Amazon Developer interview questions

I received an email from the recruiter that the hiring manager has reviewed my resume and would like to set up two phone screening sessions. Then I had the two phone screening in the same week, followed by a third phone screening which was mostly about OOP and "why I would like to go to Seattle!?". Received an email more than a month later saying that they've proceeded with another candidate!

First phone interview, which didn't go well. First question was about linked list traversal finding a node towards the tail. The algorithm I gave them ran in O(n), then they said it wasn't good enough, so I thought about reversing it and counting from the tail. That took up too much s...pace complexity so I was baffled for a while because I thought they wanted a much more efficient algorithm. Turns out they just wanted two pointers to traverse, which would only be faster than my original algorithm by a constant amount. I failed to see why that would make that much of a difference. Second question was about Comparable vs Comparator. I NEVER used comparator during my years using Java so I couldn't answer that one. Third question was finding duplicates in an array. Create another array to keep track of the repetitions, done. Last question was the hardest - determining the angle between an hour hand and minute hand on a clock. I wasn't expecting a mathematical type question, plus I never really bothered to learn how an analog clock works that well anyway. I took a long time - and screwed up the formula for it, but basically it was dividing the degrees of each quadrant and applying what I know about hours and minutes to it. Didn't do that well - cause clocks aren't exactly my area of expertise.