James Pan

原题网址：https://leetcode.com/problems/range-sum-query-2d-immutable/Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lowe

原题网址：https://leetcode.com/problems/range-sum-query-2d-mutable/Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower

原题网址：https://leetcode.com/problems/rotate-image/You are given an n x n 2D matrix representing an image.Rotate the image by 90 degrees (clockwise).Follow up:Could you do this in-place?

原题网址：https://leetcode.com/problems/search-a-2d-matrix/Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:Integers in each

原题网址：https://leetcode.com/problems/max-sum-of-sub-matrix-no-larger-than-k/Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is