Amazon Software Development Engineer interview questions

Data structure and Algorithms about Graph and trees

So the OA had 7 Debugging questions, I debugged all of them and all the test cases was passed. Then, Section 2 was 2 coding questions one was string and the other was Finding all the average value of the internal nodes i.e excluding the leaves and including the root and return the maximum average value node. I got all of my test cases passed. Section 3 was Aptitude, it was easy. Section 4 is kinda behavioral questions. The highlighting thing is I gave my best and was not shortlisted. I finished both the coding questions in 40 mins and i had 30 mins left. Both of my solutions were optimized to run in linear time. But, 6 people who had just done 1 coding question and another one with partial test cases got shortlisted. Worst selection criteria.