Hourly temperatures are laid out as an m x n grid temps that is sorted in non-increasing order both along every row (left to right) and along every column (top to bottom). Return how many readings are strictly negative.
Examples
Input: temps = [[5, 3, 1, -1], [4, 2, -2, -3], [1, -1, -4, -5]]
Output: 6
Explanation: row 0 has one negative, row 1 has two, row 2 has three.
Input: temps = [[3, 2], [1, 0]]
Output: 0
Constraints
1 <= m, n <= 500- Target: O(m + n) time, O(1) extra space.
Goals
- Use the sortedness of a grid to avoid inspecting every cell
- Carry information from one row to the next
- Return a count rather than positions