Hi All,
  I've been updating some old code that displays adverts randomly based on what weight has been applied to them.

At the moment I have:- 

    my $group = { ad1 => 5, ad2 => 10, ad3 => 20 };

    my $weighttotal  = 0;
    my @rndselect = ();
    foreach my $advert ( keys %$group ) {
        $weighttotal += $group->{$advert};
        while ( $group->{$advert} > 0 ) {
            push( @rndselect, $advert );
            $group->{$advert}--;
        }#while
    }#loop
    my $rannum = rand($weighttotal);
    $rannum  = int($rannum);
    $advertinfo->{advert} = $rndselect[$rannum];

[download]
It creates an array with each item being the name of the advert, so there will be 5 ad1, 10 ad2, and so on. It then selects a random location from the array.

Looking at it, this seems horribly inefficient, I'm guessing there is a super efficient and straight forward way to do it another monk could tell me.

Thanks
Lyle

In reply to Weighted random selection by cosmicperl

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