I've written DFS about 1-2 times a year, on average, for the last 15 years. Why do I need to? Usually, because I need to modify or create a data structure that is kind of graph-like but not quite. If someone didn't know how to write one or at least derive it, they would confuse a lot of people, so yeah it's kind of important.
No, they'd probably look it up, skim a blog for a few minutes, then figure it out and promptly forget. This is no different than forgetting the order of the arguments to socket() and accusing that person of being incapable of writing networking code.
The difference is that the arguments to socket() were arbitrarily defined, but DFS is an algorithm. Anyone who has taken a intro data structures course should be able to at least derive the pseudo code for DFS.
Yeah, given an acyclic graph print out each node's value. Passing candidates generally got it in five minutes.
Should every node's value be printed out exactly once and if so, are there nodes which have two parents? If so, I would keep the pointers in a set to mark nodes as processed but is there a more elegant solution?
Each node is an object and has a "checked" variable.
I didn't go there, but I thought the same. "Techs" seem to always be private...MIT, Cal Tech, Florida Tech, etc. (Oh, by the way, Florida Tech definitely fits the aforementioned stereotype.)
Understandable misconception, but he went there. Not being able to recognize cluelessness in other people might just be an understatement.
Palantir gets some of my sympathy. My organization has a large internship program and I've been first contact for many applicants. I found that a similar number of applicants had to be dropped either due to communication skills or an overall technical skills gap and they tended to be asian/southeast asian. Interestingly most of them fit the same profile of a bachelor's from India, 1 or 2 years at a consulting firm in…
You are comparing Apples and Oranges. The Asian student applicants on whose behalf the DoL filed the lawsuit have to be U.S citizens. If you read the suit itself, there is a lot of wiggle room for Palantir. Here is the threat (paragraph 14 B) "An order permanently enjoining Palantir and its officers, agents, successors, divisions, subsidiaries, and those persons in active concert or participation with them... " Here…
I have a sneaking suspicion that some of these "Asian" candidates are playing the race card, and actually have not so good intentions with Palantir which deals with highly sensitive information. I would be wary, and if I was Palantir, I would bite.
Yeah, given an acyclic graph print out each node's value. Passing candidates generally got it in five minutes.
Should every node's value be printed out exactly once and if so, are there nodes which have two parents? If so, I would keep the pointers in a set to mark nodes as processed but is there a more elegant solution?
I would explicitly tell them that you should revisit nodes, and give them a few examples illustrating that point -- so all they needed to do was traverse edges.
If you ignore the terminology, DFS is basically just recursively walking a graph, something which actually happens all the time in most dev jobs. I'm sure I wrote a DFS long before I had heard the term. I hate brain teaser interviews as much as the next guy, but being able to do basic operations on basic data structures is pretty much the minimum to be a developer.
> If you ignore the terminology, DFS is basically just recursively walking a graph, something which actually happens all the time in most dev jobs. In ten years of full-time professional development I have never needed to recursively walk a graph. Hell, the only data structures in the software I worked on for the first six (real-time signal processing code) didn't use any data structures other than lists, arrays, and…
Do you think you've ever had to do something as algorithmically complex as recursively walk a graph?
Sometimes these questions are used to probe the meta understanding of a candidate and using Graphs/Trees/DFS are universally understood concepts that make doing that easy.
As someone who might apply once I get my PhD, what does basic CS knowledge mean for you? Like what a tree is or fizzbuzz? Hopefully it isn't that terrible...how someone can make it through any amount of CS related schooling and not know the basics? Somewhat related anecdote, I do computational physics. I once attended "training seminar[0]" put on by the funders for using DOD supercomputers, and there was this soon-to…
Weird. No one else would want a scheduler to be FIFO, either. Rather, the actual optimization that is performed by slurm, pbs, etc. under the hood is pretty interesting. The point of schedulers is much more complicated than a straightforward queue, as they seek to project how best to utilize system resources into the future. Strange he would be so pedantic. Everyone in HPC certainly does call it a queue, as you noted…
Common problem with programmers: when they learn a term means something, they associate that term absolutely with that meaning (common in other fields with people who are highly analytical, IME).
The HPC people are referring to a "job queue", rather than a "ADT queue". Those are distinct things, the ADT queue is a much more restrictive defintion, but it's not an exclusive one. HPC queues are more like priority queues with complex ranking functions (and queues of queues), just like real-life queues where people can cut by paying more money (first class airline ticket).
You are naive. Who would be more likely to be compromised by last year's OPM database hack by the Chinese (supposedly) which contained info on most of the cleared government and contract workers in the US? * A guy of European ancestry from Anywhere, USA who has no family, friends, or relations to China, and never stepped foot there. * A naturalized US citizen from China whose friends, family, and associates still liv…
Let's say I take your reasoning and run with it. There are plenty of people of Chinese ancestry (or Asian ancestry in general) who have no family (within a few generations), friends, or relations to China, and never stepped foot there. If the objection is to naturalized US citizens from China who have still have ties to China (I am one of those people), fair enough, but then there are three problems: 1. You should be…
(I'm not who you responded to,) It is a known tactic of the Chinese government. This book has a good overview of their intelligence apparatus: https://www.amazon.com/Chinese-Intelligence-Operations-Nicho... . This isn't an abstract concern, it is something that has happened thousands of times, for political and industrial espionage and political repression.
> then got scholarships because of only ethnicity. Are you absolutely certain of that? How did you know?
I am not American. But don't you guys have that "affirmative action" thing, especially for the african american demographic?
Most top tier universities don't consider asian-americans as under-represented minorities and even hold higher standards via unwritten caps for the number of AAs admitted.
> everyone who runs an interview process realizes that 80+% of "developers" are terrible. No, 80% of people in the 'currently looking for a job developer pool' are terrible. But you have to consider that the worse a candidate is, the longer they stay in that pool. So judging developers as a whole based just on interviews makes them look much worse than they are.
Good point, that's always an important thing to remember. The average job applicant is much lower quality than the average developer.
Maybe. With a large enough population for either the job-hunters or the employed, you should regress to the mean for the total population and the deviation should also be similar. This assumes a normal distribution for the metrics that you are hired for, something that may not be in fact true, ie. Poisson or exponential distributions are reasonable. What you can take away from this: Your own developers may not be as good as you think they are OR they may be much better, same for the candidates. That particular day you interviewed them they may have been exceptional or they may have been ill and they failed, or a million other reasons. I think Google came out a while ago and said that their initial hires had no correlation to the really successful people in the company after...5(?)... years. I can't find the citation, sorry. The interviewing process is known to be broken, so trying to extrapolate to say that the job-seekers are less good at these metrics than the employed is erroneous. I'm not saying you are wrong, just that using a binary decision like this to determine these things is wrong.