Edgewater Markets C++ Developer interview questions

there was one round where interviewer asked some questions and C++ and ended the discussion without giving me chance to ask any questions, then HR contacted me and said I passed first round and have to solve home assignment, I solved it with best possible optimsation and demonstration of (lock free) multithreading skills etc. next day HR told I am not selected and asked her to give feedback on it, but did not got any