Oyo Interview Experience for 2.9 Years

Round 1:Online Coding 1 was dp based and second was stack based problem

Question 1 :  Find minimum number of bracket reversals to make the expression balanced.

Question 2 : https://www.hackerrank.com/challenges/candies/problem

Round 2:  

1. There is a matrix with different sign  on each  box, you have source and destination .Find will you reach destination or not and what can be the scenario need to handle. I answered  cycle problem can be happen  and direction can move you to out of the matrix, then he asked me to identify cyclic problem, I told him to keep visited box but he told me to optimise space so I used one slow pointer and fast pointer concept to identify loop.He was satisfied
2. Linking sibling of the tree, I solved using level order traversal modification.
3. Thread, Process difference
4. 4 person sitting in table having 4 spoon, each person need 2 spoon. There was long discussion, like what problem will you face . I answered deadlock and starvation then he asked me to write code to prevent both.
5. Design  database  for Whatsapp having contact information and group info
6. Design interview process so that i can get how many person arrive from particular company and how many round he/she have given along with feedback.
7. Stream of word coming, you have to find maximum 5 highest frequency words, I try to solve by it hashmap and sorted array, also tried by trie but he was not satisfied.

Round 3:

1.  Given an sorted array having all the number is duplicate and one number is unique. I told him about xor approach, but He asked me to do in o(logn) complexity and o(1) space.Then After some brainstorming I got the binary search approach, he was satisfied with that.
2. Maximum sum of k consecutive number  in a array, later he modified it is coming as a stream.
3. Sort the array in 0(N) having 0, 1, 2 .

All the question they want proper code with all edge cases.

Round 4 :

Lots of behaviour question like why oyo, conflict with manger and team colleague, tech wise, new learning.

Design Elevator system from scratch, He was expecting all the business case like number of person using elevator, how many elevator, building size and other real life scenario.

Round 5 :

1. Overriding and overloading diff
2. Why autowired
3. Design hotel booking system with maximum optimisation  and then he asked me to write complete code of some scenario like booking and asked to handle concurrency and db conflict .
4. Project explanation