From: Ch Skilbeck <ruby@...>
Date: 2006-08-08T07:44:05+09:00
Subject: Re: nextPowerOf2(n)

Ch Skilbeck wrote:
> Hi,
> 
> Can someone tell me if there's a better way to do this? It takes a 
> number and returns the next power of 2 up (or the original if it was 
> already a power of 2) Specifically, are there features of Ruby that I 
> should be using in this case?
> 
> Cheers,
> Charlie.
> 
> def nextPowerOf2(n)
>   raise "integer please" if !n.kind_of? Integer
>   high = 0
>   count = 0
>   (0..n.size * 8 - 2).each {|b| count += n[b] ; high = b if n[b] != 0}
>   1 << high + (count > 1 ? 1 : 0)
> end

Thankyou all - very helpful indeed. In my eagerness to use Ruby features 
I managed to almost completely forget how to code and write something 
that's orders of magnitude slower than it needed to be. This has been 
extremely useful - I'm totally digging this Ruby deal, it feels like a 
comfortable holiday home with nice weather and a good beach.

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