Exp: 3 years
Round 1 :

1. Print Inorder traversal of Binary tree which left leaf node is connected to left sibling and right leaf node is connected to right sibling(i.e no node is null except the left of leftmost node and right of rightmost node).
2. Design Data structure which can insert, delete ,fetch and getRandom in O(1) time.

Round 2 :

1. write code for Merge sort
2. find starting and end index of element in sorted array.
   ex : 1,2,2,2,2,3, target = 2;
   start index = 2
   end index = 5

Round 3 :
design Elevator system.