SizeofTree.java

public class SizeofTree {
	public int getSize(Node root){
		if(root==null){
			return 0;
		}
		return 1 + getSize(root.left) + getSize(root.right);
	}
	public static void main(String args[]){
		Node root = new Node(5);
		root.left = new Node(15);
		root.right = new Node(25);
		root.left.left = new Node(20);
		root.left.right = new Node(30);
		root.right.left = new Node(2);
		root.right.right = new Node(10);
		
		SizeofTree t = new SizeofTree();
		System.out.println("Size of the Tree is : " + t.getSize(root));
	}
}
class Node{
	int data;
	Node left;
	Node right;
	public Node(int data){
		this.data = data;
		this.left = null;
		this.right = null;
	}
}