Similar to https://leetcode.com/problems/car-pooling/
Given time interval and number of bags of each delivery. Create time series of how many bags are carried at a time.
# e.g. input format : [start_time, end_time, number_of_bags_carried]
input: [[2, 10, 3], [8,12, 4], [15,18,5]]
output: {
2: 3,
8: 7,
10: 4,
12: 0,
15: 5,
18: 0
}