You are encouraged tosolve this taskaccording to the task description, using any language you may know.

         1
        /        /         /          2       3
    / \     /
   4   5   6
  /       /  7       8   9

preorder:    1 2 4 7 5 3 6 8 9
inorder:     7 4 2 5 1 8 6 9 3
postorder:   7 4 5 2 8 9 6 3 1
level-order: 1 2 3 4 5 6 7 8 9

package com.hephec.test;

import java.util.LinkedList;
import java.util.Queue;

public class TreeTraverse {

private static class Node<T>{

public Node<T> left;
public Node(T data) {
super();
this.data = data;

}
public Node<T> getLeft() {
return left;
}
public void setLeft(Node<T> left) {
this.left = left;
}
public Node<T> getRight() {
return right;
}
public void setRight(Node<T> right) {
this.right = right;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
public Node<T> right;
public T data;

}

//preorder traverse
public static void preorder(Node<?> n){
if(n!=null){
System.out.println(n.data+" ");
preorder(n.getLeft());
preorder(n.getRight());
}
}

//inorder traverse
public static void inorder(Node<?> n){
if(n!=null){
inorder(n.getLeft());
System.out.println(n.data+" ");
inorder(n.getRight());
}
}

//postorder traverse
public static void postorder(Node<?> n){
if(n!=null){
postorder(n.getLeft());
postorder(n.getRight());
System.out.println(n.getData());
}
}

//level traverse
public static void levelorder(Node<?> n){
Queue<Node<?>> nodequeue=new LinkedList<Node<?>>();
if(n!=null){
nodequeue.add(n);
}
while(!nodequeue.isEmpty()){
Node<?> next=nodequeue.remove();
System.out.println(next.data+" ");
if(next.getLeft()!=null){
nodequeue.add(next.getLeft());
}
if(next.getRight()!=null){
nodequeue.add(next.getRight());
}
}
}

public static void main(String[] args) {
Node<Integer> one = new Node<Integer>(1);
Node<Integer> two = new Node<Integer>(2);
Node<Integer> three = new Node<Integer>(3);
Node<Integer> four = new Node<Integer>(4);
Node<Integer> five = new Node<Integer>(5);
Node<Integer> six = new Node<Integer>(6);
Node<Integer> seven = new Node<Integer>(7);
Node<Integer> eight = new Node<Integer>(8);
Node<Integer> nine = new Node<Integer>(9);
one.setLeft(two);
one.setRight(three);
two.setLeft(four);
two.setRight(five);
three.setLeft(six);
four.setLeft(seven);
six.setLeft(eight);
six.setRight(nine);
preorder(one);
System.out.println();
inorder(one);
System.out.println();
postorder(one);
System.out.println();
levelorder(one);
System.out.println();

}
}