Re: Why the function ac_maketrans defined size of array is 256?

On 02/02/2012 05:53 AM, chatsiri wrote:
> Hello All,
> 
>     I  debug code of clamav.  Aho-Corasick( AC) Algorithms concepts for matching between virus and signature
files. Step for AC is build trie ( keyword tree)  for inserting signature from virus
> database files. I  have question in step build tire before matching with input information. Why source
code in "static int ac_maketrans(struct cli_matcher *root)" [1]  define size of array is 256?.

Because the trie matches byte-by-byte, so each node has 256 children, and that includes the root.

>      In addition, Do you using the Depth First Search Algorithm( DFS) for building trie?

ac_maketrans uses BFS.

Best regards,
--Edwin
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