> 3) Write a Perl function that takes two references to arrays and returns the
> intersect of them.
> If an entry appears n times in array 1 and m times in array 2,
> the output should list that entry min(n,m) times.
> Bonus mark for one line solutions.
#!/usr/bin/perl -w
#*** compare_int_arrays_v001.pl ***#
#-------------------------------------------------
use strict;
#-------------------------------------------------
my (@i_list1, @i_list2);
push(@i_list1, int(rand(100))) for(1..200);
push(@i_list2, int(rand(20))) for(1..10);
print("value:\tlist 1:\tlist 2:\n");
print("$_->[0]\t$_->[1]\t$_->[2]\n") for(@{Intersect(\...@i_list1,
\...@i_list2)});
#-------------------------------------------------
sub Intersect
{
my ($rai_1, $rai_2) = @_;
return [] unless(ref($rai_1) eq 'ARRAY' && ref($rai_2) eq 'ARRAY');
my (%i_seen, @i_ret);
$i_seen{$_}[0]++ for(@$rai_1);
$i_seen{$_}[1]++ for(@$rai_2);
@i_ret = map [$_, $i_seen{$_}[0], $i_seen{$_}[1]],
grep $i_seen{$_}[0] && $i_seen{$_}[1],
keys(%i_seen);
return [sort({ $a->[0] <=> $b->[0]} @i_ret)];
}
#-------------------------------------------------
Torsten
