OYO Rooms Interview Experience | Set 6 (For Senior Software Developer)

First Round: (Written)

1. Maximum sum of non-contiguous elements in array

   Input : 1 12 5 4 13
   Output: 25

2. Given an array of integers, find a combination of four elements in the array whose sum is equal to a given value X.

   Input Array : 1 5 1 0 6 0
   Input Sum: 7
   Output : 1 (1 if present, else 0)

Second : (F2F)

1. Discussion of above two questions.
2. If a doubly linked list has pointers in the form of integers that represesnts memory location, and we want to manage only one reference for both prev and next node, how will the list be traversed.
3. Rotate right a binary tree

Third : (F2F)

1. Diameter of a binary tree
2. How DNS lookup works
3. SQL Query with 3 tables : Student, Class, Test

   Input : Student : SID, CID, Name
       Class : CID, Cname
       Test : TestId, WeekId, SID, Marks 

   Write a query to print average marks classwise for each week

   Output Example :

      ClassName, WeekId, Avg_Marks
      Tenth, 1, 33
      Eleventh, 1, 34
      Tenth, 2, 45
      Eleventh, 2, 21 

   Solution : select (select Cname from Class where CID = S.CID)ClassName, T.WeekId, AVG(T.Marks)
   from Test T LEFT_JOIN Student S on T.SID=S.SID
   group by ClassName, T.WeekId

4. Design a Ludo/Snake&Ladders