This preview shows pages 1–3. Sign up to view the full content.
1
Lecture 15:
Introduction to
Binary Search Trees
PIC 10B
Todd Wittman
Note
:
There is no Big C++ reading for trees.
Instead read the notes I placed online.
Binary Search Trees
s
A binary search tree
(BST) is an ordered collection of items
organized into nodes which have two pointers: left and right.
s
The values in a BST must satisfy the following rule.
s
The BST Property
:
If node x is to the left of node y, then x
≤
y.
If x is right of y, then x>y.
s
A BST can hold any type of item, as long as the item can be
ordered (defined <, >, ==).
2
left
x
≤
2
right
x>2
15
5
16
3
12
7
20
18
23
13
10
6
When visualizing a BST, we generally
don't draw the pointers to NULL.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document2
BST Terminology: Nodes
s
The node at the top is called
the root
node.
15 is the root of this tree
s
If x links to y, then x is called
a parent
and y is called a
child
.
16 is the parent of 20
15
5
16
3
12
7
20
18
23
13
10
6
s
If x can follow some path down to y, then x is called an ancestor
of y.
And y is called a descendent
This is the end of the preview. Sign up
to
access the rest of the document.
 Winter '10
 Wittman

Click to edit the document details