Interview Question: N Stacks

[@swatipatil4727]

Honestly, the best explanation to this problem that i could found on the internet! More power to you!! :)

[@vivianzhao1513]

Your explanation is pretty intuitive cause I kind of get lost when going through the code in geeksforgeesk

[@ByteByByte]

I'm glad it was helpful!

[@tanayasharma7776]

glad i looked up for this , i could not understand this even after reading articles and watching some other explanations, the way you explained it with examples helped a lot .

[@chandandwivedi2362]

I am your Huge fan. What I like most about you and your channel is that this is the place where I not only get the Solution of the problem but also idea about how to think and approach the problem. Thanks a Lot!! Keep the good work.

[@Aditrash-n5j]

Brilliant Explanation !!! (Btw, which IDE you are using )

[@sathanand]

Summary: k + 1 linkedlists (or stacks) k linkedlists' head elements are in the top[] array. 1 - linkedlist of free elements. "free' holds the head of this list. next[] array has next pointers for each element in the above lists. push --> pop from the 'free' list and make it head of one of k lists. pop --> pop from the given list (one of the k) and make it head of 'free' list.

[@ramubavireddi]

Thanks Anand. I think it is the simplest and straightforward summary/ steps of the solution.

[@mandar.vaidya]

This is the best , I did look at many places but glab found you . My best wishes with you .

[@9awan]

This is a very informative video, Sam.

[@PMPhotographyVideography]

Good job man....you explained an "unreasonable" problem so well

[@ByteByByte]

haha thanks! it is a hell of a problem for sure

[@ayushmishra3388]

This problem should be titled as "STACKS ABSURDITY!".

[@itzeltravels]

Thank you so much for explaining these questions so well, I've been looking for videos that explain interview questions, and your explanations are the most understandable by far. Thanks again for doing this, it really helps!

[@ByteByByte]

You're very welcome! Thanks for the kind words :)

[@cschandragiri]

My brain started popping out, why would someone ask this question in an interview! You won't get it unless you have seen this solution before.

[@ByteByByte]

That's definitely not true

[@JaiSinghKav]

@ 14:52 shouldn't the stack data be 7 instead of 2?

[@徐瑞斌-i8o]

It's easier to explain by just saying "using N+1 linked lists, for N stacks and one free list, all in linked list form. In detail we implement the link by an index array rather than a pointer. Finally, those N+1 linked list can reuse a same "link" array, though they should keep their own head. And use index -1 to stand for a null-pointer. The free list can in fact implemented as a stack, thus we have N+1 stacks."

[@tanzeelrana7348]

why can't we use double linked lists ?

[@karishmajain6980]

if the nextAvailable is -1 that means that the array is full. In that case do we double the size of the array or we do something else?

[@robsylvester272]

This is hot codin' dude. Well done.

[@ByteByByte]

Haha thanks!

[@aditisharma6980]

Very appropriate explaination. Thank you!

[@sumeshpandit9359]

finally, got the trick of pushing and popping.

[@udaysaiphanindra3138]

thank you for clear explanation sir.

[@ByteByByte]

you're welcome!

[@yooos3]

Brilliant video and excellent logic! Thanks a lot!

[@ByteByByte]

Thank you!

[@LegitGamer2345]

idk if you will see this but , if you can make a video on implementing n queue in an array , it would be really helpful , the code is very similar to this but I end up getting lost in it , if you make a video on it , I'm sure I would gain more insight on it.

[@sameeragrawal92]

That was best explanation, the problem is quite tricky. You helped me understand it (Y)

[@ByteByByte]

Thank you! Glad the video helped :)

[@anwarsiddiqui8210]

At 25:07 do we explicitly need to throw the IndexOutOfBoundsException, coz operation at 27:52 could also throw the same exception...

[@ByteByByte]

You're right. I think it is better code this way, though, because it's much more clear when there is going to be an exception

[@anwarsiddiqui8210]

I see, by the way very lucid explanation... #wayToGo

[@siteshp]

Thanks for explaning it so well. I loved every bit of it and sort of it had become intuitive in the middle. Keep up the good work

[@ByteByByte]

You're welceom!

[@vasan65]

Loved your way of explanation, I heard your push explanation and was able to figure out pop. Thank you so much.

[@ByteByByte]

Srinivas Jagadeesh so glad I could help!

[@codeAsCoder]

Thank you sir 😀

[@pawansaini4624]

Thanks sir, nice explanation

[@vivekshaw2437]

Thanks a lot. Brilliant Video.

[@vishvaasvardaan]

Hi thanks! Really good explanation. But is this efficient?

[@ByteByByte]

In what way?

[@ashishchaturvedi3710]

Great Work

[@ByteByByte]

thanks!

[@harshmodi5666]

Amazing explanation. Very Simple, clear and effective. Thank you so much :)

[@ByteByByte]

Thanks!

[@edwardhouser5318]

what a about creating three stacks with one array? Reply

[@ambika1107]

I am a QA from bay area looking for job. This question seem to be too much for .a QA and why would someone ask this. Its very confusing for me. I am looking at the video again and again by rewinding to understand better

[@ByteByByte]

What makes you think they would ask this of a QA? I don't know too much about QA interviews, but this is definitely reasonable for an SE

[@edwardhouser5318]

what a about creating three stack with one array?

[@ByteByByte]

You could do that, but you're limited to 3 stacks

[@rahulbhati3079]

Thanks sir

[@RaviTejaVanjarapu]

Awesome explaination !!

[@ByteByByte]

Thank you :)

[@BardzoZueDziecko]

How it's n stacks with a single array if you're using 3 arrays to implement it xD

[@JEDIWJR]

Like your video. That helps a lot man.

[@ByteByByte]

thanks!

[@aprofromuk]

maybe it wud have been easier to understand if u named the nextIndex[] array to prevNextIndex[] array illustrating its use case clearly through the name :)

[@ByteByByte]

yeah that might help. prevNext* sounds totally contradictory though :P

[@sankethb.k642]

Amazing!!!

[@rohitashwanigam]

Beautiful

[@BrianFaure1]

Why would someone dislike this video? wtf

[@ByteByByte]

[@wildglorypsn]

such a difficult and complex problem :/

[@ByteByByte]

I wouldn't necessarily expect this in an interview, but it's still good to push yourself :)

[@siddharthsharma3679]

@wildglorypsn, just make sure you dont pop your brains out.

[@cooldudeyanarp]

instead of typing the entire code u could have explained the solution on paper :(

[@ByteByByte]

I could, but I don't think it would be very easy to read. Would love a tablet to write on, though

[@jss672006]

You took 41 minutes to explain this and too much code if (top1 < top2 - 1) { top1++; arr[top1] = x; } OR top2--; arr[top2] = x; AND if (top1 >= 0 ) { int x = arr[top1]; top1--; return x;

[@ByteByByte]

I mean you would have failed your interview for not listening to the problem, but okay