From: "David A. Black" <dblack@...>
Date: 2009-09-26T21:01:32+09:00
Subject: Re: How to  remove duplicate elements in a 2D array

Hi --

On Sat, 26 Sep 2009, Thairuby ->a, b {a + b} wrote:

> I think you want an array with unique member. If the member is not
> unique
> then return the last occur of it.
>
> arr=[[ 'a',1,2,3],
> ['b',4,5,6],
> ['c',3,2,1],
> ['a',1.3,2.2,3,3],
> ['a', 2,1,3],
> ['a',2.1,1.5,3]]
>
> result = arr.inject({}){|x,y| x[y[0]]=y[1..-1]; x}.map(&:flatten)
> p result
>
> # [["a", 2.1, 1.5, 3], ["b", 4, 5, 6], ["c", 3, 2, 1]]

You could economize on intermediate objects and method calls like
this:

   result = arr.inject({}){|x,y| x[y[0]]=y; x}.values

That way, you don't take the first element out, so you don't have to
put it back.


David

-- 
David A. Black, Director
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