Print even and odd level nodes in binary tree in java

Java program for Print even and odd level nodes in binary tree. Here more solutions.

/* 
  Java program for
  Print the nodes of even and odd levels of binary tree
 */

// Binary Tree node
class TreeNode
{
    public int data;
    public TreeNode left;
    public TreeNode right;
    public TreeNode(int data)
    {
        // Set node value
        this.data = data;
        this.left = null;
        this.right = null;
    }
}
class BinaryTree
{
    public TreeNode root;

    public BinaryTree()
    {
        // Set initial tree root
        this.root = null;
     
    }
   
    // Print all nodes which is exist in odd Level
    public void oddLevel(TreeNode node, int level)
    {
        if (node != null)
        {
            if (level % 2 != 0)
            {
                System.out.print(" " + node.data);
            }
            oddLevel(node.left, level+1);
            oddLevel(node.right, level+1);
        }
    }
    // Print all nodes which is exist in even Level
    public void evenLevel(TreeNode node, int level)
    {
        if (node != null)
        {
            if (level % 2 == 0)
            {
                System.out.print(" " + node.data);
            }
            evenLevel(node.left, level+1);
            evenLevel(node.right, level+1);
        }
    }
    public static void main(String[] args)
    {
        // Create new tree
        BinaryTree tree = new BinaryTree();
        /*  
            Binary Tree
            -------------
                10
               /  \
              2    4
             /    / \
            3    6   5
             \    \
              9    7
                    \
                     11 
        */
        // Add tree nodes
        tree.root = new TreeNode(10);
        tree.root.left = new TreeNode(2);
        tree.root.left.left = new TreeNode(3);
        tree.root.left.left.right = new TreeNode(9);
        tree.root.right = new TreeNode(4);
        tree.root.right.right = new TreeNode(5);
        tree.root.right.left = new TreeNode(6);
        tree.root.right.left.right = new TreeNode(7);
        tree.root.right.left.right.right = new TreeNode(11);
        System.out.print("\n Even Level Nodes : ");
        tree.evenLevel(tree.root, 1);
        System.out.print("\n Odd Level Nodes  : ");
        tree.oddLevel(tree.root, 1);
    }
}

Output

 Even Level Nodes :  2 9 4 7
 Odd Level Nodes  :  10 3 6 11 5