TRUE STORY:
I interviewed at Google earlier in my career. In one of the interviews, the interviewer asked me to recite/reconstruct off the top of my head the convex hull algorithm. I remembered the lectures in undergrad algo class where the professor talked about it. I remembered where in CLRS it was covered. I remembered the general outline (efficient algorithms are O(n log n), because you have to sort the points as one of the steps). But I was struggling to remember the details, because, you know, I hadn't worked on that sort of thing in several _years_.
So, the interviewer started pacing around the room, impatient that I couldn't remember the details (or recite in 10 minutes what it took a professor with notes 2 lectures to go through). He told me finally "We expect Google engineers to be able to solve problems. What if you were a Google engineer, and you had to solve this problem, what would you do?"
There is, of course, only one right answer to that question, which I provided: "I would look it up in a book. I know exactly where to find it." I wouldn't spend time trying to reinvent an algorithm that someone else had already thought of.
The interviewer did not like that answer. I did not get a job offer. Now that I interview candidates at a different large tech company, I make a point to not get hung up on things that are easily researchable.
I interviewed at Google earlier in my career. In one of the interviews, the interviewer asked me to recite/reconstruct off the top of my head the convex hull algorithm. I remembered the lectures in undergrad algo class where the professor talked about it. I remembered where in CLRS it was covered. I remembered the general outline (efficient algorithms are O(n log n), because you have to sort the points as one of the steps). But I was struggling to remember the details, because, you know, I hadn't worked on that sort of thing in several _years_.
So, the interviewer started pacing around the room, impatient that I couldn't remember the details (or recite in 10 minutes what it took a professor with notes 2 lectures to go through). He told me finally "We expect Google engineers to be able to solve problems. What if you were a Google engineer, and you had to solve this problem, what would you do?"
There is, of course, only one right answer to that question, which I provided: "I would look it up in a book. I know exactly where to find it." I wouldn't spend time trying to reinvent an algorithm that someone else had already thought of.
The interviewer did not like that answer. I did not get a job offer. Now that I interview candidates at a different large tech company, I make a point to not get hung up on things that are easily researchable.