Chapter 1

1.1 Graphs:

• Is a set of points with lines connecting some of the points.

• The points are called nodes or vertices ,and the lines are called edges.

• Path in a graph is a sequence of nodes connected by edges.

• Formal definition of the graph:

    G = (V, E), where V is the set of nodes and E is the set
    of edges.
  

Has two types:

1. Undirected graph:

                   في النوع دا انت مش عارف مين رايح لمين 
   

V = {1, 2, 3, 4, 5}, E = {(1, 5), (1, 4), (2, 3), (2, 4),(3, 5)}, G = ({1, 2, 3, 4, 5}, {(1, 5),

(1, 4), (2, 3), (2, 4),(3, 5)})

1. Directed graph:

• has arrows instead of lines.

• outdegree: the number of arrows pointing from a particular node. عدد node الاسهم الي خارجة من كل

• indegree: the number of arrows pointing to a particular node. عدد الاسهم node الي داخلة لكل

          رايحة لفين node هنا انت عارف كل