Java Reference
In-Depth Information
58
if
(root ==
null
)
59
root =
new
TreeNode<T>(insertValue);
// create root node
60
else
61
root.insert(insertValue);
// call the insert method
62
}
63
64
// begin preorder traversal
65
public void
preorderTraversal()
66
{
67
preorderHelper(root);
68
}
69
70
// recursive method to perform preorder traversal
71
private void
preorderHelper(TreeNode<T> node)
72
{
73
if
(node ==
null
)
74
return
;
75
76
System.out.printf(
"%s "
, node.data);
// output node data
77
preorderHelper(node.leftNode);
// traverse left subtree
preorderHelper(node.rightNode);
// traverse right subtree
78
79
}
80
81
// begin inorder traversal
82
public void
inorderTraversal()
83
{
84
inorderHelper(root);
85
}
86
87
// recursive method to perform inorder traversal
88
private void
inorderHelper(TreeNode<T> node)
89
{
90
if
(node ==
null
)
91
return
;
92
93
inorderHelper(node.leftNode);
// traverse left subtree
94
System.out.printf(
"%s "
, node.data);
// output node data
95
inorderHelper(node.rightNode);
// traverse right subtree
96
}
97
98
// begin postorder traversal
99
100
{
101
postorderHelper(root);
102
}
103
104
// recursive method to perform postorder traversal
105
106
{
107
if
(node ==
null
)
108
return
;
109
public void
postorderTraversal()
private void
postorderHelper(TreeNode<T> node)
Fig. 21.17
|
TreeNode
and
Tree
class declarations for a binary search tree. (Part 3 of 4.)
