Re: Re: (Golf) Cryptographer's Tool #1

[srawls]

That doesn't work when 0 is in the 'alphabet.' Here's a modified solution that handles 0 properly, which is only 8 more char than yours: It adds the null character to each string, which shouldn't print on most machines (it does on my dos, not on my unix).

sub c { 
($_,$a)=@_;s!.!$h{$&}||=($a=~/./g,"$&\0")!ge;y/\0//;$_
}

Update:Fixed code as per chipmunk's comment. It's 54 chars now.

The 15 year old, freshman programmer,
Stephen Rawls

[chipmunk]

Adding extra characters to the result is not a valid solution. They may be invisible when you print them out, but they're still there.

[MeowChow]

The fix fails if a null character is present in the alphabet.

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

[srawls]

Yes it does, but the this is straight from the specification:

Given: a word, and an 'alphabet' string (and to be exact about this latter part, each character in the word and the alphabet can be represented in 7 bits, eg the printable ASCII set).

The 15 year old, freshman programmer,
Stephen Rawls

[MeowChow]

Well, let's go pickin' nits... the latin abbreviation, "eg" means "for example". So according to the spec, any 7 bit ASCII character is possible; printable ASCII characters mearly represent examples of possible 7-bit characters. If, however, Masem had written "ie", which means "that is to say", then you would be correct.

/me ducks and covers...

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

[sean]

nice, srawls... here it is down to 51:

sub c{
($_,$a)=@_;s!.!chr($h{$&}||=($a=~/./g,ord$&))!ge;$_
#23456789_123456789_123456789_123456789_123456789_1
}


It doesn't work with null either, but as i read it, thats fine.

update: oops, here's one that resets %h and is reusable, as per the given example, at 54:


sub c{
($_,$a,%h)=@_;s!.!chr($h{$&}||=($a=~/./g,ord$&))!ge;$_
#23456789_123456789_123456789_123456789_123456789_1234
}

--sean