Monday, October 20, 2008

Qualcomm Interview Questions

Recently I attended an interview with Qualcomm and was looking everywhere for interview questions. Although I could not make it in the interview, I thought it was my duty to post the questions for the benefit of others who aspire to score well.

First round was a telephonic round after which there will be a onsite day long interview session. This included three rounds of technical interview, one manager round and one HR - total five rounds. The whole procedure was very professional and an all round performance is necessary to get through.


Telephonic round

At the start of the interview, interviewer was mainly concentrating upon IPCs and Sockets, followed by VOIP protocols, and questions and C, C++.

1. Questions about pipes and message queues - difference between them, why one is better than the other, related questions.
2. Processes in message queues - (what happens when) multiple processes put in one message queue, (what happens when) reader is one, senders are many, related questions.
3. Questions related to sockets - connect() function call, questions related to select() system call - what does it return (return value number of fds), how do you manipulate the fds, questions related to readfds and writefds.
4. Questions related to SSRC, CSRC in RTP/RTCP.
5. H.245 (H.323) packet size.
6. Questions about what are CCSRL, NSRP.
7. Questions related to pure virtual function (what is).
8. What is a template.
9. What is volatile, where is it used and related questions.

After clearing the Telephonic round, I was called for interview at Qualcomm.

Round One
1. Write code to Fill 20GB of memory with "10111" bit pattern.
2. Write code to traverse a m*n array in a spiral pattern.
3. i=0, j=1
if(i,j)
printf("......");
else
printf("......");
What is the output of the code snippet?
4. Questions related to constants in C and C++, what is the difference between constants in both, etc.
5. What is name mangling in C++? Where it is used, related questions.
6. Showed a code snippet - asked questions related to that.

Round Two

1. Questions related to function pointers, array of function pointers.
2. Write code for Swap using pointers (don't use extra variable).
3. Questions related to string copy, strncpy (code snippets - writing and also showed code and asked questions on that).
4. Questions related to struct and union, differences, code snippets.

Round Three
1. Write code for deletion of nodes in Binary Search trees.
2. Write code for deletion of nodes in Double Linked List.
3. RTOS concepts related questions.
4. What is priority inversion.
5. What is scheduling policy - related questions.
6. Questions related to processes, threads, tasks.

Round Four
Manager round - Mostly questions related to Resume and Projects done.

Round Five
HR round - About Qualcomm, policies and how they are improving facilities, etc.