Graph Theory Flashcards
Graph consists of ?
Vertices and edges
Undirected graph?
Edges have no direction
degree of a vertex
No. of vertices adjacent to it
In degree of a vertex
No. of vertices directed towards a particular vertex
Out degree of a vertex
No. of vertices directed away from a particular vertex
Sum of degree=
2*no. of edges
In directed , sum of out degree=
Sum of in degree = no. of edges
outgoing edges denoted by
-
incoming edges denoted by
+
Undirected graph types
Simple graph and Multigraph
Simple graph
No parallel edge, no self loop
Multigraph
Parallel edges and self loop present
Self loop degree=
2
If n vertex simple graph, max and min degree
max-n-1
min-0
If n vertex multigraph, max and min degree
max-infinite
min-0
Null graph
0 edges
Complete graph
All edges in a simple graph
no. of edges=n(n-1)/2
Min and max edges in a complete graph
both n(n-)/2
min and max edges in null graph
0
n-regular graph
all vertices have degree n
for k regular graph no. of edges
e=(k*n)/2
Complete graph with n vertices can be represented as n-1 regular graph
yes
Every cycle graph is a
2-regular graph
Cycle graph is not possible for
vertices less than or equal to 2
Cycle graph Cn (2-regular graph with n vertices)
n vertices, n edges
Wheel graph
Using Cn-1 graph and adding 1 vertex in middle