10-week-algorithm-excercise-master/Week_09/85/maximal_rectangle.py

from typing import List


class Solution:
    def maximalRectangle(self, matrix: List[List[str]]) -> int:
        if not matrix or not matrix[0]:
            return 0
        m, n = len(matrix), len(matrix[0])

        height = [0] * n
        left = [-1] * n
        right = [n] * n
        res = 0
        for i in range(m):
            cur_left, cur_right = -1, n
            for j in range(n):
                if matrix[i][j] == '1':
                    height[j] += 1
                else:
                    height[j] = 0

            for j in range(n):
                if matrix[i][j] == '1':
                    left[j] = max(left[j], cur_left)
                else:
                    left[j] = -1
                    cur_left = j
            for j in range(n-1, -1, -1):
                if matrix[i][j] == '1':
                    right[j] = min(right[j], cur_right)
                else:
                    right[j] = n
                    cur_right = j
            for j in range(n):
                res = max(res, height[j] * (right[j] - left[j] - 1))
        return res