The process took over two months. I applied online and received a reply several days later, which was really fast. A phone interview was scheduled first. An array manipulation question was asked, followed by a further improved question based on the initial one. Then, they asked for optimization. I received a reply two days later by phone (they clearly love to contact by phone). An onsite interview was scheduled one month later. I traveled to Mountain View and San Jose. It involved four interviews in a row with a lunch break. The second interview was extremely hard. Two days later, I was rejected by phone.

Here are some hints:

• Iterator of Iterators
• HashMap
• Subsets
• Binary Tree