Valid Sudoku - LeetCode 36 - Java

[@shobhanathsharma2113]

Very simple and intuitive explanation. Really appreciate it

[@LeetCodeUniversity]

Thank you!

[@suggestaname1685]

WOW, I never thought about using a single HashSet. That is so smart, thank you for sharing and for great explanation!

[@LeetCodeUniversity]

Thank you so much!

[@andretheruler714]

thank you i was lost until i watched you video on this

[@LeetCodeUniversity]

Thank you, I am so glad I helped you out!

[@alexshay7969]

A great explanation on the individual boxes! None else explains this in their code. They just copy and memorize. A terrible way to teach. Thanks!!

[@LeetCodeUniversity]

Thank you, I am really glad you found the video helpful!

[@KittyInCali]

I went over multiple videos, this was by far the best explanation

[@LeetCodeUniversity]

Thank you! Glad it was helpful!

[@ukpauchechi]

Thanks for this explanation, wish I could give this more than one thumbs up😊

[@LeetCodeUniversity]

You are so kind. Thank you and glad it was helpful!!

[@6lack-Echo]

You should make more videos, love your explanation would watch a whole DS&A playlist by you :)

[@LeetCodeUniversity]

Thank you so much!

[@162sujiths4]

Short and crisp 👏

[@LeetCodeUniversity]

Thank you!

[@ranjitasahu19]

This is so good approach, thanks a lot.

[@LeetCodeUniversity]

Glad it was helpful!

[@amitghosh5]

this was great. I have immediately subscribed

[@LeetCodeUniversity]

Thank you so much!!

[@Jack-ke3wm]

Very smart technique! Thank you for great explanation.

[@LeetCodeUniversity]

Thank you!

[@bashierdahman4550]

Could you please post more, your videos are the best on youtube!

[@LeetCodeUniversity]

Thank you 🙏 I am having a really hard time to find the time to shoot the videos. I will try though

[@saleheen12]

Thanks. Only explanation I understood.

[@LeetCodeUniversity]

I am glad I was able to help!

[@legna516]

Please continue your content, much appreciated! Liked and subscribed.

[@LeetCodeUniversity]

I really appreciate you!

[@nitingoel258]

Thank You , very well explained !

[@LeetCodeUniversity]

Thank you so much!

[@anthonyang8494]

Very very good explanation! Ty

[@LeetCodeUniversity]

Thank you!

[@nautilus2024]

wow, awesome !

[@Miscellaneous-Things]

Great explanation as always.

[@LeetCodeUniversity]

Thank you so much!

[@foswacs4868]

Hope I am not too late to ask questions. How is it that the double for loop you wrote in the answer actual iterates through the board? For ( int i = 0; i < board.length; i ++) For (int j = 0; j < board[i].length; j ++) Isn't this how to traverse through a 2-D matrix/ array ?

[@LeetCodeUniversity]

You are exactly right. The double for loop is used to traverse over a 2-D matrix. But what is that? It is a grid composed of rows and columns. The sudoku board is a grid composed or rows and columns. So it is indeed a 2-D array/matrix. Now, board.length is finding the number of rows And board[i].length is finding the number of columns. In this case we know the board has 9 rows and 9 columns. I hope this helps. If not, please let me know exactly where you are confused and I will explain further.

[@bobzero3727]

That was great

[@LeetCodeUniversity]

Thank you!

[@amitbhattacharya356]

Time complexity will be O(n^2) ?

[@LeetCodeUniversity]

In this Question since we know the grid is 9*9 then the time is not depended on the input. We will always go over all 81 fields in the board. So the time is O(81) = O(1) aka constant time. Now, if they said that the grid is N * N then the time is O(n^2)

[@StfuSiriusly]

great explanation, I was hoping to find more but this seems to be your last video. Any plans to make more?

[@LeetCodeUniversity]

Thank you so much! Yes, I might come back to doing them. At least, I hope the videos I have helped you become a little better!