# 3212. Count Submatrices With Equal Frequency of X and Y
from typing import List
"""
given a 2d character matrix 'grid' where 'grid[i][j]' is either "X", "Y", or
".", return the number of submatrices that contain 'grid[0][0]', an equal
frequency of 'X' and 'Y', and at least one 'X'.
"""
class Solution:
def numberOfSubmatrices(self, grid: List[List[str]]) -> int:
n, ans = len(grid[0]), 0
x, y = [0] * n, [0] * n
for i in grid:
rx, ry = 0, 0
for j in range(n):
rx += i[j] == "X"
ry += i[j] == "Y"
x[j] += rx
y[j] += ry
ans += (x[j] > 0) & (x[j] == y[j])
return ans
if __name__ == "__main__":
obj = Solution()
print(obj.numberOfSubmatrices(grid=[["X", "Y", "."], ["Y", ".", "."]]))
print(obj.numberOfSubmatrices(grid=[["X", "X"], ["X", "Y"]]))
print(obj.numberOfSubmatrices(grid=[[".", "."], [".", "."]]))
