OYO Rooms Interview Experience (On-Campus)

Round 1: Round 1 was for 200 marks. 25 MCQs and 2 coding questions .The MCQs were mostly on aptitude and some were Technical (C++ output problems ) questions. Each of the MCQs carried 2 marks . One coding was a cakewalk problem (50 marks) and the other was medium level (100 marks) .
The first question was  https://www.neveropen.co.za/minimum-number-of-bracket-reversals-needed-to-make-an-expression-balanced/
The 2nd question was  https://www.neveropen.co.za/stock-buy-sell/ . I solved it recursively and it passed all the testcases .

Round 2: I got shortlisted for the next round .It was one-on-one interview . The interviewer asked me 2 questions on data structures .

• Print all the ancestors between 2 nodes of a binary tree. Its a modification to the following problem
  https://www.neveropen.co.za/lowest-common-ancestor-binary-tree-set-1/
• Given an sorted array try to find an element whose a[i]=i . I gave a linear solution to this problem . The interview told me to optimize it . So i used binary search to do the operation.  https://www.neveropen.co.za/find-a-fixed-point-in-a-given-array/

Round 3: The interviewer asked me why i wanted to join OYO and to introduce myself .Then he asked me 2 coding questions .

• https://www.neveropen.co.za/find-maximum-possible-stolen-value-houses/ . I first gave him a O(n^2) soln. He wasnt satisified with the approach and asked me to optimize it more and gave me some hint, which is how i arrived at O(n) solution.
• https://www.neveropen.co.za/find-next-greater-number-set-digits/  
• Other than the code, Difference between starving and deadlock (OS ) and why do we need so many scheduling algorithms.

Round 4: This was the last round . The interviewer asked me 2coding and a puzzle .

• https://www.neveropen.co.za/find-if-there-is-a-subarray-with-0-sum/
• https://www.neveropen.co.za/print-left-view-binary-tree/
• http://www.mytechinterviews.com/one-box-of-defective-balls . I wasnt able to reach the solution so he helped me, and then modified the question to “if there are n buckets and m defective buckets how will you find m ? “
• After all this he asked me to choose between any one of the OS, Networks, dbms . I chose OS, so he asked me, if there is a critical section and if only  two threads should access it, what should i use to do it . I told him, i would use semaphores with length of two so that at a time only 2 threads can access it.
  

After such lengthy process i finally got selected as (FTE + Intern) in oyo .