3529. Count Cells in Overlapping Horizontal and Vertical Substrings

You are given an m x n matrix grid consisting of characters and a string pattern. A horizontal substring is a contiguous sequence of characters read from left to right. If the end of a row is reached before the substring is complete, it wraps to the first column of the next row and continues as needed. You do not wrap from the bottom row back to the top. A vertical substring is a contiguous sequ