NVIDIA interview questions

Answered to a Newspaper Walk in Interview AD . There was a written test with around 50 questions . Next was interview with 4 People 1st Round - Tech Interview with Sr Team member 2nd Round - Tech Interview with Team Manager 3rd Round - Tech Interview with VP of that division 4th Round - HR Interview with HR manager

Turned in my application at the job fair. Took a simple test on the spot. Questions were not that hard. 1. Dereferencing classes without declarations 2. Find common ancestor of two nodes in a tree 3. What is surface normal? 4. Copy a rectangle in frame buffer to another position in frame buffer. Overlapping? Receievd a call 2 weeks later for first round phone interview. I was asked questions about some of the projects I did (detailed questions). Questions about threads, mutex and semaphore. Was told to implement a mutex for threads that access a shared resource. Advantages of Frequency domain analysis on images vs spatial domain analysis. 32 bit array. Want to swap them…Lookup table will be huge.How to invert the array?