最大矩形面积问题

def solution(n, array):
    stack = []
    max_area = 0
    index = 0
 
    while index < n:
        # If this bar is higher than the bar at stack top, push it to the stack
        if not stack or array[index] >= array[stack[-1]]:
            stack.append(index)
            index += 1
        else:
            # Pop the top
            top_of_stack = stack.pop()
            # Calculate the area with array[top_of_stack] as the smallest (or minimum height) bar
            area = (array[top_of_stack] *
                    ((index - stack[-1] - 1) if stack else index))
            # Update max area, if needed
            max_area = max(max_area, area)
 
    # Now pop the remaining bars from stack and calculate area
    while stack:
        top_of_stack = stack.pop()
        area = (array[top_of_stack] *
                ((index - stack[-1] - 1) if stack else index))
        max_area = max(max_area, area)
 
    return max_area
 
 
if __name__ == "__main__":
    # Add your test cases here
 
    print(solution(5, [1, 2, 3, 4, 5]) == 9)