Lenskart interview for SDE2

First Round (Written) :
1. 6 MCQs in java
2. Sliding window maximum
3. Sum of elements at same vertical level of a binary tree.
4. Reverse words of a sentence without using split or any other in built functions.
Example :
Input : Bangalore is my city
Output: city my is Bangalore

Second Round (F2F):
1. Maximum distance between two nodes of a binary tree.
2. Zigzag traversal of a binary tree.
3. Implement immutable class with secondary type attributes
4. About string pools
5. Class loading

Third Round (F2F) :
1. Design multi level car parking

Fourth Round Managerial (F2F) :
1. A design problem and design pattern to implement to solve it.
2. Detect loop in linked list.
3. Maximum sum of contiguous sub array
4. About project and some behavioral questions