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Comment by ng12 | Hacker News Reader

I can usually spot the candidates who are leetcode junkies. This is why I direct our interviews to be as pragmatic as possible. Most of our question bank comes from actual code one of our devs had to implement.

I'm fairly confident that if you've studied hard enough to solve these problems easier the studying just paid off by making you a better developer.

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Ironically, I think I develop this ability as well through solving hundreds of Leetcode questions myself. At some point I actually have to step back and think, act not to solve it too quickly otherwise the interviewer will spot me as Leetcode junkies.

This is beautiful. As selection pressure increases, the candidates evolve to mimic all the criteria of the selector.

Natural selection at work, even in our man made world...

People will just game this as well. If you already know the answer to a question coming in because you leetcode all day you could easily ask a lot of clarifying questions, identify edge cases, and give brunt force/alternative approaches before solving the question. A smart person will use that opportunity to highlight their communication skills and get an even higher grade on the interview

This is still my favorite anecdote: https://news.ycombinator.com/item?id=17106291

exactly. pretending to have not seen the question before is one of the "skills" that ppl practise on leetcode forums.

https://www.teamblind.com/post/Should-you-tell-your-intervie...

only ppl GP is catching is ppl who havent' practiced that skill. Leetcode junkies are simply outsmarting him.

Our questions aren't on leetcode and we aggressively monitor for leaks (including on Blind). You're also missing the point: we're intentionally avoiding the questions which boil down to a binary question of "do you know this algorithm or not?". Most of our questions are open-form, asking the candidate to implement a widget or interface with an API. They usually don't involve big-O or any data structure tricks. Unless you've seen the exact problem before leetcode won't help aside from general programming practice.

Also I will say that the few candidates who've tried lying about seeing a question before are not as good at acting as they think they are. Not only do you have to pretend that you've never seen the question before but if you don't stumble, second-guess yourself, refactor parts of it, etc. it's usually pretty obvious.

Now, if someone's a great actor and they've seen all four problems before and manage to impress the hiring manager -- well, what can you do. But I don't think there are very many of those.

> I can usually spot the candidates who are leetcode junkies.

what are some of the tells ?

I can tell you how I spot: 1. Doing it in Python. "Can I do this with Python instead of X? because Python is really fast to write and I don't need to worry about small helper functions"

2. Know various approaches more than ordinary people. "Ah we can solve this in various approaches. We can sort this one, and the problem will be log N, or we can use Heap and make it log K. We can use stack but does it get counted as space in the space complexity? Oh I can use deque here but let me just use Python list because Python list is very versatile, it can be anything, it can be array, can be queue, can be stack"

3. Know the solution right away even the non obvious ones. One example is the problem of next permutation. Given a number 1, 3, 2, 4, 5. Find the next permutation in O(n) time and O(1) space. This solution is easy but if you have never done it before there is no way you can come up with a solution complete with code. Another problem, given preorder and inorder list, construct the binary tree. There are many non obvious problems like this.

No offense, but it looks like you are guessing and penalizing people for using python or solving a problem you gave them too fast.

Kind of like that math teacher accusing me of cheating because I did well on the exam.

I'm not penalizing them. I don't think it is bad if someone is a Leetcode junkies. Definitely not downing points if they use Python.

But to actually answer your question. Say the role is in JavaScript, say a Frontend role and the candidates want to answer it in Python instead of JavaScript. Then it is possible that the candidate is a Leetcode junkies.

Why I know? Because I do this myself. And definitely no points subtracted from knowing and using Python.

i am about 300 leets in java but i am always jealous of concise python solutions that people post in discuss.

Debating if would be worth taking the hit of switching to python now.

I think it is worth it. I did Leetcode in JS, then in Go, then in Python.

In Python you just need to focus on the actual algorithms than the actual minuteae details such as "let me create a function to copy this array". As long as you are aware of limitations such as Python int has no restriction like Java (int32, int64) etc, because some problems require you to look into that restrictions. Python string concatenation is also O(n^2) because there is no stringbuilder in Python. Just be aware of those and it should be fine.

thank you. what you said makes sense. job market seems to be down anyways. So might as well give this a shot.

also in Python you can literally not use a computer and just write down your algorithm in a piece of paper. makes it more fun to kill time during queueing in line, commuting etc lol.

FYI, a Python list is a very bad stack.

Whoops. Correction: a Python list is a very bad queue.

Yeah, but for the purpose of algorithm interview it doesn't matter.

It does if your interviewer knows that popping from the head of a list is O(n) and they feel like being picky about it.

It's usually forgiven if you mention that you know that specific language idiosyncrasy and they'll handwave it for the purposes of the interview. If they don't, then that's what knowing alternatives is for.

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