Round 1 Interview
Hi, everyone In this article I’m sharing my SDE interview experience with Nielson, on 19/04/2024 I went through the interview with Nielsen India for the Mumbai location, they called me on-site for the interview,
I have requested, that I do it online, and they agreed and scheduled an interview hear it went:
- Brief interview about my previous work experience,
- Then couple of questions about me like, how familiar with Spring Boot, java, cloud deployments etc.
- Then the interviewer asked me to solve the question for finding the first non-repeating element in the array (below is how I did, with different approaches and complexity analysis);
Then I asked questions about the company and what they do interviewer explained at a high level after that, the interviewer ended the call, saying that would get back to me;
/*package whatever //do not write package name here */
public class Nielson {
/* ROLE : Software Engineer_Nielson
* Given an array of integers of size N, the task is to find the first non-repeating element in this array.
* arr=[1 ,2, 1, 3, 4]
*
* 0 1 2 3 4 --> 1 --> 0,1 , 2 -->1 , 3 ---> 3, ,4---> 4
*
* approach 1 :
* 1. iterate over the array : ---> calcualte the frequecy map --> should maintain the order
* 2. iterata over the created map --> if( count> 1) , smiply return that elemtn
*
* Time : O(n) + O(n) + O(log(n) ==> O(n)
* Space : O(n)
*
* Map<Integer,Integer> frqhMap=new HashMap<>();
* */
class person {
String name;
Integer age;
}
public static int firstNonRepeating(int[] arr){
/* it maintains the order*/
Map<Integer,Integer> frqhMap=new HashMap<>(); /* cpu intensive */
person[] pAtt= new person[10];
int n=arr.length;
/*iterating over the array and hashify the array with freq O(log(0)*/
for(int i : arr){
frqhMap.put(i, (frqhMap.containsKey(i) ? frqhMap.get(i) : 0) +1 );
}
// System.out.println(frqhMap);
for(int i : arr){
if(frqhMap.get(i)==1) return i;
}
return -1;
}
}