"""This problem was asked by Facebook.

Given a list of strictly positive integers, partition the list into 3 contiguous 
partitions which each sum up to the same value. If not possible, return null.

For example, given the following list:

[3, 5, 8, 0, 8]
Return the following 3 partitions:

[[3, 5],
 [8, 0],
 [8]]
Which each add up to 8.
"""