Ask HN: How to improve algorithmic problem solving (Euler)

Hi HN,

I'd like to ask if there are any resources that would be handy to train one in algorithmic problem solving?

I've been practicing on Euler for a bit, but I'm getting to some of the harder questions where brute force just doesn't really cut it anymore and I hit a complexity ceiling.

I've intuitively (after reading some books) decided that I should approach these problems in 2 steps:

- attempt to divide the tests into smaller subsets - attempt to linearly reduce the number of tests within each subset

However this doesn't seem to be sufficient when dealing with more difficult problems. And there isn't a step-by-step guide to solving any type of problem... I look at some sample solutions for the problems and go "How on earth did they get that?!"

Yes, I will continue practicing, but any advice would be good as I'm going for an interview sometime soon. =)

Regards, Daryl