1. permutation&& find the most characters which has no duplicates 2.merge the range 3.there is a string A,which has 512 bits,0 or 1; Another a string B, which has 32 bits. Does A contains B some other questions ,such as describe the process the function call in C language;the parameter of the copy constructor is reference,why?

I got an employee referral and two weeks later a phone interview was scheduled. I was asked to write some code on collabedit and asked some unix questions related to process handling and regex. In a week, I heard from them and was invited for on-site interview. I had 4 round of interviews. All interviews were one-to-one. I was asked all sort of questions ranging from explaining nature of my previous work experience, projects mentioned on resume, object oriented system concept, algorithms related to binary tree, dynamic programming, hashtables. I was required to do white-board coding but syntax was not the major concern as long as one could write pseudocode properly and explain it. Things were very smooth till the onsite interview but moved slower after that. As is well known, the hiring process in Yahoo is too bureaucratic. It took nearly 4 weeks after onsite interview to hear about the final decision. But overall, the interveiw process was nice and smooth.