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

Last Updated : 11 Jun, 2019

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