largest.py

from typing import List


class Solution:
    def largestRectangleArea(self, heights: List[int]) -> int:
        stack = [-1]
        max_area = 0
        for i in range(len(heights)):
            while stack[-1] != -1 and heights[stack[-1]] >= heights[i]:
                current_height = heights[stack.pop()]
                current_width = i - stack[-1] - 1
                max_area = max(max_area, current_height * current_width)
            stack.append(i)

        while stack[-1] != -1:
            current_height = heights[stack.pop()]
            current_width = len(heights) - stack[-1] - 1
            max_area = max(max_area, current_height * current_width)
        return max_area
    

# Tests:
if __name__ == '__main__':
    Instant = Solution()
    Solve = Instant.largestRectangleArea([2,1,5,6,2,3])  
    # [2,1,5,6,2,3] -> 10
    print(Solve)