Affordplan Software Development Engineer interview questions

In writing there were three problems : 1. Find unique number present in an array. 2. Write a programme to merge two arrays. 3. Binary Tree Inorder traversal. In F2F : 1. Time complexity & how to reduce it (for given problems in written) 2. There are two tables for Credit and Debit. They both have the same data (id, amount, date). You need to write an API which returns data having id, amount and type(Credit/Debit) with latest 10 transactions. 3. There are three threads t1,t2 and t3. t1,t2 and t3 prints "1","2","3" respectively. You need to print the following pattern : 1 2 3 3 2 1 1 2 3 3 2 1.... 4. Difference between Runnable and Callable. 5. PostOrder traversal of Binary Tree. 6. Write a query to find 3rd highest amount from Credit Amount table. (Table may have duplicate data) 7. Spring MVC architecture and Flow of request. 8. Why we need Hibernate? (Discussion on Hibernate basics) 9. There are two Sets A and B having data (Set A : {6,1,4,5} , Set B : {5,2,3,4}). You have given a sum (i.e. 8). You need to find all subset of two elements from the different set having the sum equal to given sum. (sum =8, o/p : {{6,2},{4,4},{5,3}). 10. Explain the Factory Design Pattern.