Problem 1: (5 points) Class Scheduling: Suppose you have a set of classes to schedule among a large number of lecture halls, where any class can class place in any lecture hall. Each class c, has a start time s, and finish time fi. We wish to schedule all classes using as few lecture halls as possible. Verbally describe an efficient greedy algorithm to determine which class should use which lecture hall at any given time. What is the running time of your algorithm