Amazon Internship-Software Engineer interview questions

So I applied for Summer 2019 Internship position. The process took more than 3 weeks and consist of 3 rounds. The first round consists of 7 debugging questions and quantitative question. The second round was coding round with 2 coding questions one related to array and other was related to n-ary tree to be completed in 70 mins. The final round was Interview round of 45 mins. It was a phone interview where they asked me 3 behavioral questions and one technical question. It was tough. One can crack it if they have a very strong knowledge of data structure and extremely good in coding