I once was asked the SAME puzzle at two interviews (for different companies) two weeks apart.
I'd never seen it before the first interview. In that first interview, I broke it down quickly into its component parts, and figured out where the trick had to be -- and from there quickly solved it on the spot.
In the second interview I spent a couple minutes trying to remember the solution from the first interview, and completely flubbed it. It wasn't the first part of that second interview that I flubbed, either, including arguing with one of the interviewers and basically telling him he was wrong.
Oddly enough, I got the job with the second company and worked there for almost six years. For the record, I love doing those kinds of puzzles. But I do video game development, so maybe puzzles are a bit more relevant to my industry (in that 80%+ of what we're doing is figuring out how to solve puzzles in the form of how to do something with less CPU or why a particular video card is behaving in a certain way).
I'd never seen it before the first interview. In that first interview, I broke it down quickly into its component parts, and figured out where the trick had to be -- and from there quickly solved it on the spot.
In the second interview I spent a couple minutes trying to remember the solution from the first interview, and completely flubbed it. It wasn't the first part of that second interview that I flubbed, either, including arguing with one of the interviewers and basically telling him he was wrong.
Oddly enough, I got the job with the second company and worked there for almost six years. For the record, I love doing those kinds of puzzles. But I do video game development, so maybe puzzles are a bit more relevant to my industry (in that 80%+ of what we're doing is figuring out how to solve puzzles in the form of how to do something with less CPU or why a particular video card is behaving in a certain way).