Number of Islands - Leetcode 200 - Graphs (Python)

[@GregHogg]

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

[@CyrusWong-yq4uw]

I am a Secondary student who is currently learning Python in the coding class in school and at home by myself, and I was doing this leetcode question and find this diffcult. So I looked up on KZbin and found this video, this video gives me a very clean concepts of this question for what to do. Thank you so much!

[@tauicsicsics]

Absolutely fantastic solution Greg, "flooding" (mark it with zeros) the island after found it is a great idea and a lot easier to understand then holding a "set". Please do all neetcode 169 and grind 169 problems, thank you!!

[@MuhammadFahreza]

Totally love the explanation. Your voice is very stable so really like it !

[@GregHogg]

Very glad to hear it!

[@jameshizon4861]

Had this question in interview with Disney for consulting. Thankfully I at least skimmed solution beforehand. Only had ~70% of coding part but answered most of other qs & hope I move forward.

[@GregHogg]

Did you move forward?

[@chrischika7026]

did you

[@louisuchihatm2556]

Bro, updates.

[@jameshizon4861]

Lol no they didnt think I was good fit. Perhaps my mental health from layoff getting to me. I did start a startup tho lol

[@mint6547]

i’ve been killing my brain all day over this , not being able to comprehend some other solutions i saw but this makes so much more sense to me and it’s so well explained (have an interview tomorrow ) 😭😭

[@amalnasir9940]

Best explanation for this problem everr!!! You made it so clear. Thank you sir!!

[@VictorSantos-ih3lb]

you turned this question easier, thanks for the explanation, really clear solution

[@ahmedismail._]

Best explanation I've found on this

[@Jul19n]

This really helped me out, been struggling w bfs/dfs and you cleared it up thanks!

[@ulisesgtzr]

Dude!!!!! thanks so much your explanations are very clean and simple!

[@nerik85]

Holy fuck, that crystal clear explanation. mad respect

[@dhruva1221]

Thanks Greg for the proper & detailed explanation espl updating grid position :) That helped me after looking up solution from 3 more places before.

[@GregHogg]

Amazing ❤️

[@ektasingh5967]

Amazing explanation Greg!

[@saleheen1]

After watching it for few days, I am like: Oh yeah, this is a cool problem, now that I understand.

[@Jollez]

Studying for Zon SDEI this is amazing

[@mohammadamintorabi8415]

Can you explain the "flow" of execution. When a recursive function calls itself, the execution flow "pauses" at the line where the recursive call is made and a new instance of the dfs function starts executing from the beginning, thats little bit hard to imagine and follow in mind

[@tkadosh]

Amazing explanation 😄 thanks a lot

[@adithyar3160]

Awesome Explanation my fav Canadian man

[@GregHogg]

🇨🇦🇨🇦

[@dima.garotas]

Hi, thanks for this video, just a quick question: why do we need to do dfs in up and left directions? These cells will be already considered (before (i,j) cell), because main function traverses grid from left to right, from up to buttom?

[@josephsypniewski3443]

imagine a simple graph of [[1,1], [0,1],[1,1]] This is one island. now if we arent searching up or left (in this case only left matters but it illustrates the point). So we start at (0,0) and change it from 1 to zero, we check down and its a zero so we dont continue that path, we check right change value, check down and change value and then end the call, which leaves us with all zeroes except for the bottom right index because we never moved left from (2,1). So when our program reaches that index it will count it as another island, incorrectly giving us 2 islands instead of 1

[@dima.garotas]

@@josephsypniewski3443 Got it, thanks a lot for the explanation!

[@GarouNguyen]

Thank you bro, wish you all the best

[@GregHogg]

You too!

[@mateustoledo2835]

Thanks bro, I loved the explanation

[@AnjanaOuseph]

How did you say the time complexity is O(2 m*n)

[@yassineouahmane4308]

I have a question , I head that C++ is powerful than python solving problems especially in timelimit , do you think there is implementation in python that fill this gap between the two

[@GregHogg]

C++ will always be faster. But interviewers don't care what language you use.

[@user-vany]

Hi, can you make a Meta-quest browser extension In which instead of a background? There will be transparent screens, well, or translucent ones, like Vision pro.

[@GregHogg]

What 😂

[@user-vany]

​@@GregHogg I wanted to say if it is possible to make such a browser extension so that there is a transparent theme instead of the background. You can give an analogy: there is a light theme, there is a dark one, and it would be cool to add a transparent theme for AR headsets directly to the browser as an extension (sorry, I just use a translator 😃)

[@venky3639]

Most asked question by meta

[@saleheen1]

I search a problem, I don't it from Greg Hogg, I become sad. I don't want to watch it from anyone else. 😬