From: "Wolfgang Nádasi-Donner" <wonado@...>
Date: 2007-05-12T08:55:04+09:00
Subject: Re: how to remove dups from 2 lists?

Wolfgang N�dasi-Donner schrieb:
> Or is it something like this?
> 
> ...
> --- before ---
> ["a", "b", "a", "a", "c", "a", "b", "c", "d", "e", "f", "e", "a"]
> ["a", "b", "a", "c", "d", "c", "d", "c", "c", "g", "h", "g", "c"]
> --- after ---
> ["a", "a", "b", "e", "f", "e", "a"]
> ["d", "c", "c", "g", "h", "g", "c"]

If it is the wanted direction, the program is simple.

class Array
   def remdups(b)
     a= self.dup
     b.each{|el|a.delete_at(a.index(el)) if a.include?(el)}
     a
   end
end

a = %w{a b a a c a b c d e f e a}
b = %w{a b a c d c d c c g h g c}
puts '--- before ---'
p a
p b
puts '--- after ---'
p a.remdups(b)
p b.remdups(a)
p [1,1,1,1].remdups([1,1,2])
p [1,1,2].remdups([1,1,1,1])

Output:

--- before ---
["a", "b", "a", "a", "c", "a", "b", "c", "d", "e", "f", "e", "a"]
["a", "b", "a", "c", "d", "c", "d", "c", "c", "g", "h", "g", "c"]
--- after ---
["a", "a", "b", "e", "f", "e", "a"]
["d", "c", "c", "g", "h", "g", "c"]
[1, 1]
[2]

Wolfgang N�dasi-Donner