Discrete Mathematics
(CSC 1204)
10.1 Introduction to Trees
1

What is a Tree?
2

Example 1 (p.683)•Which of the graphs shown in Figure 2 are trees?
3

.
4

Theorem 1
•
An undirected graph is a tree if and only if
there is a
unique simple path
between any
two of its vertices.
5

Rooted Tree
•
Rooted tree
: A rooted tree is a tree in which
one vertex has been designated as the root
and every edge is directed away from the root.
7

Rooted Tree
a
b
c
d
e
f
g
a
b
c
d
e
f
g
Once a vertex of a tree has been designated as the
root
of the
tree, it is possible to assign direction to each of the edges.

Ordered Rooted Tree
•
Ordered rooted tree
: An ordered rooted tree is a
rooted tree where the children of each internal
vertex are ordered.
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