowed to add leading zeros for the single-digit enciphered letters b through j, but two zeros 00 are mandatory for spaces.
• You should use : as separator, and an additional leading or trailing : is not allowed.
• You are allowed to use lowercase am and pm instead of uppercase AM and PM, as long as it's consistent.

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 with default I/O rules, so you are allowed to use STDIN/STDOUT, functions/method with the proper parameters and return-type, full programs. Your call.
• Default Loopholes are forbidden.
• If possible, please add a link with a test for your code (i.e. TIO).
• Also, adding an explanation for your answer is highly recommended.

Test cases:

Input:  "this is a clock cipher"
Output: "19:7:8:18:00:8:18:00:AM:00:2:11:14:2:10:00:2:8:15:7:4:17"

Input:  "test"
Output: "19:4:18:19"

Input:  "what time is it"
Output: "22:7:AM:19:00:19:8:12:4:00:8:18:00:8:19"

Input:  "acegikmoqsuwy bdfhjlnprtvxz"
Output: "AM:2:4:6:8:10:12:14:16:18:20:22:24:00:1:3:5:7:9:11:13:15:17:19:21:23:PM"

Input:  "easy peazy"
Output: "4:AM:18:24:00:15:4:AM:PM:24"

Answer 1

Python 2, 74 72 bytes

lambda s:':'.join(['AM','PM','00',`ord(c)-97`]['az '.find(c)]for c in s)

Try it online!

Takes input as all lowercase

Answer 2

05AB1E, 22 21 bytes

„AM24L„PM00)˜Að«s‡':ý

Try it online! or as a Test Suite

Some alternate 21 byte solutions:

':ýAð«24L„AMš„PMª00ª‡
00„AM24L„PM)˜AIk>è':ý

Answer 3

Perl 6, 47 bytes

*.ords>>.&{<<00 AM{1..24}PM>>[$_%32]}.join(":")

Try it online!

Anonymous Whatever lambda that takes a string of either case and returns the encrypted string.

Explanation:

*.ords>>.&{                         } # Map the ordinal values to
           <<              >>[$_%32]  # The index in the list
              00 AM{1..24}PM  # 00, AM, the numbers 1 to 24 and PM
                                     .join(":")   # And join with colons

Answer 4

C# (Visual C# Interactive Compiler), 70 bytes

s=>string.Join(":",s.Select(a=>a<33?"00":a<66?"AM":a>89?"PM":a%65+""))

Takes input as a string of lowercase letters. First checks if the char is a space, and if it is, converts it to 00. Next, it checks for if the char is an A, and converts it to AM. It checks again for Z and converts it to PM if it is. Lastly, if the char passes all the checks, it gets converted to its alphabetic order-1.

-2 bytes thanks to @dana

Try it online!

// Input taking a string
s => 
// Join the following IEnumerable<char> with a ":" character
string.Join(":", 
// Map all the characters in the string
s.Select(a => 
// Is the char less than 33, aka a space?
a < 33 ? 
// If so, it's a "00"
"00" 
// Else, is this an 'A'?
: a < 66 ?
// If so, convert it to "AM"
"AM" : 
// If it's not 'A' or a space, could it be a 'Z'?
a > 89 ?
// If it is, turn the character into "PM"
"PM" : 
// If it fails all of the checks above, get the characters position in the alphabet and subtract one from that.
a % 65 + ""))

Answer 5

Java (JDK), 86 bytes

s->"".join(":",s.map(c->c<33?"00":c<66?"AM":c>89?"PM":c-65+"").toArray(String[]::new))

Try it online!

Credits

• -1 byte thanks to Kevin Cruijssen

Answer 6

Pyth, 25 bytes

j\:m@+++"AM"S24"PM""00"xG

Try it online here, or verify all the test cases at once here.

j\:m@+++"AM"S24"PM""00"xGdQ   Implicit: Q=eval(input()), G=lowercase alphabet
                              Trailing dQ inferred
            S24               [1-24]
       +"AM"                  Prepend "AM"
      +        "PM"           Append "PM"
     +             "00"       Append "00" - this is the dictionary
   m                      Q   Map each element of Q, as d, using:
                       xGd      Get the index of d in G, -1 if not present (i.e. space)
    @                           Get the element from the dictionary at the above index
j\:                           Join the result on ":", implicit print

Answer 7

JavaScript (Node.js),  72  65 bytes

Takes input in lowercase.

s=>[...Buffer(s)].map(c=>c<33?'00':c>121?'PM':c-97||'AM').join`:`

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Answer 8

Ruby, 49 bytes

->a{a.map{|c|["00",:AM,*1..24,:PM][c.ord%32]}*?:}

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Port of Jo King's Perl answer. Takes input as an array of chars, returns a string with AM/PM in uppercase.

Answer 9

Red, 124 121 110 109 bytes

func[s][replace/all form collect[forall s[keep switch/default
c: -97 + s/1[0['AM]25['PM]-65["00"]][c]]]sp":"]

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Answer 10

05AB1E, 20 bytes

':ýð00:A24L„AMš„PMª‡

Greatly inspired by @Mr.Xcoder's 22-byter in the comment of the existing 05AB1E answer by @Emigna.

Takes the input as a list of lowercase characters (would be 21 bytes with a leading S if I take the input as a string).

Try it online or verify all test cases.

Explanation:

':ý            '# Join the (implicit) input list of characters by ":"
                #  i.e. ["e","a","s","y"," ","p","e","a","z","y"] → "e:a:s:y: :p:e:a:z:y"
ð00:            # Replace all spaces " " with "00"
                #  i.e. "e:a:s:y: :p:e:a:z:y" → "e:a:s:y:00:p:e:a:z:y"
A               # Push the lowercase alphabet
 24L            # Push a list in the range [1,24]
    „AMš        # Prepend "AM" at the start of this list
        „PMª    # And append "PM" at the end of the list
            ‡   # Transliterate; mapping letters to the list-items at the same indices
                # (and output the result implicitly)
                #  i.e. "e:a:s:y:00:p:e:a:z:y" → "4:AM:18:24:00:15:4:AM:PM:24"

Answer 11

Charcoal, 26 bytes

ＵＢ:Ｆθ«→≡ι ×0²a¦AM¦z¦PMＩ⌕βι

Try it online! Link is to verbose version of code. Takes input in lower case (can trivially be changed to upper case). Explanation:

ＵＢ:

Set the background character to :. This fills in the gaps between the output values created by the right movement.

Ｆθ«→

Loop over each character, leaving a gap each time. (The first move has no effect as the canvas is still empty at this point.)

≡ι ×0²a¦AM¦z¦PM

Switch on the character and if it's space, a or z then output the appropriate code. I use ×0² instead of 00 here as the latter would cost two bytes in additional separators.

Ｉ⌕βι

Otherwise output the letter's 0-indexed position in the lower case alphabet as a string.

Answer 12

Perl 5 -pl, 46 bytes

s/./("00",AM,1..24,PM)[ord($&)%32].":"/ge;chop

Case doesn't matter. To run as perl -ple '<code>'. -l option passed to perl allows to drop the last colon with chop.

Try it online!

Answer 13

Scala, 69 bytes

_.map(_.-(64)%32)map "00"+:"AM"+:1.to(24).map("".+):+"PM"mkString ":"

Try it in Scastie!

Answer 14

PowerShell, 72 69 63 bytes

$(switch($args){a{'AM'}z{'PM'}' '{'00'}default{$_-97}})-join':'

Try it online!

Takes a lowercase string and does not add a leading 0.

The string is passed to the function using splatting.

It iterates through all the characters of the string, replacing them with their encoded values.

The resulting items are then joined using ':' as separator.

-6 bytes thanks to mazzy !

Answer 15

Tcl, 100 bytes

proc C s {join [lmap c [split $s ""] {scan $c %c v
expr $v==65?"AM":$v==90?"PM":$v==32?00:$v-65}] :}

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Answer 16

C# (Visual C# Interactive Compiler), 98 bytes

s=>string.Join(':',s.Select(c=>"az ".Contains(c)?new[]{"AM","PM","00"}["az ".IndexOf(c)]:c-97+""))

Takes input as a (lowercase) char array. Try it online!

Answer 17

Jelly, 24 bytes

«"⁾PMµØAḊiȯ⁾00µe?€⁾AZj”:

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Answer 18

Vyxal, 31 22 bytes

øA‹u025"J`00ṙ§m`2ẇĿ\:j  

Thanks to @lyxal!
I'm not familiar with Vyncode so just classic version.
Try it Online!

Explanation:

øA                      # Convert letter to number (space=0 and vectorized by default)
  ‹                     # Increment (vectorized)
   u025                 # Push -1, 0 and 25
       "                # Pair top two items (0 and 25)
        J               # Join -1  (so "J shorter than 3¨ẇ)
         `00ṙ§m`        # This uncompressed to `00ampm` (how?)
                2ẇ      # Split into 2-chunks
                  Ŀ     # Transliterate: replace each item of one value in another value with the corresponding element from a third value 
                   \:j  # Join by ":"

Old version for compare:

C97-⟨65N|0|25⟩⟨‛00|‛AM|‛PM⟩Ŀ\:j

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Answer 19

Wolfram Language (Mathematica), 98 95 bytes

StringRiffle[Switch[#,1,"AM",26,"PM",0,"00",_,ToString@(#-1)]&/@LetterNumber@Characters@#,":"]&

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