Problem

• Airline Routes
• Flowcharts
• Binary relation
  • x is a proper factor(약수) of y
• Computer Networks
  • A star network
  • A ring network

Terms

Vertex (plural vertices) or Node

Edge

Degree of a vertex

• 얼마나 많은 edge들이 연결되어 있는가
• Digragh(방향성이 있는 그래프)
  • in-degree
  • out-degree

Graph

• Directed or undirected
  • undirected; an edge can't connect a vertex to itself
  • digraph
    • head, tail
    • may not have multiple occurrence of the same edge
• Weighted or not Weighted
  • weight = cost = length = distance = capacity
• Symmetric digraph
  • → reverse edge ←
• complete graphs
  • each pair of vertices