In depth questions of 3 language of your choice. I chose java c and cpp. Yes, the questions were a bit tricky. I wouldn't say tough, but tricky enough for them to reject you. You need to be prepared with the basics. make sure you are comfortable with concepts like operator overloading, pointers, string manipulation, inheritance and polymorphism. At the end there is always a question of maths. May be probability of something to do with matrices. I was asked a probability question but got it wrong although the interviewer doesn't give you feedback about it. Suggestion: It will be helpful to say what you are thinking rather than incorporating an awkward silence and since the interviewer gives you no feedback, it is a good practice to let your thoughts arrive at the the said answer rather than blurting out the answer after calculating it mentally!

Asked me to write a prototype for a simple algorithm in any programming language