Visa Interview Questions, Process, and Tips

Round duration - 60 minutes
Round difficulty - Easy

The coding test was conducted on Hackerrank platform. The test was in the evening. There were two coding questions of easy difficulty. The test was proctored, our webcam was on but not the mic. Also we were not allowed to switch tabs.
About 360 students sat in this round out which 15 were shortlisted for the next interview round.

Q1. Maximum equal elements after K operations
You are given an arbitrary array/list of integers 'ARR' of size ‘N’ and an integer ‘K’. You need to find the maximum number of elements which can be made e...read more
Ans. 
This was a very easy question as I just had to traverse both the array and maintain a count variable and a variable to store last maximum equal element encountered which I initialized to a very small number (like INT_MIN in C++) . Now while traversing whenever you encounter equal elements which are greater than last maximum equal elements then increment count by 1. In the end just print count.
Answered Anonymously
Add your answer
Q2. Number of Pairs with Given Sum
You have been given an integer array/list(arr) and a number 'Sum'. Find and return the total number of pairs in the array/list which when added, results equal to the ...read more
Ans. 
Step 1 : Create a map and store count of each unique element in the array.
Step 2 : Maintain a count variable to store the number of unique pairs of elements whose sum is K.
Step 3 : Traverse the array. Let the array be called arr and arr[i] is current element in array while traversing. If value arr[i] and K-arr[i] in map is greater than 0 then increment count and make value of arr[i] and K-arr[i] in map as 0.
Answered Anonymously
Add your answer

Round duration - 60 minutes
Round difficulty - Medium

This was an elimination round. There were 2 coding questions. Both questions were of medium level and I solved them in a given time. After this round, 29 students got shortlisted and I was one of them.

Q1. Ninja And The Dance Competetion
Ninja has been asked to organize a dance competition. Ninja decided that he will take individual entries and then will divide them into pairs. As part of the entry, he asked...read more
Ans. 
I solved this question using the map in O(n) time complexity. First I stored the count of elements in an array then by checking the condition(k > 0 && map.containsKey(i + k) || k == 0 && map.get(i) > 1), I incremented the result by one every time when condition satisfied. Below is my code for the same.

class Solution {
public int findPairs(int[] nums, int k) {
Map map = new HashMap();
for(int num : nu...read more
Answered Anonymously
Add your answer
Q2. Maximum length sub-array having absolute difference of adjacent elements either 0 or 1.
Given an array ‘A’ of ‘N’ integers, you need to find the maximum length of the sub-array such that the absolute diffe...read more
Ans. 
This was a simple array problem. I solved this using question as:
Starting from the first element of the array, find the first valid sub-array and store its length then starting from the next element (the first element that wasn’t included in the first sub-array), find another valid sub-array. Repeat the process until all the valid sub-arrays have been found then print the length of the maximum sub-array.
Answered Anonymously
Add your answer

Round duration - 60 minutes
Round difficulty - Easy

This was a technical round on Zoom. The interviewer was very friendly. He gave me one coding problem. I solved the problem and then he asked to improve time and space complexity if possible. I explained my logic very well. After this question, he asked to me explain 3NF(3rd normal form). Then we had some discussion on OOPs concepts.

Q1. LRU Cache Implementation
Design and implement a data structure for Least Recently Used (LRU) cache to support the foll...read more
Ans. Array Approach
We will use an array of type Pair<key, value> to implement our LRU Cache where the larger the index is, the more recently the key is used. Means, the 0th index denotes the least recently used pair, and the last index denotes the most recently used pair.
 
The key will be considered as accessed if we try to perform any operation on it. So while performing the get operation on a key, we will do a ...read more
Answered Anonymously
Add your answer

Round duration - 60 minutes
Round difficulty - Medium

This was another technical round. The interviewer gave me a coding problem to solve.
 

Q1.  Valid String
You have been given a string 'S' containing only three types of characters, i.e. '(', ')' and '*'.
A Valid String is defined as follows:
1. Any left parenth...read more
Ans. Brute Force
We can try each of the three possibilities for every asterisk in the string with the help of recursion. 
 
We will use a temporary string which will keep track of our current possible string. In the end, we can linearly check each possible string. If any of the possible string is a valid string, we print ‘Yes’, otherwise ‘No’.
Space Complexity: O(n)Explanation:
O(N), where ‘N’ is the length of the str...read more
Answered Anonymously
Add your answer

Round duration - 60 minutes
Round difficulty - Easy