KLA Applications Developer interview questions

I got an email from the hiring manager first. Then I had an phone interview with him. A week later, I got noticed to have an onsite interview with them. I did a 1 hour presentation in the morning and meet about 8 ppl. Then I got phone call from the recruiter the second day after my interview

First Round: They kept a technical aptitude round consisting of finding outputs for C,C++ programs and questions from Data structure and OS. Many eliminated here. Second Round: An 1:1 interview where they will ask you to explain various programs from the aptitude test. This is mainly to eliminate those who cleared apts rnd by luck. It does'nt matter even if you get a few questns wrong. They are just trying to make you understand what you got wrong or how you justify ur ans. Few eliminated here. Third Round: A 2:1 Interview where they will ask a lot of logical questions and pgm. 1) Write a pgm where letters should be in alternate cases. Ex: HeLlO wOrLd 2) Sorting by connecting boxes. 3) Reversing a sentence word by word. Ex: "Hi you" -> "iH uoy" . 4) Ques in DS, OS. They will shortlisty final list here. Fourth Round: HR round. A lot of case studies. There may be eliminations. Offer is subject to Compulsary internship.