Скачать или смотреть 💻 2D Range Sum Query - NumMatrix | JavaScript Prefix Sum Tutorial | O(1) Query Time

In this video, we’ll solve the 2D Range Sum Query - Immutable problem using JavaScript. Learn how to calculate the sum of any submatrix efficiently using a 2D prefix sum array.

We’ll implement the NumMatrix class step by step, allowing sumRegion queries to run in O(1) time after preprocessing. Perfect for coding interviews, LeetCode practice, and algorithm enthusiasts.

✨ What you’ll learn:

How to implement the NumMatrix class in JavaScript

Build and use a 2D prefix sum array

Handle multiple rectangle sum queries efficiently

Time and space complexity analysis

Example: sum of a rectangle in a matrix like

[ [3, 0, 1, 4, 2], [5, 6, 3, 2, 1], [1, 2, 0, 1, 5], [4, 1, 0, 1, 7], [1, 0, 3, 0, 5] ]

💡 Ideal for LeetCode, FAANG interview prep, and mastering Data Structures & Algorithms (DSA) in JavaScript.


#JavaScript #CodingInterview #LeetCode #NumMatrix #2DArray #PrefixSum #DSA #Programming #Algorithm #CodingChallenge #JavaScriptCoding #DataStructures #CodingTheoryGuru #WebDevelopment #MatrixProblems #AlgorithmTutorial