Last week's solution can be found here:
This week, we have a simple data set that represents times that inhabitants enter and exit rooms within their household. Assuming inhabitants have the lights of the room on whenever they are present and off when they are not (think motion detection), how many minutes were lights on in each of the rooms?
Note: If there are overlapping time entries, assume the light is on as long as someone is present in the room.
Example: Person 1 is in the room from 12:30 PM - 1:30 PM, and person 2 is in the same room from 1:00 PM to 2:00 PM. The amount of time the light was on was from 12:30 PM to 2:00 PM (do not count duplicate time).
Here is my totally overcomplicated solution, just because