leetCode170|统计有序矩阵中的负数

示例 1：

输入：grid = [[4,3,2,-1],[3,2,1,-1],[1,1,-1,-2],[-1,-1,-2,-3]]
输出：8
解释：矩阵中共有 8 个负数。
示例 2：

输入：grid = [[3,2],[1,0]]
输出：0
示例 3：

输入：grid = [[1,-1],[-1,-1]]
输出：3
示例 4：

输入：grid = [[-1]]
输出：1
 

提示：

m == grid.length
n == grid[i].length
1 <= m, n <= 100
-100 <= grid[i][j] <= 100

public  class CountNegativesTest {
    public static void main(String[] args) {
        int [][] grid={
                {4,3,2,-1},{3,2,1,-1},{1,1,-1,-2},{-1,-1,-2,-3}
        };
        int countNegatives = countNegatives(grid);
        System.out.println("countNegatives = " + countNegatives);
    }

    public static  int countNegatives(int[][] grid) {
        if (grid == null || grid.length == 0 || grid[0].length == 0) {
            return 0;
        }
        int rowLength = grid.length;
        int colLength = grid[0].length;
        int count = 0;
        for (int i = 0; i < rowLength; i++) {
            for (int j = 0; j < colLength; j++) {
                if (grid[i][j] < 0) {
                    count++;
                }
            }
        }
        return count;
    }
}