#!/usr/bin/perl

use Benchmark;

$|=1;

@list1 = ();
@list2 = ();

for $i (1..10000) {
    push @list1, int rand 100000;
    push @list2, int rand 100000;
}

print "..";

@list1 = sort @list1;
@list2 = sort @list2;

timethis(10, q{%list1 = map {$_, 1} @list1; %list2 = map {$_, 1} @list2; print ".";});

sub set_2_and {
    my ($words1, $words2, $cmp_fn) = @_;
    my ($i1, $i2) = (0, 0);
    my @and = ();
    while ($i1 < @$words1 and $i2 < @$words2) {
	my $cmp = $words1->[$i1] <=> $words2->[$i2];
	if ($cmp == 0) { push @and, $words1->[$i1]; ++$i1; ++$i2 }
	elsif ($cmp < 0) { ++$i1 }
	else { ++$i2 }
    }
    return [@and];
}