LeetCode刷题DAY 11：最大正方形

class Solution:
    def maximalSquare(self, matrix: List[List[str]]) -> int:
        if len(matrix)==0:
            return 0
        # len(matrix)得到的是矩阵行数
        st = [[0]*len(matrix[0]) for _ in range(len(matrix))]
        maxlong = []
        for i in range(len(matrix)):
            for j in range(len(matrix[0])):
                if matrix[i][j]=='1':
                    if i*j==0:
                        st[i][j]=1
                    else:
                        st[i][j]=min(st[i-1][j],st[i-1][j-1],st[i][j-1])+1
            maxlong.append(max(st[i]))
        return max(maxlong)**2