At least you had an interviewer who could speak English and explained the problem. Mine had an interviewer who just typed the problem and his English was so bad that I couldn’t get answers to any follow up questions. He kept saying “ok…ok” as I was explaining the approach and once I finished coding up my approach he said that’s not what he is looking for. I kept asking clarifying questions till the end but never got the answer since his English was incomprehensible. I don’t understand how a person like this can function assuming they have to deal with English speaking team members.