Re: Getting the intersection of n collections.

[basje]

this also works with duplicates

my $sets = [
    [1,2,3,3,3,3,4,5,6,7,8,9,10],
    [1,1,1,2,6,7],
    [3,4,5,5,5,5,6,6,6,6,7,8,9],
];

my %hash = map { $_, 1 } @{$sets->[0]};
for(my $i=1; $i<scalar(@{$sets});$i++) {
    %hash = map { $_, 1 } grep {%hash->{$_}} @{$sets->[$i]};
}

return (keys(%hash));

[johngg]

I think you may have a typo in your solution. The grep {%hash->{$_}} should perhaps be grep {$hash{$_}}.

Nice solution, though.

Cheers,

JohnGG