Write a method int size(Node tree) that returns the number of nodes in the binary tree whose root is tree.

What will be an ideal response?

Assuming a Node class

```
class Node
{
int element;
Node left, right;
Node(int el, Node left, Node right)
{
element = el;
this.left = left;
this.right = right;
}
}


```

```
int size(Node tree)
{
if (tree == null)
return 0;
else
return 1 + size(tree.left) + size(tree.right);
}

```