Driver Code
int main ( ) { Node * root = new Node ( 10 ) ; root -> left = new Node ( 20 ) ; root -> right = new Node ( 30 ) ; root -> left -> left = new Node ( 40 ) ; root -> left -> left -> left = new Node ( 70 ) ; root -> left -> right = new Node ( 50 ) ; root -> right -> left = new Node ( 60 ) ; root -> left -> left -> right = new Node ( 80 ) ; preorderIterative ( root ) ; return 0 ; }