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Re: generate combinations of lists

by gargle (Chaplain)
on Sep 28, 2005 at 07:27 UTC ( [id://495658]=note: print w/replies, xml ) Need Help??


in reply to generate combinations of lists

Hi,

update: clarification

disclaimer: bogoperm, but it does fit your description of the problem!

#!/usr/bin/perl use strict; use warnings; ############# # bogoperm! # ############# my @array = qw(a b c); my $length = @array; # faculty my $fac = 1; foreach my $f (1..$length) { $fac *= $f; } # my results my %hash = (); # internals my $check; # if equals control then we found a number my $control; # has to contain something like 123... my $index; # the number itself, it's an index! my $count = 0; # 'till this equals $fac OUTER: do { INNER: while (1) { do { $check = 0; $control = 0; $index = 0; foreach my $i (1..$length) { my $number = 1+int(rand()*$length); $index += $number * 10**($i-1); $check += 10**$number; $control += 10**$i; } $check /= 10; $control /= 10; } while ($check != $control); last INNER if defined $hash{$index}; $hash{$index}++; $count++; } } while $count != $fac; # print out the results foreach my $i (keys %hash) { my $j; do { $j = $i % 10; print $array[$j-1]; $i = ($i - $j) / 10; } while ($i > 0); print "\n"; }

output:

bash-3.00$ ./perm.pl cba acb bac cab abc bca

I'll leave it as an exercise to put the output in real lists.

Well, at least I used strict and warnings :o

--
if ( 1 ) { $postman->ring() for (1..2); }

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