1. Suppose we need to write an efficient program to store N employee records for ABC Inc where each employee record is identified by unique employee id. Consider the following ways to store the records.

   1. An array list sorted by employee id
   2. A linked list sorted by employee id
   3. A linked list not sorted
   4. A balanced binary search tree with employee id as key

   For data structure 1 -4, what is the average time to find an employee record given employee id as a key?

   O(log N), O(N), O(N), O(log N) O(N), O(log N), O(N), O(1) O(log N), O(log N), O(N), O(log N) O(log N), O(log N), O(log N), O(1) O(log N), O(log N), O(N), O(1)

2. In the previous question, for data structure 1-4, what is the average time to insert a new employee record given employee id as a key?

   O(N), O(N), O(1), O(log N) O(N), O(log N), O(N), O(1) O(log N),O(N), O(log N), O(log N) O(N), O(log N), O(log N), O(1) O(log N), O(log N), O(1), O(1)