打卡群刷题总结0921——最大正方形

class Solution:
    def maximalSquare(self, matrix: List[List[str]]) -> int:
        if len(matrix) == 0 or len(matrix[0]) == 0:
            return 0
        
        # 转换为int
        for i in range(len(matrix)):
            for j in range(len(matrix[0])):
                matrix[i][j] = int(matrix[i][j])
        
        dp = copy.copy(matrix)
        res = max(max(dp[0]), max([dp[i][0] for i in range(len(dp))]))
        for i in range(1, len(matrix)):
            for j in range(1, len(matrix[0])):
                if matrix[i][j] == 1:
                    dp[i][j] = min(dp[i][j - 1], dp[i - 1][j], dp[i - 1][j - 1]) + 1
                    if dp[i][j] > res:
                        res = dp[i][j]      
        return res * res