Amazon Software Developer Intern interview questions

The interview consisted in an online test on coding platform, there were 2 problems to solve in 90 minutes, if memory serves. The problems were easy and finished well before the time expired. However the platform which did provided feedback for the "Demo problem" did not provided any feedback whatsoever on the problems that I had to solve, probably because it was Amazons intentions. Not so peachy.

There are 3 phone interviews. One interviewer asked how to find cross elements in two given arrays.