Technical interviews were conducted by phone. Both Googlers I spoke with didn't have microphones near them (perhaps the phone was on the desk?). I could hardly hear their words. One of them was over 20 minutes late for a scheduled 45-minute call. What is more, the recruiter responded to me three weeks after the Hiring Committee meeting, whereas all my friends received a response within 5 days of it. Each time I tried to reach him, he was on holiday.

Write an algorithm to generate all subsets of a set.

Implement a data structure based on a key-value map with an expiration time.