in reply to removing the goto

I had the benefit of a direct discussion with the OP about this, which brought much clarity as to his intentions. He has an array of ~4000 elements and wants to select five non-duplicates out of there. So basically, his code can be reduced to this:
use List::Util 'shuffle'; my %unique = map { $_ => 1 } @weighteddiv; my @shuffled = shuffle(keys %unique); @selected = @shuffled[0..4];
I noticed he was randomizing the array, then selecting random indices from there, which was not only reduntdant but created the issue of potentially selecting the same element.

Update: The big array is *not* already internally unique after all, so I had to add the line to unique it.

Update 2: My solution is no longer relevant, after the OP updated with more information. However, I'm leaving my code as-is because it might help a future monk looking for a similar solution.

It's all fine and dandy until someone has to look at the code.