Problem Description
Given an m x n binary matrix mat, find the 0-indexed position of the row that contains the maximum count of ones, and the number of ones in that row. In case there are multiple rows that have the maximum count of ones, the row with the smallest row number should be selected. Return an array containing the index of the row, and the number of ones in it.
Key Insights
- The problem requires counting the number of ones in each row of a binary matrix.
- If multiple rows have the same maximum count of ones, the row with the smallest index should be returned.
- A simple iteration through each row while keeping track of the maximum count and its corresponding index can effectively solve the problem.
Space and Time Complexity
Time Complexity: O(m * n) - where m is the number of rows and n is the number of columns in the matrix. Each element is visited once. Space Complexity: O(1) - only a few variables are used for tracking the maximum count and index.
Solution
To solve the problem, we will iterate through each row of the matrix and count the number of ones. We will keep track of the maximum count of ones encountered so far and the corresponding row index. If we find a row with a higher count of ones, we update our maximum and index. If we find a row with the same count but a smaller index, we do not change our current maximum and index.