Bumble Inc. Interview Question

1st Round by Recruiter: 3 sets of questions. 1. Java - Equals & Hashcode, Arraylist & LinkedList, Threads, Collections. 2. Android - Activity lifecycle, Async Task, RecyclerView, View & ViewGroup lifecycle, Fragments. 3. Data Structure and Algorithms O(n) - Arraylist & linkedlist, HashMap - (insert, delete, access & add). 2. Round HackerRank Test: 1-5 MCQ (Java, Android & O(n)): - series of lifecycle events moving from Activity A to B. - View lifecycle on "requestLayout" & on "invalidate" - FInd time complexity of given code snippet. 6. Check balanced braces. 7. In Unsorted array find unique pair where sum of these pair is K. 8. Problem on graph subcomponents.(Zombie Cluster). 3. Round By Android Developer(mostly 2-4 years exp.) Android/Java Theory & O(n) Android: Activity LifeCycle, View LifeCycle, Opinion on why RecyclerView is lagging(scrolls slowly), Async Task, MVP, Service. JAVA: equals & hashcode, Arraylist & LInkedList, Threads, Lock, Object (wait, notify), Synchronization, Checked & Unchecked Exception, How to create unchecked exception, collections, Design Patterns. O(n): 1. ArrayList & LinkedList(Insert, add, delete, access). 2. Traverse whole items in ArrayList & LinkedList which is faster? both are O(n), O(n) but ArrayList would be faster. 4. Code Pair (HackerRank) By Senior Developer(Around 5-8 years) Opinion on why RecyclerView is lagging(scrolls slowly). Q. Write a function to reverse the integer. - what if no is negative - what if reversed no is no longer in range of integer return 0 (check with Integer.MAX_VALUE & Integer.MIN_VALUE)