Java Reference
In-Depth Information
two link instance variables. There are other kinds of trees with different numbers of
link instance variables, but the binary tree is the most common case.
Display 15.39
A Binary Tree
root
40
20
50
null
10
null
30
null
60
null
null
null
null
left subtree
right subtree
1
public class
IntTree
2 {
3
public class
IntTreeNode
4 {
5
private int
data;
6
private
IntTreeNode leftLink;
7
private
IntTreeNode rightLink;
8 }
//End of IntTreeNode inner class
9
private
IntTreeNode root;
<The methods and other inner classes are not shown.>
10 }
The instance variable named
root
serves a purpose similar to that of the instance
variable
head
in a linked list (Display 15.3). The node whose reference is in the root
instance variable is called the
root node
. Any node in the tree can be reached from the
root node by following the links.
root node
