> given a datastructure and algorithm, implement it This can be entirely appropriate for most jobs/devs, depending on the datastructure/algorithm. One of the

> given a datastructure and algorithm, implement it This can be entirely appropriate for most jobs/devs, depending on the datastructure/algorithm. One of the guys I work with sometimes asks people to implement mergesort. I was suspicious of this question at first but it's been quite good at weeding out mediocre candidates. Mediocre candidates will write broken code all over the board, and more telling, they won't understand why it's broken even when you point it out. Good candidates will generally make mistakes (because no one has mergesort code memorized and coding on a whiteboard is frankly tough), but they'll recognize them, typically on their own and always with pointers, and they'll be able to explain the issue and how to fix it once they see it. There's no trick to this question. There's no riddle, no "gotcha", and it's not a hard algorithm to understand or code. Just show that you can write minimally complex code and walk through it. It's like fizzbuzz but you can't memorize it.