in reply to "Countdown" (golf)

Following blakem's rules, 
#        1         2         3       
#234567890123456789012345678901234567
$"='';grep{/^(([@_])(?!.*\2))+$/}<D>;

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37 characters! I'm pleased with my first try at golfing. ;)

andy.

PS stuffy, good choice of puzzle! There went my lunchtime.

update: 36 

#234567890123456789012345678901234567
$"='';grep/^(([@_])(?!.*\2))+$/,<D>;

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update 2: Thanks dragonchild, 35 w/out the ;
Hmm... you're right about the duplicate letters. I can't remember whether these appear on the t.v. show - I rather suspect they do.

update, later:
This cope with duplicates, but is a lot longer:

#        1         2         3         4         5         6         7
+         8
#234567890123456789012345678901234567890123456789012345678901234567890
+12345678901
$"='';$n{$_}++for@_;grep/^((??{"([@_])"})(??{"(?!([^$1 ]*$1){$n{$1},})
+"}))+$/,<D>

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(you need to use re 'eval')
I'd rather do:
$"='';$n{$_}++for@_;grep/^(([@_])(??{"(?!([^$1 ]*$1){$n{$1},})"}))+$/,
+<D>

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(the difference being that @_ is interpolated normally here), but for some reason this isn't allowed - I get back Eval-group in insecure regular expression in regex - no idea why, since I'm using re 'eval', and @_ surely can't be tainted?

Going to dinner. andy.

Replies are listed 'Best First'.
Re: andye Re: "Countdown" (golf)
by dragonchild (Archbishop) on Nov 30, 2001 at 18:41 UTC
    As always, removing the trailing semi-colon helps. :-)

    Excellent solution!

    Update: Of course (and this wasn't specified, so it's cool!) ... this won't work with duplicate letters. blakem's does, yours doesn't. I would suspect the gameshow, though it wouldn't say this, would never give dupes.

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    We are the carpenters and bricklayers of the Information Age.

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[reply]
      It can give dupes. In fact sometimes, the letters are so bad that the best the contestants can do is get a 4-letter word.

      I couldn't find the offical Countdown website on channel4.com. But there is more info about how the game is played here.

      Simon Flack ($code or die)
      $,=reverse'"ro_';s,$,\$,;s,$,lc ref sub{},e;$,
      =~y'_"' ';eval"die";print $_,lc substr$@,0,3;
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Re: andye Re: "Countdown" (golf)
by blakem (Monsignor) on Dec 01, 2001 at 06:20 UTC
    I can shorten your 36 non-duplicate-letter attempt by 5 chars with: 
    #        1         2         3
#234567890123456789012345678901
grep/^(([@_])(?!.*\2))+$/x,<D>;

    [download]
    I think this trick might be applicable to your others as well...

    Update: I'm still trying to grok your longer ones (re eval in golf... coool) and I'm uncovering some oddities: 

    qw(a d d) 
   ad
   add
   dad

qw(a d)
   ad
   add  <= wrong... but 'dad' got correctly skipped... I think
                    add gets through because the 'd's are right
                    next to each other

    [download]
    Doubled letters (dd, tt, etc) are sneaking through... It looks like $n{'d'} needs to be temporarilly decremented when 'd' matches in the character class...

    -Blake

[reply]
[d/l]
[select]
      I can shorten your 36 non-duplicate-letter attempt by 5 chars with: /x instead of $"=''

      Clever!

      I'm not surprised the re eval ones don't work properly - I was getting some strange results while working them out. Also I was becoming confused! ;)

      andy.

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Re: andye Re: "Countdown" (golf)
by dragonchild (Archbishop) on Dec 01, 2001 at 01:45 UTC
    I can't run your update using 5.6.0 on Solaris ... it says that there's an unmatched bracket...

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    We are the carpenters and bricklayers of the Information Age.

    Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

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