[Jprogramming] tree sum and difference

[Roger Hui]

What was the solution you anticipated?



----- Original Message -----
From: Raul Miller <rauldmiller at gmail.com>
Date: Thursday, March 13, 2008 5:55
Subject: Re: [Jprogramming] tree sum and difference
To: Programming forum <programming at jsoftware.com>

> Roger Hui wrote:
> tsum3=: 4 : 0
>  d=. ((</.i.@#) y) -.&.> i=. ~.y
>  while. 1 do.
>   c=. #&>d
>   j=. (*c)#i
>   i=. c#i
>   e=. ;d
>   t=. i +//. e{x
>   if. 0 *./@:= t do. x return. end.
>   x=. (t+j{x) j}x
>   d=. i <@;/. (j i. e){d,a:
>   i=. j
>  end.
> )
> 
> That is significantly faster than I anticipated.
> 
> (and, considerably more complicated than tdiff,
> but that complication is intrinsicly a part of this
> problem.).