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