These questions aren't about "real world" situations, they are about problem solving and basic coding. Questions are good, as is a discussion on how and why these things should be implemented.
For the split array problem I rarely ask for code (only when I think it will actually help the candidate), it's just a discussion. It usually goes something like this:
Candidate: Well I can sort it first, then do a binary search.
Me: How would you sort it?
C: I'd use quicksort.
M: Can you do better than an nlogn algorithm?
C: Well I suppose since it's two pieces that are both already sorted, I can just find where they are split and then rearrange them.
M: How would you find the split?
C: I can go through each number until they stop increasing.
And so forth. The "best" solution (that I've come up with, anyway) is to find the split using a modified binary search, and then use a regular binary search on the piece that might contain your query. Not everyone gets that
and that's okay.
In addition to asking coding questions I always ask candidates about previous experience and projects they've worked on. Sometimes the answers to these questions are more important. Most of the people I have been interviewing, however, are recent graduates or students who are just finishing college and may not have much experience or many projects that really engaged them.
I spend a lot of time thinking about how I can improve interviews within the confines of how my company conducts them. I've stopped asking the permutations question as I feel that it has too much of the "aha!" factor in that either the programmer goes "aha!" and solves it or they don't.
For the split array problem I rarely ask for code (only when I think it will actually help the candidate), it's just a discussion. It usually goes something like this:
And so forth. The "best" solution (that I've come up with, anyway) is to find the split using a modified binary search, and then use a regular binary search on the piece that might contain your query. Not everyone gets that and that's okay.In addition to asking coding questions I always ask candidates about previous experience and projects they've worked on. Sometimes the answers to these questions are more important. Most of the people I have been interviewing, however, are recent graduates or students who are just finishing college and may not have much experience or many projects that really engaged them.
I spend a lot of time thinking about how I can improve interviews within the confines of how my company conducts them. I've stopped asking the permutations question as I feel that it has too much of the "aha!" factor in that either the programmer goes "aha!" and solves it or they don't.