Yahoo Software Engineer - New Grad interview questions

Applied online. Phone Interview. Reverse linked list, fibonacci series, linux command line arguments, Regex. moved onto onsite. Onsite had 4 rounds, OO design round - design a tic tac toe game. Data structure round - 2-3 tree insertion and deletion. 3rd round : some regex, was shown a 2 page code in perl for 5 minutes on timer and asked to explain what it does. more linux commands. 4th round : behavioral and open ended technical questions. Learnt from the hiring manager that I was rejected 7 days later. smooth process. testing obscure data structures wasnt expected.