10-week-algorithm-excercise-master/Week_06/221/maximal_square.py

from typing import List


class Solution:
    def maximalSquare(self, matrix: List[List[str]]) -> int:
        if not matrix or not matrix[0]:
            return 0
        m, n = len(matrix), len(matrix[0])
        l = 0
        dp = [[0] * n for _ in range(m)]

        for i in range(m):
            for j in range(n):
                if i == 0 or j == 0:
                    dp[i][j] = int(matrix[i][j])
                elif matrix[i][j] == "1":
                    dp[i][j] = min(dp[i - 1][j], dp[i][j - 1], dp[i - 1][j - 1]) + 1
                l = max(l, dp[i][j])
        return l * l