public int height(Node root){
        if(root == null){
            return 0;
        }
        int leftHeight  = height(root.left);
        int rightHeight = height(root.right);
        return Math.max(leftHeight, rightHeight) + 1;
    }
Date 07/07/2014 
@author tusroy

Youtube link - https://youtu.be/bmaeYtlO2OE
Youtube link - https://youtu.be/_SiwrPXG9-g
Youtube link - https://youtu.be/NA8B84DZYSA
src/com/interview/tree/BinaryTree.java