From: Simon Strandgaard <neoneye@...>
Date: 2005-10-16T03:31:15+09:00
Subject: Re: How to get non-unique elements from an array?

On 10/15/05, Sam Kong <sam.s.kong@gmail.com> wrote:
> I need to get non-unique elements from an array.
> The best I came up with was using a hash as a counter for each unique
> elements.

How about?

ary = [1, 1, 2, 3, 3, 4, 2, 5, 7]
#=> [1, 1, 2, 3, 3, 4, 2, 5, 7]
uary = ary.uniq; ary.map.delete_if{|i| x=uary.member?(i); uary.delete(i); x}
#=> [1, 3, 2]


--
Simon Strandgaard