public class Solution
extends Object
1351 - Count Negative Numbers in a Sorted Matrix\.
Easy
Given a `m x n` matrix `grid` which is sorted in non-increasing order both row-wise and column-wise, return _the number of **negative** numbers in_ `grid`.
**Example 1:**
**Input:** grid = \[\[4,3,2,-1],[3,2,1,-1],[1,1,-1,-2],[-1,-1,-2,-3]]
**Output:** 8
**Explanation:** There are 8 negatives number in the matrix.
**Example 2:**
**Input:** grid = \[\[3,2],[1,0]]
**Output:** 0
**Constraints:**
* `m == grid.length`
* `n == grid[i].length`
* `1 <= m, n <= 100`
* `-100 <= grid[i][j] <= 100`
**Follow up:** Could you find an `O(n + m)` solution?