[python] LeetCode84. Largest Rectangle in Histogram

题目描述

Given n non-negative integers representing the histogram’s bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.

思路

用一个栈，每找到一个局部峰值时，触发while循环，向前遍历得最大值

代码实现

class Solution(object):
    def largestRectangleArea(self, height):
        """
        :type heights: List[int]
        :rtype: int
        """
        height.append(0)
        index = [-1]
        ans = 0
        for i in range(len(height)):
            while height[i] < height[index[-1]]:
                h = height[index.pop()]
                w = i-1-index[-1]
                ans = max(ans, h*w)
            index.append(i)
        
        height.pop()
        return ans