Water collected between towers

Question

I recently came across an interview question asked by Amazon and I am not able to find an optimized algorithm to solve this question:

You are given an input array wh

Answer 1

I wrote this relying on some of the ideas above in this thread:

def get_collected_rain(towers):

    length = len(towers)
    acummulated_water=[0]*length
    left_max=[0]*length
    right_max=[0]*length

    for n in range(0,length):

        #first left item
        if n!=0:
            left_max[n]=max(towers[:n])

        #first right item
        if n!=length-1:
            right_max[n]=max(towers[n+1:length])

        acummulated_water[n]=max(min(left_max[n], right_max[n]) - towers[n], 0)

    return sum(acummulated_water)

Well ...

> print(get_collected_rain([9,8,7,8,9,5,6]))

> 5