The research you have to do is based on your previous knowledge. The less you know the more you need to learn when you are facing a problem you don't know how to solve it. But people is lazy, if they know a way to solve it they will go that way even if it is the worst way possible.
I am not talking about implementing an AVL tree without any help or resource. That is simple stupid, we have internet we must use it and save time. My point is that you need to know that there are balanced trees, know some of them and they characteristics. That knowledge will save you time when you face problems related to trees. You are not going to know all the trees because researches are working on new ones every day, but you should have some knowledge in the area.
If you interviewer drop you because you hesitate in something, maybe it is the interviewer problem and not yours. We are not perfect, we should know people will make mistakes and hesitate. I was rejected of interviews when I hesitate when they asked something about linked lists. I was happy it happened, because I was in shock when I was explanning how I did something with and A* algorithm and a octree and I couldn't believe the next question was about a linked list. I wouldn't be happy in that company.
I am not talking about implementing an AVL tree without any help or resource. That is simple stupid, we have internet we must use it and save time. My point is that you need to know that there are balanced trees, know some of them and they characteristics. That knowledge will save you time when you face problems related to trees. You are not going to know all the trees because researches are working on new ones every day, but you should have some knowledge in the area.
If you interviewer drop you because you hesitate in something, maybe it is the interviewer problem and not yours. We are not perfect, we should know people will make mistakes and hesitate. I was rejected of interviews when I hesitate when they asked something about linked lists. I was happy it happened, because I was in shock when I was explanning how I did something with and A* algorithm and a octree and I couldn't believe the next question was about a linked list. I wouldn't be happy in that company.