Trivia: recursive zip files

[willvarfar]

http://research.swtch.com/zip

[m^2]

Cool
I can totally see this being used to make some apps (antiviruses?) hang.
Wow, Total Commander's search with unlimited recursion depth didn't hang. Looks cool, but I think in this case it's a sign of a bug.

[Piotr Tarsa]

Such recursion is rather easy to detect IMO. AFAIR there were attempts to destabilize AVs by creating very reduntant ZIP files with a deep recursion (but finite) and different filenames in archives. I think AVs today are smart enough to just give up on such archives.

[willvarfar]

More trivia links:

Ukkonen's suffix tree explained nicely:

http://stackoverflow.com/questions/9...nglish#9513423

[Piotr Tarsa]

Too bad I already understand Ukkonen's on-line suffix tree construction

When learning I've started from Mark Nelson's article (as it's on the first results page in Google), but probably the most helpful things was the article http://www.allisons.org/ll/AlgDS/Tree/Suffix/ as it introduced a concept called "Bottom node" which makes algorithm more straightforward and reduces the coupling between functions. Also suffix tree applet from: http://illya-keeplearning.blogspot.c...va-applet.html was very helpful for me.

Such bottom node IMO shares a lot of similarities with order -1 coding and, indeed, the only place where I do order -1 coding in my to-be-released on-line suffix tree based compressor is when descending from bottom node to root node.

[Karhunen]

http://research.swtch.com/zip

Hmm I mentioned this to Matt a month ago.. or did I ? Time only goes in one direction, doesn't it? Anyway, good luck to the 1st person who does this in ZPAQ.
I imagine it should be easier if it were a .lzma file, as I believe there is no CRC

[Matt Mahoney]

I tried a brute force search for files that compress to themselves. Didn't work.

[m^2]

I tried a brute force search for files that compress to themselves. Didn't work.

Did you try all of them?

[willvarfar]

Trivia: http://www.ludumdare.com/compo/ is this weekend

[willvarfar]

Trivia: using BWT for search of gene sequences: http://blog.avadis-ngs.com/2012/04/e...h-using-bwt-2/