I had a Google Hangout interview where I went over two fairly simple coding problems. The engineer was really kind and helpful, even when I made small bugs. I moved on to the on-site interview a few weeks later.

For the on-site, I was in a small interview office on the boardwalk, coding on my laptop. I had four interviewers, and most of them weren't particularly friendly, except for one. They all asked the same questions about my internships for fifteen minutes, which is nice, but it took away quite a bit of time from coding. Your code has to work 100% on all test cases.

One interviewer wouldn't talk to me or look at my code until I was done, so I awkwardly talked about what I was coding to myself while he worked on his laptop. There's really no room for error, so you have to be prepared to write bug-free code very quickly. Even though most of the algorithms are fine if you study (dynamic programming, backtracking), it's still complex to code in a limited amount of time.

The whole on-site left a pretty bad taste in my mouth, and I would not want to work there in the future.

Find permutations.

Find max sums.