Re: Problem on Vitter algorithm

On Apr 25, 1:52 pm, "LiloLilo" <danilo.brambi...@xxxxxxxx> wrote:
Hi all,

I have some problems understanding Vitter algorithm. Please consider this
example:

http://en.wikipedia.org/wiki/Adaptive_Huffman_coding

suppose the new caracter after "abb" would be "a". So I have to do the
update procedure:

1. Go to node 253
2. Now I have to consider if this node does not have the highest number in a
block and if no swap it with which has the highest number.

But, this block contains nodes 253 and 254, but 254 does not contain a
caracter. So how can I swap them? It is correct If I suppose that a block
must contains only nodes with a caracter and caracters are only on leaves
nodes? So in this case the block would contain only node 253, so I don't
need to swap but only increase the counter and go on with the parent?

Thank you all!


I think you would have a better understanding if you go to
http://www.ics.uci.edu/~dan/pubs/DC-Sec4.html#Sec_4.2
The Vitter adaptive huffman is a good one to learn with I
have a bijective version on my site check it out.

David A. Scott
--
My Crypto code
http://bijective.dogma.net/crypto/scott19u.zip
http://www.jim.com/jamesd/Kong/scott19u.zip old version
My Compression code http://bijective.dogma.net/
**TO EMAIL ME drop the roman "five" **
Disclaimer:I am in no way responsible for any of the statements
made in the above text. For all I know I might be drugged.
As a famous person once said "any cryptograhic
system is only as strong as its weakest link"

.

Relevant Pages

  • Re: Problem on Vitter algorithm
    ... the caracter was never seen, or the position on the second array of ... Do you know any implementation that uses arrays? ... block and if no swap it with which has the highest number. ... My Crypto code ...
    (comp.compression)
  • Problem on Vitter algorithm
    ... I have some problems understanding Vitter algorithm. ... suppose the new caracter after "abb" would be "a". ... Now I have to consider if this node does not have the highest number in a block and if no swap it with which has the highest number. ... But, this block contains nodes 253 and 254, but 254 does not contain a caracter. ...
    (comp.compression)