Some part-time workers at a company would like to unionize. As the main instigator for this, you would like to contact all workers and give them information about such project. The easiest way to do this is to find a number of workers who could make such contacts during their work shift. In order to make this manageable to you, you would like to ask as few people as possible for helping you here. Still, together your helpers should be able to contact every worker in the company. For example, lets say you have the following 6 workers: - Bob: working from 8am to 11am - Mary: working from 7am to noon - Robert: working from 10am to 3pm - Kate: working from 1pm to 3pm - Tom: working from 2pm to 8pm - Chloe: working from 4pm to 6pm In this case, asking Mary and Tom would do the work: Mary could contact the first 3 while Tom could handle the last 3. Give an efficient greedy algorithm for doing this, assuming that you have access to the list of workers and their shift.