Ed dreams of becoming an engineer and designing power supply systems, just like his father, Red. However, Ed has heard that his father was working on the following task:
A cable company wants to lay a line to multiple neighborhoods by minimizing the amount of cable laid. They need a plan on how to complete this task, so that they can minimize the cost and save money.
Ed had no idea how to solve this task and started to doubt whether he really wanted to work on designing power supply systems anymore. However, his father Red told him that this task is easy to solve if you know a widely known concept from graph theory. What concept did Red have in mind?