Re: Finding the max()/min()

in reply to Finding the max()/min()

What I really like is writing generic min/max routines that handle more than two variables. They show the beauty of recursive functions, even though Perl doesn't handle tail-recursion¹.

Iterative:

sub max {
    my ($max, @vars) = @_;
    for (@vars) {
        $max = $_ if $_ > $max;
    }
    return $max;
}
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Recursive:

sub max {
    my ($max, $next, @vars) = @_;
    return $max if not $next;
    return max( $max > $next ? $max : $next, @vars );
}
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Interestingly enough, though this example works well in several languages, Perl's iterative version is remarkably short; I've never noticed this before. I guess I just proved myself wrong.

elusion : http://matt.diephouse.com

¹Okay, so this isn't strictly true. Using a magic goto with the & sigil and @_, you can fake it. But it's not very pretty.

Update: Fixed my mistake. Thanks, pg. (I always want to use postmodifier if and for in the same statement.) Update: Okay, so I should test my code before I post. Or find where I left my brain. Snippet 2 is fixed.

In Section Meditations