Round 2 F2F: Test Case, Test Data Enumeration and Problem Solving 1. What is the difference between Abstract Class and Interface 2. When should I go with Abstract Class and when should I use Interface? 3. What is the difference between Array and Any Collection Class? 4. What is the difference between ArrayList and LinkedList? 5. Given an array arr[] = {5, 10, 15, 25, 20, 30}; find the elements where the sum is equal to k = 25. Here you can add pick 25 and say it is equal to k, pick 2 elements to add it and say it is equal to k, or pick 'n' elements from the array and say it is equal to k. immediately find all the array elements that creating the addition to k. 6. Time complexity and Space complexity of the program you wrote. 7. Enumerate test data and write test cases for the above code
