Leetcode 3148. Maximum Difference Score in a Grid

Given an m x n grid where you can jump any distance only to the right or down and each move scores destination − source, maximize the total score over at least one move. Because scores telescope, the task reduces to picking a start and an end cell with the end strictly southeast of the start and maximizing grid[end] − grid[start] (can be done by tracking the maximum value in each cell's southeast submatrix).