Degrees in graphs II: Degree sequences
The degree sequence of a graph is the sequence of degrees of all its elements.
A Santa Claus network
Poor Santa has to travel all across the country to deliver all his presents. How does he do this?
Degrees in graphs I: the Handshake Lemma
A graph consists of objects called vertices and connections between them called edges. For every vertex, we can count how many neighbors it has, which is called its degree.
A big breakthrough in the Graph Isomorphism Problem
The graph isomorphism problem asks the computer to see if two graphs (simple networks) can be made to look precisely the same if the computer is only allowed to slide the nodes and stretch the connections (so the computer is not allowed to draw or or erase nodes or connections).