CODEWITHSUNDEEP
perlpermutation
Tyzak
Tyzak

Reputation: 2438

Perl: Using glob for permutation of values in an array with a userdefined length

I just read

How can I generate all permutations of an array in Perl? http://www.perlmonks.org/?node_id=503904 and https://metacpan.org/module/Algorithm::Permute

I want to create all possible combinations with a userdefined length of values in an array.

perlmonks did it like this:

@a= glob "{a,b,c,d,e,1,2,3,4,5}"x 2;
for(@a){print "$_ "}

and this works fine, but instead of "{a,b,c,d,e,1,2,3,4,5}" I would like to use an array

i tried this:

@a= glob @my_array x $userinput ;
for(@a){print "$_ "}

but it didn't work, how can I do that? Or how can I limit the length of permutation within Algorithm::Permute ?

Upvotes: 2

Views: 631

Answers (1)

Zaid
Zaid

Reputation: 37136

Simply generate the string from the array:

my @array = ( 'a' .. 'e', 1 .. 5 );
my $stringified = join ',', @array;
my @a = glob "{$stringified}" x 2;

say 0+@a;             # Prints '100';
say join ', ', @a;    # 'aa, ab, ac, ad ... 53, 54, 55'

One could also use a CPAN module. Like List::Gen:

use List::Gen 'cartesian';

my @permutations = cartesian { join '', @_ } map [ $_ ], ( 'a'..'e', 1..5 ) ;

Upvotes: 4

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