(jeffa) Re: Removing Duplicates in an array?

[jeffa]

Super Search is you friend! I did a super search for 'remove duplicate' in the body text and found How can I extract just the unique elements of an array?.

Jeff

R-R-R--R-R-R--R-R-R--R-R-R--R-R-R--
L-L--L-L--L-L--L-L--L-L--L-L--L-L--

[Tiefling]

Is it just me, or does the FAQ title 'How can I extract just the unique elements of an array?' not actually convey what the solution does accurately?

The unique elements of ("fish","bread","eggs","eggs","fish","butter") are ("bread","butter").

And as a quick golf question: how would you extract the genuinely unique elements of a list?

Tiefling



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Version: 3.1
GAT d++ s:- a-- C++ UL P++ L++(+) E? W+(++) N+ o? K w+(--)
!O M- V? PS+ PE- Y PGP- t+ 5 X+ R+++ tv- b+++ DI++++ D+ G+ e++ h!(-) y
+?
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[davorg]

Something like this I guess:

my @list = qw(fish bread eggs eggs fish butter);

my %check;

$check{$_}++ foreach @list;

my @unique = grep { $check{$_} == 1 } keys %check;

But I'm not much of a golfer :)

--
<http://www.dave.org.uk>

Perl Training in the UK <http://www.iterative-software.com>

[jeroenes]

At 2818 chars, I golf:

sub u{@h{@_}=@_;keys%h} 
 
print join "\t", u("fish","bread","eggs","eggs","fish","butter")
#butter  bread   fish    eggs

/me wonders how soon MeowChow will have a shorter solution...

Jeroen
"We are not alone"(FZ)
Update: Too bad. The shortest I can come with is just a rewrite of Davorg's code (he's a golfer in disguise):

sub u{$h{$_}++for@_;grep$h{$_}<2,keys%h}

[Tiefling]

Nice golf, jeroenes. Trouble is, (if your sample output is right) it answers the original question, not the one I posed as a golf. What's the shortest way to produce exactly the elements which occurs uniquely (ie: only once) in the original array? Davorg's code does the right thing, but it's a canonical answer, as he admits, rather than golf.

Tiefling (Just Another Perl Newbie)



-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GAT d++ s:- a-- C++ UL P++ L++(+) E? W+(++) N+ o? K w+(--)
!O M- V? PS+ PE- Y PGP- t+ 5 X+ R+++ tv- b+++ DI++++ D+ G+ e++ h!(-) y
+?
------END GEEK CODE BLOCK------

[MeowChow]

Well, I've already golfed it down to 30 chars, but I thought you might enjoy this rather bizarre one at 33:

sub u {
  delete@h{grep$h{$_}++,@_};keys%h
}

As with yours, my%h; should really be prepended to make the sub reusable.

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

[MeowChow]

My shortest is 30 chars:

sub u {
  grep{$a=$_;2>grep$_ eq$a,@_}@_
}

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