Applied Materials Software Engineer 2 interview questions

Interviewed for the new grad software engineer position. Only one round, asked about knowledge with C/C++, some basic signal processing, and resume items. Ended with a brain teaser. I interviewed for the entry level position (SWE 1), but after negotiation, bumped up to the next level (SWE 2). Recruiter said this bump was because of good interview performance and other existing offers.