
/* you only have to complete the function given below.  
Node is defined as  

class Node {
    public:
        int data;
        Node *left;
        Node *right;
        Node(int d) {
            data = d;
            left = NULL;
            right = NULL;
        }
};

*/

    void preOrder(Node *root) {
        if(root){
            std::cout<<root->data<<' ';
            preOrder(root->left);
            preOrder(root->right);
    }
    }
