"""
84. Largest Rectangle in Histogram
Difficulty: Hard
https://leetcode.com/problems/largest-rectangle-in-histogram/

──────────────────────────────────────────────────

Given an array of integers heights representing the histogram's bar
height where the width of each bar is 1, return the area of the
largest rectangle in the histogram.

 

Example 1:

Input: heights = [2,1,5,6,2,3]
Output: 10
Explanation: The above is a histogram where width of each bar is 1.
The largest rectangle is shown in the red area, which has an area =
10 units.

Example 2:

Input: heights = [2,4]
Output: 4

 

Constraints:

	• 1 <= heights.length <= 10^5

	• 0 <= heights[i] <= 10^4
"""

class Solution:
    def largestRectangleArea(self, heights: list[int]) -> int: