Trapping Rain Water Python Solution with Tests

lcpy gen -n 42   # by problem number
lcpy gen -s trapping_rain_water   # by problem name

Input: height = [0,1,0,2,1,0,1,3,2,1,2,1]
Output: 6

Input: height = [4,2,0,3,2,5]
Output: 9

class Solution:
    # Time: O(n)
    # Space: O(1)
    def trap(self, height: list[int]) -> int:
        if not height:
            return 0

        left, right = 0, len(height) - 1
        left_max = right_max = water = 0

        while left < right:
            if height[left] < height[right]:
                if height[left] >= left_max:
                    left_max = height[left]
                else:
                    water += left_max - height[left]
                left += 1
            else:
                if height[right] >= right_max:
                    right_max = height[right]
                else:
                    water += right_max - height[right]
                right -= 1

        return water