CommScope Developer interview questions

Onsite 1st part (Knowledge questions): (1-1:30 hrs) 1. Almost everything that I mentioned on the resume. The question pattern was DFS fashion, I mean they started with one simple topic from resume and went very far. 2. Thread vs Process. How do you solve (compute/just scan every element) a very very large matrix? I answered with four threads. Then the follow-up question was how would you combine four results? 3. What is a virtual function? How does it work under the hood? Pure virtual function? virtual table? How does the compiler know about a virtual function etc.? 2nd part: Whiteboard coding 3 string related problems. I came up with the idea to solve the first question within < minutes. It was a modified valid parenthesis question. I presented my idea and asked some clarification questions. Then started to write the solution, I tested my code with some test cases and they said it was perfect and did not ask any questions. I assume they were pretty happy because I solved the problem in O(n) time and O(1) space complexity although they were expecting O(n) space solution. The next two problems were encoding and decoding the string. But there were some tricky cases, and I mentioned them how to handle them. They seemed very positive.