A computer network consists of 6 computers. Each computer is directly connected to at least one of the other computers. Show that there are at least 2 computers in the network that are directly connected to the same number of other computers.
How can I go about solving this? I don't think there is a specific equation for a pigeon hole principle.
Each computer is mapped to the number of connections it has. These are integers from 1 to 5. You have 6 computers.