SPOILERS AHEAD

1a The runtime scales with the product of the sizes of the two arrays.
1b You'll want some sort of more linear indexing function on one of the hashes to save time. In Perl, it'd look a bit like this: 
my %b_hash = map { $_ => 1 } @b_array;
my @new_array = grep $b_hash{$_}, @a_array;

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2 
my @array = ( 'foo', 'bar', 'baz', 'cheeze whiz' );
for (my $left = 0, my $right = $#array; $left < $right; $left++, $righ
+t--) {
  @array[$left, $right] = @array[$right, $left];
}

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3 I have a column on that.

-- Randal L. Schwartz, Perl hacker

In reply to •SPOILERS Re: (OT) Interview questions -- your response? by merlyn
in thread (OT) Interview questions -- your response? by Ovid

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