class Node

{

int key;

Node left, right;

public Node(int item)

{

key = item;

left = right = null;

}

}

class BinaryTree

{

Node root;

BinaryTree()

{

root = null;

}

void insert(int key) {

root = insertRec(root, key);

}

Node insertRec(Node root, int key) {

if (root == null) {

root = new Node(key);

return root;

}

if (key < root.key)

root.left = insertRec(root.left, key);

else if (key > root.key)

root.right = insertRec(root.right, key);

return root;

}

void printPostorder(Node node)

{

if (node == null)

return;

printPostorder(node.left);

printPostorder(node.right);

System.out.print(node.key + " ");

}

void printInorder(Node node)

{

if (node == null)

return;

printInorder(node.left);

System.out.print(node.key + " ");

printInorder(node.right);

}

void printPreorder(Node node)

{

if (node == null)

return;

System.out.print(node.key + " ");

printPreorder(node.left);

printPreorder(node.right);

}

// Wrappers over above recursive functions

void printPostorder() { printPostorder(root); }

void printInorder() { printInorder(root); }

void printPreorder() { printPreorder(root); }

// Driver method

public static void main(String[] args)

{

BinaryTree tree = new BinaryTree();

/*

tree.root = new Node(1);

tree.root.left = new Node(2);

tree.root.right = new Node(3);

tree.root.left.left = new Node(4);

tree.root.left.right = new Node(5);

*/

tree.insert(50);

tree.insert(30);

tree.insert(20);

tree.insert(40);

tree.insert(70);

tree.insert(60);

tree.insert(80);

System.out.println("Preorder traversal of binary tree is ");

tree.printPreorder();

System.out.println("\nInorder traversal of binary tree is ");

tree.printInorder();

System.out.println("\nPostorder traversal of binary tree is ");

tree.printPostorder();

}

}