Example: Java Program to perform preorder tree traversal
class Node {
int item;
Node left, right;
public Node(int key) {
item = key;
left = right = null;
}
}
class Tree {
// root of Tree
Node root;
Tree() {
root = null;
}
void preorder(Node node) {
if (node == null)
return;
// traverse the root node
System.out.print(node.item + "->");
// traverse the left child
preorder(node.left);
// traverse the right child
preorder(node.right);
}
public static void main(String[] args) {
// create object of tree
Tree tree = new Tree();
// create nodes of the tree
tree.root = new Node(1);
tree.root.left = new Node(12);
tree.root.right = new Node(9);
tree.root.left.left = new Node(5);
tree.root.left.right = new Node(6);
// preorder tree traversal
System.out.println("\nPreorder traversal ");
tree.preorder(tree.root);
}
}
Output
Preorder traversal 1->12->5->6->9->
In the above example, we have implemented the tree data structure in Java. Here, we are performing the preorder traversal of the tree.