Subsets - Leetcode 78 - Recursive Backtracking (Python)

[@GregHogg]

Master Data Structures & Algorithms For FREE at AlgoMap.io!

[@NavneetKaur-x6q]

After looking at several other videos, I finally found one where all my questions were answered. Loved the simplicity of the explanation whether whiteboard, coding part or the complexity.

[@SHIHJUIheh]

Thank you for explaining drawing part in detail, especially the recursive backtracking part ! You made this concept so much easier!!!

[@GregHogg]

You're very welcome 😎

[@itsmenatika]

I've started understanding backtracking by that. In only 12 minutes. Thanks

[@anothertechguy-q9g]

Thank you a lot for explaining the transitive parts of backtracking!

[@FZRides]

Hi Greg, I found your video very intuitive. Thanks for sharing such content. Can you please make a video on "Tower of Hanoi" problem using recursion. I am unable to catch the recursive logic behind it. Can you please do it Sir.

[@chisomedoka5651]

this is gold, so intuitive . Thanks for this

[@kenkaneki5433]

better than stp neetcode guy explanation

[@olaf9063]

Great explanation, thanks. Is the time complexity not O(n * 2^n) - reason being that at each of the terminal nodes you need to copy the list, which is an O(n) operation?

[@henryhan8838]

You've inspired me, I was just wondering why we multiplied it by n.

[@DivineEdoka]

I'll like to see how you slve subset ii with this pattern as well

[@sampjm1898]

you can use a dp solution : fn(n)=fn(n-1)+{fn(n-1) and put element_n in every set that return by fn(n-1)},cache the result of f(n).,f(n-1)..... consider you need to solve all the fn(n) you can write a bottom up dp solution, consider for each fn(n) only need f(n-1) you can just maintain one layer of cache so basic case is {[element_1],[empty]} for every element in the array add this element to each set and add this set back to the result: so the 2nd iteration: {[element_1],[empty], [element_1,element_2],[element_2]} and so on sorry for my English

[@GregHogg]

I'll have to look into this. Thanks so much for sharing!

[@supremoluminary]

Do you have a link to this? I want to learn it. Thanks.

[@shubhambajaj4939]

brilliant solution. you just got yourself a new subscriber :)

[@christianjt7018]

thanks Greg your explanations are the best!

[@GregHogg]

Bro I can see from the comments that you're just flying through these questions, good for you honestly!

[@dusvn1484]

Nice video,helped me a lot!

[@nav213]

Would backtracking have to do with recursion? Is it possible to solve this in a non-recursive way? I am asking because it's really difficult to understand the recursive implementation of the code unless you memorize it. Thanks again for you awesome tutorials!!!! cheers

[@GregHogg]

You can memorize the template for how this is done, I promise the best way is through recursion

[@GarouNguyen]

bro how do you move recursion left what is line 12 code back track i + 1 , why you have two backtrack(i+1) can you explain bro

[@Alex-tm5hr]

Can you pls make a vid for subsets 2?

[@just4laughs140]

what does backtrack(i +1) mean

[@phamh79]

many thanks.

[@GarouNguyen]

bro why don't pick and pick is same backtrack(i+1) and why you recursion left i + 1 i don't understand

[@m.y.7230]

thanks for explaning dfs in drawing

[@GregHogg]

No problem!

[@anti-dn541]

Easy to understand for noob like me 👍🏻

[@GregHogg]

Oh that's so great to hear 😊

[@maskedoni3229]

Great solution

[@GregHogg]

Thanks so much!

[@Antinormanisto]

I don't understand(

[@GregHogg]

Maybe try watching it again? Backtracking is REALLY confusing at first

[@hrushik10]

thanks