Hero Engine interview questions

Had a technical phone interview. The interviewer was nice and asked basic c++ and oops concepts like 1. what does new do ? 2. static keyword 3. virtual fuctions 4. stack and heap memory. A little bit about gaming interest and my resume. Then he shared an online editor where he asked me to code a problem - string compare function. Then he showed me a piece of code and asked me to find bugs. I didn't get it immediately but it was rather simple once I saw it. It was stack memory creation and returning the variable where its not accessible. I took time to see that and also in coding did a silly mistake. I guess that's why I got rejection.