I applied through a recruiter, who scheduled a telephonic interview for the following week. The interview had three parts:

• Resume review (10-12 minutes)
• Coding challenge (45 minutes)
• Questions about the company (5 minutes)

The coding part was not difficult. However, the team still uses an old C++ style, and the interviewer did not understand C++11 syntax (like the new for loop, auto, or shared_ptr). When I asked if I should use older C++ conventions, he instructed me not to. It was somewhat frustrating to learn they are not utilizing new language features.

During the interview, the interviewer gave me the impression that he was very happy with my coding and stated he was pleased with my performance. We had a productive discussion as we developed the program. I completed both coding questions to his satisfaction.

However, a week later, I received feedback from my recruiter stating that while they considered me a strong candidate, my skillset did not match their requirements. This was surprising, as I have been working in the same field using C++ for 19 years. Perhaps the interviewer was unhappy when I began using new C++ language features.

Compress a string using a number of repeated characters followed by the actual character. For example, 'aaassbd' should be converted to '3a2s1b1d'.

Matrix multiplication (3x3 to 1x3). I forgot the actual logic, but I quickly picked it up and wrote the program once the basic logic was explained with a simple example.

Time and space complexity of the above functions.