Input:  matrix = [[0, 0, 1, 2], [0, 2, 2, 2], [2, 1, 0, 1]]
Output: 3 
Explanation:

Just my educated guess. might be right might be wrong -

The longest diagonal segment following the pattern 1, 2, 0, 2, 0, 2, 0, ... can be found starting from the element at row 2, column 1 (1-based index), going up and to the right. The segment is [1, 2, 0], which has a length of 3.