LeetCode 85 最大矩形

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LeetCode 85 最大矩形

给定一个仅包含 0 和 1 、大小为 rows x cols 的二维二进制矩阵，找出只包含 1 的最大矩形，并返回其面积。

示例 1：

输入：matrix = [["1","0","1","0","0"],["1","0","1","1","1"],["1","1","1","1","1"],["1","0","0","1","0"]]
输出：6
解释：最大矩形如上图所示。

示例 2：

输入：matrix = []
输出：0

示例 3：

输入：matrix = [["0"]]
输出：0

示例 4：

输入：matrix = [["1"]]
输出：1

示例 5：

输入：matrix = [["0","0"]]
输出：0
 

提示：

rows == matrix.length
cols == matrix[0].length
0 <= row, cols <= 200
matrix[i][j] 为 '0' 或 '1'

解题思路：

单调栈

最大矩形 - 最大矩形 - 力扣（LeetCode）

LeetCode 84 柱状图中最大的矩形_麦格芬230的博客-CSDN博客

Python代码：

class Solution:def maximalRectangle(self, matrix: List[List[str]]) -> int:m, n = len(matrix), len(matrix[0])heights = [0] * nres = 0for i in range(m):for j in range(n):if matrix[i][j] == '1':heights[j] += 1else:heights[j] = 0res = max(res, self.largestRectangleArea(heights))return resdef largestRectangleArea(self, heights):heights = [0] + heights + [0]n = len(heights)stack = [0]ans = 0for i in range(1, n):while heights[i] < heights[stack[-1]]:height = heights[stack.pop()]width = i - stack[-1] - 1ans = max(ans, height * width)stack.append(i)return ans