leetcode_42_solution_1_part_1.py

maxLefts, maxRights = [0] * len(height), [0] * len(height)

# Maxs set to edges
maxLefts[0] = height[0]
maxRights[len(height)-1] = height[len(height)-1]

i, j = 1, len(height)-2
while i < len(height):
    maxLefts[i] = max(maxLefts[i-1], height[i]) # Check this height to max height to left
    maxRights[j] = max(maxRights[j+1], height[j]) # Check this height to max height to right

    i += 1
    j -= 1

# ... and now we have the max height to the left and right for each element