Program to count leaf nodes in a binary tree

A node is a leaf node if both left and right child nodes of it are NULL.

Here is an algorithm to get the leaf node count.

getLeafCount(node)
1) If node is NULL then return 0.
2) Else If left and right child nodes are NULL return 1.
3) Else recursively calculate leaf count of the tree using below formula.
    Leaf count of a tree = Leaf count of left subtree +  Leaf count of right subtree                  Implementation:

//Java implementation to find leaf count of a given Binary tree    /* Class containing left and right child of current  node and key value*/ class Node {     int data;     Node left, right;        public Node(int item)     {         data = item;         left = right = null;     } }    public class BinaryTree {     //Root of the Binary Tree     Node root;            /* Function to get the count of leaf nodes in a binary tree*/     int getLeafCount()     {         return getLeafCount(root);     }        int getLeafCount(Node node)     {         if (node == null)             return 0;         if (node.left == null && node.right == null)             return 1;         else             return getLeafCount(node.left) + getLeafCount(node.right);     }        /* Driver program to test above functions */     public static void main(String args[])     {         /* create a tree */         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);                    /* get leaf count of the abve tree */         System.out.println("The leaf count of binary tree is : "                              + tree.getLeafCount());     } }