There was 1 coding round and 4 F2F interviews. This was for Software Developer Position(Note:-It was not for the research division in Walmart Labs)
Coding Round:-
There were 2 coding questions given in this round. The platform used is Hacker rank and we have to complete both questions in their office only in 1 hour. Usage of internet is strictly prohibited.
1. Find Maximum sum in an array such that no 2 elements are adjacent. In this, 1 more condition was also there that first and last elements should also not be taken together. This question was modification of this.
2. In a cartesian plane, there are N tanks and M objects placed. Tanks can fire in 4 directions (N, S, E, W). Position of tanks and objects are given as input and are fixed. We have to find a way to give directions to N tanks such that they will not hit any object and any other tanks. If a tank can fire in 2 directions, then a direction whose ASCII code is lesser will be given preference. Example:-
Input:-
N=2
M=3
Position of tanks
(0,0)
(1,1)
Position of Objects
(0,2)
(0,-2)
(-2,0)
Direction of N tanks should be:-
(0,0) E -> This tank should fire in east direction
(1,1) E -> This tank can fire in all 4 directions. Since E has least ASCII code in all 4 of them, so E
Round 1:-
1. Intersection and Intersection Point in 2 Linked List.
2. Questions on Multithreading in Java. About synchronised block, etc.
3. Why Java is platform independent and JVM platform dependent?
4. Difference between Java and C++.
5. Write a code for building a heap and explain its time complexity
6. k largest elements in an array
7. Some Questions on String datatype in Java
Round 2:-
1. Design a complete Railway Reservation System. Following things are checked in code:-
a. Object Oriented Programming
b. Design Patterns used(if any)
c. Are use cases are optimised or not?
2. Question on LRU cache implementation
Round 3:-
1. Design a data structure which provides the following APIs:-
a. insert element in O(1)
b. delete an element in O(1)
c. find a random element in O(1)
2. Some questions on Java basics.
3. Some discussion on projects done in current job.
4. Got 1 feedback that my knowledge of Java is not so good. So, if we hire you, then what will be your strategy to improve on your Java skills.
Round 4:-
1. Why do you want to join Walmart Labs?
2. What are the biggest challenges faced by me in my current job.