From: Ron Jeffries <ronjeffries@...>
Date: 2002-03-21T04:42:54+09:00
Subject: Re: Why is Ruby so slow? - Solution

On Wed, 20 Mar 2002 13:43:19 GMT, nobu.nokada@softhome.net wrote:

>> I'm curious. How do you do this operation in O(N+M)?
>
>Once making a hash whose keys are the minuend's elements, and
>remove the subtrahend's elements from it.  At last, for all the
>minuend's elements, add it to the result array if it is
>contained in the hash.  Oops, sorry, it was O(2*N+M).

Assumes hash lookup is O(N) which it might not be. Close enough for me tho.
Thanks!

Ronald E Jeffries
http://www.XProgramming.com
http://www.objectmentor.com
I'm giving the best advice I have. You get to decide whether it's true for you.