1. basic puzzle no need to prepare.
2. pattern finding and matching in a string.
3. common ancestor of a node in a binary tree.
4. two stack working as a queue.
5. For each node finding the left subtree node and right subtree node number.
6. File system basic program.
7. network programming basic program of socket.

Nothing special.

Once solve completely "Crack the interview" from the url http://profile.iiita.ac.in/pkmallick_03/ adfaqpublish.html for
any interview.
be very much confident while interview.
All the best!!!

It was a good experience because all the interviwer were cool guys.