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Leetcode 1351: Count Negative Numbers in a Sorted Matrix

You are given an m x n matrix grid, sorted in non-increasing order both row-wise and column-wise. Your task is to determine how many negative numbers are present in the grid.

Jun 24, 2024 - 5 min read

Leetcode 1380: Lucky Numbers in a Matrix

You are given a matrix of distinct numbers with dimensions m x n. A lucky number in the matrix is an element that is the minimum value in its row and the maximum value in its column. Your task is to find and return all such lucky numbers.

Jun 22, 2024 - 6 min read

Leetcode 1391: Check if There is a Valid Path in a Grid

You are given an m x n grid where each cell represents a street. The streets have different connections between neighboring cells. Starting from the top-left corner of the grid, you need to find if there exists a valid path to the bottom-right corner, following the direction of the streets.

Jun 20, 2024 - 8 min read

Leetcode 1476: Subrectangle Queries

You are tasked with implementing the SubrectangleQueries class which operates on a matrix representing a rectangle with integer values. The class should support two key operations: updateSubrectangle and getValue.

Jun 12, 2024 - 5 min read

Leetcode 1504: Count Submatrices With All Ones

You are given a binary matrix of size m x n where each element is either 0 or 1. Your task is to count how many submatrices consist entirely of 1s.

Jun 9, 2024 - 6 min read

Leetcode 1536: Minimum Swaps to Arrange a Binary Grid

You are given an n x n binary grid, and in one move, you can swap any two adjacent rows. The grid is valid if all the cells above the main diagonal are zeros. Your task is to return the minimum number of swaps needed to make the grid valid, or -1 if it’s not possible.

Jun 6, 2024 - 7 min read