human
Write me a the Python program you requested given the following:
Solve in Python:
Given a m * n matrix of ones and zeros, return how many square submatrices have all ones.
 
Example 1:
Input: matrix =
[
  [0,1,1,1],
  [1,1,1,1],
  [0,1,1,1]
]
Output: 15
Explanation: 
There are 10 squares of side 1.
There are 4 squares of side 2.
There is  1 square of side 3.
Total number of squares = 10 + 4 + 1 = 15.

Example 2:
Input: matrix = 
[
  [1,0,1],
  [1,1,0],
  [1,1,0]
]
Output: 7
Explanation: 
There are 6 squares of side 1.  
There is 1 square of side 2. 
Total number of squares = 6 + 1 = 7.

 
Constraints:

1 <= arr.length <= 300
1 <= arr[0].length <= 300
0 <= arr[i][j] <= 1
assistant
#Here is the Python program you requested.

class Solution:
    def countSquares(self, matrix: List[List[int]]) -> int:
        dp = [[matrix[i][j] for j in range(len(matrix[0]))] for i in range(len(matrix))]
        for i in range(1, len(matrix)):
            for j in range(1, len(matrix[0])):
                if matrix[i][j] == 0:
                    continue
                if dp[i-1][j] != 0 and dp[i][j-1] != 0 and dp[i-1][j-1] != 0:
                    dp[i][j] = min(dp[i-1][j-1], dp[i][j-1], dp[i-1][j]) + 1
        count = 0
        for row in dp:
            count += sum(row)
        return count