For the phone interview, I was asked for basic concepts about vectors, arrays, linked lists, and their differences. Another question was: Given a book and a function that returns one word at a time, how would you find the five most frequent words?

I received the invitation for an onsite interview the next day. There were four rounds. The first two were technical interviews, the third round was with HR, and the last round was with a manager.

1. There are consecutive numbers from 0 to 100, with one missing. Find out which one. Improve the algorithm. How about using a mathematical method?
2. Search and sort questions, and improve accuracy.
3. Given many left and right bracelets, how do you test if the bracelets form pairs?
4. Delete a node in a linked list.