Re: [Tcllib-devel] Revision 37 (fwd)

[Andreas K. <aku...@sh...>]

 
> now -
>  > 1761:					#we set u at the beginning of the queue
>  > 1762:						if { [lsearch $queue $u] < 0 } {
>  > 1763:							set queue [linsert $queue 0 $u]
>  > 1764:						}
> 
> Ok, this makes the index method (1) more complex, because now the
> 'linsert' happens at $at, not 0.
> 
> For 'struct::queue' the method to insert at the front is
> 'unget'. Unfortunately there is no 'seach' method however, so using
> struct::queue is not possible, contrary to what I thought before/above.
> 
> 
> I have the feeling I should step the algorithm with an example to see
> how this optimization works.
> 
> (The other branch is clear: Node not visited before, mark as visited
> and put on queue for processing).
> 
> Your 'lsearch' <=3D>  '$u ni $queue'

Ok, should you choose to go for a rewrite using $at etc. to iterate
over the queue then 'in' is not applicable anymore, because then the
option -start is needed to start your search at 'at' instead of the
beginning of the queue.

Realized that a bit late, while walking through the park.

-- 
So long,
	Andreas Kupries <aku...@sh...>
			<http://www.purl.org/NET/akupries/>
	Developer @	<http://www.activestate.com/>
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