Maximum Subarray Min-Product Python Solution

lcpy gen -n 1856   # by problem number
lcpy gen -s maximum_subarray_min_product   # by problem name

Input: nums = [1,2,3,2]
Output: 14
Explanation: The maximum min-product is achieved with the subarray [2,3,2] (minimum value is 2).
2 * (2+3+2) = 2 * 7 = 14.

Input: nums = [2,3,3,1,2]
Output: 18
Explanation: The maximum min-product is achieved with the subarray [3,3] (minimum value is 3).
3 * (3+3) = 3 * 6 = 18.

Input: nums = [3,1,5,6,4,2]
Output: 60
Explanation: The maximum min-product is achieved with the subarray [5,6,4] (minimum value is 4).
4 * (5+6+4) = 4 * 15 = 60.

class Solution:
    # Time: O(n)
    # Space: O(n)
    def max_sum_min_product(self, nums: list[int]) -> int:
        mod = 1_000_000_007
        prefix = [0]
        for num in nums:
            prefix.append(prefix[-1] + num)

        stack: list[int] = []
        best = 0
        for i, num in enumerate([*nums, 0]):
            while stack and nums[stack[-1]] >= num:
                height = nums[stack.pop()]
                left = stack[-1] if stack else -1
                best = max(best, height * (prefix[i] - prefix[left + 1]))
            stack.append(i)
        return best % mod