Microsoft Software Development Engineer interview questions

1. Design a String class. Then write code to implement Insert(). Discuss performance about Insert and Lookup. The goal is to fine a solution that achieves O(logN) for both Insert and Lookup. 2. Write code for Push/Get to implement a ring buffer based on a fixed size char buffer. 3. Communication between Client/Server for a remote file system is based on a unreliable link (99% up-time but sometimes packet can be dropped). The client can send request like Open, Read, Write, Seek, Close, Create, Delete to the server. How would this system deal with packet loss? ACK is not allowed, so you CANNOT use a TCP like protocol. 4. Write code to implement a method that returns the top 10 most frequent words in a given string.