Count Submatrices With Equal Frequency of X and Y
Medium
Provided a 2D character matrix grid, where grid[i][j] is either 'X', 'Y', or '.', produce the number of submatrices that contain:
-
grid[0][0] -
an equal frequency of
'X'and'Y'. -
at least one
'X'.
Example 1
Input: grid = [["X","Y","."],["Y",".","."]]
Output: 3
Explanation:
Example 2
Input: grid = [["X","X"],["X","Y"]]
Output: 0
Explanation: No submatrix has an equal frequency of 'X' and 'Y'.
Example 3
Input: grid = [[".","."],[".","."]]
Output: 0
Explanation: No submatrix has at least one 'X'.
Constraints
1 <= grid.length, grid[i].length <= 1000grid[i][j]is either'X','Y', or'.'.
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