Given an `m x n` matrix, if an element is 0, set its entire row and column to 0. Do it in-place with constant extra space (by using first row/column as markers).
2D list of ints.
Modified matrix in-place.
Example 1:
Input:
matrix = [[1,1,1],[1,0,1],[1,1,1]]
Output:
[[1,0,1],[0,0,0],[1,0,1]]
Explanation:
The zero at (1,1) causes its row and column to become all 0s.