Range Sum Query 2D - Immutable - Leetcode 304 - Python

0:00 - Read the problem
1:15 - Drawing Explanation
7:31 - Coding Explanation

leetcode 304

#coding #interview #python
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[blossombabalola]

Thank you Neet. This concept is a bit difficult to explain but you did a good job!

[mohammedafzal]

At first, it was a little tough to understand, but I watched this video multiple times. Now I fully understood the concept! thanks Neetcode!

[MadK]

To be honest at the start I thought I was completely off the mark, but that's exactly how I solved it, thanks for the video.

[kariuki]

My first time hearing about prefix sum but this made it easier to understand

[SkyeTian]

I understand why we are adding a top row since it would be out of bounds when we are calculating prefix sum for the first row (no "above"), but why are we also adding a left column?

[aishwaryaranghar]

Really liking the strategy of posting videos on the streak day!!

[dabobrotosarkar]

Hey Neet! You explain great! I love your videos. Can you make a video about Problem 307. Range Sum Query - Mutable?
It uses Segment Trees to optimize the algorithm. Would love to see that!

[jasdeepsinghgrover]

This can be generalized to all shapes with vertical or horizontal edges... Then we can apply inclusion exclusion principle

[hinatahyuga]

thank you so much sir, took me 3 hours to understand it

[krishnalath]

Thank You for such a wonderful explanation....

[programmermainul]

It would be great video. I am jumping on this r8 now. Cheers!

[spyboy]

I don't know what will i do. I can't think of anything while solving these problems

[ainazikmomunalieva]

Thank you! You are a master at explaining!

[DK-oxze]

What's the logic behind calculating prefix sum for each cell? What's the intuition behind the formula you used?

[reapergrim]

Line 10 : above = matrix[i][j+1]
How is this above it should be right ?

[pulakammalathy]

cant we compute the prefix matrix in place of the given matrix ?

[rajsuriyang]

one-liner:
The time limit is exceeding, Why?
return for i in range(row1, row2+1)])
Can you explain?

[Nisha.......]

Sir, will you please solve leetcode 174?

[theghostwhowalk]

Great video. Mind helping with similar video on Range sum mutable 308 which has update func. Would be great to understand Index tree implementations.

[robertlemiesz]

I would honestly never ask this in an interview. Kinda feels like you either have seen the problem and know the answer, or need to take significant amount of time deriving it. Tells you nothing about the candidate, except whether or not they do alot of leet code.