The technical round included two interesting coding questions:

• One related to multithreading and synchronization.
• The other focusing on string processing.

Overall, the questions were well-structured and tested both multithreading concepts and algorithmic thinking. I highly recommend preparing for concurrency and real-time processing challenges if you're interviewing for a similar role.

1. Multithreading Synchronization

I was given two functions, func_a() and func_b(), each running in a separate thread:

c void printA() { while(1) print("a"); }

void printB() { while(1) print("b"); }

Each function runs indefinitely, printing either "a" or "b". The task was to introduce synchronization mechanisms (such as mutexes, semaphores, or condition variables) to ensure the output alternates as ABABABAB rather than random sequences like AAA BBB or AAABBAAAAA.

This problem is similar to LeetCode 1115 - Print Foo Bar Alternately, where two threads need to synchronize their execution.

1. First Unique Character in a String

The second question involved processing a string and returning the first character that appears only once. This problem is identical to LeetCode 387 - First Unique Character in a String.

Follow-up:

The interviewer extended the question, asking how to solve it in a streaming scenario, where characters arrive one by one. This variation aligns with LeetCode 1429 - First Unique Number, requiring an efficient way to maintain the first unique character dynamically as new characters arrive.