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...
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.
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...