Generate a 6 character string from a 15 character alphabet

Question

In one of our projects at work, we recently discovered a particularly large method for generating a 6 character string from a 15 character alphabet. A few of us claimed "I bet we can get that in one line" which started a little internal game of code golf.

Your task is to beat us, which I have no doubt won't take long!

The original algorithm used the alphabet 0-9A-E, but we've experimented with other alphabets. There are therefore three subtasks.

1. Generate a 6 character string randomly selecting from an arbitrary hardcoded 15 character alphabet like ABC123!@TPOI098. (This is just an example, and should be customizable without affecting the byte count.)
2. Generate a 6 character string randomly selecting from a 15 character alphabet 0123456789ABCDE.
3. Generate a 6 character string randomly selecting from a 15 character alphabet of your choice (printable characters only please).

Each character should have equal chance of selection and repetition should be possible.

The best we have been able to manage for each of the subtasks is:

• "ABC123!@TPOI098" - 24 bytes
• "0123456789ABCDE" - 21 bytes
• Custom alphabet - 13 bytes

Your score is the sum of the bytes in each subtask's solution. i.e. our score is currently 58.

We've attempted using among others, CJam and Ruby. The original was in C#. Use any language you like, but we'll be interested to see solutions in these languages particularly

Answer 1

CJam (23 + 14 + 10 = 47 bytes)

Arbitrary alphabet: 23 bytes (online demo)

{"ABC123!@TPOI098"mR}6*

Hexadecimal alphabet: 14 bytes (online demo)

{FmrAbHb'0+}6*

Custom alphabet: ABCDEFGHIJKLMNO, 10 bytes (online demo)

{Fmr'A+}6*

Dissection

The hexadecimal one is the interesting one:

{      e# Loop...
  Fmr  e#   Select a random number from 0 to 14
  AbHb e#   Convert to base 10 and then to base 17
       e#   (i.e. add 7 if the number is greater than 9)
  '0+  e#   Add character '0' (i.e. add 48 and convert from integer to character)
       e#   Note that 'A' - '0' = 17
}6*    e# ...six times

The six characters are left on the stack and printed automatically.

Answer 2

Jelly, 38 bytes

TryItOnline links A, B, and C.

A: ABC123!@£POI098, 22 bytes

“ABC123!@£POI098”Wẋ6X€

(thinking about a compression to lessen this one)

B: 0123456789ABCDE, 8 bytes:

ØHṖWẋ6X€

C:123456789ABCDEF (choice), 8 bytes:

ØHḊWẋ6X€

How?

...Wẋ6X€ - common theme
   W     - wrap (string) in a list
    ẋ6   - repeat six times
      X€ - random choice from €ach

ØH...... - hexadecimal digit yield: "0123456789ABCDEF"

..Ṗ..... - pop: z[:-1] (B)

..Ḋ..... - dequeue: z[1:] (C)

Answer 3

Perl, 46 + 26 + 26 = 98 bytes

A lot of the credit goes to @Dom Hastings for saving 13 bytes!

The 3 programs are pretty much identical, except for the alphabet that changes.

• Hardcoded alphabet (ABC123!@)POI098 in this example) -> 46 bytes:

  say map{substr"ABC123!@)POI098",15*rand,1}1..6

• Fixed alphabet 0123456789ABCDE -> 26 bytes:

  printf"%X",rand 15for 1..6

• Custom alphabet 0123456789ABCDE in that case -> 26 bytes:

  printf"%X",rand 15for 1..6

You can put them all in a file to run them :

$ cat 6chr_strings.pl
say map{substr"ABC123!@)POI098",15*rand,1}1..6;
say "";
printf"%X",rand 15for 1..6;
say "";
printf"%X",rand 15for 1..6;
say "";
$ perl -M5.010 6chr_string.pl
CB8!8!
24D582
9ED58C

(the say ""; are just here to improve the output format)

Answer 4

R, 33+43+59 = 135 bytes

Arbitrary hard-coded alphabet (change the string to change the alphabet):

cat(sample(strsplit("ABC123!@TPOI098","")[[1]],6,1),sep="")

Alphabet of [0-9A-E]:

cat(sample(c(0:9,LETTERS[1:6]),6,1),sep="")

User-defined alphabet from stdin:

cat(sample(scan(,''),6,1),sep="")

All cases print the output word to stdout.

Answer 5

JavaScript (ES6), 167 166 164 163 bytes

Saved 1 byte thanks to Neil
Saved 2 bytes thanks to ETHproductions
Saved 1 byte thanks to premek.v

Hardcoded: "ABC123!@TPOI098" (58 bytes)

f=(n=6)=>n?"ABC123!@TPOI098"[Math.random()*15|0]+f(n-1):''

Fixed: "0123456789ABCDE" (58 57 bytes)

f=(n=6)=>n?f(n-1)+("ABCDE"[n=Math.random()*15|0]||n-5):''

Custom: "()+.1=>?M[afhnt" (51 49 48 bytes)

f=(n=6)=>n?(f+1)[Math.random()*15|0+5]+f(n-1):''

Answer 6

JavaScript (ES6), 184 bytes

Custom alphabet: 66 bytes

_=>"......".replace(/./g,c=>"ABC123!@TPOI098"[Math.random()*15|0])

0-9A-E: 63 bytes

_=>"......".replace(/./g,c=>"ABCDE"[n=Math.random()*15|0]||n-5)

0-9a-e: 55 bytes

_=>(Math.random()*11390625+1e8|0).toString(15).slice(1)

(Subtract 6 bytes if date-based randomness is permissible.)

Answer 7

q, 42 bytes

A

19 bytes

6?"ABC123!@TPOI098"

B

14 bytes

6?15#.Q.n,.Q.A

C

9 bytes

6?15#.Q.a

(uses the first fifteen letters of the alphabet)

Answer 8

Julia (36+26+21 = 83)

join(rand(["ABC123!@TPOI098"...],6))

base(15,rand(15^6:15^7-1))

join(rand('a':'o',6))

Answer 9

CJam, 48 bytes

Arbitrary alphabet, 23 bytes:

{"ABC123!@TPOI098"mR}6*

Try it online!

Hex digits, 15 bytes:

{A,'F,65>+mR}6*

Try it online!

Alphabet ABCDEFGHIJKLMNO, 10 bytes:

{Fmr'A+}6*

Try it online!

Answer 10

Ruby 47 + 37 + 31 = 115

Hardcoded: "ABC123!@TPOI098" (47)

(1..6).map{"5CABC123!@TPOI098".chars.sample}*''

Fixed: "0123456789ABCDE" (37)

(1..6).map{[*0..9,*?A..?E].sample}*''

Custom: "ABCDEFGHIJKLMNO" (31)

(1..6).map{[*?A..?O].sample}*''

Answer 11

05AB1E, 43 bytes

Arbitratry alphabet (ABC123!@TPOI098), 23 bytes Try it online

"ABC123!@TPOI098"6F.r¬?

Almost hexadecimal alphabet (0123456789ABCDE), 10 bytes Try it online

14Ýh6F.r¬?

Custom alphabet (abcdefghijklmno), 10 bytes Try it online

A15£6F.r¬?

Answer 12

Python 2, 70 + 70 + 64 = 204 bytes

from random import*
s=""
exec"s+=choice('ABC123!@TPOI098');"*6
print s

from random import*
s=""
exec"s+=choice('0123456789ABCDE');"*6
print s

from random import*
s=""
exec"s+=chr(randint(65,80));"*6
print s

Unfortunately, the second example is easier with the first method than something like choice([randint(48,57)),choice(65,69)])

Answer 13

Vitsy, 27 + 24 22 + 13 10 = 64 62 59 bytes

#1:

"ABC123!@TPOI098"6\[eR2+@O]

Try it online!

#2:

aH7+D4+H6\[eR2+@68*+O]

Try it online!

#3:

6\[eR5F-O]

Where the available characters are:

ﾖﾕﾔﾓﾒﾑﾐﾏﾎﾍﾌﾋﾊﾉﾈ

Try it online!

Answer 14

J, 24 + 24 + 18 10 = 58 bytes

8 bytes saved thanks to miles!

'ABC123!@TPOI098'{~?6#15
'0123456789ABCDE'{~?6#15
u:65+?6#15

Yeah, the second string isn't easily compressible in J:

u:47+23#.inv 12670682677028904639x
u:47+;(+i.@])/"1&.>1 10;18 5
('ABCDE',~1":i.10)
(toupper,hfd?6#15)
'0123456789ABCDE'

If a lowercase hex alphabet is fine, then there's ,hfd?6#15 for 9 bytes, as @miles noted.

Anyhow, ?6#15 is 6 random numbers between 0 and 15; {~ is take-from. u: converts numbers to chars. The last example encodes ABCDEFGHIJKLMNOP.

Bonus: general case

{~6?@##

{~6?@## is roughly:

{~6?@##  input: y
      #  length of y
  6  #   six copies of the length
   ?@    random numbers between 0 and the length
{~       taken from y

Answer 15

PHP, 46+36+35=117 bytes

Hardcoded (46 bytes)

for(;$i++<6;)echo"ABC123!@TPOI098"[rand()%15];

(47 bytes)

for(;$i++<6;)echo"ABC123!@TPOI098"[rand(0,14)];

Hexadecimal (lowercase) (36 bytes)

for(;$j++<6;)echo dechex(rand()%15);

For uppercase, 46 bytes with Hardcoded version.

Custom (A-O) (35 bytes)

for(;$k++<6;)echo chr(rand(65,79));

Answer 16

Scala, 154 bytes

Hardcoded alphabet (54 bytes):

Seq.fill(6)("ABC123!@TPOI098"((math.random*14).toInt))

Hex alphabet (54 bytes):

Seq.fill(6)("0123456789ABCDE"((math.random*14).toInt))

Custom alphabet ABCDEFGHIJKLMNO (47 bytes):

Seq.fill(6)(('A'to'O')((math.random*14).toInt))

Explanation:

Seq.fill(6)(               //build a sequence of 6 elements, where each element is...
  "ABC123!@TPOI098"(         //from the string
    (math.random*14).toInt   //take a random char
  )
)

'A'to'O' creates a sequence of 15 chars, A to O

Answer 17

Pip, 42 bytes

Hardcoded alphabet, 22 bytes:

L6ORC"ABC123!@TPOI098"

Hex digits, 11 bytes:

L6ORR15TB16

First 15 lowercase letters, 9 bytes:

L6Oz@RR15

Explanation

All three programs start with L6O: loop 6 times and output the given expression.

• RC"...": Random Choice of a character from the hard-coded string
• RR15TB16: RandRange(15), converted To Base 16
• z@RR15: lowercase alphabet z, indexed with RandRange(15)

Try it online!

Answer 18

Skript/skQuery, 108 bytes

Hardcoded (43 bytes):

random 6 char string from `A@cD%F3h9JK{mN!`

0123456789ABCDE (34 bytes):

random 6 char string from `0-9A-E`

Choice (31 bytes):

random 6 char string from `A-M`

Answer 19

Jolf, 26 + 14 + 13 = 51 bytes

Μ*S6d rG"ABC123!@TPOI098"E

Custom alphabet, 24 bytes. Try it here!

Μ*S6d r lp^0wά

0-9A-E alphabet, 14 bytes. Try it here! lp^0wά is lp (0-Z) sliced (l) from 0 to 15 (wά).

Μ*S6d r lp^1ά

1-9A-F alphabet, 13 bytes. Try it here! lp^1ά is the same as above, except from 1 to 16.

---

General method:

Μ*S6d r
M*S6d      map six newlines over this function:
      r    select random element from array.

Other attempts (using string compression):

Μ*S6d rGμpwΞ $AE

Answer 20

PowerShell v2+, 45 + 44 + 37 = 126 bytes

Fixed alphabet, 45 bytes

-join(0..5|%{'ABC123!@TPOI098'[(Random)%15]})

Nearly-hexadecimal alphabet, 44 bytes

-join[char[]](0..5|%{Random(48..57+65..69)})

Custom alphabet (A to O), 37 bytes

-join[char[]](0..5|%{Random(65..79)})

All of these follow the same pattern -- loop from 0 to 5, each iteration selecting a Random character or ASCII value, casting that as a char-array if necessary, and -joining it together into a string. That string is left on the pipeline, and output is implicit.

---

Examples

PS C:\Tools\Scripts\golfing> -join(0..5|%{'ABC123!@TPOI098'[(Random)%15]})
32ATB3

PS C:\Tools\Scripts\golfing> -join(0..5|%{'ABC123!@TPOI098'[(Random)%15]})
III@B2

PS C:\Tools\Scripts\golfing> -join(0..5|%{'ABC123!@TPOI098'[(Random)%15]})
@302O@

PS C:\Tools\Scripts\golfing> -join[char[]](0..5|%{Random(48..57+65..69)})
74E117

PS C:\Tools\Scripts\golfing> -join[char[]](0..5|%{Random(48..57+65..69)})
09D7DD

PS C:\Tools\Scripts\golfing> -join[char[]](0..5|%{Random(65..79)})
COJDFI

PS C:\Tools\Scripts\golfing> -join[char[]](0..5|%{Random(65..79)})
EAKCNJ

Answer 21

Pyke, 35 bytes

Arbitary alphabet, 20 bytes

6V"ABC123!@TPOI098"H

Try it here!

Hex alphabet, 8 bytes

6V~J15<H

Try it here!

~J15< - "0123456789abcdefghijklmno..."[:15]

Custom alphabet, 7 bytes

6VG15<H

Try it here!

G15< - alphabet[:15]

Alphabet chosen: abcdefghijklmno

6V     - repeat 6 times:
  ...  -   get alphabet
     H -  choose_random(^)