From: Zach Dennis <zdennis@...>
Date: 2005-10-18T08:58:31+09:00
Subject: Re: How to get non-unique elements from an array?

Ryan Leavengood wrote:
> On 10/17/05, Ryan Leavengood <leavengood@gmail.com> wrote:
> 
>>The results:
>>
>>Small array, lots of iterations:
>>                  user     system      total        real
>>markvh        0.391000   0.000000   0.391000 (  0.391000)
>>martin        0.390000   0.000000   0.390000 (  0.484000)
>>
>>Big array, one iteration:
>>                  user     system      total        real
>>markvh        0.015000   0.000000   0.015000 (  0.016000)
>>martin        0.000000   0.000000   0.000000 (  0.000000)
>>
>>Overall Martin's was the best. As he suspected, David's was quite
>>slow. Sam's as well.
> 
> 
> On second thought, Mark's may have been the best overall. Either way,
> both Mark's and Martin's are good algorithms. Many of the others were
> good as well.
> 

Mine isn't the shortest, but it's the fastest I've seen thus far! Twice 
as fast as the next closest! Why does everyone leave me out of benchmark, ;)

---my code
  t=[]; a.delete_if{ |e| r=(not t.include? e); t.push(e); r }
---end my code

 > "c:\ruby\bin\ruby.exe" find_non-uniques.rb -d
            user     system      total        real
delete  0.218000   0.000000   0.218000 (  0.218000) <---- MINE!!!
index   0.500000   0.000000   0.500000 (  0.547000)
grep   0.500000   0.000000   0.500000 (  0.516000)
scan   1.078000   0.000000   1.078000 (  1.172000)
inject   0.656000   0.000000   0.656000 (  0.672000)
gsub   1.250000   0.000000   1.250000 (  1.250000)
include  0.672000   0.000000   0.672000 (  0.687000)

Zach