Round-1 (Online Coding Test)

The first round comprised of 3 coding questions and it was conducted on hackerearth platform (Test Duration: 1 hour 30 minutes): –

Question 1: Count number of inversion in an array in less than O(n^2) time complexity.

Question 2: Check if a string is valid or not. A string is valid if on removing two different characters at a time, you are left with just one character in the end. If the string is empty it is not valid. If the string is valid print the remaining character.

Input: aaabb

Output: Yes

a

Input: aabb

Output: No

Solution: If count of any character is more than half of length of the string, then only it is a valid string. Time Complexity: O(n)

Question 3: Given two strings s1 and s2, where s2 is a palindrome, how many substrings(s2) are there if we are allowed to arrange s1 in any order.

Input: aabb aba

Output: 1

Input: aabbaabb aba

Output: 2

Explanation: If we arrange s1 as abab, we will have 1 substring that is s2 (aba). Similarly, if we arrange s1 as ababbaba, we will have 2 substrings that are s2(aba).

Solution: Find the count of each character in s1. Find the count of each character in s2. Find minimum of (count of ‘x’ in s1/count of ‘x’ in s2), where x is any character present in both s1 and s2. Time Complexity: O(n).

Round-2 (Technical Interview Round-1)

1) Puzzle 20 | (5 Pirates and 100 Gold Coins)

2) Given a number that generates random numbers in range 1-5(including both), use this function to create a function that generates random numbers in range 1-7(including both).

3) Find complexity of a given code.

4) Find median in a stream

5) Discussion on my projects and internship.

Round-3 (Technical Interview Round-2)

1) Discussion on projects and internship.

2) K-Sum Paths

3) Similar to Transform to Sum Tree but we don’t have to consider left child of any node.

4) Elevator Puzzle

5) Indexing, types of indexing and their overhead. B+ trees and complexity related questions.

Round-4 (Managerial Round)

1) He asked about my future plans, projects and then asked me to ask questions about Walmart labs.

Round-5 (HR Round)

1) Tell me something about yourself.

2) Discussion about internship.

3) My future plans and what I have done to achieve them.

4) If I want to pursue MS or not.

5) What I know about Walmart and other generic HR questions.

At last 7 students were selected for 6 months internship and 2 students were selected for 6 months internship+ full-time job in Bangalore.