1. Design a system like Amazon music. After finishing your design, implement a function that returns the most 10 popular singers in the database. You should define your what "popular" is. 2. Given a family tree. Design your data structures to help you implement the function that determines whether any two persons in the family tree are blood related. 3. Manager asked me about my projects and some personality questions. 4. Don't remember 5. Min number of coins to a given value. For example, given you have four kinds of values of coins, 1, 4, 9, and 16, you should find out the minimum number of coins that they sum up to 53. This is a classic DP problem.