Given a binary matrix with every row sorted, find the index of the row containing the most number of 1s.

To find the row with the most ones in a binary matrix where each row is sorted, you can use an efficient approach starting from the top-right corner. Initialize a pointer to the last column of the first row. Iterate through the matrix: if the current element is 1, move left to the previous column and record the current row as a potential candidate for the row with the most ones. If the current element is 0, move down to the next row. Continue this process until you have traversed all rows or columns. The last recorded row index will be the row containing the most ones.