OLX Groups Interview Experience (On-Campus)

Online Test(Written): First round was online test, consisting of 10 MCQ (Aptitude, turnaround time calculation from OS, to SQL query output, C++ output) questions and 2 Coding questions. 

Coding Questions:

• Activate Fountain:- The problem statement was like you have been given an array where each element is having a special property, the array indexing is from 1, where index number represents the fountain number and the range corresponding to each fountain is max(i-arr[i], 1) to min(i+arr[i], size of array); you have to find the minimum number of fountains required to completely water the field.(Field:- range of field is 1 to n(size of the array)). 
• Target sum Pair:-Given an integer array and a positive integer k, count all distinct pairs with sum equal to k. 

35  out of 450 students went to next round. 

Technical Round 1: I was asked to introduce myself. Then my resume was properly read and key strength were underlined. I was expected to explain every aspect of my project. He was continuously asking technical questions regarding each project. One of my project consisted implementation of Single Sign On using SAML. I was asked to draw basic architecture of the same. Additionally, I was asked following questions 

1. https://www.geeksforgeeks.org/find-next-greater-number-set-digits/
   Just explain your algorithm.
2. https://www.geeksforgeeks.org/level-order-traversal-in-spiral-form/ 
   Write the full code .

Was asked to explain Inner join and Left Join. Was asked a trick question on left join. 
Next I asked some company-related questions. Tech 1 done 

Technical Round 2:  Again i was asked  asked about my resume. He asked what are you doing recently. I told i was learning to write APIs .He saw i made a website from scratch, opened my website and asked me to recreate the ” Contact Us ”  page . All basic aspects 

• An html form for posting the data in database
• The basic structure of database in while data shall be stored .
• GET and POST API code .

All this were supposed to be written on paper. I did all. 

• Then i was asked to solve this: https://www.geeksforgeeks.org/design-a-stack-that-supports-getmin-in-o1-time-and-o1-extra-space/
• I panicked and forgot . Though i explained him that we need to go according to a 2x-min formula but couldnt actually complete it .He saw me struggling for say 10 mins and asked me if i want to try or change the question. I asked to change the question . Then i was asked to code the implementation of LRU cache ,everything on paper. 
• https://www.geeksforgeeks.org/lru-cache-implementation/
• I just read it while walking from my hostel to Placement Office. Implemented and explained my approach completely. 

7 went to next round. 

HR Round:   My introduction, since this was HR, I added my works as a Technical Advisor and Core member of  CodeChef and NGO. He asked me tell unusual uses of a BRICK. Then he explained salary breakup and work environment. 
6 were given Full time plus internships.