Wissen Interview Experience | Set 1 (On-Campus)

Wissen technology part of wissen Infotech came to our college for campus drive.
Website- www.wissen.com

Round 1- written test -1.5 hrs
6 coding questions
1. Find intersection of 2 sorted arrays. Note: required O(n) and no use of data structure.

2. Stock – buy and sell to gain max profit. You have to buy and sell stocks once
Input- 1 2 20 5 6
O/p – 19(20-1)

3. Print Reverse linkedlist without changing linkedlist. Note: required O(n)

4. Find whether number is cube root or not with out using math lib functions. Note: required O(n) (Hint binary search)

5. Replace 3 with 5 in an integer with out converting int to string conversion
Input- 134
Output – 154

6. Check whether 2 strings are anagram of each other.
Eg – abc & back
Output – anagram
Note- required O(n)
(Hint : use map)

Round 2 – tech1
1. Data structure
– detect Loop in linkedlist
– check whether a binary tree is binary search tree or not

2. JAVA
Multithreading and synchronization

3. OS
process, threads, semaphore, mutex, deadlock and starvation

4. DBMS
How will you print all tuples of a table?
What is foreign key and some questions on it.

Round 3- tech2
1.C++
– write struct for generic linkedlist
– dangling pointer and steps to remove
Eg-

struct node
{
   void *data;
   node *next;
}
main()
{
    node *p = new node;
    p->data = (int) new int;
    delete p;
}

remove dangling pointer caused by void* data.
Ans – overload delete operator
– destructor can be overload or not
If yes or no , why
-Why constructor can be overloaded?

-Explain whole project which is mentioned in ur resume
Which data structure did you used on ur project apart of array
Since I told him I didn’t used at specific data structure externally but internally MySQL use B+ and B tree for indexing internally
– what is B+ and B tree (I didnt know abt B+)

2. DBMS
-joins and write below query
Student table
Id l name l deptId
Department table
deptId l HODname

Find the name of HOD who has more number of students
Hint- nested query / join

– Given matrix 2*2 , 2*3 and 3*3
how will u store in single table in database

3. Java
Collection and synchronization

4. Data structure
– create special stack in which you can find min element in O(1)
– Do you have any question?

Some Questions which was asked to others
-quicksort
-arraylist vs linkedlist
-heap memory vs stack memory
-if u have given names of people and their respective countries and I need to access all names of a particular country by O(1)
Ans- map>

Round 4 – HR
Typical HR questions