Microsoft SDE-intern interview questions

first was resume shortlisting round, after which I received their mail asking me to schedule an interview. yes, I took a referral and scheduled my interview 15 days later. in round 1 they asked me 2 dsa questions of medium level one from linked list and another from tree I was able to solve both. later I received a mail that I had qualified, in next round again they asked me DSA questions from graph and trees however I was not able to solve the graph problem I received a mail stating that I have not qualified.