Microsoft Software Engineer(Internship) interview questions

I applied on their website, I received an email with a challenge code on codaility, the questions were hard. It wasn't from leetcode, the topics were graphs and trees,I wasn't expecting a graph problem

First round was online coding test and interview with recruiter. This interview was mainly introductions but I was also asked a brain teaser. Four on site technical interviews which focused on different aspects of the role.