I've read HN for two years now... made an account just a few days ago... I don't write a very good english (I understand it really well though) so I've never felt like commenting...
I've been a IOI participant twice -> and twice a looser.
I can't help but feel curious about the "shit" that was deleted.
It's not cool to just have a [dead] remark; could there be a better solution to remove the noise, yet allow curious people to find out what are the replies referring to?
Go to your profile and turn on "Show Dead". I used to leave it on because, like you, I was curious. But over time I've come to trust the deletions, and now believe that, on the whole, the deleted material simply wastes my time.
The ones that I found more interesting were the ones on line sweep and geometric algorithms.
On Fenwick's Trees; this tutorial http://www.topcoder.com/tc?module=Static&d1=tutorials... is really good. Although, the original paper is well-explained: (link to the author's website) http://www.cs.auckland.ac.nz/~peter-f/ ("A new data structure for cumulative frequency tables")
And on bit manipulation; I highly recommend you read this... you'll be thinking in zeroes and ones for a while... http://www.topcoder.com/tc?module=Static&d1=tutorials...