Alex Rivera | Logout

Code Golf: Code 39 Bar Code

Asked 2010-05-10T02:54:48.367
26

The challenge

The shortest code by character count to draw an ASCII representation of a Code 39 bar code.

Wikipedia article about Code 39: http://en.wikipedia.org/wiki/Code_39

Input

The input will be a string of legal characters for Code 39 bar codes. This means 43 characters are valid: 0-9 A-Z (space) and -.$/+%. The * character will not appear in the input as it is used as the start and stop characters.

Output

Each character encoded in Code 39 bar codes have nine elements, five bars and four spaces. Bars will be represented with # characters, and spaces will be represented with the space character. Three of the nine elements will be wide. The narrow elements will be one character wide, and the wide elements will be three characters wide. A inter-character space of a single space should be added between each character pattern. The pattern should be repeated so that the height of the bar code is eight characters high.

The start/stop character * (bWbwBwBwb) would be represented like this:

                       #   # ### ### # 
                       #   # ### ### # 
                       #   # ### ### # 
                       #   # ### ### # 
                       #   # ### ### # 
                       #   # ### ### # 
                       #   # ### ### # 
                       #   # ### ### # 
                       ^ ^ ^^ ^ ^ ^ ^^^
                       | | || | | | |||
           narrow bar -+ | || | | | |||
           wide space ---+ || | | | |||
           narrow bar -----+| | | | |||
         narrow space ------+ | | | |||
             wide bar --------+ | | |||
         narrow space ----------+ | |||
             wide bar ------------+ |||
         narrow space --------------+||
language-agnostic code-golf barcode rosetta-stone code39
Edit
Report

2 Answers

25

J, 102 characters

8#,:' #'{~,0,.~#:(3 u:'䝝啕啕啕䑅儑啕啕啕啕䗝䔑啕䕷煝䑑凝瑗屗眕凗瑵屵具瑝屝啕啕啕啕啕啕啕甗崗睅圗病巅呷甝崝圝畇嵇睑均痑巑嗇畱嵱坱煗䝗燕䗗煵䝵'){~32-~a.i.'*'(,,[)

Explanation. Read from the bottom up.:

8#,:         NB. Copy 8 times
' #'{~       NB. Turn binary 0 and 1 into space and #
,            NB. Link the array into a list
0,.~         NB. Append a 0 to the end of each row of the array.
#:           NB. Turn the list of numbers into a binary array where each row is the base-2 representation of the corresponding number
(3 u:'䝝啕啕啕䑅儑啕啕啕啕䗝䔑啕䕷煝䑑凝瑗屗眕凗瑵屵具瑝屝啕啕啕啕啕啕啕甗崗睅圗病巅呷甝崝圝畇嵇睑均痑巑嗇畱嵱坱煗䝗燕䗗煵䝵') NB. Turn this wchar string into a list of ints in range 0-65535.
{~           NB. Select numbers from the string-list whose indices are...
32-~         NB. ... 32 less than ...
a.i.         NB. ... the ascii values of ...
'*'(,,[)     NB. ... the input string with a '*' on either side!
answered 2010-05-11T00:31:40.073
5

Python 3.1, without Unicode (213 215 223 240 248 249 chars)

o=""
for c in"%r"%input():
 u="W3YZ56C$EF. 89'0HIJM/OP+%RSTUV12X4ABD-7GKLNQ".find(c);n=sum(b"))&&&,(*&2&&&)),&/8(*&1)<&/V&&&)),&/5);D&/S"[u:])-930+35*u
 while n:o+="###"[n%2*2:]+"   "[n&2:];n>>=2
print((o+"\n")*8)

Explanation:

The code 39 sequence is encoded into a base-4 number (left-most = least significant) with:

  • bw → 3
  • Bw → 2
  • bW → 1
  • BW → 0

The sequence is then sorted, e.g.

20333   Q
21233   N
21323   L
...

The difference of adjacent entries are taken, giving a list like [48, 12, 3, …]. Then 35 is added to this list to ensure the numbers fall in the ASCII range. This gives the "))&&&,…" string.

This code also has taken advantaged of the * will not appear in the input, so we may replace it by any invalid character, including '. In CPython repr("ABC") == "'ABC'", so we could get rid of 2 characters.

answered 2010-05-11T20:48:45.703

Your Answer