[Jach]

Talk is cheap, code is what matters. But maybe the interviewer wanted to save time not writing an incorrect solution if he believed your approach was wrong and you could talk yourself out of it? Did you get to step through how your solution would arrive at the number 14 given 2 eggs and 100 floors? And if you wrote it out, would it produce that number? (Personally I have no idea what you mean with the binary search approach, what is your logical list since doing it on the list of floors is wrong? But I've not thought about the egg dropping problem in a long time and have only seen the DP approach.)

It might of course be that the interviewer only knew one way to solve it, any other way was therefore wrong. Or admitting they don't understand a demonstrated other way shows weakness, so is also wrong. I'd be perfectly happy to receive rejections from companies with those sort put in charge of interviewing.

[wizzairflyer]

A funny trick is to ask this question but first give the candidate an infinite amount of eggs. Once he succeeds, ask the question with only 2 eggs. That might explain the binary search answer.

[PopeDotNinja]

The approach would have been easier way for me to answer the question. I wrote something like that to guesstimate the number of git commits on GitHub a project I didn't have time to clone a few years back (I think it was Linux). Basically I started at page 1, then went to 2, 4, 8, 16, etc. When I hit a 404, I went back 50% of the way to the previous number (e.g. if it was page 1024, the previous was 512, then I went to 768). If 50% was a 404, go to back midpoint of lower range (e.g. midpoint of 512 and 768). It if was legit, go to midpoint of upper range (e.g. between 768 and 1024). Wash/rinse/repeat. It was a fun exercise to burn some time on a slow day. If someone actually wants to see the code, reply to this comment and I'll find it, or write it again.

Now I want to go back and study up on that dynamic programming stuff again! Yay inspiration!