push @x, pack "A*", qq[@$_] while $_=$i->next;

That would probably match if not beat join, if you weren't stringifying the array twice.

Ie. Use  push @x, pack "(A*)*", @$_ while $_=$i->next;

Of course, if you want to put all the sequences as strings into an array, this is easier and probably quicker;

my @x = map join( '', @$_ ), variations_with_repetition( ["a".."z"], 4
+ );;

print scalar @x;;
456976

[download]

And if all you want to do is print the count, then:

[ 7:10:21.87] C:\test>perl -MAlgorithm::Combinatorics=:all -le"print s
+calar( () = variations_with_repetition( ["a".."z"], $ARGV[0] ) )" 4
456976

[ 7:10:27.12] C:\test>

[download]

BTW, that is one seriously quick machine you're running. What is it? (6x faster than my (admittedly ancient) box.

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority". The enemy of (IT) success is complexity.
In the absence of evidence, opinion is indistinguishable from prejudice. Suck that fhit

In reply to Re^7: list of four digit lock combinations without repeated digits by BrowserUk
in thread list of four digit lock combinations without repeated digits by Lotus1

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