I got in touch with a Google Recruiter through an employee referral. The recruiter was very helpful, and after some informal discussion about my background, they explained the interview procedure.

One week later, they organized a phone interview. Unfortunately, the phone line was quite bad, making it very hard to understand the interviewer's questions. I felt it was my unlucky day, and the entire experience was uncomfortable. All the questions were unexpected, and even small mistakes were not tolerated.

Reorganize an array of numbers in a "s1 < s2 > s3 < s4 > ..." fashion. The numbers may include duplicates.