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.

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Example 1:

Input: grid = [[4,3,2,-1],[3,2,1,-1],[1,1,-1,-2],[-1,-1,-2,-3]]Output: 8Explanation: There are 8 negatives number in the matrix.

Example 2:

Input: grid = [[3,2],[1,0]]Output: 0

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Constraints:

• m == grid.length

• n == grid[i].length

• 1 <= m, n <= 100

• -100 <= grid[i][j] <= 100

正常要O(n+m)的話，要二分法了，但是太懶了。。。

Runtime:?2 ms, faster than?21.57%?of?Java?online submissions for?Count Negative Numbers in a Sorted Matrix.

Memory Usage:?47.9 MB, less than?39.58%?of?Java?online submissions for?Count Negative Numbers in a Sorted Matrix.