leetcode-85 最大矩形

leetcode-85 最大矩形

题目描述：

给定一个仅包含 0 和 1 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。
注：用leetode-84题的思路，每一行都做一次最大矩形，挺有趣

import numpy as np
class Solution:
    def maximalRectangle(self, matrix: List[List[str]]) -> int:
        if not matrix:
            return 0
        row,col = len(matrix),len(matrix[0])
        height = [0] * col
        res = 0
        for r in matrix:
            for i in range(col):
                if r[i] == '0':
                    height[i] = 0
                else:
                    height[i] += 1
            res = max(res, self.findLarge(height))
        return res     
        
    def findLarge(self,heights):
        stack = list()
        res = 0
        heights.append(0)
        N = len(heights)
        
        for i in range(N):
            if not stack or heights[i]>heights[stack[-1]]:
                stack.append(i)
            else:
                while stack and heights[i] <= heights[stack[-1]]:
                    h = heights[stack.pop()]
                    w = i if not stack else i - stack[-1] - 1
                    res = max(res,h*w)
                stack.append(i)
        return res