From: "David A. Black" <dblack@...>
Date: 2007-08-19T20:33:37+09:00
Subject: Re: Detecting duplicates in an array, anything in the standa

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Hi --

On Sun, 19 Aug 2007, Wolfgang N=C3=A1dasi-Donner wrote:

> Thibaut Barr=C3=A8re wrote:
>> Anything more elegant ?
>
> No! :-)) - I tried it only using Arrays...
>
> a =3D [1,2,3,4,5,4,2,2]
> p a.inject([[],a[1..-1]]){|r,e|r[1].include?(e) ? [r[0]<<e, r[1][1..-1]]
> : [r[0], r[1][1..-1]]}[0].uniq # =3D> [2, 4]
> b =3D %w(a b c c)
> p b.inject([[],b[1..-1]]){|r,e|r[1].include?(e) ? [r[0]<<e, r[1][1..-1]]
> : [r[0], r[1][1..-1]]}[0].uniq # =3D> ["c"]

How about:

   >>  a =3D [1,2,3,4,5,4,2,2]
   =3D> [1, 2, 3, 4, 5, 4, 2, 2]
   >> a.inject([]) {|acc,e| acc << e unless acc.include?(e); acc }
   =3D> [1, 2, 3, 4, 5]


David

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