> Could you please solve this algorithmic puzzle within half an hour? I failed. Hiring decision made. End of story.
If that alone was the reason, then your interviewer did a bad job.
The point isn't to trick you. It's to see how you work under pressure when presented with a tough problem. What is your thought process? Do you dive right in or do you take time to chew on it? What parts of your background can you draw on to help you?
It certainly helps your chances if you can solve the problem, all else being equal, but I'd rather take someone who talks through their work but doesn't quite solve it over someone who solves it yet has trouble explaining how or why.
The best interview questions are layered. There should be a relatively easy solution solvable in multiple ways by anyone with experience programming. It should almost solve itself if you walk through the specifications. (Think fizz-buzz-level.)
But underneath that should one or two harder problems with very elegant solutions. And those are much more about the process -- about weeding out the people who would dive in without really thinking it through. If you make a mess of the whiteboard, get frustrated, start desperately erasing and rewriting the same things without ever stepping back to think through alternatives... well, that might be what I'd hold against you. It's not that you didn't solve it. It's that you didn't prove to me you could've given more time.
>>>If that alone was the reason, then your interviewer did a bad job.
Then most, if not all these of recruiters are bad. I like to think through things and take time solving problems. If I see myself doing something and struggling to complete it, I haven't thought it out properly or I have rushed into the problem.
Some people will call you "slow" which I find insulting. For example, When I read a book I like to read the actual sentences rather than skimming over them. I like perfecting details and that sometimes takes time.
I like taking my time too. The best solutions come to me after days or weeks of chewing on the problem in the back of my head.
Experienced interviewers know that this is how people solve problems. They know that time-boxing the problem is artificial, so they're not exactly evaluating you on how fast or slow you are within that time. The problems should be constructed in a way that lets them evaluate you based on your approach instead of on your solution.
Sometimes it's just a bad interview question, or not the right question for you, the interviewee. Which is why interviewing takes practice, time, and patience, from both sides of the hiring market. It's far from perfect, but more "puzzle"-like questions aren't entirely useless as long as the interviewer really knows what they're doing and how to guide the interviewee.
If that alone was the reason, then your interviewer did a bad job.
The point isn't to trick you. It's to see how you work under pressure when presented with a tough problem. What is your thought process? Do you dive right in or do you take time to chew on it? What parts of your background can you draw on to help you?
It certainly helps your chances if you can solve the problem, all else being equal, but I'd rather take someone who talks through their work but doesn't quite solve it over someone who solves it yet has trouble explaining how or why.
The best interview questions are layered. There should be a relatively easy solution solvable in multiple ways by anyone with experience programming. It should almost solve itself if you walk through the specifications. (Think fizz-buzz-level.)
But underneath that should one or two harder problems with very elegant solutions. And those are much more about the process -- about weeding out the people who would dive in without really thinking it through. If you make a mess of the whiteboard, get frustrated, start desperately erasing and rewriting the same things without ever stepping back to think through alternatives... well, that might be what I'd hold against you. It's not that you didn't solve it. It's that you didn't prove to me you could've given more time.