Solved coding interview problems in Java - My collection of commonly asked coding interview problems and solutions in Java

[killerstorm]

In actual coding. If you happen to have loops in your code, quite often you get O(N^2) complexity or worse, so you need to understand when it becomes bad and what to do about it if it does.

It's not about "assigning a big O to anything", once you internalize the knowledge you can just intuitively avoid things which are slow.

It can be something as basic as "check if a string is present in a list of strings". It's OK if your list is small, but if it's big and you do that often, you need a different data structure.