The problem with interviews I am having (I am about to graduate and have not got a job yet) is that the whole hiring process is too one-dimensional. Some companies only care about algorithmic coding competition skills that you can only achieve via competing in some sites like TopCoder, CodeChef and some other companies only care about how many years of experiences you have - does not matter what you have learned from experiences, it is just how many years that count.

Coding contest skills are very unfair to senior developers because they are out of school long time and do not have the time or motivation to engage in coding competition. And this also creates different incentive models. I have seen people who flunked very elementary CS courses (OS, networking etc.) to spend more time coding competition to get hired in big companies. This is really weird because they have to learn these things to become a real developer and they are gonna learn these things in company's time which they should know already. That being said, I personally think, problems like maze solving and inverting binary tree are fair questions. These are not exotic DP problems, these are just simple problems.

OTOH, the whole years of experience thing is unfair for new developers who do not have the experience but smart enough to learn and outperform many developers with experience who just memorized APIs over years of experience. There must be a healthy compromise between these two types of hiring.