class Solution {
public:
    int binarySearch(vector<int>& arr){
        int left = 0;
        int right = arr.size() - 1;
        int mid;

        while(left <= right){
            mid = left + (right - left) / 2;
            if(arr[mid] >= 0){
                left = mid + 1;          
            } else {
               right = mid - 1;
            }
        }
        return arr.size() - left;
    }

    int countNegatives(vector<vector<int>>& grid) {
        int m = grid.size();
        int n = grid[0].size();

        int ans = 0;

        for(auto& arr: grid){
            ans += binarySearch(arr);
        }

        return ans;
    }
};

class Solution {
public:
    int countNegatives(vector<vector<int>>& grid) {
        int m = grid.size();
        int n = grid[0].size();

        int ans = 0;
        int index = n - 1;

        for(auto& row : grid){
            while(index >= 0 && row[index] < 0){
                index--;
            }
            ans += (n - index - 1);
        }

        return ans;
    }
};