（力扣记录）84. 柱状图中最大的矩形

数据结构类型：栈

时间复杂度：O(N)

空间复杂度：O(N)

代码实现：

class Solution:
    def largestRectangleArea(self, heights: List[int]) -> int:
        stack = []
        area = 0
        for i in range(len(heights)):
            index = i
            while stack and stack[-1][1] > heights[i]:
                last_i, last_h = stack.pop()
                index = last_i
                area = max(area, last_h * (i - last_i))
            stack.append([index, heights[i]])
        
        for i, h in stack:
            area = max(area, (len(heights) - i) * h)
        
        return area