Suppose a social network contains a number of people, each of whom has one of
two \opinions" (e.g. a preference for Mac versus PC). Each person is connected
with a set of \friends", some of the other people in the network. You can choose
any person in the network and let them see the opinions of their friends, and if
most of the friends have the same opinion, them the chosen person will change
their opinion to the one shared by the majority of their friends. If there's an
equal split, you can choose their opinion. Assuming the network is connected,
can we always _nd a sequence of people so as to ensure that they all end up
with the same opinion?
