Kellton Software Engineer Interview Questions, Process, and Tips

I was asked about the star pattern questions and also moderate array and string questions

Q1. Where do you see yourself in next 4 years
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Q2. What is your future goal
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MCQ round containing mathematical questions like upstream downstream, etc

Q1. Asked about OOPs concepts, merge sort with code, quick sort with code. Discussion on problem solving questions based on OOPs
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Q1. Company polices elaborated and discussed.
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Round duration - 30 minutes
Round difficulty - Easy

It was in the evening. Questions were of moderate level.

Q1. Divide Chocolates
Ninja bought chocolate consisting of some chunks. The sweetness of each chunk is given in an array ‘ARR’. Ninja has ‘K’ friends, and he wishes to divide the chocolate into 'K' + 1...read more
Ans. Dynamic Programming
The idea is to figure out the recursive calls and optimize them using dynamic programming.
It breaks down into a problem of dividing the array into ‘K’ + 1 partitions such that the partition which has the lowest sum of sweetness is maximum as compared to all the possible partitions. It’s better to make a prefix array as we would need the prefix sum of the array in every iteration. 
Now, we will st...read more
Answered by CodingNinjas
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Round duration - 30 minutes
Round difficulty - Easy

It was in the evening. Platform used for this round was hackerrank.

Q1. Partition to K equal sum subsets
You are given an array of 'N' integers, and a positive integer 'K'. You need to determine if it is possible to divide the array into 'K' non-empty s...read more
Ans. Exhaustive Search, DFS, BackTracking.
• The underlying problem is to divide the input array into K subsets so that all the subsets have equal sums.
• So, if the sum of all the elements of the input array is not divisible by K, that is remainder != 0, then the given array can not be divided into K equal sum subsets. So, return false. Also if the largest element of the array is greater than (sum of elements of the array) / K, ...read more
Answered by CodingNinjas
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Round duration - 30 minutes
Round difficulty - Easy

It was in the evening. Platform used for this round was hackerrank. Questions were of moderate level.

Q1. Maximum Subarray Sum
You are given an array (ARR) of length N, consisting of integers. You have to find the sum of the subarray (including empty subarray) having maximum sum among all subarrays.
A subarr...read more
Ans. Brute Force Approach
Let us check for all possible subarrays of the array. For this, we run two loops, where the outer loop points to the left boundary and the inner loop points to the outer boundary of the subarray. 
Using another loop inside, find the sum of this subarray. Compare it with the maximum subarray sum obtained so far. After checking all the subarrays, simply return the maximum sum found.
Space Complexit...read more
Answered by CodingNinjas
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Round duration - 30 minutes
Round difficulty - Easy

It was in the evening. I have practiced coding questions a lot so my thinking abilities got improved. Questions were of moderate level.

Q1. Maximum length of same indexed subarrays
Given two arrays ‘A’ and ‘B’ and an integer ‘C’, the task is to find the maximum possible length, say K, of the same indexed subarrays such that the sum of the maxi...read more
Ans. Brute force
The idea is to brute force to find the maximum length subarray which satisfies the given condition.

 
• The steps are as follows:
• Maintain a variable ‘ans’, which stores the final answer.
• Loop from 1 to ‘N’ Using 'i:
• 'i' denotes the length of the subarray, which may satisfy the condition.
• Maintain an array ‘prefixSum’ which stores the prefix sum of the array ‘a’.
• To check whether the subarray of length 'i' satis...read more
Answered by CodingNinjas
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Round duration - 30 minutes
Round difficulty - Easy

It was in the evening. Platform used for this round was hackerrank. Questions were of moderate level.

Q1. Distinct Subsequences
You have been given string 'S' of length 'N' that may contain duplicate alphabets. Your task is to return the count of distinct subsequences of it.
For example:
For...read more
Ans. Brute force
• The IDea is to call a helper function so as to create all possible subsequences of the string which will contain:
  • String CUR = the possible subsequence of the string.
  • Int ID = the index of character which will either be included or excluded.
• We maintain a set to count the distinct subsequences, each time a new subsequence is created, we add it into the set. Remember, the set does not contain duplicate elements.
• ...read more
Answered by CodingNinjas
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Round duration - 30 minutes
Round difficulty - Medium

It was in the night around 9:00PM. Platform used for this round was skype.

Q1. OS Questions
What are the different operating systems?
What is monolithic kernel?
What is the difference between micro kernel and macro kernel?
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Round duration - 30 minutes
Round difficulty - Easy

It was in the evening. Platform used for this round was hackerrank. Questions were of moderate level.

Q1. Maximum length of same indexed subarrays
Given two arrays ‘A’ and ‘B’ and an integer ‘C’, the task is to find the maximum possible length, say K, of the same indexed subarrays such that the sum of the maxi...read more
Ans. Brute force
The idea is to brute force to find the maximum length subarray which satisfies the given condition.

 
• The steps are as follows:
• Maintain a variable ‘ans’, which stores the final answer.
• Loop from 1 to ‘N’ Using 'i:
• 'i' denotes the length of the subarray, which may satisfy the condition.
• Maintain an array ‘prefixSum’ which stores the prefix sum of the array ‘a’.
• To check whether the subarray of length 'i' satis...read more
Answered by CodingNinjas
View 1 more answer

Round duration - 30 minutes
Round difficulty - Easy

It was in the night around 9:00PM. Platform used for this round was skype.

Q1. OS Questions
What are the different operating systems?
What is monolithic kernel?
What is the difference between micro kernel and macro kernel?
Add your answer

Round duration - 30 minutes
Round difficulty - Medium

Q1. Two Sum
You are given an array of integers 'ARR' of length 'N' and an integer Target. Your task is to return all pairs of elements such that they add up to Target.
Note:
We cannot use th...read more
Ans. Hashing Solution
• We can store the frequency of every element in the array in a hashmap.
• We will loop over every index i, and check the frequency of (Target - ARR[i]) is the hashmap:
  • If (Target - ARR[i]) is equal to ARR[i], we will check if frequency of ARR[i] . If it is greater than 1 then we will decrease the frequency of ARR[i] by 2 and add a pair (ARR[i] , ARR[i]) to our answer.
  • Else, if the frequency of ARR[i] and Targ...read more
Answered by CodingNinjas
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Round duration - 90 minutes
Round difficulty - Medium

Q1. Minimum number of swaps required to sort an array
You have been given an array 'ARR' of 'N' distinct elements.
Your task is to find the minimum no. of swaps required to sort the array.
F...read more
Ans. Naive Approach
While iterating over the array, check the current element, and if not in the correct place, replace that element with the index of the element which should have come in this place.
 
Below is the algorithm:
1. Create a copy of the given input array and store it in temp.
2. Sort the temp array.
3. Iterate over the input array, and check whether the current element is at the right place or not by comparing it with t...read more
Answered by CodingNinjas
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Q2. Kth largest element in the unsorted array
You are given an array consisting of 'N' distinct positive integers and a number 'K'. Your task is to find the kth largest element in the array.
E...read more
Ans. Brute Force
• The most obvious brute force approach would be to sort the array in descending order and return the ‘K’th element from the beginning of the array.
• Sort the array in descending order, for sorting most of the languages have their inbuilt sort methods which are usually very fast.
• After sorting, return the element arr['K'-1](i.e. element at index ‘K’-1, considering 0-based indexing).
Space Complexity: O(1)Explanati...read more
Answered by CodingNinjas
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Round duration - 30 minutes
Round difficulty - Easy

Platform used for this round was hackerrank. 
Questions were of moderate level.

Q1. Partition to K equal sum subsets
You are given an array of 'N' integers, and a positive integer 'K'. You need to determine if it is possible to divide the array into 'K' non-empty s...read more
Ans. Exhaustive Search, DFS, BackTracking.
• The underlying problem is to divide the input array into K subsets so that all the subsets have equal sums.
• So, if the sum of all the elements of the input array is not divisible by K, that is remainder != 0, then the given array can not be divided into K equal sum subsets. So, return false. Also if the largest element of the array is greater than (sum of elements of the array) / K, ...read more
Answered by CodingNinjas
View 1 more answer

Round duration - 30 minutes
Round difficulty - Easy

Platform used for this round was skype.

Q1. OS Questions
What is monolithic kernel?
What is the difference between micro kernel and macro kernel?
Add your answer