Coding Horrors: You can gather all your technical debt into one easy framework!

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Coding Horrors: You can gather all your technical debt into one easy framework!

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coffeetable: Feb 5, 2006; TELL ME AGAIN HOW GREAT BRITAIN WOULD BE IF IT WAS RULED BY THE MERCILESS JACKBOOT OF PRINCE CHARLES

YES I DO TALK TO PLANTS ACTUALLY

comedyblissoption posted:

The candidates I've interviewed so far I've done through remote-ing and them using an IDE and filling in an implementation of a function to pass a test.

I would think whiteboards for coding should be the last resort.

Do you not sketch code out on whiteboards with colleagues either?

# ? Feb 1, 2014 23:40

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# ? May 14, 2024 02:07

NinjaDebugger: Apr 22, 2008

coffeetable posted:

Do you not sketch code out on whiteboards with colleagues either?

I generally have only used whiteboards for UML-type stuff and making sure the math works. Actual code on a whiteboard is a last resort, and I'm not really sure why people are always on about it.

# ? Feb 1, 2014 23:46

carry on then: Jul 10, 2010; by VideoGames
(and can't post for 10 years!)

The only correct answer is to hand them a printout of the source code to Linux and require a formal proof of correctness by the close of business that day.

Good luck!

# ? Feb 1, 2014 23:48

gariig: Dec 31, 2004; Beaten into submission by my fiance; Pillbug

comedyblissoption posted:

Is it better to not ask implementation of simple library functions or fizzbuzz just because someone might have memorized pseudocode for that? It seems like if you can google the problem and find it in the first page hit, it might not be a good question.

For FizzBuzz you could change it something else. I used our company name you could do SomethingAwful. I also asked for the candidates to reverse a string. They could use the internet but we didn't tell them that up front. One candidate asked right out of the gate so they got the string reversal question but almost nothing of FizzBuzz. The second didn't ask until a few minutes in. As soon as I said yes there was a flourish of keyboard strokes as they just Googled "string reversal c#" and didn't get FizzBuzz anywhere. The third person got most of FizzBuzz except they checked divisible by 3, divisible by 5, and finally divisible by 3 and 5. Which was wrong but close enough. Really glad we did the simple coding exercises because if we picked candidate #1 or #2 we would have been firing them.

I can try digging up the code. It was pretty bad

# ? Feb 1, 2014 23:50

Fuck them: Jan 21, 2011; and their bullshit

Dessert Rose posted:

I always give people Visual Studio and an internet connection because gently caress, if I can't write code without an API reference and intellisense in front of me, why should I expect someone to be able to do it in an interview?

This comes with the corollary that your code must actually compile, though.

It's also nice because I get to see your debugging process when it inevitably doesn't work in a corner case or I suggest a change.

See, I'd like that. Doing poo poo verbally or on P&P is loving frustrating.

# ? Feb 1, 2014 23:53

Fuck them: Jan 21, 2011; and their bullshit

gariig posted:

For FizzBuzz you could change it something else. I used our company name you could do SomethingAwful. I also asked for the candidates to reverse a string. They could use the internet but we didn't tell them that up front. One candidate asked right out of the gate so they got the string reversal question but almost nothing of FizzBuzz. The second didn't ask until a few minutes in. As soon as I said yes there was a flourish of keyboard strokes as they just Googled "string reversal c#" and didn't get FizzBuzz anywhere. The third person got most of FizzBuzz except they checked divisible by 3, divisible by 5, and finally divisible by 3 and 5. Which was wrong but close enough. Really glad we did the simple coding exercises because if we picked candidate #1 or #2 we would have been firing them.

I can try digging up the code. It was pretty bad

In one interview, I had to determine if a string was a palindrome. I confused C#'s with Java's substring parameters; one uses substring(StartIndex, EndIndex) and the other did substring(StartIndex, LengthFromThere). The guy was a smug gently caress about it, too, and it was hardly a secret at the time I had more experience with Java. This was all on a whiteboard with no references at all, and it was a very obvious honest mistake.

I probably dodged a bullet, though, that just reeks of insufferable bullshit.

# ? Feb 2, 2014 00:01

Plorkyeran: Mar 22, 2007; To Escape The Shackles Of The Old Forums, We Must Reject The Tribal Negativity He Endorsed

comedyblissoption posted:

Is C#'s string being an enumerable of 16-bit char instead of unicode code points a coding horror?

It has the excuse of backwards compatibility, and having unicode codepoints be the atomic units of your string is way less useful than it sounds.

Something created from scratch today with the API exposing UTF-16 strings would be a horror though.

# ? Feb 2, 2014 00:36

big trivia FAIL: May 9, 2003; "Jorge wants to be hardcore,
but his mom won't let him"

Look Around You posted:

I like how instead of letting it keep crashing and figuring out why "this cannot happen" happened, they just decided to say "gently caress it, let's keep on trucking" with the program in a potentially catastrophically invalid state.

The story of my every single day. I'm a BA and not a developer, but every single day I see something that becomes the dumbest thing I've ever seen. I cannot wait to get promoted high enough to do DB & code reviews and put them off until the day before End of Sprint.

edit: or get high enough to just fire people

big trivia FAIL fucked around with this message at 01:40 on Feb 2, 2014

# ? Feb 2, 2014 01:38

Hughlander: May 11, 2005

2banks1swap.avi posted:

In one interview, I had to determine if a string was a palindrome. I confused C#'s with Java's substring parameters; one uses substring(StartIndex, EndIndex) and the other did substring(StartIndex, LengthFromThere). The guy was a smug gently caress about it, too, and it was hardly a secret at the time I had more experience with Java. This was all on a whiteboard with no references at all, and it was a very obvious honest mistake.

I probably dodged a bullet, though, that just reeks of insufferable bullshit.

If that was actually a reason to fail an interview you totally dodged a bullet.

# ? Feb 2, 2014 02:08

comedyblissoption: Mar 15, 2006

gariig posted:

For FizzBuzz you could change it something else. I used our company name you could do SomethingAwful. I also asked for the candidates to reverse a string. They could use the internet but we didn't tell them that up front. One candidate asked right out of the gate so they got the string reversal question but almost nothing of FizzBuzz. The second didn't ask until a few minutes in. As soon as I said yes there was a flourish of keyboard strokes as they just Googled "string reversal c#" and didn't get FizzBuzz anywhere. The third person got most of FizzBuzz except they checked divisible by 3, divisible by 5, and finally divisible by 3 and 5. Which was wrong but close enough. Really glad we did the simple coding exercises because if we picked candidate #1 or #2 we would have been firing them.

I can try digging up the code. It was pretty bad

What is even the point of asking a string reversal question that they just code an implementation of by googling which garners them a success by the interviewers? It seems like a complete waste of time. Wouldn't it be way better to allow googling and just ask questions within the same realm of complexity that aren't easily google-able?

# ? Feb 2, 2014 04:07

New Yorp New Yorp: Jul 18, 2003; Only in Kenya.; Pillbug

gariig posted:

The third person got most of FizzBuzz except they checked divisible by 3, divisible by 5, and finally divisible by 3 and 5. Which was wrong but close enough.

That's the most telling part... they start trying to fix the problem, and you can see if they actually try to debug it, or if they just change things at random.

# ? Feb 2, 2014 04:34

biznatchio: Mar 31, 2001; Buglord

comedyblissoption posted:

What is even the point of asking a string reversal question that they just code an implementation of by googling which garners them a success by the interviewers? It seems like a complete waste of time. Wouldn't it be way better to allow googling and just ask questions within the same realm of complexity that aren't easily google-able?

One would presume that's what the other, less googlable problems he mentioned he always asks too are for. It's not a bad idea to give them one that's both simple and easily searched for, because whether or not they go to Google for the answer tells you a lot about them and what sort of understanding of the code they'd end up producing as an employee they'll have.

# ? Feb 2, 2014 07:44

coffeetable: Feb 5, 2006; TELL ME AGAIN HOW GREAT BRITAIN WOULD BE IF IT WAS RULED BY THE MERCILESS JACKBOOT OF PRINCE CHARLES

YES I DO TALK TO PLANTS ACTUALLY

comedyblissoption posted:

What is even the point of asking a string reversal question that they just code an implementation of by googling which garners them a success by the interviewers? It seems like a complete waste of time. Wouldn't it be way better to allow googling and just ask questions within the same realm of complexity that aren't easily google-able?

I think you're misinterpreting the intention of FizzBuzz-type questions. They're not intended to check whether someone can program, they're intended to save time. Some candidates might memorize the answer, but that doesn't matter because they're gonna be caught out at the next question you ask.

Meanwhile, anyone who has written a line of code in their life will have it out in 30s and you can get on with the interview.

# ? Feb 2, 2014 14:07

Damiya: Jul 3, 2012

biznatchio posted:

One would presume that's what the other, less googlable problems he mentioned he always asks too are for. It's not a bad idea to give them one that's both simple and easily searched for, because whether or not they go to Google for the answer tells you a lot about them and what sort of understanding of the code they'd end up producing as an employee they'll have.

Really? I don't know that I agree with that. I produce good code as an employee but if you give me a problem that I can tell is going to be well solved, many times before me, gently caress yea I'm gonna go to Google to see if there's an implementation jump off point.

It's one thing if someone is just blindly copying stack overflow with no adaptation or fitting the solution to the problem. But why would you want to hire someone that doggedly insists on reinventing every wheel?

Damiya fucked around with this message at 18:17 on Feb 2, 2014

# ? Feb 2, 2014 18:15

Steve French: Sep 8, 2003

2banks1swap.avi posted:

In one interview, I had to determine if a string was a palindrome. I confused C#'s with Java's substring parameters; one uses substring(StartIndex, EndIndex) and the other did substring(StartIndex, LengthFromThere). The guy was a smug gently caress about it, too, and it was hardly a secret at the time I had more experience with Java. This was all on a whiteboard with no references at all, and it was a very obvious honest mistake.

I probably dodged a bullet, though, that just reeks of insufferable bullshit.

What sort of solution did you have that required using a substring method?

# ? Feb 2, 2014 18:15

piratepilates: Mar 28, 2004; So I will learn to live with it. Because I can live with it. I can live with it.

Steve French posted:

What sort of solution did you have that required using a substring method?

I'm guessing:

code:


def poop (string)
	var first_half = string.substring(0, len(string)/2)
	var second_half = string.substring(len(string)/2, len(string)-1).reverse()
	return first_half == second_half

edit: wait what the hell function did I just write, that ain't right

edit: wait poo poo it is right isn't it

edit: I don't know why someone would write it like this

piratepilates fucked around with this message at 18:30 on Feb 2, 2014

# ? Feb 2, 2014 18:23

Tesseraction: Apr 5, 2009

Won't that return 'false' for palindromes with an odd number of characters due to the use of len/2 in the second_half method?

# ? Feb 2, 2014 18:32

coffeetable: Feb 5, 2006; TELL ME AGAIN HOW GREAT BRITAIN WOULD BE IF IT WAS RULED BY THE MERCILESS JACKBOOT OF PRINCE CHARLES

YES I DO TALK TO PLANTS ACTUALLY

piratepilates posted:

I'm guessing:
code:
def poop (string)
	var first_half = string.substring(0, len(string)/2)
	var second_half = string.substring(len(string)/2, len(string)-1).reverse()
	return first_half == second_half
edit: wait what the hell function did I just write, that ain't right

edit: wait poo poo it is right isn't it

Careful. When you use a pair of iterators/pointers/indices to define a range, it'll usually be half-open on the right (ie the item at the left index will be included, but not the one under the right index).

# ? Feb 2, 2014 18:34

piratepilates: Mar 28, 2004; So I will learn to live with it. Because I can live with it. I can live with it.

Yeah it would but it's not a very good solution so I wouldn't worry about it.

# ? Feb 2, 2014 18:35

Blinkz0rz: May 27, 2001; MY CONTEMPT FOR MY OWN EMPLOYEES IS ONLY MATCHED BY MY LOVE FOR TOM BRADY'S SWEATY MAGA BALLS

Steve French posted:

What sort of solution did you have that required using a substring method?

A good question.

No real reason to use substring when afaik pretty much every language has some kind of regex implementation (or punctuation replacing method) and a string reversal mechanism.

For example:

Python code:

import string
def palindrome(words):
     words_stripped = words.translate(string.maketrans("", ""), string.punctuation).replace(" ", "").lower()
     return words_stripped == words_stripped[::-1]


print(palindrome("Madam, I'm Adam"))
>>> True
print(palindrome("A man, a plan, a canal, Panama"))
>>> True
print(palindrome("Foo bar"))
>>> False

# ? Feb 2, 2014 18:46

Steve French: Sep 8, 2003

Yeah, I can't think of any reason to use a substring method when checking for a palindrome. piratepilates' code was about the closest I could think of to something reasonable, but it would be a lot easier and simpler to just reverse the whole string and skip the substring bit if you're gonna go that route.

Perhaps this is related to the real reason the guy was being a smug rear end in a top hat?

# ? Feb 2, 2014 18:52

New Yorp New Yorp: Jul 18, 2003; Only in Kenya.; Pillbug

Blinkz0rz posted:

A good question.

No real reason to use substring when afaik pretty much every language has some kind of regex implementation (or punctuation replacing method) and a string reversal mechanism.

For example:
Python code:
import string
def palindrome(words):
     words_stripped = words.translate(string.maketrans("", ""), string.punctuation).replace(" ", "").lower()
     return words_stripped == words_stripped[::-1]


print(palindrome("Madam, I'm Adam"))
>>> True
print(palindrome("A man, a plan, a canal, Panama"))
>>> True
print(palindrome("Foo bar"))
>>> False

Or, assuming sanitized input, iterate over string length/2, check string[i] == string[string.Length-1-i]. That has the added bonus of breaking out of the method if you're dealing with a string like "hello world", where 'h' != 'd'.

You can safely do length/2 because if the length is an odd number, it doesn't need to check the middle character.

[edit]
I agree that the sanest, most readable approach is definitely just to sanitize input and reverse the string, though.

# ? Feb 2, 2014 18:53

RoadCrewWorker: Nov 19, 2007; camels aren't so great

I'd be curious if there are test that go from fizzbuzz and get more and more complex just to see where/if you say "yeah that's the point where i'm not going to reinvent a wobbly, broken wheel on my own and use a well tested, documented library if it exists" because otherwise you end up with your own buggy "but it works on my dev machine/locale" date/time math or "totally safe because obscure" authentication/encryption system.

# ? Feb 2, 2014 19:15

Blinkz0rz: May 27, 2001; MY CONTEMPT FOR MY OWN EMPLOYEES IS ONLY MATCHED BY MY LOVE FOR TOM BRADY'S SWEATY MAGA BALLS

Ithaqua posted:

Or, assuming sanitized input, iterate over string length/2, check string[i] == string[string.Length-1-i]. That has the added bonus of breaking out of the method if you're dealing with a string like "hello world", where 'h' != 'd'.

You can safely do length/2 because if the length is an odd number, it doesn't need to check the middle character.

[edit]
I agree that the sanest, most readable approach is definitely just to sanitize input and reverse the string, though.

That makes sense and feels like it should be more efficient. Out of curiosity, I tested it in python:

Python code:

import string
import timeit

s = "Madam, I'm Adam"


def iter_pal(words):
    s = words.translate(string.maketrans("", ""), string.punctuation).replace(" ", "").lower()
    for i in range(len(s)/2):
        if s[i] != s[len(s)-1-i]:
            return False
    return True


def slice_pal(words):
    s = words.translate(string.maketrans("", ""), string.punctuation).replace(" ", "").lower()
    return s == s[::-1]


iter_str = "from __main__ import s, iter_pal as f"
slice_str = "from __main__ import s, slice_pal as f"

print "slice (is palindrome):", timeit.Timer('f(s)', slice_str).timeit(1000000)
print "iter (is palindrome):", timeit.Timer('f(s)', iter_str).timeit(1000000)


s = "Hello World"


print "slice (not palindrome):", timeit.Timer('f(s)', slice_str).timeit(1000000)
print "iter (not palindrome):", timeit.Timer('f(s)', iter_str).timeit(1000000)

And the results were actually faster using slices vs. iterating over half the string.

code:

$ python test.py
slice (is palindrome): 3.38231758506
iter (is palindrome): 4.36570744326
slice (not palindrome): 3.28909330655
iter (not palindrome): 3.4028108321

Color me surprised. I would figure slicing and then comparing would be way less efficient. Is there that much of an overhead on iteration that it would take longer?

# ? Feb 2, 2014 19:59

New Yorp New Yorp: Jul 18, 2003; Only in Kenya.; Pillbug

Blinkz0rz posted:

That makes sense and feels like it should be more efficient. Out of curiosity, I tested it in python:

Python code:

import string
import timeit

s = "Madam, I'm Adam"


def iter_pal(words):
    s = words.translate(string.maketrans("", ""), string.punctuation).replace(" ", "").lower()
    for i in range(len(s)/2):
        if s[i] != s[len(s)-1-i]:
            return False
    return True


def slice_pal(words):
    s = words.translate(string.maketrans("", ""), string.punctuation).replace(" ", "").lower()
    return s == s[::-1]


iter_str = "from __main__ import s, iter_pal as f"
slice_str = "from __main__ import s, slice_pal as f"

print "slice (is palindrome):", timeit.Timer('f(s)', slice_str).timeit(1000000)
print "iter (is palindrome):", timeit.Timer('f(s)', iter_str).timeit(1000000)


s = "Hello World"


print "slice (not palindrome):", timeit.Timer('f(s)', slice_str).timeit(1000000)
print "iter (not palindrome):", timeit.Timer('f(s)', iter_str).timeit(1000000)

And the results were actually faster using slices vs. iterating over half the string.

code:

$ python test.py
slice (is palindrome): 3.38231758506
iter (is palindrome): 4.36570744326
slice (not palindrome): 3.28909330655
iter (not palindrome): 3.4028108321

Color me surprised. I would figure slicing and then comparing would be way less efficient. Is there that much of an overhead on iteration that it would take longer?

Is len a function in Python? It could be iterating the entire string every time to get the length, or something silly like that.

# ? Feb 2, 2014 20:13

Crosscontaminant: Jan 18, 2007

len is a builtin function; getting the length of a sequence is O(1). It might be worth checking that out anyway, though, as well as the latter with s == reversed(s) rather than s == s[::-1].

Crosscontaminant fucked around with this message at 20:17 on Feb 2, 2014

# ? Feb 2, 2014 20:15

Nippashish: Nov 2, 2005; Let me see you dance!

I've found as a general rule that interpreting python is actually quite slow. That's one of the reasons that things like numpy are built the way they are (with a big emphasis on vectorized operations). I expect pypy would fare better with the iterator.

# ? Feb 2, 2014 20:24

Blinkz0rz: May 27, 2001; MY CONTEMPT FOR MY OWN EMPLOYEES IS ONLY MATCHED BY MY LOVE FOR TOM BRADY'S SWEATY MAGA BALLS

Crosscontaminant posted:

len is a builtin function; getting the length of a sequence is O(1). It might be worth checking that out anyway, though, as well as the latter with s == reversed(s) rather than s == s[::-1].

code:

$ python test.py
slice (is palindrome): 3.38962256376
iter (is palindrome): 4.34589570742
reversed (is palindrome): 3.38774523019
slice (not palindrome): 3.28798108419
iter (not palindrome): 3.4126956778
reversed (not palindrome): 3.28122952778

Looks like reversed is the same as using slicing. Wonder if the implementation is the same.

# ? Feb 2, 2014 20:27

NFX: Jun 2, 2008; Fun Shoe

As far as I know, the string comparison "==" just calls the __eq__ method on the built in string type, and I would imagine that's precompiled C. The only overhead is the string reversal, which is independent on whether the string is a palindrome.

# ? Feb 2, 2014 20:49

Fuck them: Jan 21, 2011; and their bullshit

I thought nobody expected best performance for off the cuff, non prepared, no research, spit it out immediately interview questions.

If someone wants me to write a library or a few methods for one why not just ask me to? That's MUCH more of a gauge of how I'd actually program at work than how I do poo poo with marker and whiteboard.

I do find it funny that split and reverse works better. I just think of it in those terms, though yes doing it char by char makes sense, and if I was doing C I'd do it that way.

I REALLY hate that interviewing is a separate skill set from programming that only slightly overlaps. At least now I know to practice it.

# ? Feb 2, 2014 21:05

Steve French: Sep 8, 2003

But could you answer my question?

# ? Feb 2, 2014 21:18

Fuck them: Jan 21, 2011; and their bullshit

I split the string into two halves, reversed one of the halves and compared them, but because I confused the parameters for .substring it wouldn't have worked in C#.

I didn't do it character by character since I was trying to avoid off-by-one errors in an interview - you're not given time to test, research, or even really a lot of time to think. Split, reverse and compare seemed safer. :smith:

# ? Feb 2, 2014 21:44

coffeetable: Feb 5, 2006; TELL ME AGAIN HOW GREAT BRITAIN WOULD BE IF IT WAS RULED BY THE MERCILESS JACKBOOT OF PRINCE CHARLES

YES I DO TALK TO PLANTS ACTUALLY

2banks1swap.avi posted:

I split the string into two halves, reversed one of the halves and compared them, but because I confused the parameters for .substring it wouldn't have worked in C#.

I didn't do it character by character since I was trying to avoid off-by-one errors in an interview - you're not given time to test, research, or even really a lot of time to think. Split, reverse and compare seemed safer.

Reverse and compare is safest/easiest. Don't need to split at all. Don't sweat it though, this is a safe space for silly mistakes.

To balance it out, all my work today is for nothing because I forgot which way the hands on a clock go round :downs:

coffeetable fucked around with this message at 22:08 on Feb 2, 2014

# ? Feb 2, 2014 22:05

Fuck them: Jan 21, 2011; and their bullshit

Meh.

At least now I have stuff I've done to talk about, and I'm not forced to do boring school questions in interviews.

# ? Feb 2, 2014 22:10

evensevenone: May 12, 2001; Glass is a solid.

Palindrome testing is kind of begging for a recursive solution. And if anyone complains about stack space you talk about tail calls. If you have to allocate a reversed string I would be fairly alarmed.

# ? Feb 3, 2014 01:33

Steve French: Sep 8, 2003

Is it? Can you show an elegant tail recursive solution?

also, just because scala

code:

  s.view == s.view.reverse

Steve French fucked around with this message at 02:12 on Feb 3, 2014

# ? Feb 3, 2014 02:03

Jabor: Jul 16, 2010; #1 Loser at SpaceChem

Steve French posted:

Is it? Can you show an elegant tail recursive solution?

if (s.length < 2) return true
else if (s[0] != s[-1]) return false
else return isPalindrome(s[1:-2])

# ? Feb 3, 2014 02:12

Deus Rex: Mar 5, 2005

Jabor posted:

if (s.length < 2) return true
else if (s[0] != s[-1]) return false
else return isPalindrome(s[1:-2])

this would be cool in a language that uses structural sharing for strings, I guess.

# ? Feb 3, 2014 02:14

Scaevolus: Apr 16, 2007

Fizzshedding: dozens of replies arguing about implementations of a trivial interview question.

# ? Feb 3, 2014 02:19

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# ? May 14, 2024 02:07

Steve French: Sep 8, 2003

Deus Rex posted:

this would be cool in a language that uses structural sharing for strings, I guess.

Allocating n/2 extra strings is cooler than allocating 1 extra string

# ? Feb 3, 2014 02:20

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Coding Horrors: You can gather all your technical debt into one easy framework!

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