Chapter 21.1, Problem 21.3CP

Program Plan Intro

Preorder traversal:

It process all the nodes of the tree in the following order.

• First, traverse the root node.
• Then, traverse all the nodes in the left subtree.
• Finally, traverse all the nodes in the right subtree.

Algorithm:

Method “preorder” to print the values stored in a binary tree is as follows:

Node preorder(Node bTree)

{

    //Check tree is not empty

    if (tree != null)

    {

        //Print the root node value

        System.out.print(bTree.value + " ");

        //Print value of left subtree

        preorder(bTree.left);

        //Print value of right subtree

        preorder(bTree.right);

    }

}