Amazon SDE - 1 interview questions

I wrote an exam in which there are 4 rounds. 1st is code debugging we have to debug the code and find errors in it.2nd is coding we have to solve 2 coding questions of data structures.3rd one is about working style assesment its just how we deal with different situations ,Finally 4rth round is apptitude rounf

It was really helpful and quite knowledgeable interviewing with an Amazonian. He did not ask for any coding but simply the approach to the question. He was mainly focussing on my logical thinking.