Need some help regarding Microsoft OA experience

Hi i has an on-campus Microsoft SDE (placement full time) oa coming, i want to maximise my efforts so can anyone tell like focus on these these topic that are company’s favourite and usually come.

I also like to know about interview prep if someone can help focus on which things more ?

I heard there were 3 round of interviews so can you inform me regarding their interview process and how to ace it ?