Question
Write a method called numberNodes that changes the data stored in a binary tree, assigning sequential integers starting with 1 to each node so that a preorder traversal will produce the numbers in order ( 1, 2, 3, etc). For example, if a variable t refers to reference tree #1, the call of t.numberNodes(); would overwrite the existing data, assigning values from 1 to 6 to the nodes so that a preorder traversal of the tree would produce 1, 2, 3, 4, 5, 6 as shown in the following diagram. Do not change the structure of the tree, only the values stored in the data fields.
Your method should return the number of nodes in the tree.
Add the above method to the IntTree class from this chapter. You may define additional private methods to implement your public method if necessary. Several problem descriptions refer to the following reference binary trees:
Answer
public int numberNodes()
{
return numberNodes(overallRoot, 0);
}
private int numberNodes(IntTreeNode root, int count)
{
if(root == null)
return count;
count++;
root.data = count;
count = numberNodes(root.left, count);
count = numberNodes(root.right, count);
return count;
}