DIY: Range Sum Query 2D — Immutable
Explore how to implement a num_matrix class in Ruby that supports fast sum queries on subregions of a 2D matrix. Understand how to initialize the matrix and retrieve sums for various rectangular regions, preparing you to handle similar algorithm problems in coding interviews.
We'll cover the following...
We'll cover the following...
Problem statement
Given an m * n matrix, you need to handle multiple queries of the following type:
Calculate the sum of the elements of the matrix inside the rectangle defined by its upper left corner, ...