Row With Maximum Ones — LeetCode 2643 Python Solution

The problem

Given a 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.

Example

Input

mat = [[0,1],[1,0]]

Output

[0,1]

Explanation

Both rows have the same number of 1's. So we return the index of the smaller row, 0, and the maximum count of ones (1). So, the answer is [0,1].

Python solution

class Solution:
    def rowAndMaximumOnes(self, mat: List[List[int]]) -> List[int]:
        ans = [0, 0]
        for i, row in enumerate(mat):
            cnt = sum(row)
            if ans[1] < cnt:
                ans = [i, cnt]
        return ans

Complexity

Pattern: Matrix and Grid

Treat a 2-D grid as a graph whose neighbours are the four adjacent cells. LeetCode 2643. Row With Maximum Ones is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Matrix.

The matrix and grid guide has the Python template for the pattern and the 216 LeetCode problems that use it.

Related problems