Walmart Labs Interview Experience | Set 18 (For Experienced)

I've 3.4 Years of experience in Java. I got a call from Walmart labs through employee referral. There were 4 rounds. Round 1: 1 Hrs

1. How to write a immutable class.
2. How eclipse makes sure of parenthesis.
3. Maximum width of Binary Tree
4. Given an array of songs length and journey time, maximum number of songs that can be played during the journey. Constraint:- Either song should be completed or should not be played. Ex:- [2, 4, 3, 5, 5, 2, 4] and Journey time = 20 Output: - 5 [2, 4, 3, 5, 5, 2, 4, 3] and Journey time = 20 Output:- 6

Round 2: Around 1.5 Hrs

1. Hashmap Implementation.
2. Kth Largest element with full heap code.
3. Maximum element in Kth window with Code
4. Get minimum element in O(1).(Use stack and without Stack)
5. Print the hierarchy of employees.(Use Hashmap) Full working code.
6. Detect loop and remove it in Linked list.
7. What is deadlock, create a deadlock (code) and how to resolve this.
8. Core Java questions

Round 3: 45 Mins

1. A depends on B, B depends on C, C depends on D, print which does not depend on any than depends on only one than two. (Use topological sort)
2. Median of Linked List
3. About the current project
4. Print even odd using multi-threading
5. One array question I couldn't remember.

Round 4: 45 Mins

1. What parameters you will take care when you design a service which is working with another service (you do not have any control).
2. LRU cache implementation
3. LFU implementation.
4. Behavioural question.

Thank you GeeksforGeeks for helping me during my interview preparation.